Merge pull request #295 from svost/patch
[novacoin.git] / src / db.cpp
index 3bdda61..e12e11e 100644 (file)
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2012 The Bitcoin developers
 // Distributed under the MIT/X11 software license, see the accompanying
-// file license.txt or http://www.opensource.org/licenses/mit-license.php.
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "headers.h"
 #include "db.h"
 #include "net.h"
+#include "util.h"
+#include "main.h"
+#include "ui_interface.h"
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/fstream.hpp>
 
+#ifndef WIN32
+#include "sys/stat.h"
+#endif
+
 using namespace std;
 using namespace boost;
 
 
 unsigned int nWalletDBUpdated;
-uint64 nAccountingEntryNumber = 0;
-
+extern bool fUseMemoryLog;
 
 
 //
 // CDB
 //
 
-static CCriticalSection cs_db;
-static bool fDbEnvInit = false;
-DbEnv dbenv(0);
-static map<string, int> mapFileUseCount;
-static map<string, Db*> mapDb;
+CDBEnv bitdb;
 
-static void EnvShutdown()
+void CDBEnv::EnvShutdown()
 {
     if (!fDbEnvInit)
         return;
 
     fDbEnvInit = false;
-    try
-    {
-        dbenv.close(0);
-    }
-    catch (const DbException& e)
+    int ret = dbenv.close(0);
+    if (ret != 0)
+        printf("EnvShutdown exception: %s (%d)\n", DbEnv::strerror(ret), ret);
+    if (!fMockDb)
+        DbEnv(0).remove(strPath.c_str(), 0);
+}
+
+CDBEnv::CDBEnv() : fDetachDB(false), fDbEnvInit(false), fMockDb(false), dbenv(DB_CXX_NO_EXCEPTIONS) { }
+
+CDBEnv::~CDBEnv()
+{
+    EnvShutdown();
+}
+
+void CDBEnv::Close()
+{
+    EnvShutdown();
+}
+
+bool CDBEnv::Open(boost::filesystem::path pathEnv_)
+{
+    if (fDbEnvInit)
+        return true;
+
+    if (fShutdown)
+        return false;
+
+    pathEnv = pathEnv_;
+    filesystem::path pathDataDir = pathEnv;
+    strPath = pathDataDir.string();
+    filesystem::path pathLogDir = pathDataDir / "database";
+    filesystem::create_directory(pathLogDir);
+    filesystem::path pathErrorFile = pathDataDir / "db.log";
+    printf("dbenv.open LogDir=%s ErrorFile=%s\n", pathLogDir.string().c_str(), pathErrorFile.string().c_str());
+
+    unsigned int nEnvFlags = 0;
+    if (GetBoolArg("-privdb", true))
+        nEnvFlags |= DB_PRIVATE;
+
+    int nDbCache = GetArgInt("-dbcache", 25);
+    dbenv.set_lg_dir(pathLogDir.string().c_str());
+    dbenv.set_cachesize(nDbCache / 1024, (nDbCache % 1024)*1048576, 1);
+    dbenv.set_lg_bsize(1048576);
+    dbenv.set_lg_max(10485760);
+
+    // Bugfix: Bump lk_max_locks default to 537000, to safely handle reorgs with up to 5 blocks reversed
+    // dbenv.set_lk_max_locks(10000);
+    dbenv.set_lk_max_locks(537000);
+
+    dbenv.set_lk_max_objects(10000);
+    dbenv.set_errfile(fopen(pathErrorFile.string().c_str(), "a")); /// debug
+    dbenv.set_flags(DB_AUTO_COMMIT, 1);
+    dbenv.set_flags(DB_TXN_WRITE_NOSYNC, 1);
+#ifdef DB_LOG_AUTO_REMOVE
+    dbenv.log_set_config(DB_LOG_AUTO_REMOVE, 1);
+#endif
+    int ret = dbenv.open(strPath.c_str(),
+                     DB_CREATE     |
+                     DB_INIT_LOCK  |
+                     DB_INIT_LOG   |
+                     DB_INIT_MPOOL |
+                     DB_INIT_TXN   |
+                     DB_THREAD     |
+                     DB_RECOVER    |
+                     nEnvFlags,
+                     S_IRUSR | S_IWUSR);
+    if (ret != 0)
+        return error("CDB() : error %s (%d) opening database environment", DbEnv::strerror(ret), ret);
+
+    fDbEnvInit = true;
+    fMockDb = false;
+
+#ifndef USE_LEVELDB
+    // Check that the number of locks is sufficient (to prevent chain fork possibility, read http://bitcoin.org/may15 for more info)
+    u_int32_t nMaxLocks;
+    if (!dbenv.get_lk_max_locks(&nMaxLocks))
     {
-        printf("EnvShutdown exception: %s (%d)\n", e.what(), e.get_errno());
+        int nBlocks, nDeepReorg;
+        std::string strMessage;
+
+        nBlocks = nMaxLocks / 48768;
+        nDeepReorg = (nBlocks - 1) / 2;
+
+        printf("Final lk_max_locks is %u, sufficient for (worst case) %d block%s in a single transaction (up to a %d-deep reorganization)\n", nMaxLocks, nBlocks, (nBlocks == 1) ? "" : "s", nDeepReorg);
+        if (nDeepReorg < 3)
+        {
+            if (nBlocks < 1)
+                strMessage = strprintf(_("Warning: DB_CONFIG has set_lk_max_locks %u, which may be too low for a single block. If this limit is reached, NovaCoin may stop working."), nMaxLocks);
+            else
+                strMessage = strprintf(_("Warning: DB_CONFIG has set_lk_max_locks %u, which may be too low for a common blockchain reorganization. If this limit is reached, NovaCoin may stop working."), nMaxLocks);
+
+            strMiscWarning = strMessage;
+            printf("*** %s\n", strMessage.c_str());
+        }
     }
-    DbEnv(0).remove(GetDataDir().c_str(), 0);
+#endif
+
+    return true;
+}
+
+void CDBEnv::MakeMock()
+{
+    if (fDbEnvInit)
+        throw runtime_error("CDBEnv::MakeMock(): already initialized");
+
+    if (fShutdown)
+        throw runtime_error("CDBEnv::MakeMock(): during shutdown");
+
+    printf("CDBEnv::MakeMock()\n");
+
+    dbenv.set_cachesize(1, 0, 1);
+    dbenv.set_lg_bsize(10485760*4);
+    dbenv.set_lg_max(10485760);
+    dbenv.set_lk_max_locks(10000);
+    dbenv.set_lk_max_objects(10000);
+    dbenv.set_flags(DB_AUTO_COMMIT, 1);
+#ifdef DB_LOG_IN_MEMORY
+    dbenv.log_set_config(DB_LOG_IN_MEMORY, fUseMemoryLog ? 1 : 0);
+#endif
+    int ret = dbenv.open(NULL,
+                     DB_CREATE     |
+                     DB_INIT_LOCK  |
+                     DB_INIT_LOG   |
+                     DB_INIT_MPOOL |
+                     DB_INIT_TXN   |
+                     DB_THREAD     |
+                     DB_PRIVATE,
+                     S_IRUSR | S_IWUSR);
+    if (ret > 0)
+        throw runtime_error(strprintf("CDBEnv::MakeMock(): error %d opening database environment", ret));
+
+    fDbEnvInit = true;
+    fMockDb = true;
+}
+
+CDBEnv::VerifyResult CDBEnv::Verify(std::string strFile, bool (*recoverFunc)(CDBEnv& dbenv, std::string strFile))
+{
+    LOCK(cs_db);
+    assert(mapFileUseCount.count(strFile) == 0);
+
+    Db db(&dbenv, 0);
+    int result = db.verify(strFile.c_str(), NULL, NULL, 0);
+    if (result == 0)
+        return VERIFY_OK;
+    else if (recoverFunc == NULL)
+        return RECOVER_FAIL;
+
+    // Try to recover:
+    bool fRecovered = (*recoverFunc)(*this, strFile);
+    return (fRecovered ? RECOVER_OK : RECOVER_FAIL);
 }
 
