Ultraprune

This switches bitcoin's transaction/block verification logic to use a
"coin database", which contains all unredeemed transaction output scripts,
amounts and heights.

The name ultraprune comes from the fact that instead of a full transaction
index, we only (need to) keep an index with unspent outputs. For now, the
blocks themselves are kept as usual, although they are only necessary for
serving, rescanning and reorganizing.

The basic datastructures are CCoins (representing the coins of a single
transaction), and CCoinsView (representing a state of the coins database).
There are several implementations for CCoinsView. A dummy, one backed by
the coins database (coins.dat), one backed by the memory pool, and one
that adds a cache on top of it. FetchInputs, ConnectInputs, ConnectBlock,
DisconnectBlock, ... now operate on a generic CCoinsView.

The block switching logic now builds a single cached CCoinsView with
changes to be committed to the database before any changes are made.
This means no uncommitted changes are ever read from the database, and
should ease the transition to another database layer which does not
support transactions (but does support atomic writes), like LevelDB.

For the getrawtransaction() RPC call, access to a txid-to-disk index
would be preferable. As this index is not necessary or even useful
for any other part of the implementation, it is not provided. Instead,
getrawtransaction() uses the coin database to find the block height,
and then scans that block to find the requested transaction. This is
slow, but should suffice for debug purposes.

src/db.cpp

@@ -244,7 +244,7 @@ CDB::CDB(const char *pszFile, const char* pszMode) :
 
             ret = pdb->open(NULL,      // Txn pointer
                             fMockDb ? NULL : pszFile,   // Filename
-                            "main",    // Logical db name
+                            fMockDb ? pszFile : "main", // Logical db name
                             DB_BTREE,  // Database type
                             nFlags,    // Flags
                             0);
@@ -273,7 +273,7 @@ CDB::CDB(const char *pszFile, const char* pszMode) :
 
 static bool IsChainFile(std::string strFile)
 {
-    if (strFile == "blkindex.dat")
+    if (strFile == "coins.dat" || strFile == "chain.dat")
         return true;
 
     return false;
@@ -475,111 +475,66 @@ void CDBEnv::Flush(bool fShutdown)
 
 
 //
-// CTxDB
+// CChainDB and CCoinsDB
 //
 
-bool CTxDB::ReadTxIndex(uint256 hash, CTxIndex& txindex)
-{
+bool CCoinsDB::HaveCoins(uint256 hash) {
     assert(!fClient);
-    txindex.SetNull();
-    return Read(make_pair(string("tx"), hash), txindex);
+    return Exists(make_pair('c', hash));
 }
 
-bool CTxDB::UpdateTxIndex(uint256 hash, const CTxIndex& txindex)
-{
+bool CCoinsDB::ReadCoins(uint256 hash, CCoins &coins) {
     assert(!fClient);
-    return Write(make_pair(string("tx"), hash), txindex);
-}
-
-bool CTxDB::AddTxIndex(const CTransaction& tx, const CDiskTxPos& pos, int nHeight)
-{
-    assert(!fClient);
-
-    // Add to tx index
-    uint256 hash = tx.GetHash();
-    CTxIndex txindex(pos, tx.vout.size());
-    return Write(make_pair(string("tx"), hash), txindex);
+    return Read(make_pair('c', hash), coins);
 }
 
-bool CTxDB::EraseTxIndex(const CTransaction& tx)
-{
-    assert(!fClient);
-    uint256 hash = tx.GetHash();
-
-    return Erase(make_pair(string("tx"), hash));
-}
-
-bool CTxDB::ContainsTx(uint256 hash)
-{
+bool CCoinsDB::WriteCoins(uint256 hash, const CCoins &coins) {
     assert(!fClient);
-    return Exists(make_pair(string("tx"), hash));
+    if (coins.IsPruned())
+        return Erase(make_pair('c', hash));
+    else
+        return Write(make_pair('c', hash), coins);
 }
 
-bool CTxDB::ReadDiskTx(uint256 hash, CTransaction& tx, CTxIndex& txindex)
+bool CChainDB::WriteBlockIndex(const CDiskBlockIndex& blockindex)
 {
-    assert(!fClient);
-    tx.SetNull();
-    if (!ReadTxIndex(hash, txindex))
-        return false;
-    return (tx.ReadFromDisk(txindex.pos));
+    return Write(make_pair('b', blockindex.GetBlockHash()), blockindex);
 }
 
-bool CTxDB::ReadDiskTx(uint256 hash, CTransaction& tx)
+bool CCoinsDB::ReadHashBestChain(uint256& hashBestChain)
 {
-    CTxIndex txindex;
-    return ReadDiskTx(hash, tx, txindex);
+    return Read('B', hashBestChain);
 }
 
-bool CTxDB::ReadDiskTx(COutPoint outpoint, CTransaction& tx, CTxIndex& txindex)
+bool CCoinsDB::WriteHashBestChain(uint256 hashBestChain)
 {
-    return ReadDiskTx(outpoint.hash, tx, txindex);
+    return Write('B', hashBestChain);
 }
 
-bool CTxDB::ReadDiskTx(COutPoint outpoint, CTransaction& tx)
+bool CChainDB::ReadBestInvalidWork(CBigNum& bnBestInvalidWork)
 {
-    CTxIndex txindex;
-    return ReadDiskTx(outpoint.hash, tx, txindex);
+    return Read('I', bnBestInvalidWork);
 }
 
-bool CTxDB::WriteBlockIndex(const CDiskBlockIndex& blockindex)
+bool CChainDB::WriteBestInvalidWork(CBigNum bnBestInvalidWork)
 {
-    return Write(make_pair(string("blockindex"), blockindex.GetBlockHash()), blockindex);
+    return Write('I', bnBestInvalidWork);
 }
 
-bool CTxDB::WriteBlockFileInfo(int nFile, const CBlockFileInfo &info) {
-    return Write(make_pair(string("blockfile"), nFile), info);
+bool CChainDB::WriteBlockFileInfo(int nFile, const CBlockFileInfo &info) {
+    return Write(make_pair('f', nFile), info);
 }
 
-bool CTxDB::ReadBlockFileInfo(int nFile, CBlockFileInfo &info) {
-    return Read(make_pair(string("blockfile"), nFile), info);
+bool CChainDB::ReadBlockFileInfo(int nFile, CBlockFileInfo &info) {
+    return Read(make_pair('f', nFile), info);
 }
 
-bool CTxDB::WriteLastBlockFile(int nFile) {
-    return Write(string("lastblockfile"), nFile);
+bool CChainDB::WriteLastBlockFile(int nFile) {
+    return Write('l', nFile);
 }
 
-bool CTxDB::ReadLastBlockFile(int &nFile) {
-    return Read(string("lastblockfile"), nFile);
-}
-
-bool CTxDB::ReadHashBestChain(uint256& hashBestChain)
-{
-    return Read(string("hashBestChain"), hashBestChain);
-}
-
-bool CTxDB::WriteHashBestChain(uint256 hashBestChain)
-{
-    return Write(string("hashBestChain"), hashBestChain);
-}
-
-bool CTxDB::ReadBestInvalidWork(CBigNum& bnBestInvalidWork)
-{
-    return Read(string("bnBestInvalidWork"), bnBestInvalidWork);
-}
-
-bool CTxDB::WriteBestInvalidWork(CBigNum bnBestInvalidWork)
-{
-    return Write(string("bnBestInvalidWork"), bnBestInvalidWork);
+bool CChainDB::ReadLastBlockFile(int &nFile) {
+    return Read('l', nFile);
 }
 
 CBlockIndex static * InsertBlockIndex(uint256 hash)
@@ -602,9 +557,9 @@ CBlockIndex static * InsertBlockIndex(uint256 hash)
     return pindexNew;
 }
 
-bool CTxDB::LoadBlockIndex()
+bool LoadBlockIndex(CCoinsDB &coindb, CChainDB &chaindb)
 {
-    if (!LoadBlockIndexGuts())
+    if (!chaindb.LoadBlockIndexGuts())
         return false;
 
     if (fRequestShutdown)
@@ -626,29 +581,39 @@ bool CTxDB::LoadBlockIndex()
     }
 
     // Load block file info
-    ReadLastBlockFile(nLastBlockFile);
+    chaindb.ReadLastBlockFile(nLastBlockFile);
     printf("LoadBlockIndex(): last block file = %i\n", nLastBlockFile);
-    if (ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile))
+    if (chaindb.ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile))
         printf("LoadBlockIndex(): last block file: %s\n", infoLastBlockFile.ToString().c_str());
  
