src/db.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2012 The Bitcoin developers
   3 // Distributed under the MIT/X11 software license, see the accompanying
   4 // file license.txt or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #include "db.h"
   7 #include "util.h"
   8 #include "main.h"
   9 #include "wallet.h"
  10 #include <boost/version.hpp>
  11 #include <boost/filesystem.hpp>
  12 #include <boost/filesystem/fstream.hpp>
  13
  14 #ifndef WIN32
  15 #include "sys/stat.h"
  16 #endif
  17
  18 using namespace std;
  19 using namespace boost;
  20
  21
  22 unsigned int nWalletDBUpdated;
  23 uint64 nAccountingEntryNumber = 0;
  24
  25
  26
  27 //
  28 // CDB
  29 //
  30
  31 static CCriticalSection cs_db;
  32 static bool fDbEnvInit = false;
  33 DbEnv dbenv(0);
  34 static map<string, int> mapFileUseCount;
  35 static map<string, Db*> mapDb;
  36
  37 static void EnvShutdown()
  38 {
  39     if (!fDbEnvInit)
  40         return;
  41
  42     fDbEnvInit = false;
  43     try
  44     {
  45         dbenv.close(0);
  46     }
  47     catch (const DbException& e)
  48     {
  49         printf("EnvShutdown exception: %s (%d)\n", e.what(), e.get_errno());
  50     }
  51     DbEnv(0).remove(GetDataDir().string().c_str(), 0);
  52 }
  53
  54 class CDBInit
  55 {
  56 public:
  57     CDBInit()
  58     {
  59     }
  60     ~CDBInit()
  61     {
  62         EnvShutdown();
  63     }
  64 }
  65 instance_of_cdbinit;
  66
  67
  68 CDB::CDB(const char *pszFile, const char* pszMode) : pdb(NULL)
  69 {
  70     int ret;
  71     if (pszFile == NULL)
  72         return;
  73
  74     fReadOnly = (!strchr(pszMode, '+') && !strchr(pszMode, 'w'));
  75     bool fCreate = strchr(pszMode, 'c');
  76     unsigned int nFlags = DB_THREAD;
  77     if (fCreate)
  78         nFlags |= DB_CREATE;
  79
  80     {
  81         LOCK(cs_db);
  82         if (!fDbEnvInit)
  83         {
  84             if (fShutdown)
  85                 return;
  86             filesystem::path pathDataDir = GetDataDir();
  87             filesystem::path pathLogDir = pathDataDir / "database";
  88             filesystem::create_directory(pathLogDir);
  89             filesystem::path pathErrorFile = pathDataDir / "db.log";
  90             printf("dbenv.open LogDir=%s ErrorFile=%s\n", pathLogDir.string().c_str(), pathErrorFile.string().c_str());
  91
  92             int nDbCache = GetArg("-dbcache", 25);
  93             dbenv.set_lg_dir(pathLogDir.string().c_str());
  94             dbenv.set_cachesize(nDbCache / 1024, (nDbCache % 1024)*1048576, 1);
  95             dbenv.set_lg_bsize(1048576);
  96             dbenv.set_lg_max(10485760);
  97             dbenv.set_lk_max_locks(10000);
  98             dbenv.set_lk_max_objects(10000);
  99             dbenv.set_errfile(fopen(pathErrorFile.string().c_str(), "a")); /// debug
 100             dbenv.set_flags(DB_AUTO_COMMIT, 1);
 101             dbenv.log_set_config(DB_LOG_AUTO_REMOVE, 1);
 102             ret = dbenv.open(pathDataDir.string().c_str(),
 103                              DB_CREATE     |
 104                              DB_INIT_LOCK  |
 105                              DB_INIT_LOG   |
 106                              DB_INIT_MPOOL |
 107                              DB_INIT_TXN   |
 108                              DB_THREAD     |
 109                              DB_RECOVER,
 110                              S_IRUSR | S_IWUSR);
 111             if (ret > 0)
 112                 throw runtime_error(strprintf("CDB() : error %d opening database environment", ret));
 113             fDbEnvInit = true;
 114         }
 115
 116         strFile = pszFile;
 117         ++mapFileUseCount[strFile];
 118         pdb = mapDb[strFile];
 119         if (pdb == NULL)
 120         {
 121             pdb = new Db(&dbenv, 0);
 122
 123             ret = pdb->open(NULL,      // Txn pointer
 124                             pszFile,   // Filename
 125                             "main",    // Logical db name
 126                             DB_BTREE,  // Database type
 127                             nFlags,    // Flags
 128                             0);
 129
 130             if (ret > 0)
 131             {
 132                 delete pdb;
 133                 pdb = NULL;
 134                 {
 135                      LOCK(cs_db);
 136                     --mapFileUseCount[strFile];
 137                 }
 138                 strFile = "";
 139                 throw runtime_error(strprintf("CDB() : can't open database file %s, error %d", pszFile, ret));
 140             }
 141
 142             if (fCreate && !Exists(string("version")))
 143             {
 144                 bool fTmp = fReadOnly;
 145                 fReadOnly = false;
 146                 WriteVersion(CLIENT_VERSION);
 147                 fReadOnly = fTmp;
 148             }
 149
 150             mapDb[strFile] = pdb;
 151         }
 152     }
 153 }
 154
 155 void CDB::Close()
 156 {