-class CDBInit
+bool CDBEnv::Salvage(std::string strFile, bool fAggressive,
+                     std::vector<CDBEnv::KeyValPair >& vResult)
 {
-public:
-    CDBInit()
+    LOCK(cs_db);
+    assert(mapFileUseCount.count(strFile) == 0);
+
+    u_int32_t flags = DB_SALVAGE;
+    if (fAggressive) flags |= DB_AGGRESSIVE;
+
+    stringstream strDump;
+
+    Db db(&dbenv, 0);
+    int result = db.verify(strFile.c_str(), NULL, &strDump, flags);
+    if (result != 0)
     {
+        printf("ERROR: db salvage failed\n");
+        return false;
     }
-    ~CDBInit()
+
+    // Format of bdb dump is ascii lines:
+    // header lines...
+    // HEADER=END
+    // hexadecimal key
+    // hexadecimal value
+    // ... repeated
+    // DATA=END
+
+    string strLine;
+    while (!strDump.eof() && strLine != "HEADER=END")
+        getline(strDump, strLine); // Skip past header
+
+    std::string keyHex, valueHex;
+    while (!strDump.eof() && keyHex != "DATA=END")
     {
-        EnvShutdown();
+        getline(strDump, keyHex);
+        if (keyHex != "DATA=END")
+        {
+            getline(strDump, valueHex);
+            vResult.push_back(make_pair(ParseHex(keyHex),ParseHex(valueHex)));
+        }
     }
+
+    return (result == 0);
 }
-instance_of_cdbinit;
 
 
-CDB::CDB(const char* pszFile, const char* pszMode) : pdb(NULL)
+void CDBEnv::CheckpointLSN(std::string strFile)
+{
+    dbenv.txn_checkpoint(0, 0, 0);
+    if (fMockDb)
+        return;
+    dbenv.lsn_reset(strFile.c_str(), 0);
+}
+
+
+CDB::CDB(const char *pszFile, const char* pszMode) :
+    pdb(NULL), activeTxn(NULL)
 {
     int ret;
     if (pszFile == NULL)
         return;
 
     fReadOnly = (!strchr(pszMode, '+') && !strchr(pszMode, 'w'));
-    bool fCreate = strchr(pszMode, 'c');
+    bool fCreate = strchr(pszMode, 'c') != NULL;
     unsigned int nFlags = DB_THREAD;
     if (fCreate)
         nFlags |= DB_CREATE;
 
-    CRITICAL_BLOCK(cs_db)
     {
-        if (!fDbEnvInit)
-        {
-            if (fShutdown)
-                return;
-            string strDataDir = GetDataDir();
-            string strLogDir = strDataDir + "/database";
-            filesystem::create_directory(strLogDir.c_str());
-            string strErrorFile = strDataDir + "/db.log";
-            printf("dbenv.open strLogDir=%s strErrorFile=%s\n", strLogDir.c_str(), strErrorFile.c_str());
-
-            dbenv.set_lg_dir(strLogDir.c_str());
-            dbenv.set_lg_max(10000000);
-            dbenv.set_lk_max_locks(10000);
-            dbenv.set_lk_max_objects(10000);
-            dbenv.set_errfile(fopen(strErrorFile.c_str(), "a")); /// debug
-            dbenv.set_flags(DB_AUTO_COMMIT, 1);
-            ret = dbenv.open(strDataDir.c_str(),
-                             DB_CREATE     |
-                             DB_INIT_LOCK  |
-                             DB_INIT_LOG   |
-                             DB_INIT_MPOOL |
-                             DB_INIT_TXN   |
-                             DB_THREAD     |
-                             DB_RECOVER,
-                             S_IRUSR | S_IWUSR);
-            if (ret > 0)
-                throw runtime_error(strprintf("CDB() : error %d opening database environment", ret));
-            fDbEnvInit = true;
-        }
+        LOCK(bitdb.cs_db);
+        if (!bitdb.Open(GetDataDir()))
+            throw runtime_error("env open failed");
 
         strFile = pszFile;
-        ++mapFileUseCount[strFile];
-        pdb = mapDb[strFile];
+        ++bitdb.mapFileUseCount[strFile];
+        pdb = bitdb.mapDb[strFile];
         if (pdb == NULL)
         {
-            pdb = new Db(&dbenv, 0);
+            pdb = new Db(&bitdb.dbenv, 0);
+
+            bool fMockDb = bitdb.IsMock();
+            if (fMockDb)
+            {
+                DbMpoolFile*mpf = pdb->get_mpf();
+                ret = mpf->set_flags(DB_MPOOL_NOFILE, 1);
+                if (ret != 0)
+                    throw runtime_error(strprintf("CDB() : failed to configure for no temp file backing for database %s", pszFile));
+            }
 
             ret = pdb->open(NULL,      // Txn pointer
-                            pszFile,   // Filename
+                            fMockDb ? NULL : pszFile,   // Filename
                             "main",    // Logical db name
                             DB_BTREE,  // Database type
                             nFlags,    // Flags
                             0);
 