     // Load hashBestChain pointer to end of best chain
-    if (!ReadHashBestChain(hashBestChain))
+    if (!coindb.ReadHashBestChain(hashBestChain))
     {
         if (pindexGenesisBlock == NULL)
             return true;
         return error("CTxDB::LoadBlockIndex() : hashBestChain not loaded");
     }
-    if (!mapBlockIndex.count(hashBestChain))
+    std::map<uint256, CBlockIndex*>::iterator it = mapBlockIndex.find(hashBestChain);
+    if (it == mapBlockIndex.end()) {
         return error("CTxDB::LoadBlockIndex() : hashBestChain not found in the block index");
-    pindexBest = mapBlockIndex[hashBestChain];
-    nBestHeight = pindexBest->nHeight;
-    bnBestChainWork = pindexBest->bnChainWork;
-    printf("LoadBlockIndex(): hashBestChain=%s  height=%d  date=%s\n",
-      hashBestChain.ToString().substr(0,20).c_str(), nBestHeight,
-      DateTimeStrFormat("%x %H:%M:%S", pindexBest->GetBlockTime()).c_str());
+    } else {
+        // set 'next' pointers in best chain
+        CBlockIndex *pindex = it->second;
+        while(pindex != NULL && pindex->pprev != NULL) {
+             CBlockIndex *pindexPrev = pindex->pprev;
+             pindexPrev->pnext = pindex;
+             pindex = pindexPrev;
+        }
+        pindexBest = it->second;
+        nBestHeight = pindexBest->nHeight;
+        bnBestChainWork = pindexBest->bnChainWork;
+    }
+    printf("LoadBlockIndex(): hashBestChain=%s  height=%d date=%s\n",
+        hashBestChain.ToString().substr(0,20).c_str(), nBestHeight,
+        DateTimeStrFormat("%x %H:%M:%S", pindexBest->GetBlockTime()).c_str());
 
     // Load bnBestInvalidWork, OK if it doesn't exist
-    ReadBestInvalidWork(bnBestInvalidWork);
+    chaindb.ReadBestInvalidWork(bnBestInvalidWork);
 
     // Verify blocks in the best chain
     int nCheckLevel = GetArg("-checklevel", 1);
@@ -664,7 +629,6 @@ bool CTxDB::LoadBlockIndex()
         if (fRequestShutdown || pindex->nHeight < nBestHeight-nCheckDepth)
             break;
         CBlock block;
-        CDiskBlockPos blockPos = pindex->GetBlockPos();
         if (!block.ReadFromDisk(pindex))
             return error("LoadBlockIndex() : block.ReadFromDisk failed");
         // check level 1: verify block validity
@@ -673,98 +637,12 @@ bool CTxDB::LoadBlockIndex()
             printf("LoadBlockIndex() : *** found bad block at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
             pindexFork = pindex->pprev;
         }
-        // check level 2: verify transaction index validity
-        if (nCheckLevel>1)
-        {
-            BOOST_FOREACH(const CTransaction &tx, block.vtx)
-            {
-                uint256 hashTx = tx.GetHash();
-                CTxIndex txindex;
-                if (ReadTxIndex(hashTx, txindex))
-                {
-                    // check level 3: checker transaction hashes
-                    if (nCheckLevel>2 || blockPos != txindex.pos.blockPos)
-                    {
-                        // either an error or a duplicate transaction
-                        CTransaction txFound;
-                        if (!txFound.ReadFromDisk(txindex.pos))
-                        {
-                            printf("LoadBlockIndex() : *** cannot read mislocated transaction %s\n", hashTx.ToString().c_str());
-                            pindexFork = pindex->pprev;
-                        }
-                        else
-                            if (txFound.GetHash() != hashTx) // not a duplicate tx
-                            {
-                                printf("LoadBlockIndex(): *** invalid tx position for %s\n", hashTx.ToString().c_str());
-                                pindexFork = pindex->pprev;
-                            }
-                    }
-                    // check level 4: check whether spent txouts were spent within the main chain
-                    unsigned int nOutput = 0;
-                    if (nCheckLevel>3)
-                    {
-                        BOOST_FOREACH(const CDiskTxPos &txpos, txindex.vSpent)
-                        {
-                            if (!txpos.IsNull())
-                            {
-                                // check level 6: check whether spent txouts were spent by a valid transaction that consume them
-                                if (nCheckLevel>5)
-                                {
-                                    CTransaction txSpend;
-                                    if (!txSpend.ReadFromDisk(txpos))
-                                    {
-                                        printf("LoadBlockIndex(): *** cannot read spending transaction of %s:%i from disk\n", hashTx.ToString().c_str(), nOutput);
-                                        pindexFork = pindex->pprev;
-                                    }
-                                    else if (!txSpend.CheckTransaction())
-                                    {
-                                        printf("LoadBlockIndex(): *** spending transaction of %s:%i is invalid\n", hashTx.ToString().c_str(), nOutput);
-                                        pindexFork = pindex->pprev;
-                                    }
-                                    else
-                                    {
-                                        bool fFound = false;
-                                        BOOST_FOREACH(const CTxIn &txin, txSpend.vin)
-                                            if (txin.prevout.hash == hashTx && txin.prevout.n == nOutput)
-                                                fFound = true;
-                                        if (!fFound)
-                                        {
-                                            printf("LoadBlockIndex(): *** spending transaction of %s:%i does not spend it\n", hashTx.ToString().c_str(), nOutput);
-                                            pindexFork = pindex->pprev;
-                                        }
-                                    }
-                                }
-                            }
-                            nOutput++;
-                        }
-                    }
-                }
-                // check level 5: check whether all prevouts are marked spent
-                if (nCheckLevel>4)
-                {
-                     BOOST_FOREACH(const CTxIn &txin, tx.vin)
-                     {
-                          CTxIndex txindex;
-                          if (ReadTxIndex(txin.prevout.hash, txindex))
-                              if (txindex.vSpent.size()-1 < txin.prevout.n || txindex.vSpent[txin.prevout.n].IsNull())
-                              {
-                                  printf("LoadBlockIndex(): *** found unspent prevout %s:%i in %s\n", txin.prevout.hash.ToString().c_str(), txin.prevout.n, hashTx.ToString().c_str());
-                                  pindexFork = pindex->pprev;
-                              }
-                     }
-                }
-            }
-        }
+        // TODO: stronger verifications
     }
     if (pindexFork && !fRequestShutdown)
     {
-        // Reorg back to the fork
-        printf("LoadBlockIndex() : *** moving best chain pointer back to block %d\n", pindexFork->nHeight);
-        CBlock block;
-        if (!block.ReadFromDisk(pindexFork))
-            return error("LoadBlockIndex() : block.ReadFromDisk failed");
-        CTxDB txdb;
-        block.SetBestChain(txdb, pindexFork);
+        // TODO: reorg back
+        return error("LoadBlockIndex(): chain database corrupted");
     }
 
     return true;
@@ -772,7 +650,7 @@ bool CTxDB::LoadBlockIndex()
 
 
 
-bool CTxDB::LoadBlockIndexGuts()
+bool CChainDB::LoadBlockIndexGuts()
 {
     // Get database cursor
     Dbc* pcursor = GetCursor();
@@ -786,7 +664,7 @@ bool CTxDB::LoadBlockIndexGuts()
         // Read next record
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         if (fFlags == DB_SET_RANGE)
-            ssKey << make_pair(string("blockindex"), uint256(0));
+            ssKey << make_pair('b', uint256(0));
         CDataStream ssValue(SER_DISK, CLIENT_VERSION);
         int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
         fFlags = DB_NEXT;
@@ -798,9 +676,9 @@ bool CTxDB::LoadBlockIndexGuts()
         // Unserialize
 
         try {
-        string strType;
-        ssKey >> strType;
-        if (strType == "blockindex" && !fRequestShutdown)
+        char chType;
+        ssKey >> chType;
+        if (chType == 'b' && !fRequestShutdown)
         {
             CDiskBlockIndex diskindex;
             ssValue >> diskindex;
@@ -808,7 +686,6 @@ bool CTxDB::LoadBlockIndexGuts()
             // Construct block index object
             CBlockIndex* pindexNew = InsertBlockIndex(diskindex.GetBlockHash());
             pindexNew->pprev          = InsertBlockIndex(diskindex.hashPrev);
-            pindexNew->pnext          = InsertBlockIndex(diskindex.hashNext);
             pindexNew->nHeight        = diskindex.nHeight;
             pindexNew->pos            = diskindex.pos;
             pindexNew->nUndoPos       = diskindex.nUndoPos;

src/db.h

@@ -17,10 +17,8 @@ class CAddress;
 class CAddrMan;
 class CBlockLocator;
 class CDiskBlockIndex;
-class CDiskTxPos;
 class CMasterKey;
 class COutPoint;
-class CTxIndex;
 class CWallet;
 class CWalletTx;
 
@@ -316,39 +314,43 @@ public:
 
 
 
