fix: Remove superfluous view update from credentials (#6545)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

.github/workflows/reusable-build-test-config.yml

@@ -298,7 +298,7 @@ jobs:
 
       - name: Upload coverage report
         if: ${{ github.repository == 'XRPLF/rippled' && !inputs.build_only && env.COVERAGE_ENABLED == 'true' }}
-        uses: codecov/codecov-action@671740ac38dd9b0130fbe1cec585b89eea48d3de # v5.5.2
+        uses: codecov/codecov-action@1af58845a975a7985b0beb0cbe6fbbb71a41dbad # v5.5.3
         with:
           disable_search: true
           disable_telem: true

include/xrpl/ledger/Credit.h

@@ -1,43 +0,0 @@
-#pragma once
-
-#include <xrpl/ledger/View.h>
-#include <xrpl/protocol/IOUAmount.h>
-#include <xrpl/protocol/STAmount.h>
-
-namespace xrpl {
-
-/** Calculate the maximum amount of IOUs that an account can hold
-    @param ledger the ledger to check against.
-    @param account the account of interest.
-    @param issuer the issuer of the IOU.
-    @param currency the IOU to check.
-    @return The maximum amount that can be held.
-*/
-/** @{ */
-STAmount
-creditLimit(
-    ReadView const& view,
-    AccountID const& account,
-    AccountID const& issuer,
-    Currency const& currency);
-
-IOUAmount
-creditLimit2(ReadView const& v, AccountID const& acc, AccountID const& iss, Currency const& cur);
-/** @} */
-
-/** Returns the amount of IOUs issued by issuer that are held by an account
-    @param ledger the ledger to check against.
-    @param account the account of interest.
-    @param issuer the issuer of the IOU.
-    @param currency the IOU to check.
-*/
-/** @{ */
-STAmount
-creditBalance(
-    ReadView const& view,
-    AccountID const& account,
-    AccountID const& issuer,
-    Currency const& currency);
-/** @} */
-
-}  // namespace xrpl

include/xrpl/ledger/View.h

@@ -4,6 +4,13 @@
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/OpenView.h>
 #include <xrpl/ledger/ReadView.h>
+#include <xrpl/ledger/helpers/AccountRootHelpers.h>
+#include <xrpl/ledger/helpers/DirectoryHelpers.h>
+#include <xrpl/ledger/helpers/MPTokenHelpers.h>
+#include <xrpl/ledger/helpers/OfferHelpers.h>
+#include <xrpl/ledger/helpers/RippleStateHelpers.h>
+#include <xrpl/ledger/helpers/TokenHelpers.h>
+#include <xrpl/ledger/helpers/VaultHelpers.h>
 #include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/MPTIssue.h>
@@ -21,7 +28,6 @@
 
 namespace xrpl {
 
-enum class WaiveTransferFee : bool { No = false, Yes };
 enum class SkipEntry : bool { No = false, Yes };
 
 //------------------------------------------------------------------------------
@@ -54,24 +60,6 @@ enum class SkipEntry : bool { No = false, Yes };
 [[nodiscard]] bool
 hasExpired(ReadView const& view, std::optional<std::uint32_t> const& exp);
 
-/** Controls the treatment of frozen account balances */
-enum FreezeHandling { fhIGNORE_FREEZE, fhZERO_IF_FROZEN };
-
-/** Controls the treatment of unauthorized MPT balances */
-enum AuthHandling { ahIGNORE_AUTH, ahZERO_IF_UNAUTHORIZED };
-
-/** Controls whether to include the account's full spendable balance */
-enum SpendableHandling { shSIMPLE_BALANCE, shFULL_BALANCE };
-
-[[nodiscard]] bool
-isGlobalFrozen(ReadView const& view, AccountID const& issuer);
-
-[[nodiscard]] bool
-isGlobalFrozen(ReadView const& view, MPTIssue const& mptIssue);
-
-[[nodiscard]] bool
-isGlobalFrozen(ReadView const& view, Asset const& asset);
-
 // Note, depth parameter is used to limit the recursion depth
 [[nodiscard]] bool
 isVaultPseudoAccountFrozen(
@@ -80,175 +68,6 @@ isVaultPseudoAccountFrozen(
     MPTIssue const& mptShare,
     int depth);
 
-[[nodiscard]] bool
-isIndividualFrozen(
-    ReadView const& view,
-    AccountID const& account,
-    Currency const& currency,
-    AccountID const& issuer);
-
-[[nodiscard]] inline bool
-isIndividualFrozen(ReadView const& view, AccountID const& account, Issue const& issue)
-{
-    return isIndividualFrozen(view, account, issue.currency, issue.account);
-}
-
-[[nodiscard]] bool
-isIndividualFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue);
-
-[[nodiscard]] inline bool
-isIndividualFrozen(ReadView const& view, AccountID const& account, Asset const& asset)
-{
-    return std::visit(
-        [&](auto const& issue) { return isIndividualFrozen(view, account, issue); }, asset.value());
-}
-
-[[nodiscard]] bool
-isFrozen(
-    ReadView const& view,
-    AccountID const& account,
-    Currency const& currency,
-    AccountID const& issuer);
-
-[[nodiscard]] inline bool
-isFrozen(ReadView const& view, AccountID const& account, Issue const& issue, int = 0 /*ignored*/)
-{
-    return isFrozen(view, account, issue.currency, issue.account);
-}
-
-[[nodiscard]] bool
-isFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue, int depth = 0);
-
-/**
- *   isFrozen check is recursive for MPT shares in a vault, descending to
- *   assets in the vault, up to maxAssetCheckDepth recursion depth. This is
- *   purely defensive, as we currently do not allow such vaults to be created.
- */
-[[nodiscard]] inline bool
-isFrozen(ReadView const& view, AccountID const& account, Asset const& asset, int depth = 0)
-{
-    return std::visit(
-        [&](auto const& issue) { return isFrozen(view, account, issue, depth); }, asset.value());
-}
-
-[[nodiscard]] inline TER
-checkFrozen(ReadView const& view, AccountID const& account, Issue const& issue)
-{
-    return isFrozen(view, account, issue) ? (TER)tecFROZEN : (TER)tesSUCCESS;
-}
-
-[[nodiscard]] inline TER
-checkFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue)
-{
-    return isFrozen(view, account, mptIssue) ? (TER)tecLOCKED : (TER)tesSUCCESS;
-}
-
-[[nodiscard]] inline TER
-checkFrozen(ReadView const& view, AccountID const& account, Asset const& asset)
-{
-    return std::visit(
-        [&](auto const& issue) { return checkFrozen(view, account, issue); }, asset.value());
-}
-
-[[nodiscard]] bool
-isAnyFrozen(
-    ReadView const& view,
-    std::initializer_list<AccountID> const& accounts,
-    MPTIssue const& mptIssue,
-    int depth = 0);
-
-[[nodiscard]] inline bool
-isAnyFrozen(
-    ReadView const& view,
-    std::initializer_list<AccountID> const& accounts,
-    Issue const& issue)
-{
-    for (auto const& account : accounts)
-    {
-        if (isFrozen(view, account, issue.currency, issue.account))
-            return true;
-    }
-    return false;
-}
-
-[[nodiscard]] inline bool
-isAnyFrozen(
-    ReadView const& view,
-    std::initializer_list<AccountID> const& accounts,
-    Asset const& asset,
-    int depth = 0)
-{
-    return std::visit(
-        [&]<ValidIssueType TIss>(TIss const& issue) {
-            if constexpr (std::is_same_v<TIss, Issue>)
-                return isAnyFrozen(view, accounts, issue);
-            else
-                return isAnyFrozen(view, accounts, issue, depth);
-        },
-        asset.value());
-}
-
-[[nodiscard]] bool
-isDeepFrozen(
-    ReadView const& view,
-    AccountID const& account,
-    Currency const& currency,
-    AccountID const& issuer);
-
-[[nodiscard]] inline bool
-isDeepFrozen(
-    ReadView const& view,
-    AccountID const& account,
-    Issue const& issue,
-    int = 0 /*ignored*/)
-{
-    return isDeepFrozen(view, account, issue.currency, issue.account);
-}
-
-[[nodiscard]] inline bool
-isDeepFrozen(
-    ReadView const& view,
-    AccountID const& account,
-    MPTIssue const& mptIssue,
-    int depth = 0)
-{
-    // Unlike IOUs, frozen / locked MPTs are not allowed to send or receive
-    // funds, so checking "deep frozen" is the same as checking "frozen".
-    return isFrozen(view, account, mptIssue, depth);
-}
-
-/**
- *   isFrozen check is recursive for MPT shares in a vault, descending to
- *   assets in the vault, up to maxAssetCheckDepth recursion depth. This is
- *   purely defensive, as we currently do not allow such vaults to be created.
- */
-[[nodiscard]] inline bool
-isDeepFrozen(ReadView const& view, AccountID const& account, Asset const& asset, int depth = 0)
-{
-    return std::visit(
-        [&](auto const& issue) { return isDeepFrozen(view, account, issue, depth); },
-        asset.value());
-}
-
-[[nodiscard]] inline TER
-checkDeepFrozen(ReadView const& view, AccountID const& account, Issue const& issue)
-{
-    return isDeepFrozen(view, account, issue) ? (TER)tecFROZEN : (TER)tesSUCCESS;
-}
-
-[[nodiscard]] inline TER
-checkDeepFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue)
-{
-    return isDeepFrozen(view, account, mptIssue) ? (TER)tecLOCKED : (TER)tesSUCCESS;
-}
-
-[[nodiscard]] inline TER
-checkDeepFrozen(ReadView const& view, AccountID const& account, Asset const& asset)
-{
-    return std::visit(
-        [&](auto const& issue) { return checkDeepFrozen(view, account, issue); }, asset.value());
-}
-
 [[nodiscard]] bool
 isLPTokenFrozen(
     ReadView const& view,
@@ -256,159 +75,6 @@ isLPTokenFrozen(
     Issue const& asset,
     Issue const& asset2);
 
-// Returns the amount an account can spend.
-//
-// If shSIMPLE_BALANCE is specified, this is the amount the account can spend
-// without going into debt.
-//
-// If shFULL_BALANCE is specified, this is the amount the account can spend
-// total. Specifically:
-// * The account can go into debt if using a trust line, and the other side has
-// a non-zero limit.
-// * If the account is the asset issuer the limit is defined by the asset /
-//   issuance.
-//
-// <-- saAmount: amount of currency held by account. May be negative.
-[[nodiscard]] STAmount
-accountHolds(
-    ReadView const& view,
-    AccountID const& account,
-    Currency const& currency,
-    AccountID const& issuer,
-    FreezeHandling zeroIfFrozen,
-    beast::Journal j,
-    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
-
-[[nodiscard]] STAmount
-accountHolds(
-    ReadView const& view,
-    AccountID const& account,
-    Issue const& issue,
-    FreezeHandling zeroIfFrozen,
-    beast::Journal j,
-    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
-
-[[nodiscard]] STAmount
-accountHolds(
-    ReadView const& view,
-    AccountID const& account,
-    MPTIssue const& mptIssue,
-    FreezeHandling zeroIfFrozen,
-    AuthHandling zeroIfUnauthorized,
-    beast::Journal j,
-    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
-
-[[nodiscard]] STAmount
-accountHolds(
-    ReadView const& view,
-    AccountID const& account,
-    Asset const& asset,
-    FreezeHandling zeroIfFrozen,
-    AuthHandling zeroIfUnauthorized,
-    beast::Journal j,
-    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
-
-// Returns the amount an account can spend of the currency type saDefault, or
-// returns saDefault if this account is the issuer of the currency in
-// question. Should be used in favor of accountHolds when questioning how much
-// an account can spend while also allowing currency issuers to spend
-// unlimited amounts of their own currency (since they can always issue more).
-[[nodiscard]] STAmount
-accountFunds(
-    ReadView const& view,
-    AccountID const& id,
-    STAmount const& saDefault,
-    FreezeHandling freezeHandling,
-    beast::Journal j);
-
-// Return the account's liquid (not reserved) XRP.  Generally prefer
-// calling accountHolds() over this interface.  However, this interface
-// allows the caller to temporarily adjust the owner count should that be
-// necessary.
-//
-// @param ownerCountAdj positive to add to count, negative to reduce count.
-[[nodiscard]] XRPAmount
-xrpLiquid(ReadView const& view, AccountID const& id, std::int32_t ownerCountAdj, beast::Journal j);
-
-/** Iterate all items in the given directory. */
-void
-forEachItem(
-    ReadView const& view,
-    Keylet const& root,
-    std::function<void(std::shared_ptr<SLE const> const&)> const& f);
-
-/** Iterate all items after an item in the given directory.
-    @param after The key of the item to start after
-    @param hint The directory page containing `after`
-    @param limit The maximum number of items to return
-    @return `false` if the iteration failed
-*/
-bool
-forEachItemAfter(
-    ReadView const& view,
-    Keylet const& root,
-    uint256 const& after,
-    std::uint64_t const hint,
-    unsigned int limit,
-    std::function<bool(std::shared_ptr<SLE const> const&)> const& f);
-
-/** Iterate all items in an account's owner directory. */
-inline void
-forEachItem(
-    ReadView const& view,
-    AccountID const& id,
-    std::function<void(std::shared_ptr<SLE const> const&)> const& f)
-{
-    return forEachItem(view, keylet::ownerDir(id), f);
-}
-
-/** Iterate all items after an item in an owner directory.
-    @param after The key of the item to start after
-    @param hint The directory page containing `after`
-    @param limit The maximum number of items to return
-    @return `false` if the iteration failed
-*/
-inline bool
-forEachItemAfter(
-    ReadView const& view,
-    AccountID const& id,
-    uint256 const& after,
-    std::uint64_t const hint,
-    unsigned int limit,
-    std::function<bool(std::shared_ptr<SLE const> const&)> const& f)
-{
-    return forEachItemAfter(view, keylet::ownerDir(id), after, hint, limit, f);
-}
-
-/** Returns IOU issuer transfer fee as Rate. Rate specifies
- * the fee as fractions of 1 billion. For example, 1% transfer rate
- * is represented as 1,010,000,000.
- * @param issuer The IOU issuer
- */
-[[nodiscard]] Rate
-transferRate(ReadView const& view, AccountID const& issuer);
-
-/** Returns MPT transfer fee as Rate. Rate specifies
- * the fee as fractions of 1 billion. For example, 1% transfer rate
- * is represented as 1,010,000,000.
- * @param issuanceID MPTokenIssuanceID of MPTTokenIssuance object
- */
-[[nodiscard]] Rate
-transferRate(ReadView const& view, MPTID const& issuanceID);
-
-/** Returns the transfer fee as Rate based on the type of token
- * @param view The ledger view
- * @param amount The amount to transfer
- */
-[[nodiscard]] Rate
-transferRate(ReadView const& view, STAmount const& amount);
-
-/** Returns `true` if the directory is empty
-    @param key The key of the directory
-*/
-[[nodiscard]] bool
-dirIsEmpty(ReadView const& view, Keylet const& k);
-
 // Return the list of enabled amendments
 [[nodiscard]] std::set<uint256>
 getEnabledAmendments(ReadView const& view);
@@ -474,81 +140,6 @@ areCompatible(
 //
 //------------------------------------------------------------------------------
 
-/** Adjust the owner count up or down. */
-void
-adjustOwnerCount(
-    ApplyView& view,
-    std::shared_ptr<SLE> const& sle,
-    std::int32_t amount,
-    beast::Journal j);
-
-/** @{ */
-/** Returns the first entry in the directory, advancing the index
-
-    @deprecated These are legacy function that are considered deprecated
-                and will soon be replaced with an iterator-based model
-                that is easier to use. You should not use them in new code.
-
-    @param view The view against which to operate
-    @param root The root (i.e. first page) of the directory to iterate
-    @param page The current page
-    @param index The index inside the current page
-    @param entry The entry at the current index
-
-    @return true if the directory isn't empty; false otherwise
- */
-bool
-cdirFirst(
-    ReadView const& view,
-    uint256 const& root,
-    std::shared_ptr<SLE const>& page,
-    unsigned int& index,
-    uint256& entry);
-
-bool
-dirFirst(
-    ApplyView& view,
-    uint256 const& root,
-    std::shared_ptr<SLE>& page,
-    unsigned int& index,
-    uint256& entry);
-/** @} */
-
-/** @{ */
-/** Returns the next entry in the directory, advancing the index
-
-    @deprecated These are legacy function that are considered deprecated
-                and will soon be replaced with an iterator-based model
-                that is easier to use. You should not use them in new code.
-
-    @param view The view against which to operate
-    @param root The root (i.e. first page) of the directory to iterate
-    @param page The current page
-    @param index The index inside the current page
-    @param entry The entry at the current index
-
-    @return true if the directory isn't empty; false otherwise
- */
-bool
-cdirNext(
-    ReadView const& view,
-    uint256 const& root,
-    std::shared_ptr<SLE const>& page,
-    unsigned int& index,
-    uint256& entry);
-
-bool
-dirNext(
-    ApplyView& view,
-    uint256 const& root,
-    std::shared_ptr<SLE>& page,
-    unsigned int& index,
-    uint256& entry);
-/** @} */
-
-[[nodiscard]] std::function<void(SLE::ref)>
-describeOwnerDir(AccountID const& account);
-
 [[nodiscard]] TER
 dirLink(
     ApplyView& view,
@@ -556,63 +147,6 @@ dirLink(
     std::shared_ptr<SLE>& object,
     SF_UINT64 const& node = sfOwnerNode);
 
-AccountID
-pseudoAccountAddress(ReadView const& view, uint256 const& pseudoOwnerKey);
-
-/**
- *
- * Create pseudo-account, storing pseudoOwnerKey into ownerField.
- *
- * The list of valid ownerField is maintained in View.cpp and the caller to
- * this function must perform necessary amendment check(s) before using a
- * field. The amendment check is **not** performed in createPseudoAccount.
- */
-[[nodiscard]] Expected<std::shared_ptr<SLE>, TER>
-createPseudoAccount(ApplyView& view, uint256 const& pseudoOwnerKey, SField const& ownerField);
-
-// Returns true if and only if sleAcct is a pseudo-account or specific
-// pseudo-accounts in pseudoFieldFilter.
-//
-// Returns false if sleAcct is
-// * NOT a pseudo-account OR
-// * NOT a ltACCOUNT_ROOT OR
-// * null pointer
-[[nodiscard]] bool
-isPseudoAccount(
-    std::shared_ptr<SLE const> sleAcct,
-    std::set<SField const*> const& pseudoFieldFilter = {});
-
-// Returns the list of fields that define an ACCOUNT_ROOT as a pseudo-account if
-// set
-// Pseudo-account designator fields MUST be maintained by including the
-// SField::sMD_PseudoAccount flag in the SField definition. (Don't forget to
-// "| SField::sMD_Default"!) The fields do NOT need to be amendment-gated,
-// since a non-active amendment will not set any field, by definition.
-// Specific properties of a pseudo-account are NOT checked here, that's what
-// InvariantCheck is for.
-[[nodiscard]] std::vector<SField const*> const&
-getPseudoAccountFields();
-
-[[nodiscard]] inline bool
-isPseudoAccount(
-    ReadView const& view,
-    AccountID const& accountId,
-    std::set<SField const*> const& pseudoFieldFilter = {})
-{
-    return isPseudoAccount(view.read(keylet::account(accountId)), pseudoFieldFilter);
-}
-
-[[nodiscard]] TER
-canAddHolding(ReadView const& view, Asset const& asset);
-
-/** Validates that the destination SLE and tag are valid
-
-   - Checks that the SLE is not null.
-   - If the SLE requires a destination tag, checks that there is a tag.
-*/
-[[nodiscard]] TER
-checkDestinationAndTag(SLE::const_ref toSle, bool hasDestinationTag);
-
 /** Checks that can withdraw funds from an object to itself or a destination.
  *
  * The receiver may be either the submitting account (sfAccount) or a different
@@ -686,351 +220,6 @@ doWithdraw(
     STAmount const& amount,
     beast::Journal j);
 