-            if (ret > 0)
+            if (ret != 0)
             {
                 delete pdb;
                 pdb = NULL;
-                CRITICAL_BLOCK(cs_db)
-                    --mapFileUseCount[strFile];
-                strFile = "";
+                --bitdb.mapFileUseCount[strFile];
+                strFile.clear();
                 throw runtime_error(strprintf("CDB() : can't open database file %s, error %d", pszFile, ret));
             }
 
@@ -135,38 +300,49 @@ CDB::CDB(const char* pszFile, const char* pszMode) : pdb(NULL)
                 fReadOnly = fTmp;
             }
 
-            mapDb[strFile] = pdb;
+            bitdb.mapDb[strFile] = pdb;
         }
     }
 }
 
+static bool IsChainFile(std::string strFile)
+{
+    if (strFile == "blkindex.dat")
+        return true;
+
+    return false;
+}
+
 void CDB::Close()
 {
     if (!pdb)
         return;
-    if (!vTxn.empty())
-        vTxn.front()->abort();
-    vTxn.clear();
+    if (activeTxn)
+        activeTxn->abort();
+    activeTxn = NULL;
     pdb = NULL;
 
     // Flush database activity from memory pool to disk log
     unsigned int nMinutes = 0;
     if (fReadOnly)
         nMinutes = 1;
-    if (strFile == "addr.dat")
+    if (IsChainFile(strFile))
         nMinutes = 2;
-    if (strFile == "blkindex.dat" && IsInitialBlockDownload() && nBestHeight % 500 != 0)
-        nMinutes = 1;
-    dbenv.txn_checkpoint(0, nMinutes, 0);
+    if (IsChainFile(strFile) && IsInitialBlockDownload())
+        nMinutes = 5;
+
+    bitdb.dbenv.txn_checkpoint(nMinutes ? GetArgUInt("-dblogsize", 100)*1024 : 0, nMinutes, 0);
 
-    CRITICAL_BLOCK(cs_db)
-        --mapFileUseCount[strFile];
+    {
+        LOCK(bitdb.cs_db);
+        --bitdb.mapFileUseCount[strFile];
+    }
 }
 
-void static CloseDb(const string& strFile)
+void CDBEnv::CloseDb(const string& strFile)
 {
-    CRITICAL_BLOCK(cs_db)
     {
+        LOCK(cs_db);
         if (mapDb[strFile] != NULL)
         {
             // Close the database handle
@@ -178,27 +354,35 @@ void static CloseDb(const string& strFile)
     }
 }
 
+bool CDBEnv::RemoveDb(const string& strFile)
+{
+    this->CloseDb(strFile);
+
+    LOCK(cs_db);
+    int rc = dbenv.dbremove(NULL, strFile.c_str(), NULL, DB_AUTO_COMMIT);
+    return (rc == 0);
+}
+
 bool CDB::Rewrite(const string& strFile, const char* pszSkip)
 {
     while (!fShutdown)
     {
-        CRITICAL_BLOCK(cs_db)
         {
-            if (!mapFileUseCount.count(strFile) || mapFileUseCount[strFile] == 0)
+            LOCK(bitdb.cs_db);
+            if (!bitdb.mapFileUseCount.count(strFile) || bitdb.mapFileUseCount[strFile] == 0)
             {
                 // Flush log data to the dat file
-                CloseDb(strFile);
-                dbenv.txn_checkpoint(0, 0, 0);
-                dbenv.lsn_reset(strFile.c_str(), 0);
-                mapFileUseCount.erase(strFile);
+                bitdb.CloseDb(strFile);
+                bitdb.CheckpointLSN(strFile);
+                bitdb.mapFileUseCount.erase(strFile);
 
                 bool fSuccess = true;
                 printf("Rewriting %s...\n", strFile.c_str());
                 string strFileRes = strFile + ".rewrite";
                 { // surround usage of db with extra {}
                     CDB db(strFile.c_str(), "r");
-                    Db* pdbCopy = new Db(&dbenv, 0);
-    
+                    Db* pdbCopy = new Db(&bitdb.dbenv, 0);
+
                     int ret = pdbCopy->open(NULL,                 // Txn pointer
                                             strFileRes.c_str(),   // Filename
                                             "main",    // Logical db name
@@ -210,13 +394,13 @@ bool CDB::Rewrite(const string& strFile, const char* pszSkip)
                         printf("Cannot create database file %s\n", strFileRes.c_str());
                         fSuccess = false;
                     }
-    
+
                     Dbc* pcursor = db.GetCursor();
-                    if (pcursor)
+                    if (pcursor) {
                         while (fSuccess)
                         {
-                            CDataStream ssKey;
-                            CDataStream ssValue;
+                            CDataStream ssKey(SER_DISK, CLIENT_VERSION);
+                            CDataStream ssValue(SER_DISK, CLIENT_VERSION);
                             int ret = db.ReadAtCursor(pcursor, ssKey, ssValue, DB_NEXT);
                             if (ret == DB_NOTFOUND)
                             {
@@ -229,9 +413,14 @@ bool CDB::Rewrite(const string& strFile, const char* pszSkip)
                                 fSuccess = false;
                                 break;
                             }
-                            if (pszSkip &&
-                                strncmp(&ssKey[0], pszSkip, std::min(ssKey.size(), strlen(pszSkip))) == 0)
-                                continue;
+
+                            if (pszSkip != NULL)
+                            {
+                                size_t pszSkipLen = strlen(pszSkip);
+                                if (strncmp(&ssKey[0], pszSkip, std::min(ssKey.size(), pszSkipLen)) == 0)
+                                    continue;
+                            }
+
                             if (strncmp(&ssKey[0], "\x07version", 8) == 0)
                             {
                                 // Update version:
@@ -244,10 +433,11 @@ bool CDB::Rewrite(const string& strFile, const char* pszSkip)
                             if (ret2 > 0)
                                 fSuccess = false;
                         }
+                    }
                     if (fSuccess)
                     {
                         db.Close();
-                        CloseDb(strFile);
+                        bitdb.CloseDb(strFile);
                         if (pdbCopy->close(0))
                             fSuccess = false;
                         delete pdbCopy;
@@ -255,10 +445,10 @@ bool CDB::Rewrite(const string& strFile, const char* pszSkip)
                 }
                 if (fSuccess)
                 {
-                    Db dbA(&dbenv, 0);
+                    Db dbA(&bitdb.dbenv, 0);
                     if (dbA.remove(strFile.c_str(), NULL, 0))
                         fSuccess = false;
-                    Db dbB(&dbenv, 0);
+                    Db dbB(&bitdb.dbenv, 0);
                     if (dbB.rename(strFileRes.c_str(), NULL, strFile.c_str(), 0))
                         fSuccess = false;
                 }
@@ -273,15 +463,16 @@ bool CDB::Rewrite(const string& strFile, const char* pszSkip)
 }
 
