Direct CCoins references

To prevent excessive copying of CCoins in and out of the CCoinsView
implementations, introduce a GetCoins() function in CCoinsViewCache
with returns a direct reference. The block validation and connection
logic is updated to require caching CCoinsViews, and exploits the
GetCoins() function heavily.

1 files changed, 14 insertions, 9 deletions

diff --git a/src/main.h b/src/main.h
index 3ee0108f46..1150ca4c02 100644
--- a/src/main.h
+++ b/src/main.h
@@ -88,6 +88,7 @@ class CDiskBlockPos;
 class CCoins;
 class CTxUndo;
 class CCoinsView;
+class CCoinsViewCache;
 
 void RegisterWallet(CWallet* pwalletIn);
 void UnregisterWallet(CWallet* pwalletIn);
@@ -480,7 +481,7 @@ public:
         @return True if all inputs (scriptSigs) use only standard transaction forms
         @see CTransaction::FetchInputs
     */
-    bool AreInputsStandard(CCoinsView& mapInputs) const;
+    bool AreInputsStandard(CCoinsViewCache& mapInputs) const;
 
     /** Count ECDSA signature operations the old-fashioned (pre-0.6) way
         @return number of sigops this transaction's outputs will produce when spent
@@ -494,7 +495,7 @@ public:
         @return maximum number of sigops required to validate this transaction's inputs
         @see CTransaction::FetchInputs
      */
-    unsigned int GetP2SHSigOpCount(CCoinsView& mapInputs) const;
+    unsigned int GetP2SHSigOpCount(CCoinsViewCache& mapInputs) const;
 
     /** Amount of bitcoins spent by this transaction.
         @return sum of all outputs (note: does not include fees)
@@ -519,7 +520,7 @@ public:
         @return	Sum of value of all inputs (scriptSigs)
         @see CTransaction::FetchInputs
      */
-    int64 GetValueIn(CCoinsView& mapInputs) const;
+    int64 GetValueIn(CCoinsViewCache& mapInputs) const;
 
     static bool AllowFree(double dPriority)
     {
@@ -570,14 +571,14 @@ public:
     bool ClientCheckInputs() const;
 
     // Check whether all prevouts of this transaction are present in the UTXO set represented by view
-    bool HaveInputs(CCoinsView &view) const;
+    bool HaveInputs(CCoinsViewCache &view) const;
 
     // Check whether all inputs of this transaction are valid (no double spends, scripts & sigs, amounts)
     // This does not modify the UTXO set
-    bool CheckInputs(CCoinsView &view, enum CheckSig_mode csmode, bool fStrictPayToScriptHash=true, bool fStrictEncodings=true) const;
+    bool CheckInputs(CCoinsViewCache &view, enum CheckSig_mode csmode, bool fStrictPayToScriptHash=true, bool fStrictEncodings=true) const;
 
     // Apply the effects of this transaction on the UTXO set represented by view
-    bool UpdateCoins(CCoinsView &view, CTxUndo &txundo, int nHeight, const uint256 &txhash) const;
+    bool UpdateCoins(CCoinsViewCache &view, CTxUndo &txundo, int nHeight, const uint256 &txhash) const;
 
     // Context-independent validity checks
     bool CheckTransaction() const;
@@ -586,7 +587,7 @@ public:
     bool AcceptToMemoryPool(bool fCheckInputs=true, bool* pfMissingInputs=NULL);
 
 protected:
-    static CTxOut GetOutputFor(const CTxIn& input, CCoinsView& mapInputs);
+    static const CTxOut &GetOutputFor(const CTxIn& input, CCoinsViewCache& mapInputs);
 };
 
 /** wrapper for CTxOut that provides a more compact serialization */
@@ -1225,10 +1226,10 @@ public:
 
 
     // Undo the effects of this block (with given index) on the UTXO set represented by coins
-    bool DisconnectBlock(CBlockIndex *pindex, CCoinsView &coins);
+    bool DisconnectBlock(CBlockIndex *pindex, CCoinsViewCache &coins);
 
     // Apply the effects of this block (with given index) on the UTXO set represented by coins
-    bool ConnectBlock(CBlockIndex *pindex, CCoinsView &coins, bool fJustCheck=false);
+    bool ConnectBlock(CBlockIndex *pindex, CCoinsViewCache &coins, bool fJustCheck=false);
 
     // Read a block from disk
     bool ReadFromDisk(const CBlockIndex* pindex, bool fReadTransactions=true);
@@ -1759,11 +1760,15 @@ public:
     bool GetCoins(uint256 txid, CCoins &coins);
     bool SetCoins(uint256 txid, const CCoins &coins);
     bool HaveCoins(uint256 txid);
+    CCoins &GetCoins(uint256 txid);
     CBlockIndex *GetBestBlock();
     bool SetBestBlock(CBlockIndex *pindex);
     bool BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockIndex *pindex);
     bool Flush();
     unsigned int GetCacheSize();
+
+private:
+    std::map<uint256,CCoins>::iterator FetchCoins(uint256 txid);
 };
 
 /** CCoinsView that brings transactions from a memorypool into view.