 157     if (!pdb)
 158         return;
 159     if (!vTxn.empty())
 160         vTxn.front()->abort();
 161     vTxn.clear();
 162     pdb = NULL;
 163
 164     // Flush database activity from memory pool to disk log
 165     unsigned int nMinutes = 0;
 166     if (fReadOnly)
 167         nMinutes = 1;
 168     if (strFile == "addr.dat")
 169         nMinutes = 2;
 170     if (strFile == "blkindex.dat" && IsInitialBlockDownload())
 171         nMinutes = 5;
 172
 173     dbenv.txn_checkpoint(nMinutes ? GetArg("-dblogsize", 100)*1024 : 0, nMinutes, 0);
 174
 175     {
 176         LOCK(cs_db);
 177         --mapFileUseCount[strFile];
 178     }
 179 }
 180
 181 void static CloseDb(const string& strFile)
 182 {
 183     {
 184         LOCK(cs_db);
 185         if (mapDb[strFile] != NULL)
 186         {
 187             // Close the database handle
 188             Db* pdb = mapDb[strFile];
 189             pdb->close(0);
 190             delete pdb;
 191             mapDb[strFile] = NULL;
 192         }
 193     }
 194 }
 195
 196 bool CDB::Rewrite(const string& strFile, const char* pszSkip)
 197 {
 198     while (!fShutdown)
 199     {
 200         {
 201             LOCK(cs_db);
 202             if (!mapFileUseCount.count(strFile) || mapFileUseCount[strFile] == 0)
 203             {
 204                 // Flush log data to the dat file
 205                 CloseDb(strFile);
 206                 dbenv.txn_checkpoint(0, 0, 0);
 207                 dbenv.lsn_reset(strFile.c_str(), 0);
 208                 mapFileUseCount.erase(strFile);
 209
 210                 bool fSuccess = true;
 211                 printf("Rewriting %s...\n", strFile.c_str());
 212                 string strFileRes = strFile + ".rewrite";
 213                 { // surround usage of db with extra {}
 214                     CDB db(strFile.c_str(), "r");
 215                     Db* pdbCopy = new Db(&dbenv, 0);
 216
 217                     int ret = pdbCopy->open(NULL,                 // Txn pointer
 218                                             strFileRes.c_str(),   // Filename
 219                                             "main",    // Logical db name
 220                                             DB_BTREE,  // Database type
 221                                             DB_CREATE,    // Flags
 222                                             0);
 223                     if (ret > 0)
 224                     {
 225                         printf("Cannot create database file %s\n", strFileRes.c_str());
 226                         fSuccess = false;
 227                     }
 228
 229                     Dbc* pcursor = db.GetCursor();
 230                     if (pcursor)
 231                         while (fSuccess)
 232                         {
 233                             CDataStream ssKey;
 234                             CDataStream ssValue;
 235                             int ret = db.ReadAtCursor(pcursor, ssKey, ssValue, DB_NEXT);
 236                             if (ret == DB_NOTFOUND)
 237                             {
 238                                 pcursor->close();
 239                                 break;
 240                             }
 241                             else if (ret != 0)
 242                             {
 243                                 pcursor->close();
 244                                 fSuccess = false;
 245                                 break;
 246                             }
 247                             if (pszSkip &&
 248                                 strncmp(&ssKey[0], pszSkip, std::min(ssKey.size(), strlen(pszSkip))) == 0)
 249                                 continue;
 250                             if (strncmp(&ssKey[0], "\x07version", 8) == 0)
 251                             {
 252                                 // Update version:
 253                                 ssValue.clear();
 254                                 ssValue << CLIENT_VERSION;
 255                             }
 256                             Dbt datKey(&ssKey[0], ssKey.size());
 257                             Dbt datValue(&ssValue[0], ssValue.size());
 258                             int ret2 = pdbCopy->put(NULL, &datKey, &datValue, DB_NOOVERWRITE);
 259                             if (ret2 > 0)
 260                                 fSuccess = false;
 261                         }
 262                     if (fSuccess)
 263                     {
 264                         db.Close();
 265                         CloseDb(strFile);
 266                         if (pdbCopy->close(0))
 267                             fSuccess = false;
 268                         delete pdbCopy;
 269                     }
 270                 }
 271                 if (fSuccess)
 272                 {
 273                     Db dbA(&dbenv, 0);
 274                     if (dbA.remove(strFile.c_str(), NULL, 0))
 275                         fSuccess = false;
 276                     Db dbB(&dbenv, 0);