 
-void DBFlush(bool fShutdown)
+void CDBEnv::Flush(bool fShutdown)
 {
+    int64_t nStart = GetTimeMillis();
     // Flush log data to the actual data file
     //  on all files that are not in use
-    printf("DBFlush(%s)%s\n", fShutdown ? "true" : "false", fDbEnvInit ? "" : " db not started");
+    printf("Flush(%s)%s\n", fShutdown ? "true" : "false", fDbEnvInit ? "" : " db not started");
     if (!fDbEnvInit)
         return;
-    CRITICAL_BLOCK(cs_db)
     {
+        LOCK(cs_db);
         map<string, int>::iterator mi = mapFileUseCount.begin();
         while (mi != mapFileUseCount.end())
         {
@@ -292,789 +483,131 @@ void DBFlush(bool fShutdown)
             {
                 // Move log data to the dat file
                 CloseDb(strFile);
+                printf("%s checkpoint\n", strFile.c_str());
                 dbenv.txn_checkpoint(0, 0, 0);
-                printf("%s flush\n", strFile.c_str());
-                dbenv.lsn_reset(strFile.c_str(), 0);
+                if (!IsChainFile(strFile) || fDetachDB) {
+                    printf("%s detach\n", strFile.c_str());
+                    if (!fMockDb)
+                        dbenv.lsn_reset(strFile.c_str(), 0);
+                }
+                printf("%s closed\n", strFile.c_str());
                 mapFileUseCount.erase(mi++);
             }
             else
                 mi++;
         }
+        printf("DBFlush(%s)%s ended %15" PRId64 "ms\n", fShutdown ? "true" : "false", fDbEnvInit ? "" : " db not started", GetTimeMillis() - nStart);
         if (fShutdown)
         {
             char** listp;
             if (mapFileUseCount.empty())
             {
                 dbenv.log_archive(&listp, DB_ARCH_REMOVE);
-                EnvShutdown();
+                Close();
             }
         }
     }
 }
 
 
-
-
-
-
 //
-// CTxDB
+// CAddrDB
 //
 
-bool CTxDB::ReadTxIndex(uint256 hash, CTxIndex& txindex)
-{
-    assert(!fClient);
-    txindex.SetNull();
-    return Read(make_pair(string("tx"), hash), txindex);
-}
 
-bool CTxDB::UpdateTxIndex(uint256 hash, const CTxIndex& txindex)
+CAddrDB::CAddrDB()
 {
-    assert(!fClient);
-    return Write(make_pair(string("tx"), hash), txindex);
+    pathAddr = GetDataDir() / "peers.dat";
 }
 
-bool CTxDB::AddTxIndex(const CTransaction& tx, const CDiskTxPos& pos, int nHeight)
+bool CAddrDB::Write(const CAddrMan& addr)
 {
-    assert(!fClient);
+    // Generate random temporary filename
+    unsigned short randv = 0;
+    RAND_bytes((unsigned char *)&randv, sizeof(randv));
+    std::string tmpfn = strprintf("peers.dat.%04x", randv);
 
-    // Add to tx index
-    uint256 hash = tx.GetHash();
-    CTxIndex txindex(pos, tx.vout.size());
-    return Write(make_pair(string("tx"), hash), txindex);
-}
-
-bool CTxDB::EraseTxIndex(const CTransaction& tx)
-{
-    assert(!fClient);
-    uint256 hash = tx.GetHash();
-
-    return Erase(make_pair(string("tx"), hash));
-}
+    // serialize addresses, checksum data up to that point, then append csum
+    CDataStream ssPeers(SER_DISK, CLIENT_VERSION);
+    ssPeers << FLATDATA(pchMessageStart);
+    ssPeers << addr;
+    uint256 hash = Hash(ssPeers.begin(), ssPeers.end());
+    ssPeers << hash;
 
-bool CTxDB::ContainsTx(uint256 hash)
-{
-    assert(!fClient);
-    return Exists(make_pair(string("tx"), hash));
-}
+    // open temp output file, and associate with CAutoFile
+    boost::filesystem::path pathTmp = GetDataDir() / tmpfn;
+    FILE *file = fopen(pathTmp.string().c_str(), "wb");
+    CAutoFile fileout = CAutoFile(file, SER_DISK, CLIENT_VERSION);
+    if (!fileout)
+        return error("CAddrman::Write() : open failed");
 