-/// Any transactors that call addEmptyHolding() in doApply must call
-/// canAddHolding() in preflight with the same View and Asset
-[[nodiscard]] TER
-addEmptyHolding(
-    ApplyView& view,
-    AccountID const& accountID,
-    XRPAmount priorBalance,
-    Issue const& issue,
-    beast::Journal journal);
-
-[[nodiscard]] TER
-addEmptyHolding(
-    ApplyView& view,
-    AccountID const& accountID,
-    XRPAmount priorBalance,
-    MPTIssue const& mptIssue,
-    beast::Journal journal);
-
-[[nodiscard]] inline TER
-addEmptyHolding(
-    ApplyView& view,
-    AccountID const& accountID,
-    XRPAmount priorBalance,
-    Asset const& asset,
-    beast::Journal journal)
-{
-    return std::visit(
-        [&]<ValidIssueType TIss>(TIss const& issue) -> TER {
-            return addEmptyHolding(view, accountID, priorBalance, issue, journal);
-        },
-        asset.value());
-}
-
-[[nodiscard]] TER
-authorizeMPToken(
-    ApplyView& view,
-    XRPAmount const& priorBalance,
-    MPTID const& mptIssuanceID,
-    AccountID const& account,
-    beast::Journal journal,
-    std::uint32_t flags = 0,
-    std::optional<AccountID> holderID = std::nullopt);
-
-// VFALCO NOTE Both STAmount parameters should just
-//             be "Amount", a unit-less number.
-//
-/** Create a trust line
-
-    This can set an initial balance.
-*/
-[[nodiscard]] TER
-trustCreate(
-    ApplyView& view,
-    bool const bSrcHigh,
-    AccountID const& uSrcAccountID,
-    AccountID const& uDstAccountID,
-    uint256 const& uIndex,      // --> ripple state entry
-    SLE::ref sleAccount,        // --> the account being set.
-    bool const bAuth,           // --> authorize account.
-    bool const bNoRipple,       // --> others cannot ripple through
-    bool const bFreeze,         // --> funds cannot leave
-    bool bDeepFreeze,           // --> can neither receive nor send funds
-    STAmount const& saBalance,  // --> balance of account being set.
-                                // Issuer should be noAccount()
-    STAmount const& saLimit,    // --> limit for account being set.
-                                // Issuer should be the account being set.
-    std::uint32_t uSrcQualityIn,
-    std::uint32_t uSrcQualityOut,
-    beast::Journal j);
-
-[[nodiscard]] TER
-removeEmptyHolding(
-    ApplyView& view,
-    AccountID const& accountID,
-    Issue const& issue,
-    beast::Journal journal);
-
-[[nodiscard]] TER
-removeEmptyHolding(
-    ApplyView& view,
-    AccountID const& accountID,
-    MPTIssue const& mptIssue,
-    beast::Journal journal);
-
-[[nodiscard]] inline TER
-removeEmptyHolding(
-    ApplyView& view,
-    AccountID const& accountID,
-    Asset const& asset,
-    beast::Journal journal)
-{
-    return std::visit(
-        [&]<ValidIssueType TIss>(TIss const& issue) -> TER {
-            return removeEmptyHolding(view, accountID, issue, journal);
-        },
-        asset.value());
-}
-
-[[nodiscard]] TER
-trustDelete(
-    ApplyView& view,
-    std::shared_ptr<SLE> const& sleRippleState,
-    AccountID const& uLowAccountID,
-    AccountID const& uHighAccountID,
-    beast::Journal j);
-
-/** Delete an offer.
-
-    Requirements:
-        The passed `sle` be obtained from a prior
-        call to view.peek()
-*/
-// [[nodiscard]] // nodiscard commented out so Flow, BookTip and others compile.
-TER
-offerDelete(ApplyView& view, std::shared_ptr<SLE> const& sle, beast::Journal j);
-
-//------------------------------------------------------------------------------
-
-//
-// Money Transfers
-//
-
-// Direct send w/o fees:
-// - Redeeming IOUs and/or sending sender's own IOUs.
-// - Create trust line of needed.
-// --> bCheckIssuer : normally require issuer to be involved.
-// [[nodiscard]] // nodiscard commented out so DirectStep.cpp compiles.
-
-/** Calls static rippleCreditIOU if saAmount represents Issue.
- * Calls static rippleCreditMPT if saAmount represents MPTIssue.
- */
-TER
-rippleCredit(
-    ApplyView& view,
-    AccountID const& uSenderID,
-    AccountID const& uReceiverID,
-    STAmount const& saAmount,
-    bool bCheckIssuer,
-    beast::Journal j);
-
-TER
-rippleLockEscrowMPT(
-    ApplyView& view,
-    AccountID const& uGrantorID,
-    STAmount const& saAmount,
-    beast::Journal j);
-
-TER
-rippleUnlockEscrowMPT(
-    ApplyView& view,
-    AccountID const& uGrantorID,
-    AccountID const& uGranteeID,
-    STAmount const& netAmount,
-    STAmount const& grossAmount,
-    beast::Journal j);
-
-/** Calls static accountSendIOU if saAmount represents Issue.
- * Calls static accountSendMPT if saAmount represents MPTIssue.
- */
-[[nodiscard]] TER
-accountSend(
-    ApplyView& view,
-    AccountID const& from,
-    AccountID const& to,
-    STAmount const& saAmount,
-    beast::Journal j,
-    WaiveTransferFee waiveFee = WaiveTransferFee::No);
-
-using MultiplePaymentDestinations = std::vector<std::pair<AccountID, Number>>;
-/** Like accountSend, except one account is sending multiple payments (with the
- *  same asset!) simultaneously
- *
- * Calls static accountSendMultiIOU if saAmount represents Issue.
- * Calls static accountSendMultiMPT if saAmount represents MPTIssue.
- */
-[[nodiscard]] TER
-accountSendMulti(
-    ApplyView& view,
-    AccountID const& senderID,
-    Asset const& asset,
-    MultiplePaymentDestinations const& receivers,
-    beast::Journal j,
-    WaiveTransferFee waiveFee = WaiveTransferFee::No);
-
-[[nodiscard]] TER
-issueIOU(
-    ApplyView& view,
-    AccountID const& account,
-    STAmount const& amount,
-    Issue const& issue,
-    beast::Journal j);
-
-[[nodiscard]] TER
-redeemIOU(
-    ApplyView& view,
-    AccountID const& account,
-    STAmount const& amount,
-    Issue const& issue,
-    beast::Journal j);
-
-[[nodiscard]] TER
-transferXRP(
-    ApplyView& view,
-    AccountID const& from,
-    AccountID const& to,
-    STAmount const& amount,
-    beast::Journal j);
-
-/* Check if MPToken (for MPT) or trust line (for IOU) exists:
- * - StrongAuth - before checking if authorization is required
- * - WeakAuth
- *    for MPT - after checking lsfMPTRequireAuth flag
- *    for IOU - do not check if trust line exists
- * - Legacy
- *    for MPT - before checking lsfMPTRequireAuth flag i.e. same as StrongAuth
- *    for IOU - do not check if trust line exists i.e. same as WeakAuth
- */
-enum class AuthType { StrongAuth, WeakAuth, Legacy };
-
-/** Check if the account lacks required authorization.
- *
- * Return tecNO_AUTH or tecNO_LINE if it does
- * and tesSUCCESS otherwise.
- *
- * If StrongAuth then return tecNO_LINE if the RippleState doesn't exist. Return
- * tecNO_AUTH if lsfRequireAuth is set on the issuer's AccountRoot, and the
- * RippleState does exist, and the RippleState is not authorized.
- *
- * If WeakAuth then return tecNO_AUTH if lsfRequireAuth is set, and the
- * RippleState exists, and is not authorized. Return tecNO_LINE if
- * lsfRequireAuth is set and the RippleState doesn't exist. Consequently, if
- * WeakAuth and lsfRequireAuth is *not* set, this function will return
- * tesSUCCESS even if RippleState does *not* exist.
- *
- * The default "Legacy" auth type is equivalent to WeakAuth.
- */
-[[nodiscard]] TER
-requireAuth(
-    ReadView const& view,
-    Issue const& issue,
-    AccountID const& account,
-    AuthType authType = AuthType::Legacy);
-
-/** Check if the account lacks required authorization.
- *
- * This will also check for expired credentials. If it is called directly
- * from preclaim, the user should convert result tecEXPIRED to tesSUCCESS and
- * proceed to also check permissions with enforceMPTokenAuthorization inside
- * doApply. This will ensure that any expired credentials are deleted.
- *
- * requireAuth check is recursive for MPT shares in a vault, descending to
- * assets in the vault, up to maxAssetCheckDepth recursion depth. This is
- * purely defensive, as we currently do not allow such vaults to be created.
- *
- * If StrongAuth then return tecNO_AUTH if MPToken doesn't exist or
- * lsfMPTRequireAuth is set and MPToken is not authorized. Vault and LoanBroker
- * pseudo-accounts are implicitly authorized.
- *
- * If WeakAuth then return tecNO_AUTH if lsfMPTRequireAuth is set and MPToken
- * doesn't exist or is not authorized (explicitly or via credentials, if
- * DomainID is set in MPTokenIssuance). Consequently, if WeakAuth and
- * lsfMPTRequireAuth is *not* set, this function will return true even if
- * MPToken does *not* exist.
- *
- * The default "Legacy" auth type is equivalent to StrongAuth.
- */
-[[nodiscard]] TER
-requireAuth(
-    ReadView const& view,
-    MPTIssue const& mptIssue,
-    AccountID const& account,
-    AuthType authType = AuthType::Legacy,
-    int depth = 0);
-
-[[nodiscard]] TER inline requireAuth(
-    ReadView const& view,
-    Asset const& asset,
-    AccountID const& account,
-    AuthType authType = AuthType::Legacy)
-{
-    return std::visit(
-        [&]<ValidIssueType TIss>(TIss const& issue_) {
-            return requireAuth(view, issue_, account, authType);
-        },
-        asset.value());
-}
-
-/** Enforce account has MPToken to match its authorization.
- *
- *   Called from doApply - it will check for expired (and delete if found any)
- *   credentials matching DomainID set in MPTokenIssuance. Must be called if
- *   requireAuth(...MPTIssue...) returned tesSUCCESS or tecEXPIRED in preclaim,
- *   which implies that preclaim should replace `tecEXPIRED` with `tesSUCCESS`
- *   in order for the transactor to proceed to doApply.
- *
- *   This function will create MPToken (if needed) on the basis of any
- *   non-expired credentials and will delete any expired credentials, indirectly
- *   via verifyValidDomain, as per DomainID (if set in MPTokenIssuance).
- *
- *   The caller does NOT need to ensure that DomainID is actually set - this
- *   function handles gracefully both cases when DomainID is set and when not.
- *
- *   The caller does NOT need to look for existing MPToken to match
- *   mptIssue/account - this function checks lsfMPTAuthorized of an existing
- *   MPToken iff DomainID is not set.
- *
- *   Do not use for accounts which hold implied permission e.g. object owners or
- *   if MPTokenIssuance does not require authorization. In both cases use
- *   MPTokenAuthorize::authorize if MPToken does not yet exist.
- */
-[[nodiscard]] TER
-enforceMPTokenAuthorization(
-    ApplyView& view,
-    MPTID const& mptIssuanceID,
-    AccountID const& account,
-    XRPAmount const& priorBalance,
-    beast::Journal j);
-
-/** Check if the destination account is allowed
- *  to receive MPT. Return tecNO_AUTH if it doesn't
- *  and tesSUCCESS otherwise.
- */
-[[nodiscard]] TER
-canTransfer(
-    ReadView const& view,
-    MPTIssue const& mptIssue,
-    AccountID const& from,
-    AccountID const& to);
-
-[[nodiscard]] TER
-canTransfer(ReadView const& view, Issue const& issue, AccountID const& from, AccountID const& to);
-
-[[nodiscard]] TER inline canTransfer(
-    ReadView const& view,
-    Asset const& asset,
-    AccountID const& from,
-    AccountID const& to)
-{
-    return std::visit(
-        [&]<ValidIssueType TIss>(TIss const& issue) -> TER {
-            return canTransfer(view, issue, from, to);
-        },
-        asset.value());
-}
-
 /** Deleter function prototype. Returns the status of the entry deletion
  * (if should not be skipped) and if the entry should be skipped. The status
  * is always tesSUCCESS if the entry should be skipped.
@@ -1052,57 +241,6 @@ cleanupOnAccountDelete(
     beast::Journal j,
     std::optional<std::uint16_t> maxNodesToDelete = std::nullopt);
 
-/** Delete trustline to AMM. The passed `sle` must be obtained from a prior
- * call to view.peek(). Fail if neither side of the trustline is AMM or
- * if ammAccountID is seated and is not one of the trustline's side.
- */
-[[nodiscard]] TER
-deleteAMMTrustLine(
-    ApplyView& view,
-    std::shared_ptr<SLE> sleState,
-    std::optional<AccountID> const& ammAccountID,
-    beast::Journal j);
-
-// From the perspective of a vault, return the number of shares to give the
-// depositor when they deposit a fixed amount of assets. Since shares are MPT
-// this number is integral and always truncated in this calculation.
-[[nodiscard]] std::optional<STAmount>
-assetsToSharesDeposit(
-    std::shared_ptr<SLE const> const& vault,
-    std::shared_ptr<SLE const> const& issuance,
-    STAmount const& assets);
-
-// From the perspective of a vault, return the number of assets to take from
-// depositor when they receive a fixed amount of shares. Note, since shares are
-// MPT, they are always an integral number.
-[[nodiscard]] std::optional<STAmount>
-sharesToAssetsDeposit(
-    std::shared_ptr<SLE const> const& vault,
-    std::shared_ptr<SLE const> const& issuance,
-    STAmount const& shares);
-
-enum class TruncateShares : bool { no = false, yes = true };
-
-// From the perspective of a vault, return the number of shares to demand from
-// the depositor when they ask to withdraw a fixed amount of assets. Since
-// shares are MPT this number is integral, and it will be rounded to nearest
-// unless explicitly requested to be truncated instead.
-[[nodiscard]] std::optional<STAmount>
-assetsToSharesWithdraw(
-    std::shared_ptr<SLE const> const& vault,
-    std::shared_ptr<SLE const> const& issuance,
-    STAmount const& assets,
-    TruncateShares truncate = TruncateShares::no);
-
-// From the perspective of a vault, return the number of assets to give the
-// depositor when they redeem a fixed amount of shares. Note, since shares are
-// MPT, they are always an integral number.
-[[nodiscard]] std::optional<STAmount>
-sharesToAssetsWithdraw(
-    std::shared_ptr<SLE const> const& vault,
-    std::shared_ptr<SLE const> const& issuance,
-    STAmount const& shares);
-
 /** Has the specified time passed?
 
     @param now  the current time

include/xrpl/ledger/helpers/AccountRootHelpers.h

@@ -0,0 +1,112 @@
+#pragma once
+
+#include <xrpl/basics/Expected.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/Rate.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/TER.h>
+
+#include <memory>
+#include <set>
+#include <vector>
+
+namespace xrpl {
+
+/** Check if the issuer has the global freeze flag set.
+    @param issuer The account to check
+    @return true if the account has global freeze set
+*/
+[[nodiscard]] bool
+isGlobalFrozen(ReadView const& view, AccountID const& issuer);
+
+// Calculate liquid XRP balance for an account.
+// This function may be used to calculate the amount of XRP that
+// the holder is able to freely spend. It subtracts reserve requirements.
+//
+// ownerCountAdj adjusts the owner count in case the caller calculates
+// before ledger entries are added or removed. Positive to add, negative
+// to subtract.
+//
+// @param ownerCountAdj positive to add to count, negative to reduce count.
+[[nodiscard]] XRPAmount
+xrpLiquid(ReadView const& view, AccountID const& id, std::int32_t ownerCountAdj, beast::Journal j);
+
+/** Adjust the owner count up or down. */
+void
+adjustOwnerCount(
+    ApplyView& view,
+    std::shared_ptr<SLE> const& sle,
+    std::int32_t amount,
+    beast::Journal j);
+
+/** Returns IOU issuer transfer fee as Rate. Rate specifies
+ * the fee as fractions of 1 billion. For example, 1% transfer rate
+ * is represented as 1,010,000,000.
+ * @param issuer The IOU issuer
+ */
+[[nodiscard]] Rate
+transferRate(ReadView const& view, AccountID const& issuer);
+
+/** Generate a pseudo-account address from a pseudo owner key.
+    @param pseudoOwnerKey The key to generate the address from
+    @return The generated account ID
+*/
+AccountID
+pseudoAccountAddress(ReadView const& view, uint256 const& pseudoOwnerKey);
+
+/** Returns the list of fields that define an ACCOUNT_ROOT as a pseudo-account
+    if set.
+
+    The list is constructed during initialization and is const after that.
+    Pseudo-account designator fields MUST be maintained by including the
+    SField::sMD_PseudoAccount flag in the SField definition.
+*/
+[[nodiscard]] std::vector<SField const*> const&
+getPseudoAccountFields();
+
+/** Returns true if and only if sleAcct is a pseudo-account or specific
+    pseudo-accounts in pseudoFieldFilter.
+
+    Returns false if sleAcct is:
+    - NOT a pseudo-account OR
+    - NOT a ltACCOUNT_ROOT OR
+    - null pointer
+*/
+[[nodiscard]] bool
+isPseudoAccount(
+    std::shared_ptr<SLE const> sleAcct,
+    std::set<SField const*> const& pseudoFieldFilter = {});
+
+/** Convenience overload that reads the account from the view. */
+[[nodiscard]] inline bool
+isPseudoAccount(
+    ReadView const& view,
+    AccountID const& accountId,
+    std::set<SField const*> const& pseudoFieldFilter = {})
+{
+    return isPseudoAccount(view.read(keylet::account(accountId)), pseudoFieldFilter);
+}
+
+/**
+ * Create pseudo-account, storing pseudoOwnerKey into ownerField.
+ *
+ * The list of valid ownerField is maintained in AccountRootHelpers.cpp and
+ * the caller to this function must perform necessary amendment check(s)
+ * before using a field. The amendment check is **not** performed in
+ * createPseudoAccount.
+ */
+[[nodiscard]] Expected<std::shared_ptr<SLE>, TER>
+createPseudoAccount(ApplyView& view, uint256 const& pseudoOwnerKey, SField const& ownerField);
+
+/** Checks the destination and tag.
+
+   - Checks that the SLE is not null.
+   - If the SLE requires a destination tag, checks that there is a tag.
+*/
+[[nodiscard]] TER
+checkDestinationAndTag(SLE::const_ref toSle, bool hasDestinationTag);
+
+}  // namespace xrpl