 277                     if (dbB.rename(strFileRes.c_str(), NULL, strFile.c_str(), 0))
 278                         fSuccess = false;
 279                 }
 280                 if (!fSuccess)
 281                     printf("Rewriting of %s FAILED!\n", strFileRes.c_str());
 282                 return fSuccess;
 283             }
 284         }
 285         Sleep(100);
 286     }
 287     return false;
 288 }
 289
 290
 291 void DBFlush(bool fShutdown)
 292 {
 293     // Flush log data to the actual data file
 294     //  on all files that are not in use
 295     printf("DBFlush(%s)%s\n", fShutdown ? "true" : "false", fDbEnvInit ? "" : " db not started");
 296     if (!fDbEnvInit)
 297         return;
 298     {
 299         LOCK(cs_db);
 300         map<string, int>::iterator mi = mapFileUseCount.begin();
 301         while (mi != mapFileUseCount.end())
 302         {
 303             string strFile = (*mi).first;
 304             int nRefCount = (*mi).second;
 305             printf("%s refcount=%d\n", strFile.c_str(), nRefCount);
 306             if (nRefCount == 0)
 307             {
 308                 // Move log data to the dat file
 309                 CloseDb(strFile);
 310                 dbenv.txn_checkpoint(0, 0, 0);
 311                 printf("%s flush\n", strFile.c_str());
 312                 dbenv.lsn_reset(strFile.c_str(), 0);
 313                 mapFileUseCount.erase(mi++);
 314             }
 315             else
 316                 mi++;
 317         }
 318         if (fShutdown)
 319         {
 320             char** listp;
 321             if (mapFileUseCount.empty())
 322             {
 323                 dbenv.log_archive(&listp, DB_ARCH_REMOVE);
 324                 EnvShutdown();
 325             }
 326         }
 327     }
 328 }
 329
 330
 331
 332
 333
 334
 335 //
 336 // CTxDB
 337 //
 338
 339 bool CTxDB::ReadTxIndex(uint256 hash, CTxIndex& txindex)
 340 {
 341     assert(!fClient);
 342     txindex.SetNull();
 343     return Read(make_pair(string("tx"), hash), txindex);
 344 }
 345
 346 bool CTxDB::UpdateTxIndex(uint256 hash, const CTxIndex& txindex)
 347 {
 348     assert(!fClient);
 349     return Write(make_pair(string("tx"), hash), txindex);
 350 }
 351
 352 bool CTxDB::AddTxIndex(const CTransaction& tx, const CDiskTxPos& pos, int nHeight)
 353 {
 354     assert(!fClient);
 355
 356     // Add to tx index
 357     uint256 hash = tx.GetHash();
 358     CTxIndex txindex(pos, tx.vout.size());
 359     return Write(make_pair(string("tx"), hash), txindex);
 360 }
 361
 362 bool CTxDB::EraseTxIndex(const CTransaction& tx)
 363 {
 364     assert(!fClient);
 365     uint256 hash = tx.GetHash();
 366
 367     return Erase(make_pair(string("tx"), hash));
 368 }
 369
 370 bool CTxDB::ContainsTx(uint256 hash)
 371 {
 372     assert(!fClient);
 373     return Exists(make_pair(string("tx"), hash));
 374 }
 375
 376 bool CTxDB::ReadOwnerTxes(uint160 hash160, int nMinHeight, vector<CTransaction>& vtx)
 377 {
 378     assert(!fClient);
 379     vtx.clear();
 380
 381     // Get cursor
 382     Dbc* pcursor = GetCursor();
 383     if (!pcursor)
 384         return false;
 385
 386     unsigned int fFlags = DB_SET_RANGE;
 387     loop
 388     {
 389         // Read next record
 390         CDataStream ssKey;
 391         if (fFlags == DB_SET_RANGE)
 392             ssKey << string("owner") << hash160 << CDiskTxPos(0, 0, 0);
 393         CDataStream ssValue;
 394         int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
 395         fFlags = DB_NEXT;
 396         if (ret == DB_NOTFOUND)
 397             break;
 398         else if (ret != 0)
 399         {
 400             pcursor->close();
 401             return false;
 402         }
 403
 404         // Unserialize
 405         string strType;
 406         uint160 hashItem;
 407         CDiskTxPos pos;
 408         ssKey >> strType >> hashItem >> pos;
 409         int nItemHeight;
 410         ssValue >> nItemHeight;
 411
 412         // Read transaction
 413         if (strType != "owner" || hashItem != hash160)
 414             break;
 415         if (nItemHeight >= nMinHeight)
 416         {
 417             vtx.resize(vtx.size()+1);
 418             if (!vtx.back().ReadFromDisk(pos))
 419             {
 420                 pcursor->close();
 421                 return false;
 422             }
 423         }
 424     }
 425
 426     pcursor->close();
 427     return true;
 428 }
 429
 430 bool CTxDB::ReadDiskTx(uint256 hash, CTransaction& tx, CTxIndex& txindex)
 431 {
 432     assert(!fClient);
 433     tx.SetNull();
 434     if (!ReadTxIndex(hash, txindex))
 435         return false;
 436     return (tx.ReadFromDisk(txindex.pos));
 437 }
 438
 439 bool CTxDB::ReadDiskTx(uint256 hash, CTransaction& tx)
 440 {
 441     CTxIndex txindex;
 442     return ReadDiskTx(hash, tx, txindex);
 443 }
 444
 445 bool CTxDB::ReadDiskTx(COutPoint outpoint, CTransaction& tx, CTxIndex& txindex)
 446 {