-/** Access to the transaction database (blkindex.dat) */
-class CTxDB : public CDB
+/** Access to the transaction database (coins.dat) */
+class CCoinsDB : public CDB
 {
 public:
-    CTxDB(const char* pszMode="r+") : CDB("blkindex.dat", pszMode) { }
+    CCoinsDB(const char* pszMode="r+") : CDB("coins.dat", pszMode) { }
 private:
-    CTxDB(const CTxDB&);
-    void operator=(const CTxDB&);
+    CCoinsDB(const CCoinsDB&);
+    void operator=(const CCoinsDB&);
 public:
-    bool ReadTxIndex(uint256 hash, CTxIndex& txindex);
-    bool UpdateTxIndex(uint256 hash, const CTxIndex& txindex);
-    bool AddTxIndex(const CTransaction& tx, const CDiskTxPos& pos, int nHeight);
-    bool EraseTxIndex(const CTransaction& tx);
-    bool ContainsTx(uint256 hash);
-    bool ReadDiskTx(uint256 hash, CTransaction& tx, CTxIndex& txindex);
-    bool ReadDiskTx(uint256 hash, CTransaction& tx);
-    bool ReadDiskTx(COutPoint outpoint, CTransaction& tx, CTxIndex& txindex);
-    bool ReadDiskTx(COutPoint outpoint, CTransaction& tx);
-    bool WriteBlockIndex(const CDiskBlockIndex& blockindex);
+    bool ReadCoins(uint256 hash, CCoins &coins);
+    bool WriteCoins(uint256 hash, const CCoins& coins);
+    bool HaveCoins(uint256 hash);
     bool ReadHashBestChain(uint256& hashBestChain);
     bool WriteHashBestChain(uint256 hashBestChain);
+};
+
+/** Access to the block database (chain.dat) */
+class CChainDB : public CDB
+{
+public:
+    CChainDB(const char* pszMode="r+") : CDB("chain.dat", pszMode) { }
+private:
+    CChainDB(const CChainDB&);
+    void operator=(const CChainDB&);
+public:
+    bool WriteBlockIndex(const CDiskBlockIndex& blockindex);
     bool ReadBestInvalidWork(CBigNum& bnBestInvalidWork);
     bool WriteBestInvalidWork(CBigNum bnBestInvalidWork);
     bool ReadBlockFileInfo(int nFile, CBlockFileInfo &fileinfo);
     bool WriteBlockFileInfo(int nFile, const CBlockFileInfo &fileinfo);
     bool ReadLastBlockFile(int &nFile);
     bool WriteLastBlockFile(int nFile);
-    bool LoadBlockIndex();
-private:
     bool LoadBlockIndexGuts();
 };
 
 
+bool LoadBlockIndex(CCoinsDB &coinsdb, CChainDB &chaindb);
 
 
 /** Access to the (IP) address database (peers.dat) */

src/init.cpp

@@ -638,14 +638,6 @@ bool AppInit2()
         return InitError(msg);
     }
 
-    if (GetBoolArg("-loadblockindextest"))
-    {
-        CTxDB txdb("r");
-        txdb.LoadBlockIndex();
-        PrintBlockTree();
-        return false;
-    }
-
     uiInterface.InitMessage(_("Loading block index..."));
     printf("Loading block index...\n");
     nStart = GetTimeMillis();

src/main.h

@@ -31,6 +31,7 @@ static const unsigned int MAX_INV_SZ = 50000;
 static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
 static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB
 static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
+static const unsigned int MEMPOOL_HEIGHT = 0x7FFFFFFF;
 static const int64 MIN_TX_FEE = 50000;
 static const int64 MIN_RELAY_TX_FEE = 10000;
 static const int64 MAX_MONEY = 21000000 * COIN;
@@ -81,9 +82,12 @@ static const uint64 nMinDiskSpace = 52428800;
 
 
 class CReserveKey;
-class CTxDB;
-class CTxIndex;
+class CCoinsDB;
+class CChainDB;
 class CDiskBlockPos;
+class CCoins;
+class CTxUndo;
+class CCoinsView;
 
 void RegisterWallet(CWallet* pwalletIn);
 void UnregisterWallet(CWallet* pwalletIn);
@@ -108,8 +112,7 @@ unsigned int ComputeMinWork(unsigned int nBase, int64 nTime);
 int GetNumBlocksOfPeers();
 bool IsInitialBlockDownload();
 std::string GetWarnings(std::string strFor);
-bool GetTransaction(const uint256 &hash, CTransaction &tx, uint256 &hashBlock);
-
+bool GetTransaction(const uint256 &hash, CTransaction &tx, uint256 &hashBlock, bool fAllowSlow = false);
 
 
 
@@ -143,62 +146,8 @@ public:
 
     void SetNull() { nFile = -1; nPos = 0; }
     bool IsNull() const { return (nFile == -1); }
-
-    void SetMemPool() { nFile = -2; nPos = 0; }
-    bool IsMemPool() const { return (nFile == -2); }
 };
 
-/** Position on disk for a particular transaction. */
-class CDiskTxPos
-{
-public:
-    CDiskBlockPos blockPos;
-    unsigned int nTxPos;
-
-    CDiskTxPos(bool fInMemPool = false)
-    {
-        SetNull();
-        if (fInMemPool)
-            blockPos.SetMemPool();
-    }
-
-    CDiskTxPos(const CDiskBlockPos &block, unsigned int nTxPosIn) : blockPos(block), nTxPos(nTxPosIn) { }
-
-    IMPLEMENT_SERIALIZE( 
-        READWRITE(blockPos);
-        READWRITE(VARINT(nTxPos));
-    )
-
-    void SetNull() { blockPos.SetNull(); nTxPos = 0; }
-    bool IsNull() const { return (nTxPos == 0); }
-    bool IsMemPool() const { return blockPos.IsMemPool(); }
-
-    friend bool operator==(const CDiskTxPos& a, const CDiskTxPos& b)
-    {
-        return (a.blockPos  == b.blockPos &&
-                a.nTxPos    == b.nTxPos);
-    }
-
-    friend bool operator!=(const CDiskTxPos& a, const CDiskTxPos& b)
-    {
-        return !(a == b);
-    }
-
-    std::string ToString() const
-    {
-        if (IsNull())
-            return "null";
-        else if (blockPos.IsMemPool())
-            return "mempool";
-        else
-            return strprintf("\"blk%05i.dat:0x%x\"", blockPos.nFile, nTxPos);
-    }
-
-    void print() const
-    {
-        printf("%s", ToString().c_str());
-    }
-};
 
 
 
@@ -413,7 +362,13 @@ enum GetMinFee_mode
     GMF_SEND,
 };
 
-typedef std::map<uint256, std::pair<CTxIndex, CTransaction> > MapPrevTx;
+// Modes for script/signature checking
+enum CheckSig_mode
+{
+    CS_NEVER,             // never validate scripts
+    CS_AFTER_CHECKPOINT,  // validate scripts after the last checkpoint
+    CS_ALWAYS             // always validate scripts
+};
 
 /** The basic transaction that is broadcasted on the network and contained in
  * blocks.  A transaction can contain multiple inputs and outputs.
@@ -525,7 +480,7 @@ public:
         @return True if all inputs (scriptSigs) use only standard transaction forms
         @see CTransaction::FetchInputs
     */
-    bool AreInputsStandard(const MapPrevTx& mapInputs) const;
+    bool AreInputsStandard(CCoinsView& 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
@@ -539,7 +494,7 @@ public:
         @return maximum number of sigops required to validate this transaction's inputs
         @see CTransaction::FetchInputs
      */
-    unsigned int GetP2SHSigOpCount(const MapPrevTx& mapInputs) const;
+    unsigned int GetP2SHSigOpCount(CCoinsView& mapInputs) const;
 
     /** Amount of bitcoins spent by this transaction.
         @return sum of all outputs (note: does not include fees)
@@ -564,7 +519,7 @@ public:
         @return	Sum of value of all inputs (scriptSigs)
         @see CTransaction::FetchInputs
      */
-    int64 GetValueIn(const MapPrevTx& mapInputs) const;
+    int64 GetValueIn(CCoinsView& mapInputs) const;
 
     static bool AllowFree(double dPriority)
     {
@@ -575,33 +530,6 @@ public:
 
     int64 GetMinFee(unsigned int nBlockSize=1, bool fAllowFree=true, enum GetMinFee_mode mode=GMF_BLOCK) const;
 
-    bool ReadFromDisk(CDiskTxPos pos, FILE** pfileRet=NULL)
-    {
-        CAutoFile filein = CAutoFile(OpenBlockFile(pos.blockPos, pfileRet==NULL), SER_DISK, CLIENT_VERSION);
-        if (!filein)
-            return error("CTransaction::ReadFromDisk() : OpenBlockFile failed");
-
-        // Read transaction
-        if (fseek(filein, pos.nTxPos, SEEK_SET) != 0)
-            return error("CTransaction::ReadFromDisk() : fseek failed");
-
-        try {
-            filein >> *this;
-        }
-        catch (std::exception &e) {
-            return error("%s() : deserialize or I/O error", __PRETTY_FUNCTION__);
-        }
-
-        // Return file pointer
-        if (pfileRet)
-        {
-            if (fseek(filein, pos.nTxPos, SEEK_SET) != 0)
-                return error("CTransaction::ReadFromDisk() : second fseek failed");
-            *pfileRet = filein.release();
-        }
-        return true;
-    }
-
     friend bool operator==(const CTransaction& a, const CTransaction& b)
     {
         return (a.nVersion  == b.nVersion &&
@@ -638,45 +566,27 @@ public:
     }
 
 
-    bool ReadFromDisk(CTxDB& txdb, COutPoint prevout, CTxIndex& txindexRet);
-    bool ReadFromDisk(CTxDB& txdb, COutPoint prevout);
-    bool ReadFromDisk(COutPoint prevout);
-    bool DisconnectInputs(CTxDB& txdb);
+    // Do all possible client-mode checks
+    bool ClientCheckInputs() const;
 
-    /** Fetch from memory and/or disk. inputsRet keys are transaction hashes.
+    // Check whether all prevouts of this transaction are present in the UTXO set represented by view
+    bool HaveInputs(CCoinsView &view) const;
 