-bool CTxDB::ReadOwnerTxes(uint160 hash160, int nMinHeight, vector<CTransaction>& vtx)
-{
-    assert(!fClient);
-    vtx.clear();
-
-    // Get cursor
-    Dbc* pcursor = GetCursor();
-    if (!pcursor)
-        return false;
-
-    unsigned int fFlags = DB_SET_RANGE;
-    loop
-    {
-        // Read next record
-        CDataStream ssKey;
-        if (fFlags == DB_SET_RANGE)
-            ssKey << string("owner") << hash160 << CDiskTxPos(0, 0, 0);
-        CDataStream ssValue;
-        int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
-        fFlags = DB_NEXT;
-        if (ret == DB_NOTFOUND)
-            break;
-        else if (ret != 0)
-        {
-            pcursor->close();
-            return false;
-        }
-
-        // Unserialize
-        string strType;
-        uint160 hashItem;
-        CDiskTxPos pos;
-        ssKey >> strType >> hashItem >> pos;
-        int nItemHeight;
-        ssValue >> nItemHeight;
-
-        // Read transaction
-        if (strType != "owner" || hashItem != hash160)
-            break;
-        if (nItemHeight >= nMinHeight)
-        {
-            vtx.resize(vtx.size()+1);
-            if (!vtx.back().ReadFromDisk(pos))
-            {
-                pcursor->close();
-                return false;
-            }
-        }
+    // Write and commit header, data
+    try {
+        fileout << ssPeers;
     }
-
-    pcursor->close();
-    return true;
-}
-
-bool CTxDB::ReadDiskTx(uint256 hash, CTransaction& tx, CTxIndex& txindex)
-{
-    assert(!fClient);
-    tx.SetNull();
-    if (!ReadTxIndex(hash, txindex))
-        return false;
-    return (tx.ReadFromDisk(txindex.pos));
-}
-
-bool CTxDB::ReadDiskTx(uint256 hash, CTransaction& tx)
-{
-    CTxIndex txindex;
-    return ReadDiskTx(hash, tx, txindex);
-}
-
-bool CTxDB::ReadDiskTx(COutPoint outpoint, CTransaction& tx, CTxIndex& txindex)
-{
-    return ReadDiskTx(outpoint.hash, tx, txindex);
-}
-
-bool CTxDB::ReadDiskTx(COutPoint outpoint, CTransaction& tx)
-{
-    CTxIndex txindex;
-    return ReadDiskTx(outpoint.hash, tx, txindex);
-}
-
-bool CTxDB::WriteBlockIndex(const CDiskBlockIndex& blockindex)
-{
-    return Write(make_pair(string("blockindex"), blockindex.GetBlockHash()), blockindex);
-}
-
-bool CTxDB::EraseBlockIndex(uint256 hash)
-{
-    return Erase(make_pair(string("blockindex"), hash));
-}
-
-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);
-}
-
-CBlockIndex static * InsertBlockIndex(uint256 hash)
-{
-    if (hash == 0)
-        return NULL;
-
-    // Return existing
-    map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hash);
-    if (mi != mapBlockIndex.end())
-        return (*mi).second;
-
-    // Create new
-    CBlockIndex* pindexNew = new CBlockIndex();
-    if (!pindexNew)
-        throw runtime_error("LoadBlockIndex() : new CBlockIndex failed");
-    mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
-    pindexNew->phashBlock = &((*mi).first);
-
-    return pindexNew;
-}
-
-bool CTxDB::LoadBlockIndex()
-{
-    // Get database cursor
-    Dbc* pcursor = GetCursor();
-    if (!pcursor)
-        return false;
-
-    // Load mapBlockIndex
-    unsigned int fFlags = DB_SET_RANGE;
-    loop
-    {
-        // Read next record
-        CDataStream ssKey;
-        if (fFlags == DB_SET_RANGE)
-            ssKey << make_pair(string("blockindex"), uint256(0));
-        CDataStream ssValue;
-        int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
-        fFlags = DB_NEXT;
-        if (ret == DB_NOTFOUND)
-            break;
-        else if (ret != 0)
-            return false;
-
-        // Unserialize
-        string strType;
-        ssKey >> strType;
-        if (strType == "blockindex")
-        {
-            CDiskBlockIndex diskindex;
-            ssValue >> diskindex;
-
-            // Construct block index object
-            CBlockIndex* pindexNew = InsertBlockIndex(diskindex.GetBlockHash());
-            pindexNew->pprev          = InsertBlockIndex(diskindex.hashPrev);
-            pindexNew->pnext          = InsertBlockIndex(diskindex.hashNext);
-            pindexNew->nFile          = diskindex.nFile;
-            pindexNew->nBlockPos      = diskindex.nBlockPos;
-            pindexNew->nHeight        = diskindex.nHeight;
-            pindexNew->nVersion       = diskindex.nVersion;
-            pindexNew->hashMerkleRoot = diskindex.hashMerkleRoot;
-            pindexNew->nTime          = diskindex.nTime;
-            pindexNew->nBits          = diskindex.nBits;
-            pindexNew->nNonce         = diskindex.nNonce;
-
-            // Watch for genesis block
-            if (pindexGenesisBlock == NULL && diskindex.GetBlockHash() == hashGenesisBlock)
-                pindexGenesisBlock = pindexNew;
-
-            if (!pindexNew->CheckIndex())
-                return error("LoadBlockIndex() : CheckIndex failed at %d", pindexNew->nHeight);
-        }
-        else
-        {
-            break;
-        }
-    }
-    pcursor->close();
-
-    // Calculate bnChainWork
-    vector<pair<int, CBlockIndex*> > vSortedByHeight;
-    vSortedByHeight.reserve(mapBlockIndex.size());
-    BOOST_FOREACH(const PAIRTYPE(uint256, CBlockIndex*)& item, mapBlockIndex)
-    {
-        CBlockIndex* pindex = item.second;
-        vSortedByHeight.push_back(make_pair(pindex->nHeight, pindex));
-    }
-    sort(vSortedByHeight.begin(), vSortedByHeight.end());
-    BOOST_FOREACH(const PAIRTYPE(int, CBlockIndex*)& item, vSortedByHeight)
-    {
-        CBlockIndex* pindex = item.second;
-        pindex->bnChainWork = (pindex->pprev ? pindex->pprev->bnChainWork : 0) + pindex->GetBlockWork();
+    catch (const std::exception&) {
+        return error("CAddrman::Write() : I/O error");
     }
+    FileCommit(fileout);
+    fileout.fclose();
 
