View.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 Ripple Labs Inc.
 
    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#ifndef RIPPLE_LEDGER_VIEW_H_INCLUDED
#define RIPPLE_LEDGER_VIEW_H_INCLUDED
 
#include <xrpl/beast/utility/Journal.h>
#include <xrpl/ledger/ApplyView.h>
#include <xrpl/ledger/OpenView.h>
#include <xrpl/ledger/ReadView.h>
#include <xrpl/protocol/Indexes.h>
#include <xrpl/protocol/MPTIssue.h>
#include <xrpl/protocol/Protocol.h>
#include <xrpl/protocol/Rate.h>
#include <xrpl/protocol/STLedgerEntry.h>
#include <xrpl/protocol/STObject.h>
#include <xrpl/protocol/Serializer.h>
#include <xrpl/protocol/TER.h>
 
#include <functional>
#include <initializer_list>
#include <map>
#include <utility>
 
namespace ripple {
 
enum class WaiveTransferFee : bool { No = false, Yes };
enum class SkipEntry : bool { No = false, Yes };
 
//------------------------------------------------------------------------------
//
// Observers
//
//------------------------------------------------------------------------------
 
[[nodiscard]] bool
hasExpired(ReadView const& view, std::optional<std::uint32_t> const& exp);
 
enum FreezeHandling { fhIGNORE_FREEZE, fhZERO_IF_FROZEN };
 
enum AuthHandling { ahIGNORE_AUTH, ahZERO_IF_UNAUTHORIZED };
 
[[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(
    ReadView const& view,
    AccountID const& account,
    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);
 
[[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]] bool
isLPTokenFrozen(
    ReadView const& view,
    AccountID const& account,
    Issue const& asset,
    Issue const& asset2);
 
// Returns the amount an account can spend without going into debt.
//
// <-- 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);
 
[[nodiscard]] STAmount
accountHolds(
    ReadView const& view,
    AccountID const& account,
    Issue const& issue,
    FreezeHandling zeroIfFrozen,
    beast::Journal j);
 
[[nodiscard]] STAmount
accountHolds(
    ReadView const& view,
    AccountID const& account,
    MPTIssue const& mptIssue,
    FreezeHandling zeroIfFrozen,
    AuthHandling zeroIfUnauthorized,
    beast::Journal j);
 
[[nodiscard]] STAmount
accountHolds(
    ReadView const& view,
    AccountID const& account,
    Asset const& asset,
    FreezeHandling zeroIfFrozen,
    AuthHandling zeroIfUnauthorized,
    beast::Journal j);
 
// 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);
 
void
forEachItem(
    ReadView const& view,
    Keylet const& root,
    std::function<void(std::shared_ptr<SLE const> const&)> const& f);
 
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);
 
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);
}
 
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);
}
 
[[nodiscard]] Rate
transferRate(ReadView const& view, AccountID const& issuer);
 
[[nodiscard]] Rate
transferRate(ReadView const& view, MPTID const& issuanceID);
 
[[nodiscard]] Rate
transferRate(ReadView const& view, STAmount const& amount);
 
[[nodiscard]] bool
dirIsEmpty(ReadView const& view, Keylet const& k);
 
// Return the list of enabled amendments
[[nodiscard]] std::set<uint256>
getEnabledAmendments(ReadView const& view);
 
// Return a map of amendments that have achieved majority
using majorityAmendments_t = std::map<uint256, NetClock::time_point>;
[[nodiscard]] majorityAmendments_t
getMajorityAmendments(ReadView const& view);
 
[[nodiscard]] std::optional<uint256>
hashOfSeq(ReadView const& ledger, LedgerIndex seq, beast::Journal journal);
 
inline LedgerIndex
getCandidateLedger(LedgerIndex requested)
{
    return (requested + 255) & (~255);
}
 
[[nodiscard]] bool
areCompatible(
    ReadView const& validLedger,
    ReadView const& testLedger,
    beast::Journal::Stream& s,
    char const* reason);
 
[[nodiscard]] bool
areCompatible(
    uint256 const& validHash,
    LedgerIndex validIndex,
    ReadView const& testLedger,
    beast::Journal::Stream& s,
    char const* reason);
 
//------------------------------------------------------------------------------
//
// Modifiers
//
//------------------------------------------------------------------------------
 
void
adjustOwnerCount(
    ApplyView& view,
    std::shared_ptr<SLE> const& sle,
    std::int32_t amount,
    beast::Journal j);
 
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);
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, AccountID const& owner, std::shared_ptr<SLE>& object);
 
AccountID
pseudoAccountAddress(ReadView const& view, uint256 const& pseudoOwnerKey);
 
[[nodiscard]] Expected<std::shared_ptr<SLE>, TER>
createPseudoAccount(
    ApplyView& view,
    uint256 const& pseudoOwnerKey,
    SField const& ownerField);
 
// Returns true iff sleAcct is a pseudo-account.
//
// 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);
 
[[nodiscard]] inline bool
isPseudoAccount(ReadView const& view, AccountID accountId)
{
    return isPseudoAccount(view.read(keylet::account(accountId)));
}
 
[[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.
//
[[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);
 
// [[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.
 
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);
 
[[nodiscard]] TER
accountSend(
    ApplyView& view,
    AccountID const& from,
    AccountID const& to,
    STAmount const& saAmount,
    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 };
 
[[nodiscard]] TER
requireAuth(
    ReadView const& view,
    Issue const& issue,
    AccountID const& account,
    AuthType authType = AuthType::Legacy);
 
[[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());
}
 
[[nodiscard]] TER
enforceMPTokenAuthorization(
    ApplyView& view,
    MPTID const& mptIssuanceID,
    AccountID const& account,
    XRPAmount const& priorBalance,
    beast::Journal j);
 
[[nodiscard]] TER
canTransfer(
    ReadView const& view,
    MPTIssue const& mptIssue,
    AccountID const& from,
    AccountID const& to);
 
using EntryDeleter = std::function<std::pair<TER, SkipEntry>(
    LedgerEntryType,
    uint256 const&,
    std::shared_ptr<SLE>&)>;
[[nodiscard]] TER
cleanupOnAccountDelete(
    ApplyView& view,
    Keylet const& ownerDirKeylet,
    EntryDeleter const& deleter,
    beast::Journal j,
    std::optional<std::uint16_t> maxNodesToDelete = std::nullopt);
 
[[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);
 
bool
after(NetClock::time_point now, std::uint32_t mark);
 
}  // namespace ripple
 
#endif