-     @param[in] txdb	Transaction database
-     @param[in] mapTestPool	List of pending changes to the transaction index database
-     @param[in] fBlock	True if being called to add a new best-block to the chain
-     @param[in] fMiner	True if being called by CreateNewBlock
-     @param[out] inputsRet	Pointers to this transaction's inputs
-     @param[out] fInvalid	returns true if transaction is invalid
-     @return	Returns true if all inputs are in txdb or mapTestPool
-     */
-    bool FetchInputs(CTxDB& txdb, const std::map<uint256, CTxIndex>& mapTestPool,
-                     bool fBlock, bool fMiner, MapPrevTx& inputsRet, bool& fInvalid);
-
-    /** Sanity check previous transactions, then, if all checks succeed,
-        mark them as spent by this transaction.
-
-        @param[in] inputs	Previous transactions (from FetchInputs)
-        @param[out] mapTestPool	Keeps track of inputs that need to be updated on disk
-        @param[in] posThisTx	Position of this transaction on disk
-        @param[in] pindexBlock
-        @param[in] fBlock	true if called from ConnectBlock
-        @param[in] fMiner	true if called from CreateNewBlock
-        @param[in] fStrictPayToScriptHash	true if fully validating p2sh transactions
-        @return Returns true if all checks succeed
-     */
-    bool ConnectInputs(MapPrevTx inputs,
-                       std::map<uint256, CTxIndex>& mapTestPool, const CDiskTxPos& posThisTx,
-                       const CBlockIndex* pindexBlock, bool fBlock, bool fMiner, bool fStrictPayToScriptHash=true);
-    bool ClientConnectInputs();
+    // 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;
+
+    // Apply the effects of this transaction on the UTXO set represented by view
+    bool UpdateCoins(CCoinsView &view, CTxUndo &txundo, int nHeight) const;
+
+    // Context-independent validity checks
     bool CheckTransaction() const;
-    bool AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs=true, bool* pfMissingInputs=NULL);
+
+    // Try to accept this transaction into the memory pool
+    bool AcceptToMemoryPool(CCoinsDB& coinsdb, bool fCheckInputs=true, bool* pfMissingInputs=NULL);
 
 protected:
-    const CTxOut& GetOutputFor(const CTxIn& input, const MapPrevTx& inputs) const;
+    static CTxOut GetOutputFor(const CTxIn& input, CCoinsView& mapInputs);
 };
 
 /** wrapper for CTxOut that provides a more compact serialization */
@@ -752,6 +662,7 @@ public:
 class CTxUndo
 {
 public:
+    // undo information for all txins
     std::vector<CTxInUndo> vprevout;
 
     IMPLEMENT_SERIALIZE(
@@ -763,7 +674,7 @@ public:
 class CBlockUndo
 {
 public:
-    std::vector<CTxUndo> vtxundo;
+    std::vector<CTxUndo> vtxundo; // for all but the coinbase
 
     IMPLEMENT_SERIALIZE(
         READWRITE(vtxundo);
@@ -789,7 +700,7 @@ public:
 
         // Flush stdio buffers and commit to disk before returning
         fflush(fileout);
-        if (!IsInitialBlockDownload() || (nBestHeight+1) % 500 == 0)
+        if (!IsInitialBlockDownload())
             FileCommit(fileout);
 
         return true;
@@ -1084,66 +995,16 @@ public:
     int GetDepthInMainChain() const { CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet); }
     bool IsInMainChain() const { return GetDepthInMainChain() > 0; }
     int GetBlocksToMaturity() const;
-    bool AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs=true);
+    bool AcceptToMemoryPool(CCoinsDB& coinsdb, bool fCheckInputs=true);
     bool AcceptToMemoryPool();
 };
 
 
 
 
-/**  A txdb record that contains the disk location of a transaction and the
- * locations of transactions that spend its outputs.  vSpent is really only
- * used as a flag, but having the location is very helpful for debugging.
- */
-class CTxIndex
-{
-public:
-    CDiskTxPos pos;
-    std::vector<CDiskTxPos> vSpent;
-
-    CTxIndex()
-    {
-        SetNull();
-    }
-
-    CTxIndex(const CDiskTxPos& posIn, unsigned int nOutputs)
-    {
-        pos = posIn;
-        vSpent.resize(nOutputs);
-    }
-
-    IMPLEMENT_SERIALIZE
-    (
-        if (!(nType & SER_GETHASH))
-            READWRITE(nVersion);
-        READWRITE(pos);
-        READWRITE(vSpent);
-    )
-
-    void SetNull()
-    {
-        pos.SetNull();
-        vSpent.clear();
-    }
-
-    bool IsNull()
-    {
-        return pos.IsNull();
-    }
 
-    friend bool operator==(const CTxIndex& a, const CTxIndex& b)
-    {
-        return (a.pos    == b.pos &&
-                a.vSpent == b.vSpent);
-    }
 
-    friend bool operator!=(const CTxIndex& a, const CTxIndex& b)
-    {
-        return !(a == b);
-    }
-    int GetDepthInMainChain() const;
 
-};
 
 
 
@@ -1155,9 +1016,6 @@ public:
  * to everyone and the block is added to the block chain.  The first transaction
  * in the block is a special one that creates a new coin owned by the creator
  * of the block.
- *
- * Blocks are appended to blk0001.dat files on disk.  Their location on disk
- * is indexed by CBlockIndex objects in memory.
  */
 class CBlock
 {
@@ -1305,7 +1163,7 @@ public:
 
         // Flush stdio buffers and commit to disk before returning
         fflush(fileout);
-        if (!IsInitialBlockDownload() || (nBestHeight+1) % 500 == 0)
+        if (!IsInitialBlockDownload())
             FileCommit(fileout);
 
         return true;
@@ -1360,16 +1218,26 @@ public:
     }
 
 
-    bool DisconnectBlock(CTxDB& txdb, CBlockIndex* pindex);
-    bool ConnectBlock(CTxDB& txdb, CBlockIndex* pindex, bool fJustCheck=false);
+    // Undo the effects of this block (with given index) on the UTXO set represented by coins
+    bool DisconnectBlock(CBlockIndex *pindex, CCoinsView &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);
+
+    // Read a block from disk
     bool ReadFromDisk(const CBlockIndex* pindex, bool fReadTransactions=true);
-    bool SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew);
+
+    // Make this block (with given index) the new tip of the active block chain
+    bool SetBestChain(CBlockIndex* pindexNew);
+
+    // Add this block to the block index, and if necessary, switch the active block chain to this
     bool AddToBlockIndex(const CDiskBlockPos &pos);
+
+    // Context-independent validity checks
     bool CheckBlock(bool fCheckPOW=true, bool fCheckMerkleRoot=true) const;
-    bool AcceptBlock();
 
-private:
-    bool SetBestChainInner(CTxDB& txdb, CBlockIndex *pindexNew);
+    // Store block on disk
+    bool AcceptBlock();
 };
 
 
@@ -1412,7 +1280,7 @@ public:
      }
 
      std::string ToString() const {
-         return strprintf("CBlockFileInfo(blocks=%u, size=%lu, heights=%u..%u, time=%s..%s)", nBlocks, nSize, nHeightFirst, nHeightLast, DateTimeStrFormat("%Y-%m-%d", nTimeFirst).c_str(), DateTimeStrFormat("%Y-%m-%d", nTimeLast).c_str());
+         return strprintf("CBlockFileInfo(blocks=%u, size=%u, heights=%u..%u, time=%s..%s)", nBlocks, nSize, nHeightFirst, nHeightLast, DateTimeStrFormat("%Y-%m-%d", nTimeFirst).c_str(), DateTimeStrFormat("%Y-%m-%d", nTimeLast).c_str());
      }
 
      // update statistics (does not update nSize)
@@ -1466,7 +1334,7 @@ public:
         pnext = NULL;
         nHeight = 0;
         pos.SetNull();
-        nUndoPos = (unsigned int)(-1);
+        nUndoPos = 0;
         bnChainWork = 0;
 
         nVersion       = 0;
@@ -1499,10 +1367,10 @@ public:
 
     CDiskBlockPos GetUndoPos() const {
         CDiskBlockPos ret = pos;
-        if (nUndoPos == (unsigned int)(-1))
+        if (nUndoPos == 0)
             ret.SetNull();
         else
-            ret.nPos = nUndoPos;
+            ret.nPos = nUndoPos - 1;
         return ret;
     }
 
@@ -1604,18 +1472,13 @@ class CDiskBlockIndex : public CBlockIndex
 {
 public:
     uint256 hashPrev;
-    uint256 hashNext;
 
-    CDiskBlockIndex()
-    {
+    CDiskBlockIndex() {
         hashPrev = 0;
-        hashNext = 0;
     }
 
-    explicit CDiskBlockIndex(CBlockIndex* pindex) : CBlockIndex(*pindex)
-    {
+    explicit CDiskBlockIndex(CBlockIndex* pindex) : CBlockIndex(*pindex) {
         hashPrev = (pprev ? pprev->GetBlockHash() : 0);
-        hashNext = (pnext ? pnext->GetBlockHash() : 0);
     }
 
     IMPLEMENT_SERIALIZE
@@ -1623,7 +1486,6 @@ public:
         if (!(nType & SER_GETHASH))
             READWRITE(nVersion);
 