 447     return ReadDiskTx(outpoint.hash, tx, txindex);
 448 }
 449
 450 bool CTxDB::ReadDiskTx(COutPoint outpoint, CTransaction& tx)
 451 {
 452     CTxIndex txindex;
 453     return ReadDiskTx(outpoint.hash, tx, txindex);
 454 }
 455
 456 bool CTxDB::WriteBlockIndex(const CDiskBlockIndex& blockindex)
 457 {
 458     return Write(make_pair(string("blockindex"), blockindex.GetBlockHash()), blockindex);
 459 }
 460
 461 bool CTxDB::EraseBlockIndex(uint256 hash)
 462 {
 463     return Erase(make_pair(string("blockindex"), hash));
 464 }
 465
 466 bool CTxDB::ReadHashBestChain(uint256& hashBestChain)
 467 {
 468     return Read(string("hashBestChain"), hashBestChain);
 469 }
 470
 471 bool CTxDB::WriteHashBestChain(uint256 hashBestChain)
 472 {
 473     return Write(string("hashBestChain"), hashBestChain);
 474 }
 475
 476 bool CTxDB::ReadBestInvalidWork(CBigNum& bnBestInvalidWork)
 477 {
 478     return Read(string("bnBestInvalidWork"), bnBestInvalidWork);
 479 }
 480
 481 bool CTxDB::WriteBestInvalidWork(CBigNum bnBestInvalidWork)
 482 {
 483     return Write(string("bnBestInvalidWork"), bnBestInvalidWork);
 484 }
 485
 486 CBlockIndex static * InsertBlockIndex(uint256 hash)
 487 {
 488     if (hash == 0)
 489         return NULL;
 490
 491     // Return existing
 492     map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hash);
 493     if (mi != mapBlockIndex.end())
 494         return (*mi).second;
 495
 496     // Create new
 497     CBlockIndex* pindexNew = new CBlockIndex();
 498     if (!pindexNew)
 499         throw runtime_error("LoadBlockIndex() : new CBlockIndex failed");
 500     mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
 501     pindexNew->phashBlock = &((*mi).first);
 502
 503     return pindexNew;
 504 }
 505
 506 bool CTxDB::LoadBlockIndex()
 507 {
 508     // Get database cursor
 509     Dbc* pcursor = GetCursor();
 510     if (!pcursor)
 511         return false;
 512
 513     // Load mapBlockIndex
 514     unsigned int fFlags = DB_SET_RANGE;
 515     loop
 516     {
 517         // Read next record
 518         CDataStream ssKey;
 519         if (fFlags == DB_SET_RANGE)
 520             ssKey << make_pair(string("blockindex"), uint256(0));
 521         CDataStream ssValue;
 522         int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
 523         fFlags = DB_NEXT;
 524         if (ret == DB_NOTFOUND)
 525             break;
 526         else if (ret != 0)
 527             return false;
 528
 529         // Unserialize
 530         string strType;
 531         ssKey >> strType;
 532         if (strType == "blockindex")
 533         {
 534             CDiskBlockIndex diskindex;
 535             ssValue >> diskindex;
 536
 537             // Construct block index object
 538             CBlockIndex* pindexNew = InsertBlockIndex(diskindex.GetBlockHash());
 539             pindexNew->pprev          = InsertBlockIndex(diskindex.hashPrev);
 540             pindexNew->pnext          = InsertBlockIndex(diskindex.hashNext);
 541             pindexNew->nFile          = diskindex.nFile;
 542             pindexNew->nBlockPos      = diskindex.nBlockPos;
 543             pindexNew->nHeight        = diskindex.nHeight;
 544             pindexNew->nVersion       = diskindex.nVersion;
 545             pindexNew->hashMerkleRoot = diskindex.hashMerkleRoot;
 546             pindexNew->nTime          = diskindex.nTime;
 547             pindexNew->nBits          = diskindex.nBits;
 548             pindexNew->nNonce         = diskindex.nNonce;
 549
 550             // Watch for genesis block
 551             if (pindexGenesisBlock == NULL && diskindex.GetBlockHash() == hashGenesisBlock)
 552                 pindexGenesisBlock = pindexNew;
 553
 554             if (!pindexNew->CheckIndex())
 555                 return error("LoadBlockIndex() : CheckIndex failed at %d", pindexNew->nHeight);
 556         }
 557         else
 558         {
 559             break;
 560         }
 561     }
 562     pcursor->close();
 563
 564     // Calculate bnChainWork
 565     vector<pair<int, CBlockIndex*> > vSortedByHeight;
 566     vSortedByHeight.reserve(mapBlockIndex.size());
 567     BOOST_FOREACH(const PAIRTYPE(uint256, CBlockIndex*)& item, mapBlockIndex)
 568     {
 569         CBlockIndex* pindex = item.second;
 570         vSortedByHeight.push_back(make_pair(pindex->nHeight, pindex));
 571     }
 572     sort(vSortedByHeight.begin(), vSortedByHeight.end());
 573     BOOST_FOREACH(const PAIRTYPE(int, CBlockIndex*)& item, vSortedByHeight)
 574     {
 575         CBlockIndex* pindex = item.second;
 576         pindex->bnChainWork = (pindex->pprev ? pindex->pprev->bnChainWork : 0) + pindex->GetBlockWork();
 577     }
 578
 579     // Load hashBestChain pointer to end of best chain
 580     if (!ReadHashBestChain(hashBestChain))
 581     {
 582         if (pindexGenesisBlock == NULL)
 583             return true;
 584         return error("CTxDB::LoadBlockIndex() : hashBestChain not loaded");
 585     }