include/xrpl/ledger/helpers/DirectoryHelpers.h

@@ -0,0 +1,223 @@
+#pragma once
+
+#include <xrpl/beast/utility/instrumentation.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/TER.h>
+
+#include <functional>
+#include <memory>
+#include <type_traits>
+
+namespace xrpl {
+
+namespace detail {
+
+template <
+    class V,
+    class N,
+    class = std::enable_if_t<
+        std::is_same_v<std::remove_cv_t<N>, SLE> && std::is_base_of_v<ReadView, V>>>
+bool
+internalDirNext(
+    V& view,
+    uint256 const& root,
+    std::shared_ptr<N>& page,
+    unsigned int& index,
+    uint256& entry)
+{
+    auto const& svIndexes = page->getFieldV256(sfIndexes);
+    XRPL_ASSERT(index <= svIndexes.size(), "xrpl::detail::internalDirNext : index inside range");
+
+    if (index >= svIndexes.size())
+    {
+        auto const next = page->getFieldU64(sfIndexNext);
+
+        if (!next)
+        {
+            entry.zero();
+            return false;
+        }
+
+        if constexpr (std::is_const_v<N>)
+        {
+            page = view.read(keylet::page(root, next));
+        }
+        else
+        {
+            page = view.peek(keylet::page(root, next));
+        }
+
+        XRPL_ASSERT(page, "xrpl::detail::internalDirNext : non-null root");
+
+        if (!page)
+            return false;
+
+        index = 0;
+
+        return internalDirNext(view, root, page, index, entry);
+    }
+
+    entry = svIndexes[index++];
+    return true;
+}
+
+template <
+    class V,
+    class N,
+    class = std::enable_if_t<
+        std::is_same_v<std::remove_cv_t<N>, SLE> && std::is_base_of_v<ReadView, V>>>
+bool
+internalDirFirst(
+    V& view,
+    uint256 const& root,
+    std::shared_ptr<N>& page,
+    unsigned int& index,
+    uint256& entry)
+{
+    if constexpr (std::is_const_v<N>)
+    {
+        page = view.read(keylet::page(root));
+    }
+    else
+    {
+        page = view.peek(keylet::page(root));
+    }
+
+    if (!page)
+        return false;
+
+    index = 0;
+
+    return internalDirNext(view, root, page, index, entry);
+}
+
+}  // namespace detail
+
+/** @{ */
+/** Returns the first entry in the directory, advancing the index
+
+    @deprecated These are legacy function that are considered deprecated
+                and will soon be replaced with an iterator-based model
+                that is easier to use. You should not use them in new code.
+
+    @param view The view against which to operate
+    @param root The root (i.e. first page) of the directory to iterate
+    @param page The current page
+    @param index The index inside the current page
+    @param entry The entry at the current index
+
+    @return true if the directory isn't empty; false otherwise
+ */
+bool
+cdirFirst(
+    ReadView const& view,
+    uint256 const& root,
+    std::shared_ptr<SLE const>& page,
+    unsigned int& index,
+    uint256& entry);
+
+bool
+dirFirst(
+    ApplyView& view,
+    uint256 const& root,
+    std::shared_ptr<SLE>& page,
+    unsigned int& index,
+    uint256& entry);
+/** @} */
+
+/** @{ */
+/** Returns the next entry in the directory, advancing the index
+
+    @deprecated These are legacy function that are considered deprecated
+                and will soon be replaced with an iterator-based model
+                that is easier to use. You should not use them in new code.
+
+    @param view The view against which to operate
+    @param root The root (i.e. first page) of the directory to iterate
+    @param page The current page
+    @param index The index inside the current page
+    @param entry The entry at the current index
+
+    @return true if the directory isn't empty; false otherwise
+ */
+bool
+cdirNext(
+    ReadView const& view,
+    uint256 const& root,
+    std::shared_ptr<SLE const>& page,
+    unsigned int& index,
+    uint256& entry);
+
+bool
+dirNext(
+    ApplyView& view,
+    uint256 const& root,
+    std::shared_ptr<SLE>& page,
+    unsigned int& index,
+    uint256& entry);
+/** @} */
+
+/** Iterate all items in the given directory. */
+void
+forEachItem(
+    ReadView const& view,
+    Keylet const& root,
+    std::function<void(std::shared_ptr<SLE const> const&)> const& f);
+
+/** Iterate all items after an item in the given directory.
+    @param after The key of the item to start after
+    @param hint The directory page containing `after`
+    @param limit The maximum number of items to return
+    @return `false` if the iteration failed
+*/
+bool
+forEachItemAfter(
+    ReadView const& view,
+    Keylet const& root,
+    uint256 const& after,
+    std::uint64_t const hint,
+    unsigned int limit,
+    std::function<bool(std::shared_ptr<SLE const> const&)> const& f);
+
+/** Iterate all items in an account's owner directory. */
+inline void
+forEachItem(
+    ReadView const& view,
+    AccountID const& id,
+    std::function<void(std::shared_ptr<SLE const> const&)> const& f)
+{
+    return forEachItem(view, keylet::ownerDir(id), f);
+}
+
+/** Iterate all items after an item in an owner directory.
+    @param after The key of the item to start after
+    @param hint The directory page containing `after`
+    @param limit The maximum number of items to return
+    @return `false` if the iteration failed
+*/
+inline bool
+forEachItemAfter(
+    ReadView const& view,
+    AccountID const& id,
+    uint256 const& after,
+    std::uint64_t const hint,
+    unsigned int limit,
+    std::function<bool(std::shared_ptr<SLE const> const&)> const& f)
+{
+    return forEachItemAfter(view, keylet::ownerDir(id), after, hint, limit, f);
+}
+
+/** Returns `true` if the directory is empty
+    @param key The key of the directory
+*/
+[[nodiscard]] bool
+dirIsEmpty(ReadView const& view, Keylet const& k);
+
+/** Returns a function that sets the owner on a directory SLE */
+[[nodiscard]] std::function<void(SLE::ref)>
+describeOwnerDir(AccountID const& account);
+
+}  // namespace xrpl

include/xrpl/ledger/helpers/MPTokenHelpers.h

@@ -0,0 +1,160 @@
+#pragma once
+
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/ledger/helpers/TokenHelpers.h>
+#include <xrpl/protocol/MPTIssue.h>
+#include <xrpl/protocol/Rate.h>
+#include <xrpl/protocol/STAmount.h>
+#include <xrpl/protocol/TER.h>
+
+#include <initializer_list>
+#include <optional>
+
+namespace xrpl {
+
+//------------------------------------------------------------------------------
+//
+// Freeze checking (MPT-specific)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] bool
+isGlobalFrozen(ReadView const& view, MPTIssue const& mptIssue);
+
+[[nodiscard]] bool
+isIndividualFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue);
+
+[[nodiscard]] bool
+isFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue, int depth = 0);
+
+[[nodiscard]] bool
+isAnyFrozen(
+    ReadView const& view,
+    std::initializer_list<AccountID> const& accounts,
+    MPTIssue const& mptIssue,
+    int depth = 0);
+
+//------------------------------------------------------------------------------
+//
+// Transfer rate (MPT-specific)
+//
+//------------------------------------------------------------------------------
+
+/** Returns MPT transfer fee as Rate. Rate specifies
+ * the fee as fractions of 1 billion. For example, 1% transfer rate
+ * is represented as 1,010,000,000.
+ * @param issuanceID MPTokenIssuanceID of MPTTokenIssuance object
+ */
+[[nodiscard]] Rate
+transferRate(ReadView const& view, MPTID const& issuanceID);
+
+//------------------------------------------------------------------------------
+//
+// Holding checks (MPT-specific)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] TER
+canAddHolding(ReadView const& view, MPTIssue const& mptIssue);
+
+//------------------------------------------------------------------------------
+//
+// Authorization (MPT-specific)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] TER
+authorizeMPToken(
+    ApplyView& view,
+    XRPAmount const& priorBalance,
+    MPTID const& mptIssuanceID,
+    AccountID const& account,
+    beast::Journal journal,
+    std::uint32_t flags = 0,
+    std::optional<AccountID> holderID = std::nullopt);
+
+/** Check if the account lacks required authorization for MPT.
+ *
+ * requireAuth check is recursive for MPT shares in a vault, descending to
+ * assets in the vault, up to maxAssetCheckDepth recursion depth. This is
+ * purely defensive, as we currently do not allow such vaults to be created.
+ */
+[[nodiscard]] TER
+requireAuth(
+    ReadView const& view,
+    MPTIssue const& mptIssue,
+    AccountID const& account,
+    AuthType authType = AuthType::Legacy,
+    int depth = 0);
+
+/** Enforce account has MPToken to match its authorization.
+ *
+ *   Called from doApply - it will check for expired (and delete if found any)
+ *   credentials matching DomainID set in MPTokenIssuance. Must be called if
+ *   requireAuth(...MPTIssue...) returned tesSUCCESS or tecEXPIRED in preclaim.
+ */
+[[nodiscard]] TER
+enforceMPTokenAuthorization(
+    ApplyView& view,
+    MPTID const& mptIssuanceID,
+    AccountID const& account,
+    XRPAmount const& priorBalance,
+    beast::Journal j);
+
+/** Check if the destination account is allowed
+ *  to receive MPT. Return tecNO_AUTH if it doesn't
+ *  and tesSUCCESS otherwise.
+ */
+[[nodiscard]] TER
+canTransfer(
+    ReadView const& view,
+    MPTIssue const& mptIssue,
+    AccountID const& from,
+    AccountID const& to);
+
+//------------------------------------------------------------------------------
+//
+// Empty holding operations (MPT-specific)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] TER
+addEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    XRPAmount priorBalance,
+    MPTIssue const& mptIssue,
+    beast::Journal journal);
+
+[[nodiscard]] TER
+removeEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    MPTIssue const& mptIssue,
+    beast::Journal journal);
+
+//------------------------------------------------------------------------------
+//
+// Escrow operations (MPT-specific)
+//
+//------------------------------------------------------------------------------
+
+TER
+rippleLockEscrowMPT(
+    ApplyView& view,
+    AccountID const& uGrantorID,
+    STAmount const& saAmount,
+    beast::Journal j);
+
+TER
+rippleUnlockEscrowMPT(
+    ApplyView& view,
+    AccountID const& uGrantorID,
+    AccountID const& uGranteeID,
+    STAmount const& netAmount,
+    STAmount const& grossAmount,
+    beast::Journal j);
+
+}  // namespace xrpl

include/xrpl/ledger/helpers/OfferHelpers.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/TER.h>
+
+#include <memory>
+
+namespace xrpl {
+
+/** Delete an offer.
+
+    Requirements:
+        The offer must exist.
+        The caller must have already checked permissions.
+
+    @param view The ApplyView to modify.
+    @param sle The offer to delete.
+    @param j Journal for logging.
+
+    @return tesSUCCESS on success, otherwise an error code.
+*/
+// [[nodiscard]] // nodiscard commented out so Flow, BookTip and others compile.
+TER
+offerDelete(ApplyView& view, std::shared_ptr<SLE> const& sle, beast::Journal j);
+
+}  // namespace xrpl

include/xrpl/ledger/helpers/RippleStateHelpers.h

@@ -0,0 +1,255 @@
+#pragma once
+
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/ledger/helpers/TokenHelpers.h>
+#include <xrpl/protocol/IOUAmount.h>
+#include <xrpl/protocol/Issue.h>
+#include <xrpl/protocol/STAmount.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/TER.h>
+
+//------------------------------------------------------------------------------
+//
+// RippleState (Trustline) helpers
+//
+//------------------------------------------------------------------------------
+
+namespace xrpl {
+
+//------------------------------------------------------------------------------
+//
+// Credit functions (from Credit.h)
+//
+//------------------------------------------------------------------------------
+
+/** Calculate the maximum amount of IOUs that an account can hold
+    @param view the ledger to check against.
+    @param account the account of interest.
+    @param issuer the issuer of the IOU.
+    @param currency the IOU to check.
+    @return The maximum amount that can be held.
+*/
+/** @{ */
+STAmount
+creditLimit(
+    ReadView const& view,
+    AccountID const& account,
+    AccountID const& issuer,
+    Currency const& currency);
+
+IOUAmount
+creditLimit2(ReadView const& v, AccountID const& acc, AccountID const& iss, Currency const& cur);
+/** @} */
+
+/** Returns the amount of IOUs issued by issuer that are held by an account
+    @param view the ledger to check against.
+    @param account the account of interest.
+    @param issuer the issuer of the IOU.
+    @param currency the IOU to check.
+*/
+/** @{ */
+STAmount
+creditBalance(
+    ReadView const& view,
+    AccountID const& account,
+    AccountID const& issuer,
+    Currency const& currency);
+/** @} */
+
+//------------------------------------------------------------------------------
+//
+// Freeze checking (IOU-specific)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] bool
+isIndividualFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    Currency const& currency,
+    AccountID const& issuer);
+
+[[nodiscard]] inline bool
+isIndividualFrozen(ReadView const& view, AccountID const& account, Issue const& issue)
+{
+    return isIndividualFrozen(view, account, issue.currency, issue.account);
+}
+
+[[nodiscard]] bool
+isFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    Currency const& currency,
+    AccountID const& issuer);
+
+[[nodiscard]] inline bool
+isFrozen(ReadView const& view, AccountID const& account, Issue const& issue)
+{
+    return isFrozen(view, account, issue.currency, issue.account);
+}
+
+// Overload with depth parameter for uniformity with MPTIssue version.
+// The depth parameter is ignored for IOUs since they don't have vault recursion.
+[[nodiscard]] inline bool
+isFrozen(ReadView const& view, AccountID const& account, Issue const& issue, int /*depth*/)
+{
+    return isFrozen(view, account, issue);
+}
+
+[[nodiscard]] bool
+isDeepFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    Currency const& currency,
+    AccountID const& issuer);
+
+[[nodiscard]] inline bool
+isDeepFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    Issue const& issue,
+    int = 0 /*ignored*/)
+{
+    return isDeepFrozen(view, account, issue.currency, issue.account);
+}
+
+[[nodiscard]] inline TER
+checkDeepFrozen(ReadView const& view, AccountID const& account, Issue const& issue)
+{
+    return isDeepFrozen(view, account, issue) ? (TER)tecFROZEN : (TER)tesSUCCESS;
+}
+
+//------------------------------------------------------------------------------
+//
+// Trust line operations
+//
+//------------------------------------------------------------------------------
+
+/** Create a trust line
+
+    This can set an initial balance.
+*/
+[[nodiscard]] TER
+trustCreate(
+    ApplyView& view,
+    bool const bSrcHigh,
+    AccountID const& uSrcAccountID,
+    AccountID const& uDstAccountID,
+    uint256 const& uIndex,      // --> ripple state entry
+    SLE::ref sleAccount,        // --> the account being set.
+    bool const bAuth,           // --> authorize account.
+    bool const bNoRipple,       // --> others cannot ripple through
+    bool const bFreeze,         // --> funds cannot leave
+    bool bDeepFreeze,           // --> can neither receive nor send funds
+    STAmount const& saBalance,  // --> balance of account being set.
+                                // Issuer should be noAccount()
+    STAmount const& saLimit,    // --> limit for account being set.
+                                // Issuer should be the account being set.
+    std::uint32_t uQualityIn,
+    std::uint32_t uQualityOut,
+    beast::Journal j);
+
+[[nodiscard]] TER
+trustDelete(
+    ApplyView& view,
+    std::shared_ptr<SLE> const& sleRippleState,
+    AccountID const& uLowAccountID,
+    AccountID const& uHighAccountID,
+    beast::Journal j);
+
+//------------------------------------------------------------------------------
+//
+// IOU issuance/redemption
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] TER
+issueIOU(
+    ApplyView& view,
+    AccountID const& account,
+    STAmount const& amount,
+    Issue const& issue,
+    beast::Journal j);
+
+[[nodiscard]] TER
+redeemIOU(
+    ApplyView& view,
+    AccountID const& account,
+    STAmount const& amount,
+    Issue const& issue,
+    beast::Journal j);
+
+//------------------------------------------------------------------------------
+//
+// Authorization and transfer checks (IOU-specific)
+//
+//------------------------------------------------------------------------------
+
+/** Check if the account lacks required authorization.
+ *
+ * Return tecNO_AUTH or tecNO_LINE if it does
+ * and tesSUCCESS otherwise.
+ *
+ * If StrongAuth then return tecNO_LINE if the RippleState doesn't exist. Return
+ * tecNO_AUTH if lsfRequireAuth is set on the issuer's AccountRoot, and the
+ * RippleState does exist, and the RippleState is not authorized.
+ *
+ * If WeakAuth then return tecNO_AUTH if lsfRequireAuth is set, and the
+ * RippleState exists, and is not authorized. Return tecNO_LINE if
+ * lsfRequireAuth is set and the RippleState doesn't exist. Consequently, if
+ * WeakAuth and lsfRequireAuth is *not* set, this function will return
+ * tesSUCCESS even if RippleState does *not* exist.
+ *
+ * The default "Legacy" auth type is equivalent to WeakAuth.
+ */
+[[nodiscard]] TER
+requireAuth(
+    ReadView const& view,
+    Issue const& issue,
+    AccountID const& account,
+    AuthType authType = AuthType::Legacy);
+
+/** Check if the destination account is allowed
+ *  to receive IOU. Return terNO_RIPPLE if rippling is
+ *  disabled on both sides and tesSUCCESS otherwise.
+ */
+[[nodiscard]] TER
+canTransfer(ReadView const& view, Issue const& issue, AccountID const& from, AccountID const& to);
+
+//------------------------------------------------------------------------------
+//
+// Empty holding operations (IOU-specific)
+//
+//------------------------------------------------------------------------------
+
+/// Any transactors that call addEmptyHolding() in doApply must call
+/// canAddHolding() in preflight with the same View and Asset
+[[nodiscard]] TER
+addEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    XRPAmount priorBalance,
+    Issue const& issue,
+    beast::Journal journal);
+
+[[nodiscard]] TER
+removeEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    Issue const& issue,
+    beast::Journal journal);
+
+/** Delete trustline to AMM. The passed `sle` must be obtained from a prior
+ * call to view.peek(). Fail if neither side of the trustline is AMM or
+ * if ammAccountID is seated and is not one of the trustline's side.
+ */
+[[nodiscard]] TER
+deleteAMMTrustLine(
+    ApplyView& view,
+    std::shared_ptr<SLE> sleState,
+    std::optional<AccountID> const& ammAccountID,
+    beast::Journal j);
+
+}  // namespace xrpl

include/xrpl/ledger/helpers/TokenHelpers.h

@@ -0,0 +1,286 @@
+#pragma once
+
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/protocol/Asset.h>
+#include <xrpl/protocol/MPTIssue.h>
+#include <xrpl/protocol/Rate.h>
+#include <xrpl/protocol/STAmount.h>
+#include <xrpl/protocol/TER.h>
+
+#include <initializer_list>
+#include <vector>
+
+namespace xrpl {
+
+//------------------------------------------------------------------------------
+//
+// Enums for token handling
+//
+//------------------------------------------------------------------------------
+
+/** Controls the treatment of frozen account balances */
+enum FreezeHandling { fhIGNORE_FREEZE, fhZERO_IF_FROZEN };
+
+/** Controls the treatment of unauthorized MPT balances */
+enum AuthHandling { ahIGNORE_AUTH, ahZERO_IF_UNAUTHORIZED };
+
+/** Controls whether to include the account's full spendable balance */
+enum SpendableHandling { shSIMPLE_BALANCE, shFULL_BALANCE };
+
+enum class WaiveTransferFee : bool { No = false, Yes };
+
+/* Check if MPToken (for MPT) or trust line (for IOU) exists:
+ * - StrongAuth - before checking if authorization is required
+ * - WeakAuth
+ *    for MPT - after checking lsfMPTRequireAuth flag
+ *    for IOU - do not check if trust line exists
+ * - Legacy
+ *    for MPT - before checking lsfMPTRequireAuth flag i.e. same as StrongAuth
+ *    for IOU - do not check if trust line exists i.e. same as WeakAuth
+ */
+enum class AuthType { StrongAuth, WeakAuth, Legacy };
+
+//------------------------------------------------------------------------------
+//
+// Freeze checking (Asset-based dispatchers)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] bool
+isGlobalFrozen(ReadView const& view, Asset const& asset);
+
+[[nodiscard]] bool
+isIndividualFrozen(ReadView const& view, AccountID const& account, Asset const& asset);
+
+/**
+ *   isFrozen check is recursive for MPT shares in a vault, descending to
+ *   assets in the vault, up to maxAssetCheckDepth recursion depth. This is
+ *   purely defensive, as we currently do not allow such vaults to be created.
+ */
+[[nodiscard]] bool
+isFrozen(ReadView const& view, AccountID const& account, Asset const& asset, int depth = 0);
+
+[[nodiscard]] TER
+checkFrozen(ReadView const& view, AccountID const& account, Issue const& issue);
+
+[[nodiscard]] TER
+checkFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue);
+
+[[nodiscard]] TER
+checkFrozen(ReadView const& view, AccountID const& account, Asset const& asset);
+
+[[nodiscard]] bool
+isAnyFrozen(
+    ReadView const& view,
+    std::initializer_list<AccountID> const& accounts,
+    Issue const& issue);
+
+[[nodiscard]] bool
+isAnyFrozen(
+    ReadView const& view,
+    std::initializer_list<AccountID> const& accounts,
+    Asset const& asset,
+    int depth = 0);
+
+[[nodiscard]] bool
+isDeepFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    MPTIssue const& mptIssue,
+    int depth = 0);
+
+/**
+ *   isFrozen check is recursive for MPT shares in a vault, descending to
+ *   assets in the vault, up to maxAssetCheckDepth recursion depth. This is
+ *   purely defensive, as we currently do not allow such vaults to be created.
+ */
+[[nodiscard]] bool
+isDeepFrozen(ReadView const& view, AccountID const& account, Asset const& asset, int depth = 0);
+
+[[nodiscard]] TER
+checkDeepFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue);
+
+[[nodiscard]] TER
+checkDeepFrozen(ReadView const& view, AccountID const& account, Asset const& asset);
+
+//------------------------------------------------------------------------------
+//
+// Account balance functions (Asset-based dispatchers)
+//
+//------------------------------------------------------------------------------
+
+// Returns the amount an account can spend.
+//
+// If shSIMPLE_BALANCE is specified, this is the amount the account can spend
+// without going into debt.
+//
+// If shFULL_BALANCE is specified, this is the amount the account can spend
+// total. Specifically:
+// * The account can go into debt if using a trust line, and the other side has
+// a non-zero limit.
+// * If the account is the asset issuer the limit is defined by the asset /
+//   issuance.
+//
+// <-- saAmount: amount of currency held by account. May be negative.
+[[nodiscard]] STAmount
+accountHolds(
+    ReadView const& view,
+    AccountID const& account,
+    Currency const& currency,
+    AccountID const& issuer,
+    FreezeHandling zeroIfFrozen,
+    beast::Journal j,
+    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
+
+[[nodiscard]] STAmount
+accountHolds(
+    ReadView const& view,
+    AccountID const& account,
+    Issue const& issue,
+    FreezeHandling zeroIfFrozen,
+    beast::Journal j,
+    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
+
+[[nodiscard]] STAmount
+accountHolds(
+    ReadView const& view,
+    AccountID const& account,
+    MPTIssue const& mptIssue,
+    FreezeHandling zeroIfFrozen,
+    AuthHandling zeroIfUnauthorized,
+    beast::Journal j,
+    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
+
+[[nodiscard]] STAmount
+accountHolds(
+    ReadView const& view,
+    AccountID const& account,
+    Asset const& asset,
+    FreezeHandling zeroIfFrozen,
+    AuthHandling zeroIfUnauthorized,
+    beast::Journal j,
+    SpendableHandling includeFullBalance = shSIMPLE_BALANCE);
+
+// Returns the amount an account can spend of the currency type saDefault, or
+// returns saDefault if this account is the issuer of the currency in
+// question. Should be used in favor of accountHolds when questioning how much
+// an account can spend while also allowing currency issuers to spend
+// unlimited amounts of their own currency (since they can always issue more).
+[[nodiscard]] STAmount
+accountFunds(
+    ReadView const& view,
+    AccountID const& id,
+    STAmount const& saDefault,
+    FreezeHandling freezeHandling,
+    beast::Journal j);
+
+/** Returns the transfer fee as Rate based on the type of token
+ * @param view The ledger view
+ * @param amount The amount to transfer
+ */
+[[nodiscard]] Rate
+transferRate(ReadView const& view, STAmount const& amount);
+
+//------------------------------------------------------------------------------
+//
+// Holding operations (Asset-based dispatchers)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] TER
+canAddHolding(ReadView const& view, Asset const& asset);
+
+[[nodiscard]] TER
+addEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    XRPAmount priorBalance,
+    Asset const& asset,
+    beast::Journal journal);
+
+[[nodiscard]] TER
+removeEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    Asset const& asset,
+    beast::Journal journal);
+
+//------------------------------------------------------------------------------
+//
+// Authorization and transfer checks (Asset-based dispatchers)
+//
+//------------------------------------------------------------------------------
+
+[[nodiscard]] TER
+requireAuth(
+    ReadView const& view,
+    Asset const& asset,
+    AccountID const& account,
+    AuthType authType = AuthType::Legacy);
+
+[[nodiscard]] TER
+canTransfer(ReadView const& view, Asset const& asset, AccountID const& from, AccountID const& to);
+
+//------------------------------------------------------------------------------
+//
+// Money Transfers (Asset-based dispatchers)
+//
+//------------------------------------------------------------------------------
+
+// Direct send w/o fees:
+// - Redeeming IOUs and/or sending sender's own IOUs.
+// - Create trust line of needed.
+// --> bCheckIssuer : normally require issuer to be involved.
+// [[nodiscard]] // nodiscard commented out so DirectStep.cpp compiles.
+
+/** Calls static rippleCreditIOU if saAmount represents Issue.
+ * Calls static rippleCreditMPT if saAmount represents MPTIssue.
+ */
+TER
+rippleCredit(
+    ApplyView& view,
+    AccountID const& uSenderID,
+    AccountID const& uReceiverID,
+    STAmount const& saAmount,
+    bool bCheckIssuer,
+    beast::Journal j);
+
+/** Calls static accountSendIOU if saAmount represents Issue.
+ * Calls static accountSendMPT if saAmount represents MPTIssue.
+ */
+[[nodiscard]] TER
+accountSend(
+    ApplyView& view,
+    AccountID const& from,
+    AccountID const& to,
+    STAmount const& saAmount,
+    beast::Journal j,
+    WaiveTransferFee waiveFee = WaiveTransferFee::No);
+
+using MultiplePaymentDestinations = std::vector<std::pair<AccountID, Number>>;
+/** Like accountSend, except one account is sending multiple payments (with the
+ *  same asset!) simultaneously
+ *
+ * Calls static accountSendMultiIOU if saAmount represents Issue.
+ * Calls static accountSendMultiMPT if saAmount represents MPTIssue.
+ */
+[[nodiscard]] TER
+accountSendMulti(
+    ApplyView& view,
+    AccountID const& senderID,
+    Asset const& asset,
+    MultiplePaymentDestinations const& receivers,
+    beast::Journal j,
+    WaiveTransferFee waiveFee = WaiveTransferFee::No);
+
+[[nodiscard]] TER
+transferXRP(
+    ApplyView& view,
+    AccountID const& from,
+    AccountID const& to,
+    STAmount const& amount,
+    beast::Journal j);
+
+}  // namespace xrpl