-        READWRITE(hashNext);
         READWRITE(nHeight);
         READWRITE(pos);
         READWRITE(nUndoPos);
@@ -1654,10 +1516,9 @@ public:
     {
         std::string str = "CDiskBlockIndex(";
         str += CBlockIndex::ToString();
-        str += strprintf("\n                hashBlock=%s, hashPrev=%s, hashNext=%s)",
+        str += strprintf("\n                hashBlock=%s, hashPrev=%s)",
             GetBlockHash().ToString().c_str(),
-            hashPrev.ToString().substr(0,20).c_str(),
-            hashNext.ToString().substr(0,20).c_str());
+            hashPrev.ToString().substr(0,20).c_str());
         return str;
     }
 
@@ -1815,12 +1676,13 @@ public:
     std::map<uint256, CTransaction> mapTx;
     std::map<COutPoint, CInPoint> mapNextTx;
 
-    bool accept(CTxDB& txdb, CTransaction &tx,
+    bool accept(CCoinsDB& coinsdb, CTransaction &tx,
                 bool fCheckInputs, bool* pfMissingInputs);
     bool addUnchecked(const uint256& hash, CTransaction &tx);
     bool remove(CTransaction &tx);
     void clear();
     void queryHashes(std::vector<uint256>& vtxid);
+    void pruneSpent(const uint256& hash, CCoins &coins);
 
     unsigned long size()
     {
@@ -1841,4 +1703,86 @@ public:
 
 extern CTxMemPool mempool;
 
+/** Abstract view on the open txout dataset. */
+class CCoinsView
+{
+public:
+    // Retrieve the CCoins (unspent transaction outputs) for a given txid
+    virtual bool GetCoins(uint256 txid, CCoins &coins);
+
+    // Modify the CCoins for a given txid
+    virtual bool SetCoins(uint256 txid, const CCoins &coins);
+
+    // Just check whether we have data for a given txid.
+    // This may (but cannot always) return true for fully spent transactions
+    virtual bool HaveCoins(uint256 txid);
+
+    // Retrieve the block index whose state this CCoinsView currently represents
+    virtual CBlockIndex *GetBestBlock();
+
+    // Modify the currently active block index
+    virtual bool SetBestBlock(CBlockIndex *pindex);
+};
+
+/** CCoinsView backed by another CCoinsView */
+class CCoinsViewBacked : public CCoinsView
+{
+protected:
+    CCoinsView *base;
+
+public:
+    CCoinsViewBacked(CCoinsView &viewIn);
+    bool GetCoins(uint256 txid, CCoins &coins);
+    bool SetCoins(uint256 txid, const CCoins &coins);
+    bool HaveCoins(uint256 txid);
+    CBlockIndex *GetBestBlock();
+    bool SetBestBlock(CBlockIndex *pindex);
+    void SetBackend(CCoinsView &viewIn);
+};
+
+
+/** CCoinsView backed by a CCoinsDB */
+class CCoinsViewDB : public CCoinsView
+{
+protected:
+    CCoinsDB &db;
+public:
+    CCoinsViewDB(CCoinsDB &dbIn);
+    bool GetCoins(uint256 txid, CCoins &coins);
+    bool SetCoins(uint256 txid, const CCoins &coins);
+    bool HaveCoins(uint256 txid);
+    CBlockIndex *GetBestBlock();
+    bool SetBestBlock(CBlockIndex *pindex);
+};
+
+/** CCoinsView that adds a memory cache for transactions to another CCoinsView */
+class CCoinsViewCache : public CCoinsViewBacked
+{
+protected:
+    CBlockIndex *pindexTip;
+    std::map<uint256,CCoins> cacheCoins;
+
+public:
+    CCoinsViewCache(CCoinsView &baseIn, bool fDummy = false);
+    bool GetCoins(uint256 txid, CCoins &coins);
+    bool SetCoins(uint256 txid, const CCoins &coins);
+    bool HaveCoins(uint256 txid);
+    CBlockIndex *GetBestBlock();
+    bool SetBestBlock(CBlockIndex *pindex);
+    bool Flush();
+};
+
+/** CCoinsView that brings transactions from a memorypool into view.
+    It does not check for spendings by memory pool transactions. */
+class CCoinsViewMemPool : public CCoinsViewBacked
+{
+protected:
+    CTxMemPool &mempool;
+
+public:
+    CCoinsViewMemPool(CCoinsView &baseIn, CTxMemPool &mempoolIn);
+    bool GetCoins(uint256 txid, CCoins &coins);
+    bool HaveCoins(uint256 txid);
+};
+
 #endif

src/qt/transactiondesc.cpp

@@ -234,7 +234,8 @@ QString TransactionDesc::toHTML(CWallet *wallet, CWalletTx &wtx)
             strHTML += "<br><b>" + tr("Transaction") + ":</b><br>";
             strHTML += GUIUtil::HtmlEscape(wtx.ToString(), true);
 
-            CTxDB txdb("r"); // To fetch source txouts
+            CCoinsDB coindb("r"); // To fetch source txouts
+            CCoinsViewDB coins(coindb);
 
             strHTML += "<br><b>" + tr("Inputs") + ":</b>";
             strHTML += "<ul>";
@@ -245,8 +246,8 @@ QString TransactionDesc::toHTML(CWallet *wallet, CWalletTx &wtx)
                 {
                     COutPoint prevout = txin.prevout;
 
-                    CTransaction prev;
-                    if(txdb.ReadDiskTx(prevout.hash, prev))
+                    CCoins prev;
+                    if(coins.GetCoins(prevout.hash, prev))
                     {
                         if (prevout.n < prev.vout.size())
                         {

src/rpcmining.cpp

@@ -198,7 +198,7 @@ Value getwork(const Array& params, bool fHelp)
 
 Value getblocktemplate(const Array& params, bool fHelp)
 {
-    if (fHelp || params.size() > 1)
+    if (fHelp || params.size() != 1)
         throw runtime_error(
             "getblocktemplate [params]\n"
             "Returns data needed to construct a block to work on:\n"
@@ -281,7 +281,9 @@ Value getblocktemplate(const Array& params, bool fHelp)
     Array transactions;
     map<uint256, int64_t> setTxIndex;
     int i = 0;
-    CTxDB txdb("r");
+    CCoinsDB coindb("r");
+    CCoinsViewDB viewdb(coindb);
+    CCoinsViewCache view(viewdb);
     BOOST_FOREACH (CTransaction& tx, pblock->vtx)
     {
         uint256 txHash = tx.GetHash();
@@ -298,25 +300,21 @@ Value getblocktemplate(const Array& params, bool fHelp)
 
         entry.push_back(Pair("hash", txHash.GetHex()));
 
-        MapPrevTx mapInputs;
-        map<uint256, CTxIndex> mapUnused;
-        bool fInvalid = false;
-        if (tx.FetchInputs(txdb, mapUnused, false, false, mapInputs, fInvalid))
+        Array deps;
+        BOOST_FOREACH (const CTxIn &in, tx.vin)
         {
-            entry.push_back(Pair("fee", (int64_t)(tx.GetValueIn(mapInputs) - tx.GetValueOut())));
-
-            Array deps;
-            BOOST_FOREACH (MapPrevTx::value_type& inp, mapInputs)
-            {
-                if (setTxIndex.count(inp.first))
-                    deps.push_back(setTxIndex[inp.first]);
-            }
-            entry.push_back(Pair("depends", deps));
+            if (setTxIndex.count(in.prevout.hash))
+                deps.push_back(setTxIndex[in.prevout.hash]);
+        }
+        entry.push_back(Pair("depends", deps));
 
-            int64_t nSigOps = tx.GetLegacySigOpCount();
-            nSigOps += tx.GetP2SHSigOpCount(mapInputs);
-            entry.push_back(Pair("sigops", nSigOps));
+        int64_t nSigOps = tx.GetLegacySigOpCount();
+        if (tx.HaveInputs(view))
+        {
+            entry.push_back(Pair("fee", (int64_t)(tx.GetValueIn(view) - tx.GetValueOut())));
+            nSigOps += tx.GetP2SHSigOpCount(view);
         }
+        entry.push_back(Pair("sigops", nSigOps));
 
         transactions.push_back(entry);
     }
@@ -364,18 +362,17 @@ Value submitblock(const Array& params, bool fHelp)
 
     vector<unsigned char> blockData(ParseHex(params[0].get_str()));
     CDataStream ssBlock(blockData, SER_NETWORK, PROTOCOL_VERSION);
-    CBlock block;
+    CBlock pblock;
     try {
-        ssBlock >> block;
+        ssBlock >> pblock;
     }
     catch (std::exception &e) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed");
     }
 
-    bool fAccepted = ProcessBlock(NULL, &block);
+    bool fAccepted = ProcessBlock(NULL, &pblock);
     if (!fAccepted)
         return "rejected";
 
     return Value::null;
 }
-

src/rpcrawtransaction.cpp

@@ -118,7 +118,7 @@ Value getrawtransaction(const Array& params, bool fHelp)
 
     CTransaction tx;
     uint256 hashBlock = 0;
-    if (!GetTransaction(hash, tx, hashBlock))
+    if (!GetTransaction(hash, tx, hashBlock, true))
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "No information available about transaction");
 
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
@@ -335,26 +335,22 @@ Value signrawtransaction(const Array& params, bool fHelp)
     bool fComplete = true;
 