 586     if (!mapBlockIndex.count(hashBestChain))
 587         return error("CTxDB::LoadBlockIndex() : hashBestChain not found in the block index");
 588     pindexBest = mapBlockIndex[hashBestChain];
 589     nBestHeight = pindexBest->nHeight;
 590     bnBestChainWork = pindexBest->bnChainWork;
 591     printf("LoadBlockIndex(): hashBestChain=%s  height=%d\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight);
 592
 593     // Load bnBestInvalidWork, OK if it doesn't exist
 594     ReadBestInvalidWork(bnBestInvalidWork);
 595
 596     // Verify blocks in the best chain
 597     int nCheckLevel = GetArg("-checklevel", 1);
 598     int nCheckDepth = GetArg( "-checkblocks", 2500);
 599     if (nCheckDepth == 0)
 600         nCheckDepth = 1000000000; // suffices until the year 19000
 601     if (nCheckDepth > nBestHeight)
 602         nCheckDepth = nBestHeight;
 603     printf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel);
 604     CBlockIndex* pindexFork = NULL;
 605     map<pair<unsigned int, unsigned int>, CBlockIndex*> mapBlockPos;
 606     for (CBlockIndex* pindex = pindexBest; pindex && pindex->pprev; pindex = pindex->pprev)
 607     {
 608         if (pindex->nHeight < nBestHeight-nCheckDepth)
 609             break;
 610         CBlock block;
 611         if (!block.ReadFromDisk(pindex))
 612             return error("LoadBlockIndex() : block.ReadFromDisk failed");
 613         // check level 1: verify block validity
 614         if (nCheckLevel>0 && !block.CheckBlock())
 615         {
 616             printf("LoadBlockIndex() : *** found bad block at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
 617             pindexFork = pindex->pprev;
 618         }
 619         // check level 2: verify transaction index validity
 620         if (nCheckLevel>1)
 621         {
 622             pair<unsigned int, unsigned int> pos = make_pair(pindex->nFile, pindex->nBlockPos);
 623             mapBlockPos[pos] = pindex;
 624             BOOST_FOREACH(const CTransaction &tx, block.vtx)
 625             {
 626                 uint256 hashTx = tx.GetHash();
 627                 CTxIndex txindex;
 628                 if (ReadTxIndex(hashTx, txindex))
 629                 {
 630                     // check level 3: checker transaction hashes
 631                     if (nCheckLevel>2 || pindex->nFile != txindex.pos.nFile || pindex->nBlockPos != txindex.pos.nBlockPos)
 632                     {
 633                         // either an error or a duplicate transaction
 634                         CTransaction txFound;
 635                         if (!txFound.ReadFromDisk(txindex.pos))
 636                         {
 637                             printf("LoadBlockIndex() : *** cannot read mislocated transaction %s\n", hashTx.ToString().c_str());
 638                             pindexFork = pindex->pprev;
 639                         }
 640                         else
 641                             if (txFound.GetHash() != hashTx) // not a duplicate tx
 642                             {
 643                                 printf("LoadBlockIndex(): *** invalid tx position for %s\n", hashTx.ToString().c_str());
 644                                 pindexFork = pindex->pprev;
 645                             }
 646                     }
 647                     // check level 4: check whether spent txouts were spent within the main chain
 648                     int nOutput = 0;
 649                     if (nCheckLevel>3)
 650                     {
 651                         BOOST_FOREACH(const CDiskTxPos &txpos, txindex.vSpent)
 652                         {
 653                             if (!txpos.IsNull())
 654                             {
 655                                 pair<unsigned int, unsigned int> posFind = make_pair(txpos.nFile, txpos.nBlockPos);
 656                                 if (!mapBlockPos.count(posFind))
 657                                 {
 658                                     printf("LoadBlockIndex(): *** found bad spend at %d, hashBlock=%s, hashTx=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str(), hashTx.ToString().c_str());
 659                                     pindexFork = pindex->pprev;
 660                                 }
 661                                 // check level 6: check whether spent txouts were spent by a valid transaction that consume them
 662                                 if (nCheckLevel>5)
 663                                 {
 664                                     CTransaction txSpend;
 665                                     if (!txSpend.ReadFromDisk(txpos))
 666                                     {
 667                                         printf("LoadBlockIndex(): *** cannot read spending transaction of %s:%i from disk\n", hashTx.ToString().c_str(), nOutput);
 668                                         pindexFork = pindex->pprev;
 669                                     }