include/xrpl/ledger/helpers/VaultHelpers.h

@@ -0,0 +1,81 @@
+#pragma once
+
+#include <xrpl/protocol/STAmount.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+
+#include <memory>
+#include <optional>
+
+namespace xrpl {
+
+/** From the perspective of a vault, return the number of shares to give
+    depositor when they offer a fixed amount of assets. Note, since shares are
+    MPT, this number is integral and always truncated in this calculation.
+
+    @param vault The vault SLE.
+    @param issuance The MPTokenIssuance SLE for the vault's shares.
+    @param assets The amount of assets to convert.
+
+    @return The number of shares, or nullopt on error.
+*/
+[[nodiscard]] std::optional<STAmount>
+assetsToSharesDeposit(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& assets);
+
+/** From the perspective of a vault, return the number of assets to take from
+    depositor when they receive a fixed amount of shares. Note, since shares are
+    MPT, they are always an integral number.
+
+    @param vault The vault SLE.
+    @param issuance The MPTokenIssuance SLE for the vault's shares.
+    @param shares The amount of shares to convert.
+
+    @return The number of assets, or nullopt on error.
+*/
+[[nodiscard]] std::optional<STAmount>
+sharesToAssetsDeposit(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& shares);
+
+/** Controls whether to truncate shares instead of rounding. */
+enum class TruncateShares : bool { no = false, yes = true };
+
+/** From the perspective of a vault, return the number of shares to demand from
+    the depositor when they ask to withdraw a fixed amount of assets. Since
+    shares are MPT this number is integral, and it will be rounded to nearest
+    unless explicitly requested to be truncated instead.
+
+    @param vault The vault SLE.
+    @param issuance The MPTokenIssuance SLE for the vault's shares.
+    @param assets The amount of assets to convert.
+    @param truncate Whether to truncate instead of rounding.
+
+    @return The number of shares, or nullopt on error.
+*/
+[[nodiscard]] std::optional<STAmount>
+assetsToSharesWithdraw(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& assets,
+    TruncateShares truncate = TruncateShares::no);
+
+/** From the perspective of a vault, return the number of assets to give the
+    depositor when they redeem a fixed amount of shares. Note, since shares are
+    MPT, they are always an integral number.
+
+    @param vault The vault SLE.
+    @param issuance The MPTokenIssuance SLE for the vault's shares.
+    @param shares The amount of shares to convert.
+
+    @return The number of assets, or nullopt on error.
+*/
+[[nodiscard]] std::optional<STAmount>
+sharesToAssetsWithdraw(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& shares);
+
+}  // namespace xrpl

include/xrpl/tx/Transactor.h

@@ -116,12 +116,12 @@ protected:
     AccountID const account_;
     XRPAmount preFeeBalance_{};  // Balance before fees.
 
+    virtual ~Transactor() = default;
     Transactor(Transactor const&) = delete;
     Transactor&
     operator=(Transactor const&) = delete;
 
 public:
-    virtual ~Transactor() = default;
     enum ConsequencesFactoryType { Normal, Blocker, Custom };
     /** Process the transaction. */
     ApplyResult
@@ -139,20 +139,6 @@ public:
         return ctx_.view();
     }
 
-    /** Check all invariants for the current transaction.
-     *
-     *  Runs transaction-specific invariants first (visitInvariantEntry +
-     *  finalizeInvariants), then protocol-level invariants.  Protocol
-     *  invariants are skipped if a transaction invariant already failed.
-     *
-     *  @param result  the tentative TER from transaction processing.
-     *  @param fee     the fee consumed by the transaction.
-     *
-     *  @return the final TER after all invariant checks.
-     */
-    [[nodiscard]] TER
-    checkInvariants(TER result, XRPAmount fee);
-
     /////////////////////////////////////////////////////
     /*
     These static functions are called from invoke_preclaim<Tx>
@@ -243,49 +229,6 @@ protected:
     virtual TER
     doApply() = 0;
 
-    /** Inspect a single ledger entry modified by this transaction.
-     *
-     *  Called once for every SLE created, modified, or deleted by the
-     *  transaction, before finalizeInvariants.  Implementations should
-     *  accumulate whatever state they need to verify transaction-specific
-     *  post-conditions.
-     *
-     *  @param isDelete  true if the entry was erased from the ledger.
-     *  @param before    the entry's state before the transaction (nullptr
-     *                   for newly created entries).
-     *  @param after     the entry's state after the transaction (nullptr
-     *                   when isDelete is true).
-     */
-    virtual void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) = 0;
-
-    /** Check transaction-specific post-conditions after all entries have
-     *  been visited.
-     *
-     *  Called once after every modified ledger entry has been passed to
-     *  visitInvariantEntry.  Returns true if all transaction-specific
-     *  invariants hold, or false to fail the transaction with
-     *  tecINVARIANT_FAILED.
-     *
-     *  @param tx    the transaction being applied.
-     *  @param result the tentative TER result so far.
-     *  @param fee   the fee consumed by the transaction.
-     *  @param view  read-only view of the ledger after the transaction.
-     *  @param j     journal for logging invariant failures.
-     *
-     *  @return true if all invariants pass; false otherwise.
-     */
-    [[nodiscard]] virtual bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) = 0;
-
     /** Compute the minimum fee required to process a transaction
         with a given baseFee based on the current server load.
 
@@ -391,21 +334,6 @@ private:
     */
     static NotTEC
     preflight2(PreflightContext const& ctx);
-
-    /** Check transaction-specific invariants only.
-     *
-     *  Walks every modified ledger entry via visitInvariantEntry, then
-     *  calls finalizeInvariants on the derived transactor.  Returns
-     *  tecINVARIANT_FAILED if any transaction invariant is violated.
-     *
-     *  @param result  the tentative TER from transaction processing.
-     *  @param fee     the fee consumed by the transaction.
-     *
-     *  @return the original result if all invariants pass, or
-     *          tecINVARIANT_FAILED otherwise.
-     */
-    [[nodiscard]] TER
-    checkTransactionInvariants(TER result, XRPAmount fee);
 };
 
 inline bool

include/xrpl/tx/applySteps.h

@@ -3,8 +3,6 @@
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/ApplyViewImpl.h>
 
-#include <memory>
-
 namespace xrpl {
 
 class ServiceRegistry;
@@ -343,15 +341,4 @@ calculateDefaultBaseFee(ReadView const& view, STTx const& tx);
 ApplyResult
 doApply(PreclaimResult const& preclaimResult, ServiceRegistry& registry, OpenView& view);
 
-class ApplyContext;
-class Transactor;
-
-/** Create a concrete Transactor subclass for the given ApplyContext.
- *
- *  The transaction type is determined from the STTx held in the context.
- *  Returns nullptr if the transaction type is unknown.
- */
-std::unique_ptr<Transactor>
-makeTransactor(ApplyContext& ctx);
-
 }  // namespace xrpl

include/xrpl/tx/paths/detail/StrandFlow.h

@@ -1,7 +1,8 @@
 #pragma once
 
 #include <xrpl/basics/Log.h>
-#include <xrpl/ledger/Credit.h>
+#include <xrpl/ledger/View.h>
+#include <xrpl/ledger/helpers/RippleStateHelpers.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/IOUAmount.h>
 #include <xrpl/protocol/XRPAmount.h>

include/xrpl/tx/transactors/account/AccountDelete.h

@@ -27,20 +27,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/account/AccountSet.h

@@ -31,20 +31,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/account/SetRegularKey.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/account/SignerListSet.h

@@ -41,20 +41,6 @@ public:
     void
     preCompute() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     // Interface used by AccountDelete
     static TER
     removeFromLedger(

include/xrpl/tx/transactors/bridge/XChainBridge.h

@@ -26,20 +26,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 class BridgeModify : public Transactor
@@ -62,20 +48,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 using XChainModifyBridge = BridgeModify;
@@ -109,20 +81,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------
@@ -150,20 +108,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------
@@ -193,20 +137,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------
@@ -236,20 +166,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 class XChainAddAccountCreateAttestation : public Transactor
@@ -270,20 +186,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------
@@ -328,20 +230,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 using XChainAccountCreateCommit = XChainCreateAccountCommit;

include/xrpl/tx/transactors/check/CheckCancel.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/check/CheckCash.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/check/CheckCreate.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/credentials/CredentialAccept.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/credentials/CredentialCreate.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/credentials/CredentialDelete.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/delegate/DelegateSet.h

@@ -22,20 +22,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     // Interface used by AccountDelete
     static TER
     deleteDelegate(

include/xrpl/tx/transactors/dex/AMMBid.h

@@ -62,20 +62,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/dex/AMMClawback.h

@@ -25,20 +25,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
 private:
     TER
     applyGuts(Sandbox& view);

include/xrpl/tx/transactors/dex/AMMCreate.h

@@ -58,20 +58,6 @@ public:
     /** Attempt to create the AMM instance. */
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/dex/AMMDelete.h

@@ -30,20 +30,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/dex/AMMDeposit.h

@@ -63,20 +63,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
 private:
     std::pair<TER, bool>
     applyGuts(Sandbox& view);

include/xrpl/tx/transactors/dex/AMMVote.h

@@ -47,20 +47,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/dex/AMMWithdraw.h

@@ -70,20 +70,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     /** Equal-asset withdrawal (LPTokens) of some AMM instance pools
      * shares represented by the number of LPTokens .
      * The trading fee is not charged.

include/xrpl/tx/transactors/dex/OfferCancel.h

@@ -22,20 +22,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/dex/OfferCreate.h

@@ -40,20 +40,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
 private:
     std::pair<TER, bool>
     applyGuts(Sandbox& view, Sandbox& view_cancel);

include/xrpl/tx/transactors/did/DIDDelete.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/did/DIDSet.h

@@ -18,20 +18,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/escrow/EscrowCancel.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/escrow/EscrowCreate.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/escrow/EscrowFinish.h

@@ -30,20 +30,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/lending/LoanBrokerCoverClawback.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanBrokerCoverDeposit.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanBrokerCoverWithdraw.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanBrokerDelete.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanBrokerSet.h

@@ -27,20 +27,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanDelete.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanManage.h

@@ -58,20 +58,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanPay.h

@@ -30,20 +30,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 //------------------------------------------------------------------------------

include/xrpl/tx/transactors/lending/LoanSet.h

@@ -38,20 +38,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
 public:
     static std::uint32_t constexpr minPaymentTotal = 1;
     static std::uint32_t constexpr defaultPaymentTotal = 1;

include/xrpl/tx/transactors/nft/NFTokenAcceptOffer.h

@@ -34,20 +34,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/nft/NFTokenBurn.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/nft/NFTokenCancelOffer.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/nft/NFTokenCreateOffer.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/nft/NFTokenMint.h

@@ -30,20 +30,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     // Public to support unit tests.
     static uint256
     createNFTokenID(

include/xrpl/tx/transactors/nft/NFTokenModify.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/oracle/OracleDelete.h

@@ -31,20 +31,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     static TER
     deleteOracle(
         ApplyView& view,

include/xrpl/tx/transactors/oracle/OracleSet.h

@@ -30,20 +30,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/payment/DepositPreauth.h

@@ -25,20 +25,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     // Interface used by AccountDelete
     static TER
     removeFromLedger(ApplyView& view, uint256 const& delIndex, beast::Journal j);

include/xrpl/tx/transactors/payment/Payment.h

@@ -39,20 +39,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/payment_channel/PaymentChannelClaim.h

@@ -27,20 +27,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/payment_channel/PaymentChannelCreate.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/payment_channel/PaymentChannelFund.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/permissioned_domain/PermissionedDomainDelete.h

@@ -22,20 +22,6 @@ public:
     /** Attempt to delete the Permissioned Domain. */
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/permissioned_domain/PermissionedDomainSet.h

@@ -25,20 +25,6 @@ public:
     /** Attempt to create the Permissioned Domain. */
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/system/Batch.h

@@ -33,20 +33,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     static constexpr auto disabledTxTypes = std::to_array<TxType>({
         ttVAULT_CREATE,
         ttVAULT_SET,

include/xrpl/tx/transactors/system/Change.h

@@ -18,20 +18,6 @@ public:
     void
     preCompute() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     static XRPAmount
     calculateBaseFee(ReadView const& view, STTx const& tx)
     {

include/xrpl/tx/transactors/system/LedgerStateFix.h

@@ -28,20 +28,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/system/TicketCreate.h

@@ -59,20 +59,6 @@ public:
     /** Precondition: fee collection is likely.  Attempt to create ticket(s). */
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/token/Clawback.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/token/MPTokenAuthorize.h

@@ -40,20 +40,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/token/MPTokenIssuanceCreate.h

@@ -41,20 +41,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
     static Expected<MPTID, TER>
     create(ApplyView& view, beast::Journal journal, MPTCreateArgs const& args);
 };

include/xrpl/tx/transactors/token/MPTokenIssuanceDestroy.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/token/MPTokenIssuanceSet.h

@@ -30,20 +30,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/token/TrustSet.h

@@ -28,20 +28,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/vault/VaultClawback.h

@@ -22,20 +22,6 @@ public:
     TER
     doApply() override;
 
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
-
 private:
     Expected<std::pair<STAmount, STAmount>, TER>
     assetsToClawback(

include/xrpl/tx/transactors/vault/VaultCreate.h

@@ -27,20 +27,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/vault/VaultDelete.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/vault/VaultDeposit.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/vault/VaultSet.h

@@ -24,20 +24,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

include/xrpl/tx/transactors/vault/VaultWithdraw.h

@@ -21,20 +21,6 @@ public:
 
     TER
     doApply() override;
-
-    void
-    visitInvariantEntry(
-        bool isDelete,
-        std::shared_ptr<SLE const> const& before,
-        std::shared_ptr<SLE const> const& after) override;
-
-    [[nodiscard]] bool
-    finalizeInvariants(
-        STTx const& tx,
-        TER result,
-        XRPAmount fee,
-        ReadView const& view,
-        beast::Journal const& j) override;
 };
 