     // Fetch previous transactions (inputs):
-    map<COutPoint, CScript> mapPrevOut;
-    for (unsigned int i = 0; i < mergedTx.vin.size(); i++)
+    CCoinsView viewDummy;
+    CCoinsViewCache view(viewDummy);
     {
-        CTransaction tempTx;
-        MapPrevTx mapPrevTx;
-        CTxDB txdb("r");
-        map<uint256, CTxIndex> unused;
-        bool fInvalid;
-
-        // FetchInputs aborts on failure, so we go one at a time.
-        tempTx.vin.push_back(mergedTx.vin[i]);
-        tempTx.FetchInputs(txdb, unused, false, false, mapPrevTx, fInvalid);
-
-        // Copy results into mapPrevOut:
-        BOOST_FOREACH(const CTxIn& txin, tempTx.vin)
-        {
+        LOCK(mempool.cs);
+        CCoinsDB coinsdb("r");
+        CCoinsViewDB viewDB(coinsdb);
+        CCoinsViewMemPool viewMempool(viewDB, mempool);
+        view.SetBackend(viewMempool); // temporarily switch cache backend to db+mempool view
+
+        BOOST_FOREACH(const CTxIn& txin, mergedTx.vin) {
             const uint256& prevHash = txin.prevout.hash;
-            if (mapPrevTx.count(prevHash) && mapPrevTx[prevHash].second.vout.size()>txin.prevout.n)
-                mapPrevOut[txin.prevout] = mapPrevTx[prevHash].second.vout[txin.prevout.n].scriptPubKey;
+            CCoins coins;
+            view.GetCoins(prevHash, coins); // this is certainly allowed to fail
         }
+
+        view.SetBackend(viewDummy); // switch back to avoid locking db/mempool too long
     }
 
     // Add previous txouts given in the RPC call:
@@ -386,20 +382,19 @@ Value signrawtransaction(const Array& params, bool fHelp)
             vector<unsigned char> pkData(ParseHex(pkHex));
             CScript scriptPubKey(pkData.begin(), pkData.end());
 
-            COutPoint outpoint(txid, nOut);
-            if (mapPrevOut.count(outpoint))
-            {
-                // Complain if scriptPubKey doesn't match
-                if (mapPrevOut[outpoint] != scriptPubKey)
-                {
+            CCoins coins;
+            if (view.GetCoins(txid, coins)) {
+                if (coins.IsAvailable(nOut) && coins.vout[nOut].scriptPubKey != scriptPubKey) {
                     string err("Previous output scriptPubKey mismatch:\n");
-                    err = err + mapPrevOut[outpoint].ToString() + "\nvs:\n"+
+                    err = err + coins.vout[nOut].scriptPubKey.ToString() + "\nvs:\n"+
                         scriptPubKey.ToString();
                     throw JSONRPCError(RPC_DESERIALIZATION_ERROR, err);
                 }
+                // what todo if txid is known, but the actual output isn't?
             }
-            else
-                mapPrevOut[outpoint] = scriptPubKey;
+            coins.vout[nOut].scriptPubKey = scriptPubKey;
+            coins.vout[nOut].nValue = 0; // we don't know the actual output value
+            view.SetCoins(txid, coins);
         }
     }
 
@@ -452,12 +447,13 @@ Value signrawtransaction(const Array& params, bool fHelp)
     for (unsigned int i = 0; i < mergedTx.vin.size(); i++)
     {
         CTxIn& txin = mergedTx.vin[i];
-        if (mapPrevOut.count(txin.prevout) == 0)
+        CCoins coins;
+        if (!view.GetCoins(txin.prevout.hash, coins) || !coins.IsAvailable(txin.prevout.n))
         {
             fComplete = false;
             continue;
         }
-        const CScript& prevPubKey = mapPrevOut[txin.prevout];
+        const CScript& prevPubKey = coins.vout[txin.prevout.n].scriptPubKey;
 
         txin.scriptSig.clear();
         // Only sign SIGHASH_SINGLE if there's a corresponding output:
@@ -505,24 +501,27 @@ Value sendrawtransaction(const Array& params, bool fHelp)
     }
     uint256 hashTx = tx.GetHash();
 
-    // See if the transaction is already in a block
-    // or in the memory pool:
-    CTransaction existingTx;
-    uint256 hashBlock = 0;
-    if (GetTransaction(hashTx, existingTx, hashBlock))
+    bool fHave = false;
+    CCoins existingCoins;
     {
-        if (hashBlock != 0)
-            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, string("transaction already in block ")+hashBlock.GetHex());
+        CCoinsDB coinsdb("r");
+        {
+            CCoinsViewDB coinsviewDB(coinsdb);
+            CCoinsViewMemPool coinsview(coinsviewDB, mempool);
+            fHave = coinsview.GetCoins(hashTx, existingCoins);
+        }
+        if (!fHave) {
+            // push to local node
+            if (!tx.AcceptToMemoryPool(coinsdb))
+                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX rejected");
+        }
+    }
+    if (fHave) {
+        if (existingCoins.nHeight < 1000000000)
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "transaction already in block chain");
         // Not in block, but already in the memory pool; will drop
         // through to re-relay it.
-    }
-    else
-    {
-        // push to local node
-        CTxDB txdb("r");
-        if (!tx.AcceptToMemoryPool(txdb))
-            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX rejected");
-
+    } else {
         SyncWithWallets(tx, NULL, true);
     }
     RelayMessage(CInv(MSG_TX, hashTx), tx);

src/script.cpp

@@ -1719,7 +1719,7 @@ bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CTrans
     return SignSignature(keystore, txout.scriptPubKey, txTo, nIn, nHashType);
 }
 
-bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, bool fStrictEncodings, int nHashType)
+bool VerifySignature(const CCoins& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, bool fStrictEncodings, int nHashType)
 {
     assert(nIn < txTo.vin.size());
     const CTxIn& txin = txTo.vin[nIn];
@@ -1727,9 +1727,6 @@ bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsig
         return false;
     const CTxOut& txout = txFrom.vout[txin.prevout.n];
 
-    if (txin.prevout.hash != txFrom.GetHash())
-        return false;
-
     return VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, fValidatePayToScriptHash, fStrictEncodings, nHashType);
 }
 

src/script.h

@@ -14,6 +14,7 @@
 #include "keystore.h"
 #include "bignum.h"
 
+class CCoins;
 class CTransaction;
 
 /** Signature hash types/flags */
@@ -667,7 +668,7 @@ bool SignSignature(const CKeyStore& keystore, const CScript& fromPubKey, CTransa
 bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
 bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn,
                   bool fValidatePayToScriptHash, bool fStrictEncodings, int nHashType);
-bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, bool fStrictEncodings, int nHashType);
+bool VerifySignature(const CCoins& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, bool fStrictEncodings, int nHashType);
 
 // Given two sets of signatures for scriptPubKey, possibly with OP_0 placeholders,
 // combine them intelligently and return the result.

src/test/DoS_tests.cpp

@@ -278,7 +278,7 @@ BOOST_AUTO_TEST_CASE(DoS_checkSig)
     mst1 = boost::posix_time::microsec_clock::local_time();
     for (unsigned int i = 0; i < 5; i++)
         for (unsigned int j = 0; j < tx.vin.size(); j++)
-            BOOST_CHECK(VerifySignature(orphans[j], tx, j, true, true, SIGHASH_ALL));
+            BOOST_CHECK(VerifySignature(CCoins(orphans[j], MEMPOOL_HEIGHT), tx, j, true, true, SIGHASH_ALL));
     mst2 = boost::posix_time::microsec_clock::local_time();
     msdiff = mst2 - mst1;
     long nManyValidate = msdiff.total_milliseconds();
@@ -289,13 +289,13 @@ BOOST_AUTO_TEST_CASE(DoS_checkSig)
     // Empty a signature, validation should fail:
     CScript save = tx.vin[0].scriptSig;
     tx.vin[0].scriptSig = CScript();
-    BOOST_CHECK(!VerifySignature(orphans[0], tx, 0, true, true, SIGHASH_ALL));
+    BOOST_CHECK(!VerifySignature(CCoins(orphans[0], MEMPOOL_HEIGHT), tx, 0, true, true, SIGHASH_ALL));
     tx.vin[0].scriptSig = save;
 
     // Swap signatures, validation should fail:
     std::swap(tx.vin[0].scriptSig, tx.vin[1].scriptSig);
-    BOOST_CHECK(!VerifySignature(orphans[0], tx, 0, true, true, SIGHASH_ALL));
-    BOOST_CHECK(!VerifySignature(orphans[1], tx, 1, true, true, SIGHASH_ALL));
+    BOOST_CHECK(!VerifySignature(CCoins(orphans[0], MEMPOOL_HEIGHT), tx, 0, true, true, SIGHASH_ALL));
+    BOOST_CHECK(!VerifySignature(CCoins(orphans[1], MEMPOOL_HEIGHT), tx, 1, true, true, SIGHASH_ALL));
     std::swap(tx.vin[0].scriptSig, tx.vin[1].scriptSig);
 