 670                                     else if (!txSpend.CheckTransaction())
 671                                     {
 672                                         printf("LoadBlockIndex(): *** spending transaction of %s:%i is invalid\n", hashTx.ToString().c_str(), nOutput);
 673                                         pindexFork = pindex->pprev;
 674                                     }
 675                                     else
 676                                     {
 677                                         bool fFound = false;
 678                                         BOOST_FOREACH(const CTxIn &txin, txSpend.vin)
 679                                             if (txin.prevout.hash == hashTx && txin.prevout.n == nOutput)
 680                                                 fFound = true;
 681                                         if (!fFound)
 682                                         {
 683                                             printf("LoadBlockIndex(): *** spending transaction of %s:%i does not spend it\n", hashTx.ToString().c_str(), nOutput);
 684                                             pindexFork = pindex->pprev;
 685                                         }
 686                                     }
 687                                 }
 688                             }
 689                             nOutput++;
 690                         }
 691                     }
 692                 }
 693                 // check level 5: check whether all prevouts are marked spent
 694                 if (nCheckLevel>4)
 695                 {
 696                      BOOST_FOREACH(const CTxIn &txin, tx.vin)
 697                      {
 698                           CTxIndex txindex;
 699                           if (ReadTxIndex(txin.prevout.hash, txindex))
 700                               if (txindex.vSpent.size()-1 < txin.prevout.n || txindex.vSpent[txin.prevout.n].IsNull())
 701                               {
 702                                   printf("LoadBlockIndex(): *** found unspent prevout %s:%i in %s\n", txin.prevout.hash.ToString().c_str(), txin.prevout.n, hashTx.ToString().c_str());
 703                                   pindexFork = pindex->pprev;
 704                               }
 705                      }
 706                 }
 707             }
 708         }
 709     }
 710     if (pindexFork)
 711     {
 712         // Reorg back to the fork
 713         printf("LoadBlockIndex() : *** moving best chain pointer back to block %d\n", pindexFork->nHeight);
 714         CBlock block;
 715         if (!block.ReadFromDisk(pindexFork))
 716             return error("LoadBlockIndex() : block.ReadFromDisk failed");
 717         CTxDB txdb;
 718         block.SetBestChain(txdb, pindexFork);
 719     }
 720
 721     return true;
 722 }
 723
 724
 725
 726
 727
 728 //
 729 // CAddrDB
 730 //
 731
 732 bool CAddrDB::WriteAddrman(const CAddrMan& addrman)
 733 {
 734     return Write(string("addrman"), addrman);
 735 }
 736
 737 bool CAddrDB::LoadAddresses()
 738 {
 739     if (Read(string("addrman"), addrman))
 740     {
 741         printf("Loaded %i addresses\n", addrman.size());
 742         return true;
 743     }
 744
 745     // Read pre-0.6 addr records
 746
 747     vector<CAddress> vAddr;
 748     vector<vector<unsigned char> > vDelete;
 749
 750     // Get cursor
 751     Dbc* pcursor = GetCursor();
 752     if (!pcursor)
 753         return false;
 754
 755     loop
 756     {
 757         // Read next record
 758         CDataStream ssKey;
 759         CDataStream ssValue;
 760         int ret = ReadAtCursor(pcursor, ssKey, ssValue);
 761         if (ret == DB_NOTFOUND)
 762             break;
 763         else if (ret != 0)
 764             return false;
 765
 766         // Unserialize
 767         string strType;
 768         ssKey >> strType;
 769         if (strType == "addr")
 770         {
 771             CAddress addr;
 772             ssValue >> addr;
 773             vAddr.push_back(addr);
 774         }
 775     }
 776     pcursor->close();
 777
 778     addrman.Add(vAddr, CNetAddr("0.0.0.0"));
 779     printf("Loaded %i addresses\n", addrman.size());
 780
 781     // Note: old records left; we ran into hangs-on-startup
 782     // bugs for some users who (we think) were running after
 783     // an unclean shutdown.
 784
 785     return true;
 786 }
 787
 788 bool LoadAddresses()
 789 {
 790     return CAddrDB("cr+").LoadAddresses();
 791 }
 792
 793
 794
 795
 796 //
 797 // CWalletDB
 798 //
 799
 800 bool CWalletDB::WriteName(const string& strAddress, const string& strName)
 801 {
 802     nWalletDBUpdated++;
 803     return Write(make_pair(string("name"), strAddress), strName);
 804 }
 805
 806 bool CWalletDB::EraseName(const string& strAddress)
 807 {
 808     // This should only be used for sending addresses, never for receiving addresses,
 809     // receiving addresses must always have an address book entry if they're not change return.
