Refactor MetaView (RIPD-954):

Obsolete functionality is removed. DeferredCredits is moved
to a new class PaymentView, and used in RippleCalc.

src/ripple/ledger/View.h

@@ -21,6 +21,11 @@
 #define RIPPLE_LEDGER_VIEW_H_INCLUDED
 
 #include <ripple/protocol/STLedgerEntry.h>
+#include <ripple/protocol/TER.h>
+#include <ripple/core/Config.h>
+#include <ripple/ledger/View.h>
+#include <ripple/ledger/ViewAPIBasics.h>
+#include <functional>
 #include <boost/optional.hpp>
 
 namespace ripple {
@@ -154,11 +159,14 @@ public:
 
     //--------------------------------------------------------------------------
 
-    // Unfortunately necessary for DeferredCredits
+    // Called to adjust returned balances
+    // This is required to support PaymentView
+
     virtual
     STAmount
-    deprecatedBalance (AccountID const& account,
-        AccountID const& issuer, STAmount const& amount) const
+    balanceHook (AccountID const& account,
+        AccountID const& issuer,
+            STAmount const& amount) const
     {
         return amount;
     }
@@ -288,15 +296,254 @@ public:
     bool
     openLedger() const = 0;
 
-    // Unfortunately necessary for DeferredCredits
+    //--------------------------------------------------------------------------
+
+    // Called when a credit is made to an account
+    // This is required to support PaymentView
     virtual
     void
-    deprecatedCreditHint (AccountID const& from,
-        AccountID const& to, STAmount const& amount)
+    creditHook (AccountID const& from,
+        AccountID const& to,
+            STAmount const& amount)
     {
     }
 };
 