     // Exercise -maxsigcachesize code:
@@ -305,7 +305,7 @@ BOOST_AUTO_TEST_CASE(DoS_checkSig)
     BOOST_CHECK(SignSignature(keystore, orphans[0], tx, 0));
     BOOST_CHECK(tx.vin[0].scriptSig != oldSig);
     for (unsigned int j = 0; j < tx.vin.size(); j++)
-        BOOST_CHECK(VerifySignature(orphans[j], tx, j, true, true, SIGHASH_ALL));
+        BOOST_CHECK(VerifySignature(CCoins(orphans[j], MEMPOOL_HEIGHT), tx, j, true, true, SIGHASH_ALL));
     mapArgs.erase("-maxsigcachesize");
 
     LimitOrphanTxSize(0);

src/test/script_P2SH_tests.cpp

@@ -105,7 +105,7 @@ BOOST_AUTO_TEST_CASE(sign)
         {
             CScript sigSave = txTo[i].vin[0].scriptSig;
             txTo[i].vin[0].scriptSig = txTo[j].vin[0].scriptSig;
-            bool sigOK = VerifySignature(txFrom, txTo[i], 0, true, true, 0);
+            bool sigOK = VerifySignature(CCoins(txFrom, 0), txTo[i], 0, true, true, 0);
             if (i == j)
                 BOOST_CHECK_MESSAGE(sigOK, strprintf("VerifySignature %d %d", i, j));
             else
@@ -243,7 +243,8 @@ BOOST_AUTO_TEST_CASE(switchover)
 
 BOOST_AUTO_TEST_CASE(AreInputsStandard)
 {
-    std::map<uint256, std::pair<CTxIndex, CTransaction> > mapInputs;
+    CCoinsView coinsDummy;
+    CCoinsViewCache coins(coinsDummy);
     CBasicKeyStore keystore;
     CKey key[3];
     vector<CKey> keys;
@@ -264,23 +265,29 @@ BOOST_AUTO_TEST_CASE(AreInputsStandard)
     CScript pay1of3; pay1of3.SetMultisig(1, keys);
 
     txFrom.vout[0].scriptPubKey = payScriptHash1;
+    txFrom.vout[0].nValue = 1000;
     txFrom.vout[1].scriptPubKey = pay1;
+    txFrom.vout[1].nValue = 2000;
     txFrom.vout[2].scriptPubKey = pay1of3;
+    txFrom.vout[2].nValue = 3000;
 
     // Last three non-standard:
     CScript empty;
     keystore.AddCScript(empty);
     txFrom.vout[3].scriptPubKey = empty;
+    txFrom.vout[3].nValue = 4000;
     // Can't use SetPayToScriptHash, it checks for the empty Script. So:
     txFrom.vout[4].scriptPubKey << OP_HASH160 << Hash160(empty) << OP_EQUAL;
+    txFrom.vout[4].nValue = 5000;
     CScript oneOfEleven;
     oneOfEleven << OP_1;
     for (int i = 0; i < 11; i++)
         oneOfEleven << key[0].GetPubKey();
     oneOfEleven << OP_11 << OP_CHECKMULTISIG;
     txFrom.vout[5].scriptPubKey.SetDestination(oneOfEleven.GetID());
+    txFrom.vout[5].nValue = 6000;
 
-    mapInputs[txFrom.GetHash()] = make_pair(CTxIndex(), txFrom);
+    coins.SetCoins(txFrom.GetHash(), CCoins(txFrom, 0));
 
     CTransaction txTo;
     txTo.vout.resize(1);
@@ -297,21 +304,22 @@ BOOST_AUTO_TEST_CASE(AreInputsStandard)
     txTo.vin[2].prevout.hash = txFrom.GetHash();
     BOOST_CHECK(SignSignature(keystore, txFrom, txTo, 2));
 
-    BOOST_CHECK(txTo.AreInputsStandard(mapInputs));
-    BOOST_CHECK_EQUAL(txTo.GetP2SHSigOpCount(mapInputs), 1);
+    BOOST_CHECK(txTo.AreInputsStandard(coins));
+    BOOST_CHECK_EQUAL(txTo.GetP2SHSigOpCount(coins), 1);
 
     // Make sure adding crap to the scriptSigs makes them non-standard:
     for (int i = 0; i < 3; i++)
     {
         CScript t = txTo.vin[i].scriptSig;
         txTo.vin[i].scriptSig = (CScript() << 11) + t;
-        BOOST_CHECK(!txTo.AreInputsStandard(mapInputs));
+        BOOST_CHECK(!txTo.AreInputsStandard(coins));
         txTo.vin[i].scriptSig = t;
     }
 
     CTransaction txToNonStd;
     txToNonStd.vout.resize(1);
     txToNonStd.vout[0].scriptPubKey.SetDestination(key[1].GetPubKey().GetID());
+    txToNonStd.vout[0].nValue = 1000;
     txToNonStd.vin.resize(2);
     txToNonStd.vin[0].prevout.n = 4;
     txToNonStd.vin[0].prevout.hash = txFrom.GetHash();
@@ -320,11 +328,11 @@ BOOST_AUTO_TEST_CASE(AreInputsStandard)
     txToNonStd.vin[1].prevout.hash = txFrom.GetHash();
     txToNonStd.vin[1].scriptSig << OP_0 << Serialize(oneOfEleven);
 
-    BOOST_CHECK(!txToNonStd.AreInputsStandard(mapInputs));
-    BOOST_CHECK_EQUAL(txToNonStd.GetP2SHSigOpCount(mapInputs), 11);
+    BOOST_CHECK(!txToNonStd.AreInputsStandard(coins));
+    BOOST_CHECK_EQUAL(txToNonStd.GetP2SHSigOpCount(coins), 11);
 
     txToNonStd.vin[0].scriptSig.clear();
-    BOOST_CHECK(!txToNonStd.AreInputsStandard(mapInputs));
+    BOOST_CHECK(!txToNonStd.AreInputsStandard(coins));
 }
 
 BOOST_AUTO_TEST_SUITE_END()

src/test/transaction_tests.cpp

@@ -173,7 +173,7 @@ BOOST_AUTO_TEST_CASE(basic_transaction_tests)
 // paid to a TX_PUBKEYHASH.
 //
 static std::vector<CTransaction>
-SetupDummyInputs(CBasicKeyStore& keystoreRet, MapPrevTx& inputsRet)
+SetupDummyInputs(CBasicKeyStore& keystoreRet, CCoinsView & coinsRet)
 {
     std::vector<CTransaction> dummyTransactions;
     dummyTransactions.resize(2);
@@ -192,14 +192,14 @@ SetupDummyInputs(CBasicKeyStore& keystoreRet, MapPrevTx& inputsRet)
     dummyTransactions[0].vout[0].scriptPubKey << key[0].GetPubKey() << OP_CHECKSIG;
     dummyTransactions[0].vout[1].nValue = 50*CENT;
     dummyTransactions[0].vout[1].scriptPubKey << key[1].GetPubKey() << OP_CHECKSIG;
-    inputsRet[dummyTransactions[0].GetHash()] = make_pair(CTxIndex(), dummyTransactions[0]);
+    coinsRet.SetCoins(dummyTransactions[0].GetHash(), CCoins(dummyTransactions[0], 0));
 
     dummyTransactions[1].vout.resize(2);
     dummyTransactions[1].vout[0].nValue = 21*CENT;
     dummyTransactions[1].vout[0].scriptPubKey.SetDestination(key[2].GetPubKey().GetID());
     dummyTransactions[1].vout[1].nValue = 22*CENT;
     dummyTransactions[1].vout[1].scriptPubKey.SetDestination(key[3].GetPubKey().GetID());
-    inputsRet[dummyTransactions[1].GetHash()] = make_pair(CTxIndex(), dummyTransactions[1]);
+    coinsRet.SetCoins(dummyTransactions[1].GetHash(), CCoins(dummyTransactions[1], 0));
 
     return dummyTransactions;
 }
@@ -207,8 +207,9 @@ SetupDummyInputs(CBasicKeyStore& keystoreRet, MapPrevTx& inputsRet)
 BOOST_AUTO_TEST_CASE(test_Get)
 {
     CBasicKeyStore keystore;
-    MapPrevTx dummyInputs;
-    std::vector<CTransaction> dummyTransactions = SetupDummyInputs(keystore, dummyInputs);
+    CCoinsView coinsDummy;
+    CCoinsViewCache coins(coinsDummy);
+    std::vector<CTransaction> dummyTransactions = SetupDummyInputs(keystore, coins);
 
     CTransaction t1;
     t1.vin.resize(3);
@@ -225,25 +226,24 @@ BOOST_AUTO_TEST_CASE(test_Get)
     t1.vout[0].nValue = 90*CENT;
     t1.vout[0].scriptPubKey << OP_1;
 
-    BOOST_CHECK(t1.AreInputsStandard(dummyInputs));
-    BOOST_CHECK_EQUAL(t1.GetValueIn(dummyInputs), (50+21+22)*CENT);
+    BOOST_CHECK(t1.AreInputsStandard(coins));
+    BOOST_CHECK_EQUAL(t1.GetValueIn(coins), (50+21+22)*CENT);
 
     // Adding extra junk to the scriptSig should make it non-standard:
     t1.vin[0].scriptSig << OP_11;
-    BOOST_CHECK(!t1.AreInputsStandard(dummyInputs));
+    BOOST_CHECK(!t1.AreInputsStandard(coins));
 
     // ... as should not having enough:
     t1.vin[0].scriptSig = CScript();
-    BOOST_CHECK(!t1.AreInputsStandard(dummyInputs));
+    BOOST_CHECK(!t1.AreInputsStandard(coins));
 }
 