 810     nWalletDBUpdated++;
 811     return Erase(make_pair(string("name"), strAddress));
 812 }
 813
 814 bool CWalletDB::ReadAccount(const string& strAccount, CAccount& account)
 815 {
 816     account.SetNull();
 817     return Read(make_pair(string("acc"), strAccount), account);
 818 }
 819
 820 bool CWalletDB::WriteAccount(const string& strAccount, const CAccount& account)
 821 {
 822     return Write(make_pair(string("acc"), strAccount), account);
 823 }
 824
 825 bool CWalletDB::WriteAccountingEntry(const CAccountingEntry& acentry)
 826 {
 827     return Write(boost::make_tuple(string("acentry"), acentry.strAccount, ++nAccountingEntryNumber), acentry);
 828 }
 829
 830 int64 CWalletDB::GetAccountCreditDebit(const string& strAccount)
 831 {
 832     list<CAccountingEntry> entries;
 833     ListAccountCreditDebit(strAccount, entries);
 834
 835     int64 nCreditDebit = 0;
 836     BOOST_FOREACH (const CAccountingEntry& entry, entries)
 837         nCreditDebit += entry.nCreditDebit;
 838
 839     return nCreditDebit;
 840 }
 841
 842 void CWalletDB::ListAccountCreditDebit(const string& strAccount, list<CAccountingEntry>& entries)
 843 {
 844     bool fAllAccounts = (strAccount == "*");
 845
 846     Dbc* pcursor = GetCursor();
 847     if (!pcursor)
 848         throw runtime_error("CWalletDB::ListAccountCreditDebit() : cannot create DB cursor");
 849     unsigned int fFlags = DB_SET_RANGE;
 850     loop
 851     {
 852         // Read next record
 853         CDataStream ssKey;
 854         if (fFlags == DB_SET_RANGE)
 855             ssKey << boost::make_tuple(string("acentry"), (fAllAccounts? string("") : strAccount), uint64(0));
 856         CDataStream ssValue;
 857         int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
 858         fFlags = DB_NEXT;
 859         if (ret == DB_NOTFOUND)
 860             break;
 861         else if (ret != 0)
 862         {
 863             pcursor->close();
 864             throw runtime_error("CWalletDB::ListAccountCreditDebit() : error scanning DB");
 865         }
 866
 867         // Unserialize
 868         string strType;
 869         ssKey >> strType;
 870         if (strType != "acentry")
 871             break;
 872         CAccountingEntry acentry;
 873         ssKey >> acentry.strAccount;
 874         if (!fAllAccounts && acentry.strAccount != strAccount)
 875             break;
 876
 877         ssValue >> acentry;
 878         entries.push_back(acentry);
 879     }
 880
 881     pcursor->close();
 882 }
 883
 884
 885 int CWalletDB::LoadWallet(CWallet* pwallet)
 886 {
 887     pwallet->vchDefaultKey.clear();
 888     int nFileVersion = 0;
 889     vector<uint256> vWalletUpgrade;
 890     bool fIsEncrypted = false;
 891
 892     //// todo: shouldn't we catch exceptions and try to recover and continue?
 893     {
 894         LOCK(pwallet->cs_wallet);
 895         int nMinVersion = 0;
 896         if (Read((string)"minversion", nMinVersion))
 897         {
 898             if (nMinVersion > CLIENT_VERSION)
 899                 return DB_TOO_NEW;
 900             pwallet->LoadMinVersion(nMinVersion);
 901         }
 902
 903         // Get cursor
 904         Dbc* pcursor = GetCursor();
 905         if (!pcursor)
 906         {
 907             printf("Error getting wallet database cursor\n");
 908             return DB_CORRUPT;
 909         }
 910
 911         loop
 912         {
 913             // Read next record
 914             CDataStream ssKey;
 915             CDataStream ssValue;
 916             int ret = ReadAtCursor(pcursor, ssKey, ssValue);
 917             if (ret == DB_NOTFOUND)
 918                 break;
 919             else if (ret != 0)
 920             {
 921                 printf("Error reading next record from wallet database\n");
 922                 return DB_CORRUPT;
 923             }
 924
 925             // Unserialize
 926             // Taking advantage of the fact that pair serialization
 927             // is just the two items serialized one after the other
 928             string strType;
 929             ssKey >> strType;
 930             if (strType == "name")
 931             {
 932                 string strAddress;
 933                 ssKey >> strAddress;
 934                 ssValue >> pwallet->mapAddressBook[strAddress];
 935             }
 936             else if (strType == "tx")
 937             {
 938                 uint256 hash;
 939                 ssKey >> hash;
 940                 CWalletTx& wtx = pwallet->mapWallet[hash];
 941                 ssValue >> wtx;
 942                 wtx.BindWallet(pwallet);
 943
 944                 if (wtx.GetHash() != hash)
 945                     printf("Error in wallet.dat, hash mismatch\n");
 946
 947                 // Undo serialize changes in 31600
 948                 if (31404 <= wtx.fTimeReceivedIsTxTime && wtx.fTimeReceivedIsTxTime <= 31703)