-    // Load hashBestChain pointer to end of best chain
-    if (!ReadHashBestChain(hashBestChain))
-    {
-        if (pindexGenesisBlock == NULL)
-            return true;
-        return error("CTxDB::LoadBlockIndex() : hashBestChain not loaded");
-    }
-    if (!mapBlockIndex.count(hashBestChain))
-        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\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight);
-
-    // Load bnBestInvalidWork, OK if it doesn't exist
-    ReadBestInvalidWork(bnBestInvalidWork);
-
-    // Verify blocks in the best chain
-    CBlockIndex* pindexFork = NULL;
-    for (CBlockIndex* pindex = pindexBest; pindex && pindex->pprev; pindex = pindex->pprev)
-    {
-        if (pindex->nHeight < nBestHeight-2500 && !mapArgs.count("-checkblocks"))
-            break;
-        CBlock block;
-        if (!block.ReadFromDisk(pindex))
-            return error("LoadBlockIndex() : block.ReadFromDisk failed");
-        if (!block.CheckBlock())
-        {
-            printf("LoadBlockIndex() : *** found bad block at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
-            pindexFork = pindex->pprev;
-        }
-    }
-    if (pindexFork)
-    {
-        // 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);
-    }
+    // replace existing peers.dat, if any, with new peers.dat.XXXX
+    if (!RenameOver(pathTmp, pathAddr))
+        return error("CAddrman::Write() : Rename-into-place failed");
 
     return true;
 }
 
-
-
-
-
-//
-// CAddrDB
-//
-
-bool CAddrDB::WriteAddress(const CAddress& addr)
+bool CAddrDB::Read(CAddrMan& addr)
 {
-    return Write(make_pair(string("addr"), addr.GetKey()), addr);
-}
+    // open input file, and associate with CAutoFile
+    FILE *file = fopen(pathAddr.string().c_str(), "rb");
+    CAutoFile filein = CAutoFile(file, SER_DISK, CLIENT_VERSION);
+    if (!filein)
+        return error("CAddrman::Read() : open failed");
 
-bool CAddrDB::EraseAddress(const CAddress& addr)
-{
-    return Erase(make_pair(string("addr"), addr.GetKey()));
-}
+    // use file size to size memory buffer
+    int fileSize = GetFilesize(filein);
+    int dataSize = fileSize - sizeof(uint256);
+    //Don't try to resize to a negative number if file is small
+    if ( dataSize < 0 ) dataSize = 0;
+    vector<unsigned char> vchData;
+    vchData.resize(dataSize);
+    uint256 hashIn;
 
-bool CAddrDB::LoadAddresses()
-{
-    CRITICAL_BLOCK(cs_mapAddresses)
-    {
-        // Get cursor
-        Dbc* pcursor = GetCursor();
-        if (!pcursor)
-            return false;
-
-        loop
-        {
-            // Read next record
-            CDataStream ssKey;
-            CDataStream ssValue;
-            int ret = ReadAtCursor(pcursor, ssKey, ssValue);
-            if (ret == DB_NOTFOUND)
-                break;
-            else if (ret != 0)
-                return false;
-
-            // Unserialize
-            string strType;
-            ssKey >> strType;
-            if (strType == "addr")
-            {
-                CAddress addr;
-                ssValue >> addr;
-                mapAddresses.insert(make_pair(addr.GetKey(), addr));
-            }
-        }
-        pcursor->close();
-
-        printf("Loaded %d addresses\n", mapAddresses.size());
+    // read data and checksum from file
+    try {
+        filein.read((char *)&vchData[0], dataSize);
+        filein >> hashIn;
     }
-
-    return true;
-}
-
-bool LoadAddresses()
-{
-    return CAddrDB("cr+").LoadAddresses();
-}
-
-
-
-
-//
-// CWalletDB
-//
-
-bool CWalletDB::WriteName(const string& strAddress, const string& strName)
-{
-    nWalletDBUpdated++;
-    return Write(make_pair(string("name"), strAddress), strName);
-}
-
-bool CWalletDB::EraseName(const string& strAddress)
-{
-    // This should only be used for sending addresses, never for receiving addresses,
-    // receiving addresses must always have an address book entry if they're not change return.
-    nWalletDBUpdated++;
-    return Erase(make_pair(string("name"), strAddress));
-}
-
-bool CWalletDB::ReadAccount(const string& strAccount, CAccount& account)
-{
-    account.SetNull();
-    return Read(make_pair(string("acc"), strAccount), account);
-}
-
-bool CWalletDB::WriteAccount(const string& strAccount, const CAccount& account)
-{
-    return Write(make_pair(string("acc"), strAccount), account);
-}
-
-bool CWalletDB::WriteAccountingEntry(const CAccountingEntry& acentry)
-{
-    return Write(boost::make_tuple(string("acentry"), acentry.strAccount, ++nAccountingEntryNumber), acentry);
-}
-
-int64 CWalletDB::GetAccountCreditDebit(const string& strAccount)
-{
-    list<CAccountingEntry> entries;
-    ListAccountCreditDebit(strAccount, entries);
-
-    int64 nCreditDebit = 0;
-    BOOST_FOREACH (const CAccountingEntry& entry, entries)
-        nCreditDebit += entry.nCreditDebit;
-
-    return nCreditDebit;
-}
-
-void CWalletDB::ListAccountCreditDebit(const string& strAccount, list<CAccountingEntry>& entries)
-{
-    bool fAllAccounts = (strAccount == "*");
-
-    Dbc* pcursor = GetCursor();
-    if (!pcursor)
-        throw runtime_error("CWalletDB::ListAccountCreditDebit() : cannot create DB cursor");
-    unsigned int fFlags = DB_SET_RANGE;
-    loop
-    {
-        // Read next record
-        CDataStream ssKey;
-        if (fFlags == DB_SET_RANGE)
-            ssKey << boost::make_tuple(string("acentry"), (fAllAccounts? string("") : strAccount), uint64(0));
-        CDataStream ssValue;
-        int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
-        fFlags = DB_NEXT;
-        if (ret == DB_NOTFOUND)
-            break;
-        else if (ret != 0)
-        {
-            pcursor->close();
-            throw runtime_error("CWalletDB::ListAccountCreditDebit() : error scanning DB");
-        }
-
-        // Unserialize
-        string strType;
-        ssKey >> strType;
-        if (strType != "acentry")
-            break;
-        CAccountingEntry acentry;
-        ssKey >> acentry.strAccount;
-        if (!fAllAccounts && acentry.strAccount != strAccount)
-            break;
-
-        ssValue >> acentry;
-        entries.push_back(acentry);
+    catch (const std::exception&) {
+        return error("CAddrman::Read() 2 : I/O error or stream data corrupted");
     }
+    filein.fclose();
 
-    pcursor->close();
-}
-
-
-int CWalletDB::LoadWallet(CWallet* pwallet)
-{
-    pwallet->vchDefaultKey.clear();
-    int nFileVersion = 0;
-    vector<uint256> vWalletUpgrade;
-    bool fIsEncrypted = false;
-
-    // Modify defaults
-#ifndef WIN32
-    // Tray icon sometimes disappears on 9.10 karmic koala 64-bit, leaving no way to access the program
-    fMinimizeToTray = false;
-    fMinimizeOnClose = false;
-#endif
+    CDataStream ssPeers(vchData, SER_DISK, CLIENT_VERSION);
 