 }  // namespace xrpl

src/libxrpl/ledger/Credit.cpp

@@ -1,60 +0,0 @@
-#include <xrpl/ledger/ReadView.h>
-#include <xrpl/protocol/AmountConversions.h>
-#include <xrpl/protocol/Indexes.h>
-#include <xrpl/protocol/STAmount.h>
-
-namespace xrpl {
-
-STAmount
-creditLimit(
-    ReadView const& view,
-    AccountID const& account,
-    AccountID const& issuer,
-    Currency const& currency)
-{
-    STAmount result(Issue{currency, account});
-
-    auto sleRippleState = view.read(keylet::line(account, issuer, currency));
-
-    if (sleRippleState)
-    {
-        result = sleRippleState->getFieldAmount(account < issuer ? sfLowLimit : sfHighLimit);
-        result.setIssuer(account);
-    }
-
-    XRPL_ASSERT(result.getIssuer() == account, "xrpl::creditLimit : result issuer match");
-    XRPL_ASSERT(result.getCurrency() == currency, "xrpl::creditLimit : result currency match");
-    return result;
-}
-
-IOUAmount
-creditLimit2(ReadView const& v, AccountID const& acc, AccountID const& iss, Currency const& cur)
-{
-    return toAmount<IOUAmount>(creditLimit(v, acc, iss, cur));
-}
-
-STAmount
-creditBalance(
-    ReadView const& view,
-    AccountID const& account,
-    AccountID const& issuer,
-    Currency const& currency)
-{
-    STAmount result(Issue{currency, account});
-
-    auto sleRippleState = view.read(keylet::line(account, issuer, currency));
-
-    if (sleRippleState)
-    {
-        result = sleRippleState->getFieldAmount(sfBalance);
-        if (account < issuer)
-            result.negate();
-        result.setIssuer(account);
-    }
-
-    XRPL_ASSERT(result.getIssuer() == account, "xrpl::creditBalance : result issuer match");
-    XRPL_ASSERT(result.getCurrency() == currency, "xrpl::creditBalance : result currency match");
-    return result;
-}
-
-}  // namespace xrpl

src/libxrpl/ledger/helpers/AccountRootHelpers.cpp

@@ -0,0 +1,247 @@
+#include <xrpl/ledger/helpers/AccountRootHelpers.h>
+//
+#include <xrpl/basics/Log.h>
+#include <xrpl/beast/utility/instrumentation.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/digest.h>
+
+#include <algorithm>
+#include <limits>
+
+namespace xrpl {
+
+bool
+isGlobalFrozen(ReadView const& view, AccountID const& issuer)
+{
+    if (isXRP(issuer))
+        return false;
+    if (auto const sle = view.read(keylet::account(issuer)))
+        return sle->isFlag(lsfGlobalFreeze);
+    return false;
+}
+
+// An owner count cannot be negative. If adjustment would cause a negative
+// owner count, clamp the owner count at 0. Similarly for overflow. This
+// adjustment allows the ownerCount to be adjusted up or down in multiple steps.
+// If id != std::nullopt, then do error reporting.
+//
+// Returns adjusted owner count.
+static std::uint32_t
+confineOwnerCount(
+    std::uint32_t current,
+    std::int32_t adjustment,
+    std::optional<AccountID> const& id = std::nullopt,
+    beast::Journal j = beast::Journal{beast::Journal::getNullSink()})
+{
+    std::uint32_t adjusted{current + adjustment};
+    if (adjustment > 0)
+    {
+        // Overflow is well defined on unsigned
+        if (adjusted < current)
+        {
+            if (id)
+            {
+                JLOG(j.fatal()) << "Account " << *id << " owner count exceeds max!";
+            }
+            adjusted = std::numeric_limits<std::uint32_t>::max();
+        }
+    }
+    else
+    {
+        // Underflow is well defined on unsigned
+        if (adjusted > current)
+        {
+            if (id)
+            {
+                JLOG(j.fatal()) << "Account " << *id << " owner count set below 0!";
+            }
+            adjusted = 0;
+            XRPL_ASSERT(!id, "xrpl::confineOwnerCount : id is not set");
+        }
+    }
+    return adjusted;
+}
+
+XRPAmount
+xrpLiquid(ReadView const& view, AccountID const& id, std::int32_t ownerCountAdj, beast::Journal j)
+{
+    auto const sle = view.read(keylet::account(id));
+    if (sle == nullptr)
+        return beast::zero;
+
+    // Return balance minus reserve
+    std::uint32_t const ownerCount =
+        confineOwnerCount(view.ownerCountHook(id, sle->getFieldU32(sfOwnerCount)), ownerCountAdj);
+
+    // Pseudo-accounts have no reserve requirement
+    auto const reserve =
+        isPseudoAccount(sle) ? XRPAmount{0} : view.fees().accountReserve(ownerCount);
+
+    auto const fullBalance = sle->getFieldAmount(sfBalance);
+
+    auto const balance = view.balanceHook(id, xrpAccount(), fullBalance);
+
+    STAmount const amount = (balance < reserve) ? STAmount{0} : balance - reserve;
+
+    JLOG(j.trace()) << "accountHolds:" << " account=" << to_string(id)
+                    << " amount=" << amount.getFullText()
+                    << " fullBalance=" << fullBalance.getFullText()
+                    << " balance=" << balance.getFullText() << " reserve=" << reserve
+                    << " ownerCount=" << ownerCount << " ownerCountAdj=" << ownerCountAdj;
+
+    return amount.xrp();
+}
+
+Rate
+transferRate(ReadView const& view, AccountID const& issuer)
+{
+    auto const sle = view.read(keylet::account(issuer));
+
+    if (sle && sle->isFieldPresent(sfTransferRate))
+        return Rate{sle->getFieldU32(sfTransferRate)};
+
+    return parityRate;
+}
+
+void
+adjustOwnerCount(
+    ApplyView& view,
+    std::shared_ptr<SLE> const& sle,
+    std::int32_t amount,
+    beast::Journal j)
+{
+    if (!sle)
+        return;
+    XRPL_ASSERT(amount, "xrpl::adjustOwnerCount : nonzero amount input");
+    std::uint32_t const current{sle->getFieldU32(sfOwnerCount)};
+    AccountID const id = (*sle)[sfAccount];
+    std::uint32_t const adjusted = confineOwnerCount(current, amount, id, j);
+    view.adjustOwnerCountHook(id, current, adjusted);
+    sle->at(sfOwnerCount) = adjusted;
+    view.update(sle);
+}
+
+AccountID
+pseudoAccountAddress(ReadView const& view, uint256 const& pseudoOwnerKey)
+{
+    // This number must not be changed without an amendment
+    constexpr std::uint16_t maxAccountAttempts = 256;
+    for (std::uint16_t i = 0; i < maxAccountAttempts; ++i)
+    {
+        ripesha_hasher rsh;
+        auto const hash = sha512Half(i, view.header().parentHash, pseudoOwnerKey);
+        rsh(hash.data(), hash.size());
+        AccountID const ret{static_cast<ripesha_hasher::result_type>(rsh)};
+        if (!view.read(keylet::account(ret)))
+            return ret;
+    }
+    return beast::zero;
+}
+
+// Pseudo-account designator fields MUST be maintained by including the
+// SField::sMD_PseudoAccount flag in the SField definition. (Don't forget to
+// "| SField::sMD_Default"!) The fields do NOT need to be amendment-gated,
+// since a non-active amendment will not set any field, by definition.
+// Specific properties of a pseudo-account are NOT checked here, that's what
+// InvariantCheck is for.
+[[nodiscard]] std::vector<SField const*> const&
+getPseudoAccountFields()
+{
+    static std::vector<SField const*> const pseudoFields = []() {
+        auto const ar = LedgerFormats::getInstance().findByType(ltACCOUNT_ROOT);
+        if (!ar)
+        {
+            // LCOV_EXCL_START
+            LogicError(
+                "xrpl::getPseudoAccountFields : unable to find account root "
+                "ledger format");
+            // LCOV_EXCL_STOP
+        }
+        auto const& soTemplate = ar->getSOTemplate();
+
+        std::vector<SField const*> pseudoFields;
+        for (auto const& field : soTemplate)
+        {
+            if (field.sField().shouldMeta(SField::sMD_PseudoAccount))
+                pseudoFields.emplace_back(&field.sField());
+        }
+        return pseudoFields;
+    }();
+    return pseudoFields;
+}
+
+[[nodiscard]] bool
+isPseudoAccount(
+    std::shared_ptr<SLE const> sleAcct,
+    std::set<SField const*> const& pseudoFieldFilter)
+{
+    auto const& fields = getPseudoAccountFields();
+
+    // Intentionally use defensive coding here because it's cheap and makes the
+    // semantics of true return value clean.
+    return sleAcct && sleAcct->getType() == ltACCOUNT_ROOT &&
+        std::count_if(
+            fields.begin(), fields.end(), [&sleAcct, &pseudoFieldFilter](SField const* sf) -> bool {
+                return sleAcct->isFieldPresent(*sf) &&
+                    (pseudoFieldFilter.empty() || pseudoFieldFilter.contains(sf));
+            }) > 0;
+}
+
+Expected<std::shared_ptr<SLE>, TER>
+createPseudoAccount(ApplyView& view, uint256 const& pseudoOwnerKey, SField const& ownerField)
+{
+    [[maybe_unused]]
+    auto const& fields = getPseudoAccountFields();
+    XRPL_ASSERT(
+        std::count_if(
+            fields.begin(),
+            fields.end(),
+            [&ownerField](SField const* sf) -> bool { return *sf == ownerField; }) == 1,
+        "xrpl::createPseudoAccount : valid owner field");
+
+    auto const accountId = pseudoAccountAddress(view, pseudoOwnerKey);
+    if (accountId == beast::zero)
+        return Unexpected(tecDUPLICATE);
+
+    // Create pseudo-account.
+    auto account = std::make_shared<SLE>(keylet::account(accountId));
+    account->setAccountID(sfAccount, accountId);
+    account->setFieldAmount(sfBalance, STAmount{});
+
+    // Pseudo-accounts can't submit transactions, so set the sequence number
+    // to 0 to make them easier to spot and verify, and add an extra level
+    // of protection.
+    std::uint32_t const seqno =                           //
+        view.rules().enabled(featureSingleAssetVault) ||  //
+            view.rules().enabled(featureLendingProtocol)  //
+        ? 0                                               //
+        : view.seq();
+    account->setFieldU32(sfSequence, seqno);
+    // Ignore reserves requirement, disable the master key, allow default
+    // rippling, and enable deposit authorization to prevent payments into
+    // pseudo-account.
+    account->setFieldU32(sfFlags, lsfDisableMaster | lsfDefaultRipple | lsfDepositAuth);
+    // Link the pseudo-account with its owner object.
+    account->setFieldH256(ownerField, pseudoOwnerKey);
+
+    view.insert(account);
+
+    return account;
+}
+
+[[nodiscard]] TER
+checkDestinationAndTag(SLE::const_ref toSle, bool hasDestinationTag)
+{
+    if (toSle == nullptr)
+        return tecNO_DST;
+
+    // The tag is basically account-specific information we don't
+    // understand, but we can require someone to fill it in.
+    if (toSle->isFlag(lsfRequireDestTag) && !hasDestinationTag)
+        return tecDST_TAG_NEEDED;  // Cannot send without a tag
+
+    return tesSUCCESS;
+}
+
+}  // namespace xrpl

src/libxrpl/ledger/helpers/CredentialHelpers.cpp

@@ -1,5 +1,7 @@
-#include <xrpl/ledger/CredentialHelpers.h>
+#include <xrpl/ledger/helpers/CredentialHelpers.h>
+//
 #include <xrpl/ledger/View.h>
+#include <xrpl/ledger/helpers/AccountRootHelpers.h>
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/digest.h>
 

src/libxrpl/ledger/helpers/DirectoryHelpers.cpp

@@ -0,0 +1,177 @@
+#include <xrpl/ledger/helpers/DirectoryHelpers.h>
+//
+#include <xrpl/protocol/LedgerFormats.h>
+
+namespace xrpl {
+
+bool
+dirFirst(
+    ApplyView& view,
+    uint256 const& root,
+    std::shared_ptr<SLE>& page,
+    unsigned int& index,
+    uint256& entry)
+{
+    return detail::internalDirFirst(view, root, page, index, entry);
+}
+
+bool
+dirNext(
+    ApplyView& view,
+    uint256 const& root,
+    std::shared_ptr<SLE>& page,
+    unsigned int& index,
+    uint256& entry)
+{
+    return detail::internalDirNext(view, root, page, index, entry);
+}
+
+bool
+cdirFirst(
+    ReadView const& view,
+    uint256 const& root,
+    std::shared_ptr<SLE const>& page,
+    unsigned int& index,
+    uint256& entry)
+{
+    return detail::internalDirFirst(view, root, page, index, entry);
+}
+
+bool
+cdirNext(
+    ReadView const& view,
+    uint256 const& root,
+    std::shared_ptr<SLE const>& page,
+    unsigned int& index,
+    uint256& entry)
+{
+    return detail::internalDirNext(view, root, page, index, entry);
+}
+
+void
+forEachItem(
+    ReadView const& view,
+    Keylet const& root,
+    std::function<void(std::shared_ptr<SLE const> const&)> const& f)
+{
+    XRPL_ASSERT(root.type == ltDIR_NODE, "xrpl::forEachItem : valid root type");
+
+    if (root.type != ltDIR_NODE)
+        return;
+
+    auto pos = root;
+
+    while (true)
+    {
+        auto sle = view.read(pos);
+        if (!sle)
+            return;
+        for (auto const& key : sle->getFieldV256(sfIndexes))
+            f(view.read(keylet::child(key)));
+        auto const next = sle->getFieldU64(sfIndexNext);
+        if (!next)
+            return;
+        pos = keylet::page(root, next);
+    }
+}
+
+bool
+forEachItemAfter(
+    ReadView const& view,
+    Keylet const& root,
+    uint256 const& after,
+    std::uint64_t const hint,
+    unsigned int limit,
+    std::function<bool(std::shared_ptr<SLE const> const&)> const& f)
+{
+    XRPL_ASSERT(root.type == ltDIR_NODE, "xrpl::forEachItemAfter : valid root type");
+
+    if (root.type != ltDIR_NODE)
+        return false;
+
+    auto currentIndex = root;
+
+    // If startAfter is not zero try jumping to that page using the hint
+    if (after.isNonZero())
+    {
+        auto const hintIndex = keylet::page(root, hint);
+
+        if (auto hintDir = view.read(hintIndex))
+        {
+            for (auto const& key : hintDir->getFieldV256(sfIndexes))
+            {
+                if (key == after)
+                {
+                    // We found the hint, we can start here
+                    currentIndex = hintIndex;
+                    break;
+                }
+            }
+        }
+
+        bool found = false;
+        for (;;)
+        {
+            auto const ownerDir = view.read(currentIndex);
+            if (!ownerDir)
+                return found;
+            for (auto const& key : ownerDir->getFieldV256(sfIndexes))
+            {
+                if (!found)
+                {
+                    if (key == after)
+                        found = true;
+                }
+                else if (f(view.read(keylet::child(key))) && limit-- <= 1)
+                {
+                    return found;
+                }
+            }
+
+            auto const uNodeNext = ownerDir->getFieldU64(sfIndexNext);
+            if (uNodeNext == 0)
+                return found;
+            currentIndex = keylet::page(root, uNodeNext);
+        }
+    }
+    else
+    {
+        for (;;)
+        {
+            auto const ownerDir = view.read(currentIndex);
+            if (!ownerDir)
+                return true;
+            for (auto const& key : ownerDir->getFieldV256(sfIndexes))
+            {
+                if (f(view.read(keylet::child(key))) && limit-- <= 1)
+                    return true;
+            }
+            auto const uNodeNext = ownerDir->getFieldU64(sfIndexNext);
+            if (uNodeNext == 0)
+                return true;
+            currentIndex = keylet::page(root, uNodeNext);
+        }
+    }
+}
+
+bool
+dirIsEmpty(ReadView const& view, Keylet const& k)
+{
+    auto const sleNode = view.read(k);
+    if (!sleNode)
+        return true;
+    if (!sleNode->getFieldV256(sfIndexes).empty())
+        return false;
+    // The first page of a directory may legitimately be empty even if there
+    // are other pages (the first page is the anchor page) so check to see if
+    // there is another page. If there is, the directory isn't empty.
+    return sleNode->getFieldU64(sfIndexNext) == 0;
+}
+
+std::function<void(SLE::ref)>
+describeOwnerDir(AccountID const& account)
+{
+    return [account](std::shared_ptr<SLE> const& sle) { (*sle)[sfOwner] = account; };
+}
+
+}  // namespace xrpl