+//------------------------------------------------------------------------------
+//
+// Observers
+//
+//------------------------------------------------------------------------------
+
+/** Reflects the fee settings for a particular ledger. */
+class Fees
+{
+private:
+    std::uint64_t base_;        // Reference tx cost (drops)
+    std::uint32_t units_;       // Reference fee units
+    std::uint32_t reserve_;     // Reserve base (drops)
+    std::uint32_t increment_;   // Reserve increment (drops)
+
+public:
+    Fees (BasicView const& view,
+        Config const& config);
+
+    /** Returns the account reserve given the owner count, in drops.
+
+        The reserve is calculated as the reserve base plus
+        the reserve increment times the number of increments.
+    */
+    std::uint64_t
+    reserve (std::size_t ownerCount) const
+    {
+        return reserve_ + ownerCount * increment_;
+    }
+};
+
+bool
+isGlobalFrozen (BasicView const& view,
+    AccountID const& issuer);
+
+// Returns the amount an account can spend without going into debt.
+//
+// <-- saAmount: amount of currency held by account. May be negative.
+STAmount
+accountHolds (BasicView const& view,
+    AccountID const& account, Currency const& currency,
+        AccountID const& issuer, FreezeHandling zeroIfFrozen,
+            Config const& config);
+
+STAmount
+accountFunds (BasicView const& view, AccountID const& id,
+    STAmount const& saDefault, FreezeHandling freezeHandling,
+        Config const& config);
+
+/** Iterate all items in an account's owner directory. */
+void
+forEachItem (BasicView const& view, AccountID const& id,
+    std::function<void (std::shared_ptr<SLE const> const&)> 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
+*/
+bool
+forEachItemAfter (BasicView 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&)> f);
+
+std::uint32_t
+rippleTransferRate (BasicView const& view,
+    AccountID const& issuer);
+
+std::uint32_t
+rippleTransferRate (BasicView const& view,
+    AccountID const& uSenderID,
+        AccountID const& uReceiverID,
+            AccountID const& issuer);
+
+/** Returns `true` if the directory is empty
+    @param key The key of the directory
+*/
+bool
+dirIsEmpty (BasicView const& view,
+    Keylet const& k);
+
+// Return the first entry and advance uDirEntry.
+// <-- true, if had a next entry.
+// VFALCO Fix these clumsy routines with an iterator
+bool
+cdirFirst (BasicView const& view,
+    uint256 const& uRootIndex,  // --> Root of directory.
+    std::shared_ptr<SLE const>& sleNode,      // <-> current node
+    unsigned int& uDirEntry,    // <-- next entry
+    uint256& uEntryIndex);      // <-- The entry, if available. Otherwise, zero.
+
+// Return the current entry and advance uDirEntry.
+// <-- true, if had a next entry.
+// VFALCO Fix these clumsy routines with an iterator
+bool
+cdirNext (BasicView const& view,
+    uint256 const& uRootIndex,  // --> Root of directory
+    std::shared_ptr<SLE const>& sleNode,      // <-> current node
+    unsigned int& uDirEntry,    // <-> next entry
+    uint256& uEntryIndex);      // <-- The entry, if available. Otherwise, zero.
+
+//------------------------------------------------------------------------------
+//
+// Modifiers
+//
+//------------------------------------------------------------------------------
+
+/** Adjust the owner count up or down. */
+void
+adjustOwnerCount (View& view,
+    std::shared_ptr<SLE> const& sle,
+        int amount);
+
+// Return the first entry and advance uDirEntry.
+// <-- true, if had a next entry.
+// VFALCO Fix these clumsy routines with an iterator
+bool
+dirFirst (View& view,
+    uint256 const& uRootIndex,  // --> Root of directory.
+    std::shared_ptr<SLE>& sleNode,      // <-> current node
+    unsigned int& uDirEntry,    // <-- next entry
+    uint256& uEntryIndex);      // <-- The entry, if available. Otherwise, zero.
+
+// Return the current entry and advance uDirEntry.
+// <-- true, if had a next entry.
+// VFALCO Fix these clumsy routines with an iterator
+bool
+dirNext (View& view,
+    uint256 const& uRootIndex,  // --> Root of directory
+    std::shared_ptr<SLE>& sleNode,      // <-> current node
+    unsigned int& uDirEntry,    // <-> next entry
+    uint256& uEntryIndex);      // <-- The entry, if available. Otherwise, zero.
+
+// <--     uNodeDir: For deletion, present to make dirDelete efficient.
+// -->   uRootIndex: The index of the base of the directory.  Nodes are based off of this.
+// --> uLedgerIndex: Value to add to directory.
+// Only append. This allow for things that watch append only structure to just monitor from the last node on ward.
+// Within a node with no deletions order of elements is sequential.  Otherwise, order of elements is random.
+TER
+dirAdd (View& view,
+    std::uint64_t&                      uNodeDir,      // Node of entry.
+    uint256 const&                      uRootIndex,
+    uint256 const&                      uLedgerIndex,
+    std::function<void (SLE::ref, bool)> fDescriber);
+
+TER
+dirDelete (View& view,
+    const bool           bKeepRoot,
+    const std::uint64_t& uNodeDir,      // Node item is mentioned in.
+    uint256 const&       uRootIndex,
+    uint256 const&       uLedgerIndex,  // Item being deleted
+    const bool           bStable,
+    const bool           bSoft);
+
+// VFALCO NOTE Both STAmount parameters should just
+//             be "Amount", a unit-less number.
+//
+/** Create a trust line
+
+    This can set an initial balance.
+*/
+TER
+trustCreate (View& view,
+    const bool      bSrcHigh,
+    AccountID const&  uSrcAccountID,
+    AccountID const&  uDstAccountID,
+    uint256 const&  uIndex,             // --> ripple state entry
+    SLE::ref        sleAccount,         // --> the account being set.
+    const bool      bAuth,              // --> authorize account.
+    const bool      bNoRipple,          // --> others cannot ripple through
+    const bool      bFreeze,            // --> funds cannot leave
+    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);
+
+TER
+trustDelete (View& view,
+    std::shared_ptr<SLE> const& sleRippleState,
+        AccountID const& uLowAccountID,
+            AccountID const& uHighAccountID);
+
+/** Delete an offer.
+
+    Requirements:
+        The passed `sle` be obtained from a prior
+        call to view.peek()
+*/
+TER
+offerDelete (View& view,
+    std::shared_ptr<SLE> const& sle);
+
+//------------------------------------------------------------------------------
+
+//
+// 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.
+TER
+rippleCredit (View& view,
+    AccountID const& uSenderID, AccountID const& uReceiverID,
+    const STAmount & saAmount, bool bCheckIssuer);
+
+TER
+accountSend (View& view,
+    AccountID const& from,
+        AccountID const& to,
+            const STAmount & saAmount);
+
+TER 
+issueIOU (View& view,
+    AccountID const& account,
+        STAmount const& amount,
+            Issue const& issue);
+
+TER
+redeemIOU (View& view,
+    AccountID const& account,
+        STAmount const& amount,
+            Issue const& issue);
+
+TER
+transferXRP (View& view,
+    AccountID const& from,
+        AccountID const& to,
+            STAmount const& amount);
+
 } // ripple
 
 #endif