-    //// todo: shouldn't we catch exceptions and try to recover and continue?
-    CRITICAL_BLOCK(pwallet->cs_wallet)
-    {
-        // Get cursor
-        Dbc* pcursor = GetCursor();
-        if (!pcursor)
-            return DB_CORRUPT;
+    // verify stored checksum matches input data
+    uint256 hashTmp = Hash(ssPeers.begin(), ssPeers.end());
+    if (hashIn != hashTmp)
+        return error("CAddrman::Read() : checksum mismatch; data corrupted");
 
-        loop
-        {
-            // Read next record
-            CDataStream ssKey;
-            CDataStream ssValue;
-            int ret = ReadAtCursor(pcursor, ssKey, ssValue);
-            if (ret == DB_NOTFOUND)
-                break;
-            else if (ret != 0)
-                return DB_CORRUPT;
-
-            // Unserialize
-            // Taking advantage of the fact that pair serialization
-            // is just the two items serialized one after the other
-            string strType;
-            ssKey >> strType;
-            if (strType == "name")
-            {
-                string strAddress;
-                ssKey >> strAddress;
-                ssValue >> pwallet->mapAddressBook[strAddress];
-            }
-            else if (strType == "tx")
-            {
-                uint256 hash;
-                ssKey >> hash;
-                CWalletTx& wtx = pwallet->mapWallet[hash];
-                ssValue >> wtx;
-                wtx.BindWallet(pwallet);
+    unsigned char pchMsgTmp[4];
+    try {
+        // de-serialize file header (pchMessageStart magic number) and
+        ssPeers >> FLATDATA(pchMsgTmp);
 
-                if (wtx.GetHash() != hash)
-                    printf("Error in wallet.dat, hash mismatch\n");
+        // verify the network matches ours
+        if (memcmp(pchMsgTmp, pchMessageStart, sizeof(pchMsgTmp)))
+            return error("CAddrman::Read() : invalid network magic number");
 
-                // Undo serialize changes in 31600
-                if (31404 <= wtx.fTimeReceivedIsTxTime && wtx.fTimeReceivedIsTxTime <= 31703)
-                {
-                    if (!ssValue.empty())
-                    {
-                        char fTmp;
-                        char fUnused;
-                        ssValue >> fTmp >> fUnused >> wtx.strFromAccount;
-                        printf("LoadWallet() upgrading tx ver=%d %d '%s' %s\n", wtx.fTimeReceivedIsTxTime, fTmp, wtx.strFromAccount.c_str(), hash.ToString().c_str());
-                        wtx.fTimeReceivedIsTxTime = fTmp;
-                    }
-                    else
-                    {
-                        printf("LoadWallet() repairing tx ver=%d %s\n", wtx.fTimeReceivedIsTxTime, hash.ToString().c_str());
-                        wtx.fTimeReceivedIsTxTime = 0;
-                    }
-                    vWalletUpgrade.push_back(hash);
-                }
-
-                //// debug print
-                //printf("LoadWallet  %s\n", wtx.GetHash().ToString().c_str());
-                //printf(" %12I64d  %s  %s  %s\n",
-                //    wtx.vout[0].nValue,
-                //    DateTimeStrFormat("%x %H:%M:%S", wtx.GetBlockTime()).c_str(),
-                //    wtx.hashBlock.ToString().substr(0,20).c_str(),
-                //    wtx.mapValue["message"].c_str());
-            }
-            else if (strType == "acentry")
-            {
-                string strAccount;
-                ssKey >> strAccount;
-                uint64 nNumber;
-                ssKey >> nNumber;
-                if (nNumber > nAccountingEntryNumber)
-                    nAccountingEntryNumber = nNumber;
-            }
-            else if (strType == "key" || strType == "wkey")
-            {
-                vector<unsigned char> vchPubKey;
-                ssKey >> vchPubKey;
-                CKey key;
-                if (strType == "key")
-                {
-                    CPrivKey pkey;
-                    ssValue >> pkey;
-                    key.SetPubKey(vchPubKey);
-                    key.SetPrivKey(pkey);
-                    if (key.GetPubKey() != vchPubKey || !key.IsValid())
-                        return DB_CORRUPT;
-                }
-                else
-                {
-                    CWalletKey wkey;
-                    ssValue >> wkey;
-                    key.SetPubKey(vchPubKey);
-                    key.SetPrivKey(wkey.vchPrivKey);
-                    if (key.GetPubKey() != vchPubKey || !key.IsValid())
-                        return DB_CORRUPT;
-                }
-                if (!pwallet->LoadKey(key))
-                    return DB_CORRUPT;
-            }
-            else if (strType == "mkey")
-            {
-                unsigned int nID;
-                ssKey >> nID;
-                CMasterKey kMasterKey;
-                ssValue >> kMasterKey;
-                if(pwallet->mapMasterKeys.count(nID) != 0)
-                    return DB_CORRUPT;
-                pwallet->mapMasterKeys[nID] = kMasterKey;
-                if (pwallet->nMasterKeyMaxID < nID)
-                    pwallet->nMasterKeyMaxID = nID;
-            }
-            else if (strType == "ckey")
-            {
-                vector<unsigned char> vchPubKey;
-                ssKey >> vchPubKey;
-                vector<unsigned char> vchPrivKey;
-                ssValue >> vchPrivKey;
-                if (!pwallet->LoadCryptedKey(vchPubKey, vchPrivKey))
-                    return DB_CORRUPT;
-                fIsEncrypted = true;
-            }
-            else if (strType == "defaultkey")
-            {
-                ssValue >> pwallet->vchDefaultKey;
-            }
-            else if (strType == "pool")
-            {
-                int64 nIndex;
-                ssKey >> nIndex;
-                pwallet->setKeyPool.insert(nIndex);
-            }
-            else if (strType == "version")
-            {
-                ssValue >> nFileVersion;
-                if (nFileVersion == 10300)
-                    nFileVersion = 300;
-            }
-            else if (strType == "setting")
-            {
-                string strKey;
-                ssKey >> strKey;
-
-                // Options
-#ifndef QT_GUI
-                if (strKey == "fGenerateBitcoins")  ssValue >> fGenerateBitcoins;
-#endif
-                if (strKey == "nTransactionFee")    ssValue >> nTransactionFee;
-                if (strKey == "fLimitProcessors")   ssValue >> fLimitProcessors;
-                if (strKey == "nLimitProcessors")   ssValue >> nLimitProcessors;
-                if (strKey == "fMinimizeToTray")    ssValue >> fMinimizeToTray;
-                if (strKey == "fMinimizeOnClose")   ssValue >> fMinimizeOnClose;
-                if (strKey == "fUseProxy")          ssValue >> fUseProxy;
-                if (strKey == "addrProxy")          ssValue >> addrProxy;
-                if (fHaveUPnP && strKey == "fUseUPnP")           ssValue >> fUseUPnP;
-            }
-            else if (strType == "minversion")
-            {
-                int nMinVersion = 0;
-                ssValue >> nMinVersion;
-                if (nMinVersion > CLIENT_VERSION)
-                    return DB_TOO_NEW;
-            }
-            else if (strType == "cscript")
-            {
-                uint160 hash;
-                ssKey >> hash;
-                CScript script;
-                ssValue >> script;
-                if (!pwallet->LoadCScript(script))
-                    return DB_CORRUPT;
-            }
-        }
-        pcursor->close();
+        // de-serialize address data into one CAddrMan object
+        ssPeers >> addr;
     }
-
-    BOOST_FOREACH(uint256 hash, vWalletUpgrade)
-        WriteTx(hash, pwallet->mapWallet[hash]);
-
-    printf("nFileVersion = %d\n", nFileVersion);
-    printf("fGenerateBitcoins = %d\n", fGenerateBitcoins);
-    printf("nTransactionFee = %"PRI64d"\n", nTransactionFee);
-    printf("fMinimizeToTray = %d\n", fMinimizeToTray);
-    printf("fMinimizeOnClose = %d\n", fMinimizeOnClose);
-    printf("fUseProxy = %d\n", fUseProxy);
-    printf("addrProxy = %s\n", addrProxy.ToString().c_str());
-    if (fHaveUPnP)
-        printf("fUseUPnP = %d\n", fUseUPnP);
-
-
-    // Rewrite encrypted wallets of versions 0.4.0 and 0.5.0rc:
-    if (fIsEncrypted && (nFileVersion == 40000 || nFileVersion == 50000))
-        return DB_NEED_REWRITE;
-
-    if (nFileVersion < CLIENT_VERSION) // Update
-    {
-        // Get rid of old debug.log file in current directory
-        if (nFileVersion <= 105 && !pszSetDataDir[0])
-            unlink("debug.log");
-
-        WriteVersion(CLIENT_VERSION);
+    catch (const std::exception&) {
+        return error("CAddrman::Read() : I/O error or stream data corrupted");
     }
 