src/libxrpl/ledger/helpers/MPTokenHelpers.cpp

@@ -0,0 +1,766 @@
+#include <xrpl/ledger/helpers/MPTokenHelpers.h>
+//
+#include <xrpl/basics/Log.h>
+#include <xrpl/ledger/helpers/AccountRootHelpers.h>
+#include <xrpl/ledger/helpers/CredentialHelpers.h>
+#include <xrpl/ledger/helpers/DirectoryHelpers.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/TxFlags.h>
+
+namespace xrpl {
+
+// Forward declarations for functions that remain in View.h/cpp
+bool
+isVaultPseudoAccountFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    MPTIssue const& mptShare,
+    int depth);
+
+[[nodiscard]] TER
+dirLink(
+    ApplyView& view,
+    AccountID const& owner,
+    std::shared_ptr<SLE>& object,
+    SF_UINT64 const& node = sfOwnerNode);
+
+bool
+isGlobalFrozen(ReadView const& view, MPTIssue const& mptIssue)
+{
+    if (auto const sle = view.read(keylet::mptIssuance(mptIssue.getMptID())))
+        return sle->isFlag(lsfMPTLocked);
+    return false;
+}
+
+bool
+isIndividualFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue)
+{
+    if (auto const sle = view.read(keylet::mptoken(mptIssue.getMptID(), account)))
+        return sle->isFlag(lsfMPTLocked);
+    return false;
+}
+
+bool
+isFrozen(ReadView const& view, AccountID const& account, MPTIssue const& mptIssue, int depth)
+{
+    return isGlobalFrozen(view, mptIssue) || isIndividualFrozen(view, account, mptIssue) ||
+        isVaultPseudoAccountFrozen(view, account, mptIssue, depth);
+}
+
+[[nodiscard]] bool
+isAnyFrozen(
+    ReadView const& view,
+    std::initializer_list<AccountID> const& accounts,
+    MPTIssue const& mptIssue,
+    int depth)
+{
+    if (isGlobalFrozen(view, mptIssue))
+        return true;
+
+    for (auto const& account : accounts)
+    {
+        if (isIndividualFrozen(view, account, mptIssue))
+            return true;
+    }
+
+    for (auto const& account : accounts)
+    {
+        if (isVaultPseudoAccountFrozen(view, account, mptIssue, depth))
+            return true;
+    }
+
+    return false;
+}
+
+Rate
+transferRate(ReadView const& view, MPTID const& issuanceID)
+{
+    // fee is 0-50,000 (0-50%), rate is 1,000,000,000-2,000,000,000
+    // For example, if transfer fee is 50% then 10,000 * 50,000 = 500,000
+    // which represents 50% of 1,000,000,000
+    if (auto const sle = view.read(keylet::mptIssuance(issuanceID));
+        sle && sle->isFieldPresent(sfTransferFee))
+        return Rate{1'000'000'000u + 10'000 * sle->getFieldU16(sfTransferFee)};
+
+    return parityRate;
+}
+
+[[nodiscard]] TER
+canAddHolding(ReadView const& view, MPTIssue const& mptIssue)
+{
+    auto mptID = mptIssue.getMptID();
+    auto issuance = view.read(keylet::mptIssuance(mptID));
+    if (!issuance)
+    {
+        return tecOBJECT_NOT_FOUND;
+    }
+    if (!issuance->isFlag(lsfMPTCanTransfer))
+    {
+        return tecNO_AUTH;
+    }
+
+    return tesSUCCESS;
+}
+
+[[nodiscard]] TER
+addEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    XRPAmount priorBalance,
+    MPTIssue const& mptIssue,
+    beast::Journal journal)
+{
+    auto const& mptID = mptIssue.getMptID();
+    auto const mpt = view.peek(keylet::mptIssuance(mptID));
+    if (!mpt)
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+    if (mpt->isFlag(lsfMPTLocked))
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+    if (view.peek(keylet::mptoken(mptID, accountID)))
+        return tecDUPLICATE;
+    if (accountID == mptIssue.getIssuer())
+        return tesSUCCESS;
+
+    return authorizeMPToken(view, priorBalance, mptID, accountID, journal);
+}
+
+[[nodiscard]] TER
+authorizeMPToken(
+    ApplyView& view,
+    XRPAmount const& priorBalance,
+    MPTID const& mptIssuanceID,
+    AccountID const& account,
+    beast::Journal journal,
+    std::uint32_t flags,
+    std::optional<AccountID> holderID)
+{
+    auto const sleAcct = view.peek(keylet::account(account));
+    if (!sleAcct)
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    // If the account that submitted the tx is a holder
+    // Note: `account_` is holder's account
+    //       `holderID` is NOT used
+    if (!holderID)
+    {
+        // When a holder wants to unauthorize/delete a MPT, the ledger must
+        //      - delete mptokenKey from owner directory
+        //      - delete the MPToken
+        if (flags & tfMPTUnauthorize)
+        {
+            auto const mptokenKey = keylet::mptoken(mptIssuanceID, account);
+            auto const sleMpt = view.peek(mptokenKey);
+            if (!sleMpt || (*sleMpt)[sfMPTAmount] != 0)
+                return tecINTERNAL;  // LCOV_EXCL_LINE
+
+            if (!view.dirRemove(
+                    keylet::ownerDir(account), (*sleMpt)[sfOwnerNode], sleMpt->key(), false))
+                return tecINTERNAL;  // LCOV_EXCL_LINE
+
+            adjustOwnerCount(view, sleAcct, -1, journal);
+
+            view.erase(sleMpt);
+            return tesSUCCESS;
+        }
+
+        // A potential holder wants to authorize/hold a mpt, the ledger must:
+        //      - add the new mptokenKey to the owner directory
+        //      - create the MPToken object for the holder
+
+        // The reserve that is required to create the MPToken. Note
+        // that although the reserve increases with every item
+        // an account owns, in the case of MPTokens we only
+        // *enforce* a reserve if the user owns more than two
+        // items. This is similar to the reserve requirements of trust lines.
+        std::uint32_t const uOwnerCount = sleAcct->getFieldU32(sfOwnerCount);
+        XRPAmount const reserveCreate(
+            (uOwnerCount < 2) ? XRPAmount(beast::zero)
+                              : view.fees().accountReserve(uOwnerCount + 1));
+
+        if (priorBalance < reserveCreate)
+            return tecINSUFFICIENT_RESERVE;
+
+        // Defensive check before we attempt to create MPToken for the issuer
+        auto const mpt = view.read(keylet::mptIssuance(mptIssuanceID));
+        if (!mpt || mpt->getAccountID(sfIssuer) == account)
+        {
+            // LCOV_EXCL_START
+            UNREACHABLE("xrpl::authorizeMPToken : invalid issuance or issuers token");
+            if (view.rules().enabled(featureLendingProtocol))
+                return tecINTERNAL;
+            // LCOV_EXCL_STOP
+        }
+
+        auto const mptokenKey = keylet::mptoken(mptIssuanceID, account);
+        auto mptoken = std::make_shared<SLE>(mptokenKey);
+        if (auto ter = dirLink(view, account, mptoken))
+            return ter;  // LCOV_EXCL_LINE
+
+        (*mptoken)[sfAccount] = account;
+        (*mptoken)[sfMPTokenIssuanceID] = mptIssuanceID;
+        (*mptoken)[sfFlags] = 0;
+        view.insert(mptoken);
+
+        // Update owner count.
+        adjustOwnerCount(view, sleAcct, 1, journal);
+
+        return tesSUCCESS;
+    }
+
+    auto const sleMptIssuance = view.read(keylet::mptIssuance(mptIssuanceID));
+    if (!sleMptIssuance)
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    // If the account that submitted this tx is the issuer of the MPT
+    // Note: `account_` is issuer's account
+    //       `holderID` is holder's account
+    if (account != (*sleMptIssuance)[sfIssuer])
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    auto const sleMpt = view.peek(keylet::mptoken(mptIssuanceID, *holderID));
+    if (!sleMpt)
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    std::uint32_t const flagsIn = sleMpt->getFieldU32(sfFlags);
+    std::uint32_t flagsOut = flagsIn;
+
+    // Issuer wants to unauthorize the holder, unset lsfMPTAuthorized on
+    // their MPToken
+    if (flags & tfMPTUnauthorize)
+    {
+        flagsOut &= ~lsfMPTAuthorized;
+    }
+    // Issuer wants to authorize a holder, set lsfMPTAuthorized on their
+    // MPToken
+    else
+    {
+        flagsOut |= lsfMPTAuthorized;
+    }
+
+    if (flagsIn != flagsOut)
+        sleMpt->setFieldU32(sfFlags, flagsOut);
+
+    view.update(sleMpt);
+    return tesSUCCESS;
+}
+
+[[nodiscard]] TER
+removeEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    MPTIssue const& mptIssue,
+    beast::Journal journal)
+{
+    // If the account is the issuer, then no token should exist. MPTs do not
+    // have the legacy ability to create such a situation, but check anyway. If
+    // a token does exist, it will get deleted. If not, return success.
+    bool const accountIsIssuer = accountID == mptIssue.getIssuer();
+    auto const& mptID = mptIssue.getMptID();
+    auto const mptoken = view.peek(keylet::mptoken(mptID, accountID));
+    if (!mptoken)
+        return accountIsIssuer ? (TER)tesSUCCESS : (TER)tecOBJECT_NOT_FOUND;
+    // Unlike a trust line, if the account is the issuer, and the token has a
+    // balance, it can not just be deleted, because that will throw the issuance
+    // accounting out of balance, so fail. Since this should be impossible
+    // anyway, I'm not going to put any effort into it.
+    if (mptoken->at(sfMPTAmount) != 0)
+        return tecHAS_OBLIGATIONS;
+
+    return authorizeMPToken(
+        view,
+        {},  // priorBalance
+        mptID,
+        accountID,
+        journal,
+        tfMPTUnauthorize  // flags
+    );
+}
+
+[[nodiscard]] TER
+requireAuth(
+    ReadView const& view,
+    MPTIssue const& mptIssue,
+    AccountID const& account,
+    AuthType authType,
+    int depth)
+{
+    auto const mptID = keylet::mptIssuance(mptIssue.getMptID());
+    auto const sleIssuance = view.read(mptID);
+    if (!sleIssuance)
+        return tecOBJECT_NOT_FOUND;
+
+    auto const mptIssuer = sleIssuance->getAccountID(sfIssuer);
+
+    // issuer is always "authorized"
+    if (mptIssuer == account)  // Issuer won't have MPToken
+        return tesSUCCESS;
+
+    bool const featureSAVEnabled = view.rules().enabled(featureSingleAssetVault);
+
+    if (featureSAVEnabled)
+    {
+        if (depth >= maxAssetCheckDepth)
+            return tecINTERNAL;  // LCOV_EXCL_LINE
+
+        // requireAuth is recursive if the issuer is a vault pseudo-account
+        auto const sleIssuer = view.read(keylet::account(mptIssuer));
+        if (!sleIssuer)
+            return tefINTERNAL;  // LCOV_EXCL_LINE
+
+        if (sleIssuer->isFieldPresent(sfVaultID))
+        {
+            auto const sleVault = view.read(keylet::vault(sleIssuer->getFieldH256(sfVaultID)));
+            if (!sleVault)
+                return tefINTERNAL;  // LCOV_EXCL_LINE
+
+            auto const asset = sleVault->at(sfAsset);
+            if (auto const err = std::visit(
+                    [&]<ValidIssueType TIss>(TIss const& issue) {
+                        if constexpr (std::is_same_v<TIss, Issue>)
+                        {
+                            return requireAuth(view, issue, account, authType);
+                        }
+                        else
+                        {
+                            return requireAuth(view, issue, account, authType, depth + 1);
+                        }
+                    },
+                    asset.value());
+                !isTesSuccess(err))
+                return err;
+        }
+    }
+
+    auto const mptokenID = keylet::mptoken(mptID.key, account);
+    auto const sleToken = view.read(mptokenID);
+
+    // if account has no MPToken, fail
+    if (!sleToken && (authType == AuthType::StrongAuth || authType == AuthType::Legacy))
+        return tecNO_AUTH;
+
+    // Note, this check is not amendment-gated because DomainID will be always
+    // empty **unless** writing to it has been enabled by an amendment
+    auto const maybeDomainID = sleIssuance->at(~sfDomainID);
+    if (maybeDomainID)
+    {
+        XRPL_ASSERT(
+            sleIssuance->getFieldU32(sfFlags) & lsfMPTRequireAuth,
+            "xrpl::requireAuth : issuance requires authorization");
+        // ter = tefINTERNAL | tecOBJECT_NOT_FOUND | tecNO_AUTH | tecEXPIRED
+        auto const ter = credentials::validDomain(view, *maybeDomainID, account);
+        if (isTesSuccess(ter))
+        {
+            return ter;  // Note: sleToken might be null
+        }
+        if (!sleToken)
+        {
+            return ter;
+        }
+        // We ignore error from validDomain if we found sleToken, as it could
+        // belong to someone who is explicitly authorized e.g. a vault owner.
+    }
+
+    if (featureSAVEnabled)
+    {
+        // Implicitly authorize Vault and LoanBroker pseudo-accounts
+        if (isPseudoAccount(view, account, {&sfVaultID, &sfLoanBrokerID}))
+            return tesSUCCESS;
+    }
+
+    // mptoken must be authorized if issuance enabled requireAuth
+    if (sleIssuance->isFlag(lsfMPTRequireAuth) &&
+        (!sleToken || !sleToken->isFlag(lsfMPTAuthorized)))
+        return tecNO_AUTH;
+
+    return tesSUCCESS;  // Note: sleToken might be null
+}
+
+[[nodiscard]] TER
+enforceMPTokenAuthorization(
+    ApplyView& view,
+    MPTID const& mptIssuanceID,
+    AccountID const& account,
+    XRPAmount const& priorBalance,  // for MPToken authorization
+    beast::Journal j)
+{
+    auto const sleIssuance = view.read(keylet::mptIssuance(mptIssuanceID));
+    if (!sleIssuance)
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+
+    XRPL_ASSERT(
+        sleIssuance->isFlag(lsfMPTRequireAuth),
+        "xrpl::enforceMPTokenAuthorization : authorization required");
+
+    if (account == sleIssuance->at(sfIssuer))
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+
+    auto const keylet = keylet::mptoken(mptIssuanceID, account);
+    auto const sleToken = view.read(keylet);  //  NOTE: might be null
+    auto const maybeDomainID = sleIssuance->at(~sfDomainID);
+    bool expired = false;
+    bool const authorizedByDomain = [&]() -> bool {
+        // NOTE: defensive here, should be checked in preclaim
+        if (!maybeDomainID.has_value())
+            return false;  // LCOV_EXCL_LINE
+
+        auto const ter = verifyValidDomain(view, account, *maybeDomainID, j);
+        if (isTesSuccess(ter))
+            return true;
+        if (ter == tecEXPIRED)
+            expired = true;
+        return false;
+    }();
+
+    if (!authorizedByDomain && sleToken == nullptr)
+    {
+        // Could not find MPToken and won't create one, could be either of:
+        //
+        // 1. Field sfDomainID not set in MPTokenIssuance or
+        // 2. Account has no matching and accepted credentials or
+        // 3. Account has all expired credentials (deleted in verifyValidDomain)
+        //
+        // Either way, return tecNO_AUTH and there is nothing else to do
+        return expired ? tecEXPIRED : tecNO_AUTH;
+    }
+    if (!authorizedByDomain && maybeDomainID.has_value())
+    {
+        // Found an MPToken but the account is not authorized and we expect
+        // it to have been authorized by the domain. This could be because the
+        // credentials used to create the MPToken have expired or been deleted.
+        return expired ? tecEXPIRED : tecNO_AUTH;
+    }
+    if (!authorizedByDomain)
+    {
+        // We found an MPToken, but sfDomainID is not set, so this is a classic
+        // MPToken which requires authorization by the token issuer.
+        XRPL_ASSERT(
+            sleToken != nullptr && !maybeDomainID.has_value(),
+            "xrpl::enforceMPTokenAuthorization : found MPToken");
+        if (sleToken->isFlag(lsfMPTAuthorized))
+            return tesSUCCESS;
+
+        return tecNO_AUTH;
+    }
+    if (authorizedByDomain && sleToken != nullptr)
+    {
+        // Found an MPToken, authorized by the domain. Ignore authorization flag
+        // lsfMPTAuthorized because it is meaningless. Return tesSUCCESS
+        XRPL_ASSERT(
+            maybeDomainID.has_value(),
+            "xrpl::enforceMPTokenAuthorization : found MPToken for domain");
+        return tesSUCCESS;
+    }
+    if (authorizedByDomain)
+    {
+        // Could not find MPToken but there should be one because we are
+        // authorized by domain. Proceed to create it, then return tesSUCCESS
+        XRPL_ASSERT(
+            maybeDomainID.has_value() && sleToken == nullptr,
+            "xrpl::enforceMPTokenAuthorization : new MPToken for domain");
+        if (auto const err = authorizeMPToken(
+                view,
+                priorBalance,   // priorBalance
+                mptIssuanceID,  // mptIssuanceID
+                account,        // account
+                j);
+            !isTesSuccess(err))
+            return err;
+
+        return tesSUCCESS;
+    }
+
+    // LCOV_EXCL_START
+    UNREACHABLE("xrpl::enforceMPTokenAuthorization : condition list is incomplete");
+    return tefINTERNAL;
+    // LCOV_EXCL_STOP
+}
+
+TER
+canTransfer(
+    ReadView const& view,
+    MPTIssue const& mptIssue,
+    AccountID const& from,
+    AccountID const& to)
+{
+    auto const mptID = keylet::mptIssuance(mptIssue.getMptID());
+    auto const sleIssuance = view.read(mptID);
+    if (!sleIssuance)
+        return tecOBJECT_NOT_FOUND;
+
+    if (!(sleIssuance->getFieldU32(sfFlags) & lsfMPTCanTransfer))
+    {
+        if (from != (*sleIssuance)[sfIssuer] && to != (*sleIssuance)[sfIssuer])
+            return TER{tecNO_AUTH};
+    }
+    return tesSUCCESS;
+}
+
+TER
+rippleLockEscrowMPT(
+    ApplyView& view,
+    AccountID const& sender,
+    STAmount const& amount,
+    beast::Journal j)
+{
+    auto const mptIssue = amount.get<MPTIssue>();
+    auto const mptID = keylet::mptIssuance(mptIssue.getMptID());
+    auto sleIssuance = view.peek(mptID);
+    if (!sleIssuance)
+    {  // LCOV_EXCL_START
+        JLOG(j.error()) << "rippleLockEscrowMPT: MPT issuance not found for "
+                        << mptIssue.getMptID();
+        return tecOBJECT_NOT_FOUND;
+    }  // LCOV_EXCL_STOP
+
+    if (amount.getIssuer() == sender)
+    {  // LCOV_EXCL_START
+        JLOG(j.error()) << "rippleLockEscrowMPT: sender is the issuer, cannot lock MPTs.";
+        return tecINTERNAL;
+    }  // LCOV_EXCL_STOP
+
+    // 1. Decrease the MPT Holder MPTAmount
+    // 2. Increase the MPT Holder EscrowedAmount
+    {
+        auto const mptokenID = keylet::mptoken(mptID.key, sender);
+        auto sle = view.peek(mptokenID);
+        if (!sle)
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleLockEscrowMPT: MPToken not found for " << sender;
+            return tecOBJECT_NOT_FOUND;
+        }  // LCOV_EXCL_STOP
+
+        auto const amt = sle->getFieldU64(sfMPTAmount);
+        auto const pay = amount.mpt().value();
+
+        // Underflow check for subtraction
+        if (!canSubtract(STAmount(mptIssue, amt), STAmount(mptIssue, pay)))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleLockEscrowMPT: insufficient MPTAmount for "
+                            << to_string(sender) << ": " << amt << " < " << pay;
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        (*sle)[sfMPTAmount] = amt - pay;
+
+        // Overflow check for addition
+        uint64_t const locked = (*sle)[~sfLockedAmount].value_or(0);
+
+        if (!canAdd(STAmount(mptIssue, locked), STAmount(mptIssue, pay)))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleLockEscrowMPT: overflow on locked amount for "
+                            << to_string(sender) << ": " << locked << " + " << pay;
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        if (sle->isFieldPresent(sfLockedAmount))
+        {
+            (*sle)[sfLockedAmount] += pay;
+        }
+        else
+        {
+            sle->setFieldU64(sfLockedAmount, pay);
+        }
+
+        view.update(sle);
+    }
+
+    // 1. Increase the Issuance EscrowedAmount
+    // 2. DO NOT change the Issuance OutstandingAmount
+    {
+        uint64_t const issuanceEscrowed = (*sleIssuance)[~sfLockedAmount].value_or(0);
+        auto const pay = amount.mpt().value();
+
+        // Overflow check for addition
+        if (!canAdd(STAmount(mptIssue, issuanceEscrowed), STAmount(mptIssue, pay)))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleLockEscrowMPT: overflow on issuance "
+                               "locked amount for "
+                            << mptIssue.getMptID() << ": " << issuanceEscrowed << " + " << pay;
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        if (sleIssuance->isFieldPresent(sfLockedAmount))
+        {
+            (*sleIssuance)[sfLockedAmount] += pay;
+        }
+        else
+        {
+            sleIssuance->setFieldU64(sfLockedAmount, pay);
+        }
+
+        view.update(sleIssuance);
+    }
+    return tesSUCCESS;
+}
+
+TER
+rippleUnlockEscrowMPT(
+    ApplyView& view,
+    AccountID const& sender,
+    AccountID const& receiver,
+    STAmount const& netAmount,
+    STAmount const& grossAmount,
+    beast::Journal j)
+{
+    if (!view.rules().enabled(fixTokenEscrowV1))
+    {
+        XRPL_ASSERT(
+            netAmount == grossAmount, "xrpl::rippleUnlockEscrowMPT : netAmount == grossAmount");
+    }
+
+    auto const& issuer = netAmount.getIssuer();
+    auto const& mptIssue = netAmount.get<MPTIssue>();
+    auto const mptID = keylet::mptIssuance(mptIssue.getMptID());
+    auto sleIssuance = view.peek(mptID);
+    if (!sleIssuance)
+    {  // LCOV_EXCL_START
+        JLOG(j.error()) << "rippleUnlockEscrowMPT: MPT issuance not found for "
+                        << mptIssue.getMptID();
+        return tecOBJECT_NOT_FOUND;
+    }  // LCOV_EXCL_STOP
+
+    // Decrease the Issuance EscrowedAmount
+    {
+        if (!sleIssuance->isFieldPresent(sfLockedAmount))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleUnlockEscrowMPT: no locked amount in issuance for "
+                            << mptIssue.getMptID();
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        auto const locked = sleIssuance->getFieldU64(sfLockedAmount);
+        auto const redeem = grossAmount.mpt().value();
+
+        // Underflow check for subtraction
+        if (!canSubtract(STAmount(mptIssue, locked), STAmount(mptIssue, redeem)))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleUnlockEscrowMPT: insufficient locked amount for "
+                            << mptIssue.getMptID() << ": " << locked << " < " << redeem;
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        auto const newLocked = locked - redeem;
+        if (newLocked == 0)
+        {
+            sleIssuance->makeFieldAbsent(sfLockedAmount);
+        }
+        else
+        {
+            sleIssuance->setFieldU64(sfLockedAmount, newLocked);
+        }
+        view.update(sleIssuance);
+    }
+
+    if (issuer != receiver)
+    {
+        // Increase the MPT Holder MPTAmount
+        auto const mptokenID = keylet::mptoken(mptID.key, receiver);
+        auto sle = view.peek(mptokenID);
+        if (!sle)
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleUnlockEscrowMPT: MPToken not found for " << receiver;
+            return tecOBJECT_NOT_FOUND;
+        }  // LCOV_EXCL_STOP
+
+        auto current = sle->getFieldU64(sfMPTAmount);
+        auto delta = netAmount.mpt().value();
+
+        // Overflow check for addition
+        if (!canAdd(STAmount(mptIssue, current), STAmount(mptIssue, delta)))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleUnlockEscrowMPT: overflow on MPTAmount for "
+                            << to_string(receiver) << ": " << current << " + " << delta;
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        (*sle)[sfMPTAmount] += delta;
+        view.update(sle);
+    }
+    else
+    {
+        // Decrease the Issuance OutstandingAmount
+        auto const outstanding = sleIssuance->getFieldU64(sfOutstandingAmount);
+        auto const redeem = netAmount.mpt().value();
+
+        // Underflow check for subtraction
+        if (!canSubtract(STAmount(mptIssue, outstanding), STAmount(mptIssue, redeem)))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleUnlockEscrowMPT: insufficient outstanding amount for "
+                            << mptIssue.getMptID() << ": " << outstanding << " < " << redeem;
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        sleIssuance->setFieldU64(sfOutstandingAmount, outstanding - redeem);
+        view.update(sleIssuance);
+    }
+
+    if (issuer == sender)
+    {  // LCOV_EXCL_START
+        JLOG(j.error()) << "rippleUnlockEscrowMPT: sender is the issuer, "
+                           "cannot unlock MPTs.";
+        return tecINTERNAL;
+    }  // LCOV_EXCL_STOP
+    // Decrease the MPT Holder EscrowedAmount
+    auto const mptokenID = keylet::mptoken(mptID.key, sender);
+    auto sle = view.peek(mptokenID);
+    if (!sle)
+    {  // LCOV_EXCL_START
+        JLOG(j.error()) << "rippleUnlockEscrowMPT: MPToken not found for " << sender;
+        return tecOBJECT_NOT_FOUND;
+    }  // LCOV_EXCL_STOP
+
+    if (!sle->isFieldPresent(sfLockedAmount))
+    {  // LCOV_EXCL_START
+        JLOG(j.error()) << "rippleUnlockEscrowMPT: no locked amount in MPToken for "
+                        << to_string(sender);
+        return tecINTERNAL;
+    }  // LCOV_EXCL_STOP
+
+    auto const locked = sle->getFieldU64(sfLockedAmount);
+    auto const delta = grossAmount.mpt().value();
+
+    // Underflow check for subtraction
+    if (!canSubtract(STAmount(mptIssue, locked), STAmount(mptIssue, delta)))
+    {  // LCOV_EXCL_START
+        JLOG(j.error()) << "rippleUnlockEscrowMPT: insufficient locked amount for "
+                        << to_string(sender) << ": " << locked << " < " << delta;
+        return tecINTERNAL;
+    }  // LCOV_EXCL_STOP
+
+    auto const newLocked = locked - delta;
+    if (newLocked == 0)
+    {
+        sle->makeFieldAbsent(sfLockedAmount);
+    }
+    else
+    {
+        sle->setFieldU64(sfLockedAmount, newLocked);
+    }
+    view.update(sle);
+
+    // Note: The gross amount is the amount that was locked, the net
+    // amount is the amount that is being unlocked. The difference is the fee
+    // that was charged for the transfer. If this difference is greater than
+    // zero, we need to update the outstanding amount.
+    auto const diff = grossAmount.mpt().value() - netAmount.mpt().value();
+    if (diff != 0)
+    {
+        auto const outstanding = sleIssuance->getFieldU64(sfOutstandingAmount);
+        // Underflow check for subtraction
+        if (!canSubtract(STAmount(mptIssue, outstanding), STAmount(mptIssue, diff)))
+        {  // LCOV_EXCL_START
+            JLOG(j.error()) << "rippleUnlockEscrowMPT: insufficient outstanding amount for "
+                            << mptIssue.getMptID() << ": " << outstanding << " < " << diff;
+            return tecINTERNAL;
+        }  // LCOV_EXCL_STOP
+
+        sleIssuance->setFieldU64(sfOutstandingAmount, outstanding - diff);
+        view.update(sleIssuance);
+    }
+    return tesSUCCESS;
+}
+
+}  // namespace xrpl