 BOOST_AUTO_TEST_CASE(test_GetThrow)
 {
     CBasicKeyStore keystore;
-    MapPrevTx dummyInputs;
-    std::vector<CTransaction> dummyTransactions = SetupDummyInputs(keystore, dummyInputs);
-
-    MapPrevTx missingInputs;
+    CCoinsView coinsDummy;
+    CCoinsViewCache coins(coinsDummy);
+    std::vector<CTransaction> dummyTransactions = SetupDummyInputs(keystore, coins);
 
     CTransaction t1;
     t1.vin.resize(3);
@@ -257,8 +257,8 @@ BOOST_AUTO_TEST_CASE(test_GetThrow)
     t1.vout[0].nValue = 90*CENT;
     t1.vout[0].scriptPubKey << OP_1;
 
-    BOOST_CHECK_THROW(t1.AreInputsStandard(missingInputs), runtime_error);
-    BOOST_CHECK_THROW(t1.GetValueIn(missingInputs), runtime_error);
+    BOOST_CHECK_THROW(t1.AreInputsStandard(coinsDummy), runtime_error);
+    BOOST_CHECK_THROW(t1.GetValueIn(coinsDummy), runtime_error);
 }
 
 BOOST_AUTO_TEST_SUITE_END()

src/wallet.cpp

@@ -685,7 +685,7 @@ void CWalletTx::GetAccountAmounts(const string& strAccount, int64& nReceived,
     }
 }
 
-void CWalletTx::AddSupportingTransactions(CTxDB& txdb)
+void CWalletTx::AddSupportingTransactions()
 {
     vtxPrev.clear();
 
@@ -696,7 +696,6 @@ void CWalletTx::AddSupportingTransactions(CTxDB& txdb)
         BOOST_FOREACH(const CTxIn& txin, vin)
             vWorkQueue.push_back(txin.prevout.hash);
 
-        // This critsect is OK because txdb is already open
         {
             LOCK(pwallet->cs_wallet);
             map<uint256, const CMerkleTx*> mapWalletPrev;
@@ -720,15 +719,6 @@ void CWalletTx::AddSupportingTransactions(CTxDB& txdb)
                 {
                     tx = *mapWalletPrev[hash];
                 }
-                else if (!fClient && txdb.ReadDiskTx(hash, tx))
-                {
-                    ;
-                }
-                else
-                {
-                    printf("ERROR: AddSupportingTransactions() : unsupported transaction\n");
-                    continue;
-                }
 
                 int nDepth = tx.SetMerkleBranch();
                 vtxPrev.push_back(tx);
@@ -775,49 +765,36 @@ int CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
     return ret;
 }
 
-int CWallet::ScanForWalletTransaction(const uint256& hashTx)
-{
-    CTransaction tx;
-    tx.ReadFromDisk(COutPoint(hashTx, 0));
-    if (AddToWalletIfInvolvingMe(tx, NULL, true, true))
-        return 1;
-    return 0;
-}
-
 void CWallet::ReacceptWalletTransactions()
 {
-    CTxDB txdb("r");
+    CCoinsDB coinsdb("r");
     bool fRepeat = true;
     while (fRepeat)
     {
         LOCK(cs_wallet);
         fRepeat = false;
-        vector<CDiskTxPos> vMissingTx;
+        bool fMissing = false;
         BOOST_FOREACH(PAIRTYPE(const uint256, CWalletTx)& item, mapWallet)
         {
             CWalletTx& wtx = item.second;
             if (wtx.IsCoinBase() && wtx.IsSpent(0))
                 continue;
 
-            CTxIndex txindex;
+            CCoins coins;
             bool fUpdated = false;
-            if (txdb.ReadTxIndex(wtx.GetHash(), txindex))
+            bool fNotFound = coinsdb.ReadCoins(wtx.GetHash(), coins);
+            if (!fNotFound || wtx.GetDepthInMainChain() > 0)
             {
                 // Update fSpent if a tx got spent somewhere else by a copy of wallet.dat
-                if (txindex.vSpent.size() != wtx.vout.size())
-                {
-                    printf("ERROR: ReacceptWalletTransactions() : txindex.vSpent.size() %"PRIszu" != wtx.vout.size() %"PRIszu"\n", txindex.vSpent.size(), wtx.vout.size());
-                    continue;
-                }
-                for (unsigned int i = 0; i < txindex.vSpent.size(); i++)
+                for (unsigned int i = 0; i < wtx.vout.size(); i++)
                 {
                     if (wtx.IsSpent(i))
                         continue;
-                    if (!txindex.vSpent[i].IsNull() && IsMine(wtx.vout[i]))
+                    if ((i >= coins.vout.size() || coins.vout[i].IsNull()) && IsMine(wtx.vout[i]))
                     {
                         wtx.MarkSpent(i);
                         fUpdated = true;
-                        vMissingTx.push_back(txindex.vSpent[i]);
+                        fMissing = true;
                     }
                 }
                 if (fUpdated)
@@ -831,10 +808,10 @@ void CWallet::ReacceptWalletTransactions()
             {
                 // Re-accept any txes of ours that aren't already in a block
                 if (!wtx.IsCoinBase())
-                    wtx.AcceptWalletTransaction(txdb, false);
+                    wtx.AcceptWalletTransaction(coinsdb, false);
             }
         }
-        if (!vMissingTx.empty())
+        if (fMissing)
         {
             // TODO: optimize this to scan just part of the block chain?
             if (ScanForWalletTransactions(pindexGenesisBlock))
@@ -843,21 +820,21 @@ void CWallet::ReacceptWalletTransactions()
     }
 }
 
-void CWalletTx::RelayWalletTransaction(CTxDB& txdb)
+void CWalletTx::RelayWalletTransaction(CCoinsDB& coinsdb)
 {
     BOOST_FOREACH(const CMerkleTx& tx, vtxPrev)
     {
         if (!tx.IsCoinBase())
         {
             uint256 hash = tx.GetHash();
-            if (!txdb.ContainsTx(hash))
+            if (!coinsdb.HaveCoins(hash))
                 RelayMessage(CInv(MSG_TX, hash), (CTransaction)tx);
         }
     }
     if (!IsCoinBase())
     {
         uint256 hash = GetHash();
-        if (!txdb.ContainsTx(hash))
+        if (!coinsdb.HaveCoins(hash))
         {
             printf("Relaying wtx %s\n", hash.ToString().substr(0,10).c_str());
             RelayMessage(CInv(MSG_TX, hash), (CTransaction)*this);
@@ -867,8 +844,8 @@ void CWalletTx::RelayWalletTransaction(CTxDB& txdb)
 
 void CWalletTx::RelayWalletTransaction()
 {
-   CTxDB txdb("r");
-   RelayWalletTransaction(txdb);
+   CCoinsDB coinsdb("r");
+   RelayWalletTransaction(coinsdb);
 }
 
 void CWallet::ResendWalletTransactions()
@@ -891,7 +868,7 @@ void CWallet::ResendWalletTransactions()
 
     // Rebroadcast any of our txes that aren't in a block yet
     printf("ResendWalletTransactions()\n");
-    CTxDB txdb("r");
+    CCoinsDB coinsdb("r");
     {
         LOCK(cs_wallet);
         // Sort them in chronological order
@@ -907,7 +884,7 @@ void CWallet::ResendWalletTransactions()
         BOOST_FOREACH(PAIRTYPE(const unsigned int, CWalletTx*)& item, mapSorted)
         {
             CWalletTx& wtx = *item.second;
-            wtx.RelayWalletTransaction(txdb);
+            wtx.RelayWalletTransaction(coinsdb);
         }
     }
 }
@@ -1162,8 +1139,6 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
 
     {
         LOCK2(cs_main, cs_wallet);
-        // txdb must be opened before the mapWallet lock
-        CTxDB txdb("r");
         {
             nFeeRet = nTransactionFee;
             loop
@@ -1253,7 +1228,7 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
                 }
 
                 // Fill vtxPrev by copying from previous transactions vtxPrev
-                wtxNew.AddSupportingTransactions(txdb);
+                wtxNew.AddSupportingTransactions();
                 wtxNew.fTimeReceivedIsTxTime = true;
 
                 break;

src/wallet.h

@@ -166,7 +166,6 @@ public:
     bool EraseFromWallet(uint256 hash);
     void WalletUpdateSpent(const CTransaction& prevout);
     int ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate = false);
-    int ScanForWalletTransaction(const uint256& hashTx);
     void ReacceptWalletTransactions();
     void ResendWalletTransactions();
     int64 GetBalance() const;
@@ -659,12 +658,12 @@ public:
     int64 GetTxTime() const;
     int GetRequestCount() const;
 
-    void AddSupportingTransactions(CTxDB& txdb);
+    void AddSupportingTransactions();
 
-    bool AcceptWalletTransaction(CTxDB& txdb, bool fCheckInputs=true);
+    bool AcceptWalletTransaction(CCoinsDB& coinsdb, bool fCheckInputs=true);
     bool AcceptWalletTransaction();
 
-    void RelayWalletTransaction(CTxDB& txdb);
+    void RelayWalletTransaction(CCoinsDB& coinsdb);
     void RelayWalletTransaction();
 };