-    return DB_LOAD_OK;
-}
-
-void ThreadFlushWalletDB(void* parg)
-{
-    const string& strFile = ((const string*)parg)[0];
-    static bool fOneThread;
-    if (fOneThread)
-        return;
-    fOneThread = true;
-    if (!GetBoolArg("-flushwallet", true))
-        return;
-
-    unsigned int nLastSeen = nWalletDBUpdated;
-    unsigned int nLastFlushed = nWalletDBUpdated;
-    int64 nLastWalletUpdate = GetTime();
-    while (!fShutdown)
-    {
-        Sleep(500);
-
-        if (nLastSeen != nWalletDBUpdated)
-        {
-            nLastSeen = nWalletDBUpdated;
-            nLastWalletUpdate = GetTime();
-        }
-
-        if (nLastFlushed != nWalletDBUpdated && GetTime() - nLastWalletUpdate >= 2)
-        {
-            TRY_CRITICAL_BLOCK(cs_db)
-            {
-                // Don't do this if any databases are in use
-                int nRefCount = 0;
-                map<string, int>::iterator mi = mapFileUseCount.begin();
-                while (mi != mapFileUseCount.end())
-                {
-                    nRefCount += (*mi).second;
-                    mi++;
-                }
-
-                if (nRefCount == 0 && !fShutdown)
-                {
-                    map<string, int>::iterator mi = mapFileUseCount.find(strFile);
-                    if (mi != mapFileUseCount.end())
-                    {
-                        printf("%s ", DateTimeStrFormat("%x %H:%M:%S", GetTime()).c_str());
-                        printf("Flushing wallet.dat\n");
-                        nLastFlushed = nWalletDBUpdated;
-                        int64 nStart = GetTimeMillis();
-
-                        // Flush wallet.dat so it's self contained
-                        CloseDb(strFile);
-                        dbenv.txn_checkpoint(0, 0, 0);
-                        dbenv.lsn_reset(strFile.c_str(), 0);
-
-                        mapFileUseCount.erase(mi++);
-                        printf("Flushed wallet.dat %"PRI64d"ms\n", GetTimeMillis() - nStart);
-                    }
-                }
-            }
-        }
-    }
+    return true;
 }
 
-bool BackupWallet(const CWallet& wallet, const string& strDest)
-{
-    if (!wallet.fFileBacked)
-        return false;
-    while (!fShutdown)
-    {
-        CRITICAL_BLOCK(cs_db)
-        {
-            if (!mapFileUseCount.count(wallet.strWalletFile) || mapFileUseCount[wallet.strWalletFile] == 0)
-            {
-                // Flush log data to the dat file
-                CloseDb(wallet.strWalletFile);
-                dbenv.txn_checkpoint(0, 0, 0);
-                dbenv.lsn_reset(wallet.strWalletFile.c_str(), 0);
-                mapFileUseCount.erase(wallet.strWalletFile);
-
-                // Copy wallet.dat
-                filesystem::path pathSrc(GetDataDir() + "/" + wallet.strWalletFile);
-                filesystem::path pathDest(strDest);
-                if (filesystem::is_directory(pathDest))
-                    pathDest = pathDest / wallet.strWalletFile;
-#if BOOST_VERSION >= 104000
-                filesystem::copy_file(pathSrc, pathDest, filesystem::copy_option::overwrite_if_exists);
-#else
-                filesystem::copy_file(pathSrc, pathDest);
-#endif
-                printf("copied wallet.dat to %s\n", pathDest.string().c_str());
-
-                return true;
-            }
-        }
-        Sleep(100);
-    }
-    return false;
-}