src/libxrpl/ledger/helpers/OfferHelpers.cpp

@@ -0,0 +1,58 @@
+#include <xrpl/ledger/helpers/OfferHelpers.h>
+//
+#include <xrpl/ledger/helpers/AccountRootHelpers.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/st.h>
+
+namespace xrpl {
+
+TER
+offerDelete(ApplyView& view, std::shared_ptr<SLE> const& sle, beast::Journal j)
+{
+    if (!sle)
+        return tesSUCCESS;
+    auto offerIndex = sle->key();
+    auto owner = sle->getAccountID(sfAccount);
+
+    // Detect legacy directories.
+    uint256 uDirectory = sle->getFieldH256(sfBookDirectory);
+
+    if (!view.dirRemove(keylet::ownerDir(owner), sle->getFieldU64(sfOwnerNode), offerIndex, false))
+    {
+        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
+    }
+
+    if (!view.dirRemove(keylet::page(uDirectory), sle->getFieldU64(sfBookNode), offerIndex, false))
+    {
+        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
+    }
+
+    if (sle->isFieldPresent(sfAdditionalBooks))
+    {
+        XRPL_ASSERT(
+            sle->isFlag(lsfHybrid) && sle->isFieldPresent(sfDomainID),
+            "xrpl::offerDelete : should be a hybrid domain offer");
+
+        auto const& additionalBookDirs = sle->getFieldArray(sfAdditionalBooks);
+
+        for (auto const& bookDir : additionalBookDirs)
+        {
+            auto const& dirIndex = bookDir.getFieldH256(sfBookDirectory);
+            auto const& dirNode = bookDir.getFieldU64(sfBookNode);
+
+            if (!view.dirRemove(keylet::page(dirIndex), dirNode, offerIndex, false))
+            {
+                return tefBAD_LEDGER;  // LCOV_EXCL_LINE
+            }
+        }
+    }
+
+    adjustOwnerCount(view, view.peek(keylet::account(owner)), -1, j);
+
+    view.erase(sle);
+
+    return tesSUCCESS;
+}
+
+}  // namespace xrpl

src/libxrpl/ledger/helpers/RippleStateHelpers.cpp

@@ -0,0 +1,759 @@
+#include <xrpl/ledger/helpers/RippleStateHelpers.h>
+//
+#include <xrpl/basics/Log.h>
+#include <xrpl/ledger/ApplyView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/ledger/helpers/AccountRootHelpers.h>
+#include <xrpl/ledger/helpers/DirectoryHelpers.h>
+#include <xrpl/protocol/AmountConversions.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/Rules.h>
+
+namespace xrpl {
+
+//------------------------------------------------------------------------------
+//
+// Credit functions (from Credit.cpp)
+//
+//------------------------------------------------------------------------------
+
+STAmount
+creditLimit(
+    ReadView const& view,
+    AccountID const& account,
+    AccountID const& issuer,
+    Currency const& currency)
+{
+    STAmount result(Issue{currency, account});
+
+    auto sleRippleState = view.read(keylet::line(account, issuer, currency));
+
+    if (sleRippleState)
+    {
+        result = sleRippleState->getFieldAmount(account < issuer ? sfLowLimit : sfHighLimit);
+        result.setIssuer(account);
+    }
+
+    XRPL_ASSERT(result.getIssuer() == account, "xrpl::creditLimit : result issuer match");
+    XRPL_ASSERT(result.getCurrency() == currency, "xrpl::creditLimit : result currency match");
+    return result;
+}
+
+IOUAmount
+creditLimit2(ReadView const& v, AccountID const& acc, AccountID const& iss, Currency const& cur)
+{
+    return toAmount<IOUAmount>(creditLimit(v, acc, iss, cur));
+}
+
+STAmount
+creditBalance(
+    ReadView const& view,
+    AccountID const& account,
+    AccountID const& issuer,
+    Currency const& currency)
+{
+    STAmount result(Issue{currency, account});
+
+    auto sleRippleState = view.read(keylet::line(account, issuer, currency));
+
+    if (sleRippleState)
+    {
+        result = sleRippleState->getFieldAmount(sfBalance);
+        if (account < issuer)
+            result.negate();
+        result.setIssuer(account);
+    }
+
+    XRPL_ASSERT(result.getIssuer() == account, "xrpl::creditBalance : result issuer match");
+    XRPL_ASSERT(result.getCurrency() == currency, "xrpl::creditBalance : result currency match");
+    return result;
+}
+
+//------------------------------------------------------------------------------
+//
+// Freeze checking (IOU-specific)
+//
+//------------------------------------------------------------------------------
+
+bool
+isIndividualFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    Currency const& currency,
+    AccountID const& issuer)
+{
+    if (isXRP(currency))
+        return false;
+    if (issuer != account)
+    {
+        // Check if the issuer froze the line
+        auto const sle = view.read(keylet::line(account, issuer, currency));
+        if (sle && sle->isFlag((issuer > account) ? lsfHighFreeze : lsfLowFreeze))
+            return true;
+    }
+    return false;
+}
+
+// Can the specified account spend the specified currency issued by
+// the specified issuer or does the freeze flag prohibit it?
+bool
+isFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    Currency const& currency,
+    AccountID const& issuer)
+{
+    if (isXRP(currency))
+        return false;
+    auto sle = view.read(keylet::account(issuer));
+    if (sle && sle->isFlag(lsfGlobalFreeze))
+        return true;
+    if (issuer != account)
+    {
+        // Check if the issuer froze the line
+        sle = view.read(keylet::line(account, issuer, currency));
+        if (sle && sle->isFlag((issuer > account) ? lsfHighFreeze : lsfLowFreeze))
+            return true;
+    }
+    return false;
+}
+
+bool
+isDeepFrozen(
+    ReadView const& view,
+    AccountID const& account,
+    Currency const& currency,
+    AccountID const& issuer)
+{
+    if (isXRP(currency))
+    {
+        return false;
+    }
+
+    if (issuer == account)
+    {
+        return false;
+    }
+
+    auto const sle = view.read(keylet::line(account, issuer, currency));
+    if (!sle)
+    {
+        return false;
+    }
+
+    return sle->isFlag(lsfHighDeepFreeze) || sle->isFlag(lsfLowDeepFreeze);
+}
+
+//------------------------------------------------------------------------------
+//
+// Trust line operations
+//
+//------------------------------------------------------------------------------
+
+TER
+trustCreate(
+    ApplyView& view,
+    bool const bSrcHigh,
+    AccountID const& uSrcAccountID,
+    AccountID const& uDstAccountID,
+    uint256 const& uIndex,      // --> ripple state entry
+    SLE::ref sleAccount,        // --> the account being set.
+    bool const bAuth,           // --> authorize account.
+    bool const bNoRipple,       // --> others cannot ripple through
+    bool const bFreeze,         // --> funds cannot leave
+    bool bDeepFreeze,           // --> can neither receive nor send funds
+    STAmount const& saBalance,  // --> balance of account being set.
+                                // Issuer should be noAccount()
+    STAmount const& saLimit,    // --> limit for account being set.
+                                // Issuer should be the account being set.
+    std::uint32_t uQualityIn,
+    std::uint32_t uQualityOut,
+    beast::Journal j)
+{
+    JLOG(j.trace()) << "trustCreate: " << to_string(uSrcAccountID) << ", "
+                    << to_string(uDstAccountID) << ", " << saBalance.getFullText();
+
+    auto const& uLowAccountID = !bSrcHigh ? uSrcAccountID : uDstAccountID;
+    auto const& uHighAccountID = bSrcHigh ? uSrcAccountID : uDstAccountID;
+    if (uLowAccountID == uHighAccountID)
+    {
+        // LCOV_EXCL_START
+        UNREACHABLE("xrpl::trustCreate : trust line to self");
+        if (view.rules().enabled(featureLendingProtocol))
+            return tecINTERNAL;
+        // LCOV_EXCL_STOP
+    }
+
+    auto const sleRippleState = std::make_shared<SLE>(ltRIPPLE_STATE, uIndex);
+    view.insert(sleRippleState);
+
+    auto lowNode = view.dirInsert(
+        keylet::ownerDir(uLowAccountID), sleRippleState->key(), describeOwnerDir(uLowAccountID));
+
+    if (!lowNode)
+        return tecDIR_FULL;  // LCOV_EXCL_LINE
+
+    auto highNode = view.dirInsert(
+        keylet::ownerDir(uHighAccountID), sleRippleState->key(), describeOwnerDir(uHighAccountID));
+
+    if (!highNode)
+        return tecDIR_FULL;  // LCOV_EXCL_LINE
+
+    bool const bSetDst = saLimit.getIssuer() == uDstAccountID;
+    bool const bSetHigh = bSrcHigh ^ bSetDst;
+
+    XRPL_ASSERT(sleAccount, "xrpl::trustCreate : non-null SLE");
+    if (!sleAccount)
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+
+    XRPL_ASSERT(
+        sleAccount->getAccountID(sfAccount) == (bSetHigh ? uHighAccountID : uLowAccountID),
+        "xrpl::trustCreate : matching account ID");
+    auto const slePeer = view.peek(keylet::account(bSetHigh ? uLowAccountID : uHighAccountID));
+    if (!slePeer)
+        return tecNO_TARGET;
+
+    // Remember deletion hints.
+    sleRippleState->setFieldU64(sfLowNode, *lowNode);
+    sleRippleState->setFieldU64(sfHighNode, *highNode);
+
+    sleRippleState->setFieldAmount(bSetHigh ? sfHighLimit : sfLowLimit, saLimit);
+    sleRippleState->setFieldAmount(
+        bSetHigh ? sfLowLimit : sfHighLimit,
+        STAmount(Issue{saBalance.getCurrency(), bSetDst ? uSrcAccountID : uDstAccountID}));
+
+    if (uQualityIn)
+        sleRippleState->setFieldU32(bSetHigh ? sfHighQualityIn : sfLowQualityIn, uQualityIn);
+
+    if (uQualityOut)
+        sleRippleState->setFieldU32(bSetHigh ? sfHighQualityOut : sfLowQualityOut, uQualityOut);
+
+    std::uint32_t uFlags = bSetHigh ? lsfHighReserve : lsfLowReserve;
+
+    if (bAuth)
+    {
+        uFlags |= (bSetHigh ? lsfHighAuth : lsfLowAuth);
+    }
+    if (bNoRipple)
+    {
+        uFlags |= (bSetHigh ? lsfHighNoRipple : lsfLowNoRipple);
+    }
+    if (bFreeze)
+    {
+        uFlags |= (bSetHigh ? lsfHighFreeze : lsfLowFreeze);
+    }
+    if (bDeepFreeze)
+    {
+        uFlags |= (bSetHigh ? lsfHighDeepFreeze : lsfLowDeepFreeze);
+    }
+
+    if ((slePeer->getFlags() & lsfDefaultRipple) == 0)
+    {
+        // The other side's default is no rippling
+        uFlags |= (bSetHigh ? lsfLowNoRipple : lsfHighNoRipple);
+    }
+
+    sleRippleState->setFieldU32(sfFlags, uFlags);
+    adjustOwnerCount(view, sleAccount, 1, j);
+
+    // ONLY: Create ripple balance.
+    sleRippleState->setFieldAmount(sfBalance, bSetHigh ? -saBalance : saBalance);
+
+    view.creditHook(uSrcAccountID, uDstAccountID, saBalance, saBalance.zeroed());
+
+    return tesSUCCESS;
+}
+
+TER
+trustDelete(
+    ApplyView& view,
+    std::shared_ptr<SLE> const& sleRippleState,
+    AccountID const& uLowAccountID,
+    AccountID const& uHighAccountID,
+    beast::Journal j)
+{
+    // Detect legacy dirs.
+    std::uint64_t uLowNode = sleRippleState->getFieldU64(sfLowNode);
+    std::uint64_t uHighNode = sleRippleState->getFieldU64(sfHighNode);
+
+    JLOG(j.trace()) << "trustDelete: Deleting ripple line: low";
+
+    if (!view.dirRemove(keylet::ownerDir(uLowAccountID), uLowNode, sleRippleState->key(), false))
+    {
+        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
+    }
+
+    JLOG(j.trace()) << "trustDelete: Deleting ripple line: high";
+
+    if (!view.dirRemove(keylet::ownerDir(uHighAccountID), uHighNode, sleRippleState->key(), false))
+    {
+        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
+    }
+
+    JLOG(j.trace()) << "trustDelete: Deleting ripple line: state";
+    view.erase(sleRippleState);
+
+    return tesSUCCESS;
+}
+
+//------------------------------------------------------------------------------
+//
+// IOU issuance/redemption
+//
+//------------------------------------------------------------------------------
+
+static bool
+updateTrustLine(
+    ApplyView& view,
+    SLE::pointer state,
+    bool bSenderHigh,
+    AccountID const& sender,
+    STAmount const& before,
+    STAmount const& after,
+    beast::Journal j)
+{
+    if (!state)
+        return false;
+    std::uint32_t const flags(state->getFieldU32(sfFlags));
+
+    auto sle = view.peek(keylet::account(sender));
+    if (!sle)
+        return false;
+
+    // YYY Could skip this if rippling in reverse.
+    if (before > beast::zero
+        // Sender balance was positive.
+        && after <= beast::zero
+        // Sender is zero or negative.
+        && (flags & (!bSenderHigh ? lsfLowReserve : lsfHighReserve))
+        // Sender reserve is set.
+        && static_cast<bool>(flags & (!bSenderHigh ? lsfLowNoRipple : lsfHighNoRipple)) !=
+            static_cast<bool>(sle->getFlags() & lsfDefaultRipple) &&
+        !(flags & (!bSenderHigh ? lsfLowFreeze : lsfHighFreeze)) &&
+        !state->getFieldAmount(!bSenderHigh ? sfLowLimit : sfHighLimit)
+        // Sender trust limit is 0.
+        && !state->getFieldU32(!bSenderHigh ? sfLowQualityIn : sfHighQualityIn)
+        // Sender quality in is 0.
+        && !state->getFieldU32(!bSenderHigh ? sfLowQualityOut : sfHighQualityOut))
+    // Sender quality out is 0.
+    {
+        // VFALCO Where is the line being deleted?
+        // Clear the reserve of the sender, possibly delete the line!
+        adjustOwnerCount(view, sle, -1, j);
+
+        // Clear reserve flag.
+        state->setFieldU32(sfFlags, flags & (!bSenderHigh ? ~lsfLowReserve : ~lsfHighReserve));
+
+        // Balance is zero, receiver reserve is clear.
+        if (!after  // Balance is zero.
+            && !(flags & (bSenderHigh ? lsfLowReserve : lsfHighReserve)))
+            return true;
+    }
+    return false;
+}
+
+TER
+issueIOU(
+    ApplyView& view,
+    AccountID const& account,
+    STAmount const& amount,
+    Issue const& issue,
+    beast::Journal j)
+{
+    XRPL_ASSERT(
+        !isXRP(account) && !isXRP(issue.account),
+        "xrpl::issueIOU : neither account nor issuer is XRP");
+
+    // Consistency check
+    XRPL_ASSERT(issue == amount.issue(), "xrpl::issueIOU : matching issue");
+
+    // Can't send to self!
+    XRPL_ASSERT(issue.account != account, "xrpl::issueIOU : not issuer account");
+
+    JLOG(j.trace()) << "issueIOU: " << to_string(account) << ": " << amount.getFullText();
+
+    bool bSenderHigh = issue.account > account;
+
+    auto const index = keylet::line(issue.account, account, issue.currency);
+
+    if (auto state = view.peek(index))
+    {
+        STAmount final_balance = state->getFieldAmount(sfBalance);
+
+        if (bSenderHigh)
+            final_balance.negate();  // Put balance in sender terms.
+
+        STAmount const start_balance = final_balance;
+
+        final_balance -= amount;
+
+        auto const must_delete = updateTrustLine(
+            view, state, bSenderHigh, issue.account, start_balance, final_balance, j);
+
+        view.creditHook(issue.account, account, amount, start_balance);
+
+        if (bSenderHigh)
+            final_balance.negate();
+
+        // Adjust the balance on the trust line if necessary. We do this even
+        // if we are going to delete the line to reflect the correct balance
+        // at the time of deletion.
+        state->setFieldAmount(sfBalance, final_balance);
+        if (must_delete)
+        {
+            return trustDelete(
+                view,
+                state,
+                bSenderHigh ? account : issue.account,
+                bSenderHigh ? issue.account : account,
+                j);
+        }
+
+        view.update(state);
+
+        return tesSUCCESS;
+    }
+
+    // NIKB TODO: The limit uses the receiver's account as the issuer and
+    // this is unnecessarily inefficient as copying which could be avoided
+    // is now required. Consider available options.
+    STAmount const limit(Issue{issue.currency, account});
+    STAmount final_balance = amount;
+
+    final_balance.setIssuer(noAccount());
+
+    auto const receiverAccount = view.peek(keylet::account(account));
+    if (!receiverAccount)
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+
+    bool noRipple = (receiverAccount->getFlags() & lsfDefaultRipple) == 0;
+
+    return trustCreate(
+        view,
+        bSenderHigh,
+        issue.account,
+        account,
+        index.key,
+        receiverAccount,
+        false,
+        noRipple,
+        false,
+        false,
+        final_balance,
+        limit,
+        0,
+        0,
+        j);
+}
+
+TER
+redeemIOU(
+    ApplyView& view,
+    AccountID const& account,
+    STAmount const& amount,
+    Issue const& issue,
+    beast::Journal j)
+{
+    XRPL_ASSERT(
+        !isXRP(account) && !isXRP(issue.account),
+        "xrpl::redeemIOU : neither account nor issuer is XRP");
+
+    // Consistency check
+    XRPL_ASSERT(issue == amount.issue(), "xrpl::redeemIOU : matching issue");
+
+    // Can't send to self!
+    XRPL_ASSERT(issue.account != account, "xrpl::redeemIOU : not issuer account");
+
+    JLOG(j.trace()) << "redeemIOU: " << to_string(account) << ": " << amount.getFullText();
+
+    bool bSenderHigh = account > issue.account;
+
+    if (auto state = view.peek(keylet::line(account, issue.account, issue.currency)))
+    {
+        STAmount final_balance = state->getFieldAmount(sfBalance);
+
+        if (bSenderHigh)
+            final_balance.negate();  // Put balance in sender terms.
+
+        STAmount const start_balance = final_balance;
+
+        final_balance -= amount;
+
+        auto const must_delete =
+            updateTrustLine(view, state, bSenderHigh, account, start_balance, final_balance, j);
+
+        view.creditHook(account, issue.account, amount, start_balance);
+
+        if (bSenderHigh)
+            final_balance.negate();
+
+        // Adjust the balance on the trust line if necessary. We do this even
+        // if we are going to delete the line to reflect the correct balance
+        // at the time of deletion.
+        state->setFieldAmount(sfBalance, final_balance);
+
+        if (must_delete)
+        {
+            return trustDelete(
+                view,
+                state,
+                bSenderHigh ? issue.account : account,
+                bSenderHigh ? account : issue.account,
+                j);
+        }
+
+        view.update(state);
+        return tesSUCCESS;
+    }
+
+    // In order to hold an IOU, a trust line *MUST* exist to track the
+    // balance. If it doesn't, then something is very wrong. Don't try
+    // to continue.
+    // LCOV_EXCL_START
+    JLOG(j.fatal()) << "redeemIOU: " << to_string(account) << " attempts to "
+                    << "redeem " << amount.getFullText() << " but no trust line exists!";
+
+    return tefINTERNAL;
+    // LCOV_EXCL_STOP
+}
+
+//------------------------------------------------------------------------------
+//
+// Authorization and transfer checks (IOU-specific)
+//
+//------------------------------------------------------------------------------
+
+TER
+requireAuth(ReadView const& view, Issue const& issue, AccountID const& account, AuthType authType)
+{
+    if (isXRP(issue) || issue.account == account)
+        return tesSUCCESS;
+
+    auto const trustLine = view.read(keylet::line(account, issue.account, issue.currency));
+    // If account has no line, and this is a strong check, fail
+    if (!trustLine && authType == AuthType::StrongAuth)
+        return tecNO_LINE;
+
+    // If this is a weak or legacy check, or if the account has a line, fail if
+    // auth is required and not set on the line
+    if (auto const issuerAccount = view.read(keylet::account(issue.account));
+        issuerAccount && (*issuerAccount)[sfFlags] & lsfRequireAuth)
+    {
+        if (trustLine)
+        {
+            return ((*trustLine)[sfFlags] & ((account > issue.account) ? lsfLowAuth : lsfHighAuth))
+                ? tesSUCCESS
+                : TER{tecNO_AUTH};
+        }
+        return TER{tecNO_LINE};
+    }
+
+    return tesSUCCESS;
+}
+
+TER
+canTransfer(ReadView const& view, Issue const& issue, AccountID const& from, AccountID const& to)
+{
+    if (issue.native())
+        return tesSUCCESS;
+
+    auto const& issuerId = issue.getIssuer();
+    if (issuerId == from || issuerId == to)
+        return tesSUCCESS;
+    auto const sleIssuer = view.read(keylet::account(issuerId));
+    if (sleIssuer == nullptr)
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+
+    auto const isRippleDisabled = [&](AccountID account) -> bool {
+        // Line might not exist, but some transfers can create it. If this
+        // is the case, just check the default ripple on the issuer account.
+        auto const line = view.read(keylet::line(account, issue));
+        if (line)
+        {
+            bool const issuerHigh = issuerId > account;
+            return line->isFlag(issuerHigh ? lsfHighNoRipple : lsfLowNoRipple);
+        }
+        return sleIssuer->isFlag(lsfDefaultRipple) == false;
+    };
+
+    // Fail if rippling disabled on both trust lines
+    if (isRippleDisabled(from) && isRippleDisabled(to))
+        return terNO_RIPPLE;
+
+    return tesSUCCESS;
+}
+
+//------------------------------------------------------------------------------
+//
+// Empty holding operations (IOU-specific)
+//
+//------------------------------------------------------------------------------
+
+TER
+addEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    XRPAmount priorBalance,
+    Issue const& issue,
+    beast::Journal journal)
+{
+    // Every account can hold XRP. An issuer can issue directly.
+    if (issue.native() || accountID == issue.getIssuer())
+        return tesSUCCESS;
+
+    auto const& issuerId = issue.getIssuer();
+    auto const& currency = issue.currency;
+    if (isGlobalFrozen(view, issuerId))
+        return tecFROZEN;  // LCOV_EXCL_LINE
+
+    auto const& srcId = issuerId;
+    auto const& dstId = accountID;
+    auto const high = srcId > dstId;
+    auto const index = keylet::line(srcId, dstId, currency);
+    auto const sleSrc = view.peek(keylet::account(srcId));
+    auto const sleDst = view.peek(keylet::account(dstId));
+    if (!sleDst || !sleSrc)
+        return tefINTERNAL;  // LCOV_EXCL_LINE
+    if (!sleSrc->isFlag(lsfDefaultRipple))
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+    // If the line already exists, don't create it again.
+    if (view.read(index))
+        return tecDUPLICATE;
+
+    // Can the account cover the trust line reserve ?
+    std::uint32_t const ownerCount = sleDst->at(sfOwnerCount);
+    if (priorBalance < view.fees().accountReserve(ownerCount + 1))
+        return tecNO_LINE_INSUF_RESERVE;
+
+    return trustCreate(
+        view,
+        high,
+        srcId,
+        dstId,
+        index.key,
+        sleDst,
+        /*bAuth=*/false,
+        /*bNoRipple=*/true,
+        /*bFreeze=*/false,
+        /*deepFreeze*/ false,
+        /*saBalance=*/STAmount{Issue{currency, noAccount()}},
+        /*saLimit=*/STAmount{Issue{currency, dstId}},
+        /*uQualityIn=*/0,
+        /*uQualityOut=*/0,
+        journal);
+}
+
+TER
+removeEmptyHolding(
+    ApplyView& view,
+    AccountID const& accountID,
+    Issue const& issue,
+    beast::Journal journal)
+{
+    if (issue.native())
+    {
+        auto const sle = view.read(keylet::account(accountID));
+        if (!sle)
+            return tecINTERNAL;  // LCOV_EXCL_LINE
+
+        auto const balance = sle->getFieldAmount(sfBalance);
+        if (balance.xrp() != 0)
+            return tecHAS_OBLIGATIONS;
+
+        return tesSUCCESS;
+    }
+
+    // `asset` is an IOU.
+    // If the account is the issuer, then no line should exist. Check anyway.
+    // If a line does exist, it will get deleted. If not, return success.
+    bool const accountIsIssuer = accountID == issue.account;
+    auto const line = view.peek(keylet::line(accountID, issue));
+    if (!line)
+        return accountIsIssuer ? (TER)tesSUCCESS : (TER)tecOBJECT_NOT_FOUND;
+    if (!accountIsIssuer && line->at(sfBalance)->iou() != beast::zero)
+        return tecHAS_OBLIGATIONS;
+
+    // Adjust the owner count(s)
+    if (line->isFlag(lsfLowReserve))
+    {
+        // Clear reserve for low account.
+        auto sleLowAccount = view.peek(keylet::account(line->at(sfLowLimit)->getIssuer()));
+        if (!sleLowAccount)
+            return tecINTERNAL;  // LCOV_EXCL_LINE
+
+        adjustOwnerCount(view, sleLowAccount, -1, journal);
+        // It's not really necessary to clear the reserve flag, since the line
+        // is about to be deleted, but this will make the metadata reflect an
+        // accurate state at the time of deletion.
+        line->clearFlag(lsfLowReserve);
+    }
+
+    if (line->isFlag(lsfHighReserve))
+    {
+        // Clear reserve for high account.
+        auto sleHighAccount = view.peek(keylet::account(line->at(sfHighLimit)->getIssuer()));
+        if (!sleHighAccount)
+            return tecINTERNAL;  // LCOV_EXCL_LINE
+
+        adjustOwnerCount(view, sleHighAccount, -1, journal);
+        // It's not really necessary to clear the reserve flag, since the line
+        // is about to be deleted, but this will make the metadata reflect an
+        // accurate state at the time of deletion.
+        line->clearFlag(lsfHighReserve);
+    }
+
+    return trustDelete(
+        view, line, line->at(sfLowLimit)->getIssuer(), line->at(sfHighLimit)->getIssuer(), journal);
+}
+
+TER
+deleteAMMTrustLine(
+    ApplyView& view,
+    std::shared_ptr<SLE> sleState,
+    std::optional<AccountID> const& ammAccountID,
+    beast::Journal j)
+{
+    if (!sleState || sleState->getType() != ltRIPPLE_STATE)
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    auto const& [low, high] = std::minmax(
+        sleState->getFieldAmount(sfLowLimit).getIssuer(),
+        sleState->getFieldAmount(sfHighLimit).getIssuer());
+    auto sleLow = view.peek(keylet::account(low));
+    auto sleHigh = view.peek(keylet::account(high));
+    if (!sleLow || !sleHigh)
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    bool const ammLow = sleLow->isFieldPresent(sfAMMID);
+    bool const ammHigh = sleHigh->isFieldPresent(sfAMMID);
+
+    // can't both be AMM
+    if (ammLow && ammHigh)
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    // at least one must be
+    if (!ammLow && !ammHigh)
+        return terNO_AMM;
+
+    // one must be the target amm
+    if (ammAccountID && (low != *ammAccountID && high != *ammAccountID))
+        return terNO_AMM;
+
+    if (auto const ter = trustDelete(view, sleState, low, high, j); !isTesSuccess(ter))
+    {
+        JLOG(j.error()) << "deleteAMMTrustLine: failed to delete the trustline.";
+        return ter;
+    }
+
+    auto const uFlags = !ammLow ? lsfLowReserve : lsfHighReserve;
+    if (!(sleState->getFlags() & uFlags))
+        return tecINTERNAL;  // LCOV_EXCL_LINE
+
+    adjustOwnerCount(view, !ammLow ? sleLow : sleHigh, -1, j);
+
+    return tesSUCCESS;
+}
+
+}  // namespace xrpl

src/libxrpl/ledger/helpers/VaultHelpers.cpp

@@ -0,0 +1,112 @@
+#include <xrpl/ledger/helpers/VaultHelpers.h>
+//
+#include <xrpl/basics/Number.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/st.h>
+
+namespace xrpl {
+
+[[nodiscard]] std::optional<STAmount>
+assetsToSharesDeposit(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& assets)
+{
+    XRPL_ASSERT(!assets.negative(), "xrpl::assetsToSharesDeposit : non-negative assets");
+    XRPL_ASSERT(
+        assets.asset() == vault->at(sfAsset),
+        "xrpl::assetsToSharesDeposit : assets and vault match");
+    if (assets.negative() || assets.asset() != vault->at(sfAsset))
+        return std::nullopt;  // LCOV_EXCL_LINE
+
+    Number const assetTotal = vault->at(sfAssetsTotal);
+    STAmount shares{vault->at(sfShareMPTID)};
+    if (assetTotal == 0)
+    {
+        return STAmount{
+            shares.asset(),
+            Number(assets.mantissa(), assets.exponent() + vault->at(sfScale)).truncate()};
+    }
+
+    Number const shareTotal = issuance->at(sfOutstandingAmount);
+    shares = ((shareTotal * assets) / assetTotal).truncate();
+    return shares;
+}
+
+[[nodiscard]] std::optional<STAmount>
+sharesToAssetsDeposit(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& shares)
+{
+    XRPL_ASSERT(!shares.negative(), "xrpl::sharesToAssetsDeposit : non-negative shares");
+    XRPL_ASSERT(
+        shares.asset() == vault->at(sfShareMPTID),
+        "xrpl::sharesToAssetsDeposit : shares and vault match");
+    if (shares.negative() || shares.asset() != vault->at(sfShareMPTID))
+        return std::nullopt;  // LCOV_EXCL_LINE
+
+    Number const assetTotal = vault->at(sfAssetsTotal);
+    STAmount assets{vault->at(sfAsset)};
+    if (assetTotal == 0)
+    {
+        return STAmount{
+            assets.asset(), shares.mantissa(), shares.exponent() - vault->at(sfScale), false};
+    }
+
+    Number const shareTotal = issuance->at(sfOutstandingAmount);
+    assets = (assetTotal * shares) / shareTotal;
+    return assets;
+}
+
+[[nodiscard]] std::optional<STAmount>
+assetsToSharesWithdraw(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& assets,
+    TruncateShares truncate)
+{
+    XRPL_ASSERT(!assets.negative(), "xrpl::assetsToSharesWithdraw : non-negative assets");
+    XRPL_ASSERT(
+        assets.asset() == vault->at(sfAsset),
+        "xrpl::assetsToSharesWithdraw : assets and vault match");
+    if (assets.negative() || assets.asset() != vault->at(sfAsset))
+        return std::nullopt;  // LCOV_EXCL_LINE
+
+    Number assetTotal = vault->at(sfAssetsTotal);
+    assetTotal -= vault->at(sfLossUnrealized);
+    STAmount shares{vault->at(sfShareMPTID)};
+    if (assetTotal == 0)
+        return shares;
+    Number const shareTotal = issuance->at(sfOutstandingAmount);
+    Number result = (shareTotal * assets) / assetTotal;
+    if (truncate == TruncateShares::yes)
+        result = result.truncate();
+    shares = result;
+    return shares;
+}
+
+[[nodiscard]] std::optional<STAmount>
+sharesToAssetsWithdraw(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& shares)
+{
+    XRPL_ASSERT(!shares.negative(), "xrpl::sharesToAssetsDeposit : non-negative shares");
+    XRPL_ASSERT(
+        shares.asset() == vault->at(sfShareMPTID),
+        "xrpl::sharesToAssetsWithdraw : shares and vault match");
+    if (shares.negative() || shares.asset() != vault->at(sfShareMPTID))
+        return std::nullopt;  // LCOV_EXCL_LINE
+
+    Number assetTotal = vault->at(sfAssetsTotal);
+    assetTotal -= vault->at(sfLossUnrealized);
+    STAmount assets{vault->at(sfAsset)};
+    if (assetTotal == 0)
+        return assets;
+    Number const shareTotal = issuance->at(sfOutstandingAmount);
+    assets = (assetTotal * shares) / shareTotal;
+    return assets;
+}
+
+}  // namespace xrpl

src/libxrpl/tx/ApplyContext.cpp

@@ -104,7 +104,7 @@ ApplyContext::checkInvariantsHelper(
         // call each check's finalizer to see that it passes
         if (!std::all_of(finalizers.cbegin(), finalizers.cend(), [](auto const& b) { return b; }))
         {
-            JLOG(journal.fatal()) << "Transaction has failed one or more global invariants: "
+            JLOG(journal.fatal()) << "Transaction has failed one or more invariants: "
                                   << to_string(tx.getJson(JsonOptions::none));
 
             return failInvariantCheck(result);
@@ -112,7 +112,7 @@ ApplyContext::checkInvariantsHelper(
     }
     catch (std::exception const& ex)
     {
-        JLOG(journal.fatal()) << "Transaction caused an exception in a global invariant"
+        JLOG(journal.fatal()) << "Transaction caused an exception in an invariant"
                               << ", ex: " << ex.what()
                               << ", tx: " << to_string(tx.getJson(JsonOptions::none));
 

src/libxrpl/tx/Transactor.cpp

@@ -2,8 +2,8 @@
 #include <xrpl/basics/contract.h>
 #include <xrpl/core/NetworkIDService.h>
 #include <xrpl/json/to_string.h>
-#include <xrpl/ledger/CredentialHelpers.h>
 #include <xrpl/ledger/View.h>
+#include <xrpl/ledger/helpers/CredentialHelpers.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/Protocol.h>
@@ -1060,60 +1060,6 @@ Transactor::trapTransaction(uint256 txHash) const
     JLOG(j_.debug()) << "Transaction trapped: " << txHash;
 }
 
-[[nodiscard]] TER
-Transactor::checkTransactionInvariants(TER result, XRPAmount fee)
-{
-    try
-    {
-        // Phase 1: visit modified entries
-        ctx_.visit([this](
-                       uint256 const&,
-                       bool isDelete,
-                       std::shared_ptr<SLE const> const& before,
-                       std::shared_ptr<SLE const> const& after) {
-            this->visitInvariantEntry(isDelete, before, after);
-        });
-        // Phase 2: finalize
-        if (!this->finalizeInvariants(ctx_.tx, result, fee, ctx_.view(), ctx_.journal))
-        {
-            JLOG(ctx_.journal.fatal()) <<  //
-                "Transaction has failed one or more transaction invariants";
-            return tecINVARIANT_FAILED;
-        }
-    }
-    catch (std::exception const& ex)
-    {
-        JLOG(ctx_.journal.fatal()) <<                               //
-            "Exception while checking transaction invariants: " <<  //
-            ex.what() <<                                            //
-            ", tx: " <<                                             //
-            to_string(ctx_.tx.getJson(JsonOptions::none));
-
-        return tecINVARIANT_FAILED;
-    }
-
-    return result;
-}
-
-[[nodiscard]] TER
-Transactor::checkInvariants(TER result, XRPAmount fee)
-{
-    // Transaction invariants first (more specific). These check post-conditions of the specific
-    // transaction. If these fail, the transaction's core logic is wrong.
-    auto const txResult = checkTransactionInvariants(result, fee);
-
-    // Protocol invariants second (broader). These check properties that must hold regardless of
-    // transaction type.
-    auto const protoResult = ctx_.checkInvariants(result, fee);
-
-    // Fail if either check failed. tef (fatal) takes priority over tec.
-    if (txResult == tefINVARIANT_FAILED || protoResult == tefINVARIANT_FAILED)
-        return tefINVARIANT_FAILED;
-    if (txResult == tecINVARIANT_FAILED || protoResult == tecINVARIANT_FAILED)
-        return tecINVARIANT_FAILED;
-
-    return result;
-}
 //------------------------------------------------------------------------------
 ApplyResult
 Transactor::operator()()
@@ -1266,20 +1212,22 @@ Transactor::operator()()
 
     if (applied)
     {
-        result = checkInvariants(result, fee);
+        // Check invariants: if `tecINVARIANT_FAILED` is not returned, we can
+        // proceed to apply the tx
+        result = ctx_.checkInvariants(result, fee);
+
         if (result == tecINVARIANT_FAILED)
         {
-            // Reset to fee-claim only
+            // if invariants checking failed again, reset the context and
+            // attempt to only claim a fee.
             auto const resetResult = reset(fee);
             if (!isTesSuccess(resetResult.first))
                 result = resetResult.first;
 
             fee = resetResult.second;
 
-            // Check invariants again to ensure the fee claiming doesn't violate
-            // invariants. After reset, only protocol invariants are re-checked.
-            // Transaction invariants are not meaningful here — the transaction's
-            // effects have been rolled back.
+            // Check invariants again to ensure the fee claiming doesn't
+            // violate invariants.
             if (isTesSuccess(result) || isTecClaim(result))
                 result = ctx_.checkInvariants(result, fee);
         }

src/libxrpl/tx/applySteps.cpp

@@ -295,15 +295,6 @@ invoke_apply(ApplyContext& ctx)
     }
 }
 
-std::unique_ptr<Transactor>
-makeTransactor(ApplyContext& ctx)
-{
-    return with_txn_type(
-        ctx.view().rules(), ctx.tx.getTxnType(), [&]<typename T>() -> std::unique_ptr<Transactor> {
-            return std::make_unique<T>(ctx);
-        });
-}
-
 PreflightResult
 preflight(
     ServiceRegistry& registry,

src/libxrpl/tx/invariants/PermissionedDomainInvariant.cpp

@@ -1,7 +1,7 @@
 #include <xrpl/tx/invariants/PermissionedDomainInvariant.h>
 //
 #include <xrpl/beast/utility/instrumentation.h>
-#include <xrpl/ledger/CredentialHelpers.h>
+#include <xrpl/ledger/helpers/CredentialHelpers.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/STArray.h>
 #include <xrpl/protocol/TxFormats.h>

src/libxrpl/tx/paths/Flow.cpp

@@ -1,5 +1,5 @@
 #include <xrpl/basics/Log.h>
-#include <xrpl/ledger/Credit.h>
+#include <xrpl/ledger/helpers/RippleStateHelpers.h>
 #include <xrpl/protocol/IOUAmount.h>
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/paths/Flow.h>

src/libxrpl/tx/transactors/account/AccountDelete.cpp

@@ -1,7 +1,7 @@
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/utility/instrumentation.h>
-#include <xrpl/ledger/CredentialHelpers.h>
 #include <xrpl/ledger/View.h>
+#include <xrpl/ledger/helpers/CredentialHelpers.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/Protocol.h>
@@ -399,23 +399,4 @@ AccountDelete::doApply()
     return tesSUCCESS;
 }
 
-void
-AccountDelete::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-AccountDelete::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
 }  // namespace xrpl

src/libxrpl/tx/transactors/account/AccountSet.cpp

@@ -628,18 +628,4 @@ AccountSet::doApply()
     return tesSUCCESS;
 }
 
-void
-AccountSet::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-AccountSet::finalizeInvariants(STTx const&, TER, XRPAmount, ReadView const&, beast::Journal const&)
-{
-    return true;
-}
-
 }  // namespace xrpl

src/libxrpl/tx/transactors/account/SetRegularKey.cpp

@@ -68,23 +68,4 @@ SetRegularKey::doApply()
     return tesSUCCESS;
 }
 
-void
-SetRegularKey::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-SetRegularKey::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
 }  // namespace xrpl

src/libxrpl/tx/transactors/account/SignerListSet.cpp

@@ -385,23 +385,4 @@ SignerListSet::writeSignersToSLE(SLE::pointer const& ledgerEntry, std::uint32_t
     ledgerEntry->setFieldArray(sfSignerEntries, toLedger);
 }
 
-void
-SignerListSet::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-SignerListSet::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
 }  // namespace xrpl

src/libxrpl/tx/transactors/bridge/XChainBridge.cpp

@@ -2197,151 +2197,4 @@ XChainCreateAccountCommit::doApply()
     return tesSUCCESS;
 }
 
-void
-XChainCreateBridge::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-XChainCreateBridge::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
-void
-BridgeModify::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-BridgeModify::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
-void
-XChainClaim::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-XChainClaim::finalizeInvariants(STTx const&, TER, XRPAmount, ReadView const&, beast::Journal const&)
-{
-    return true;
-}
-
-void
-XChainCommit::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-XChainCommit::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
-void
-XChainCreateClaimID::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-XChainCreateClaimID::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
-void
-XChainAddClaimAttestation::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-XChainAddClaimAttestation::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
-void
-XChainAddAccountCreateAttestation::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-XChainAddAccountCreateAttestation::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
-void
-XChainCreateAccountCommit::visitInvariantEntry(
-    bool,
-    std::shared_ptr<SLE const> const&,
-    std::shared_ptr<SLE const> const&)
-{
-}
-
-bool
-XChainCreateAccountCommit::finalizeInvariants(
-    STTx const&,
-    TER,
-    XRPAmount,
-    ReadView const&,
-    beast::Journal const&)
-{
-    return true;
-}
-
 }  // namespace xrpl