 949                 {
 950                     if (!ssValue.empty())
 951                     {
 952                         char fTmp;
 953                         char fUnused;
 954                         ssValue >> fTmp >> fUnused >> wtx.strFromAccount;
 955                         printf("LoadWallet() upgrading tx ver=%d %d '%s' %s\n", wtx.fTimeReceivedIsTxTime, fTmp, wtx.strFromAccount.c_str(), hash.ToString().c_str());
 956                         wtx.fTimeReceivedIsTxTime = fTmp;
 957                     }
 958                     else
 959                     {
 960                         printf("LoadWallet() repairing tx ver=%d %s\n", wtx.fTimeReceivedIsTxTime, hash.ToString().c_str());
 961                         wtx.fTimeReceivedIsTxTime = 0;
 962                     }
 963                     vWalletUpgrade.push_back(hash);
 964                 }
 965
 966                 //// debug print
 967                 //printf("LoadWallet  %s\n", wtx.GetHash().ToString().c_str());
 968                 //printf(" %12I64d  %s  %s  %s\n",
 969                 //    wtx.vout[0].nValue,
 970                 //    DateTimeStrFormat("%x %H:%M:%S", wtx.GetBlockTime()).c_str(),
 971                 //    wtx.hashBlock.ToString().substr(0,20).c_str(),
 972                 //    wtx.mapValue["message"].c_str());
 973             }
 974             else if (strType == "acentry")
 975             {
 976                 string strAccount;
 977                 ssKey >> strAccount;
 978                 uint64 nNumber;
 979                 ssKey >> nNumber;
 980                 if (nNumber > nAccountingEntryNumber)
 981                     nAccountingEntryNumber = nNumber;
 982             }
 983             else if (strType == "key" || strType == "wkey")
 984             {
 985                 vector<unsigned char> vchPubKey;
 986                 ssKey >> vchPubKey;
 987                 CKey key;
 988                 if (strType == "key")
 989                 {
 990                     CPrivKey pkey;
 991                     ssValue >> pkey;
 992                     key.SetPubKey(vchPubKey);
 993                     key.SetPrivKey(pkey);
 994                     if (key.GetPubKey() != vchPubKey)
 995                     {
 996                         printf("Error reading wallet database: CPrivKey pubkey inconsistency\n");
 997                         return DB_CORRUPT;
 998                     }
 999                     if (!key.IsValid())
1000                     {
1001                         printf("Error reading wallet database: invalid CPrivKey\n");
1002                         return DB_CORRUPT;
1003                     }
1004                 }
1005                 else
1006                 {
1007                     CWalletKey wkey;
1008                     ssValue >> wkey;
1009                     key.SetPubKey(vchPubKey);
1010                     key.SetPrivKey(wkey.vchPrivKey);
1011                     if (key.GetPubKey() != vchPubKey)
1012                     {
1013                         printf("Error reading wallet database: CWalletKey pubkey inconsistency\n");
1014                         return DB_CORRUPT;
1015                     }
1016                     if (!key.IsValid())
1017                     {
1018                         printf("Error reading wallet database: invalid CWalletKey\n");
1019                         return DB_CORRUPT;
1020                     }
1021                 }
1022                 if (!pwallet->LoadKey(key))
1023                 {
1024                     printf("Error reading wallet database: LoadKey failed\n");
1025                     return DB_CORRUPT;
1026                 }
1027             }
1028             else if (strType == "mkey")
1029             {
1030                 unsigned int nID;
1031                 ssKey >> nID;
1032                 CMasterKey kMasterKey;
1033                 ssValue >> kMasterKey;
1034                 if(pwallet->mapMasterKeys.count(nID) != 0)
1035                 {
1036                     printf("Error reading wallet database: duplicate CMasterKey id %u\n", nID);
1037                     return DB_CORRUPT;
1038                 }
1039                 pwallet->mapMasterKeys[nID] = kMasterKey;
1040                 if (pwallet->nMasterKeyMaxID < nID)
1041                     pwallet->nMasterKeyMaxID = nID;
1042             }
1043             else if (strType == "ckey")
1044             {
1045                 vector<unsigned char> vchPubKey;
1046                 ssKey >> vchPubKey;
1047                 vector<unsigned char> vchPrivKey;
1048                 ssValue >> vchPrivKey;
1049                 if (!pwallet->LoadCryptedKey(vchPubKey, vchPrivKey))
1050                 {
1051                     printf("Error reading wallet database: LoadCryptedKey failed\n");
1052                     return DB_CORRUPT;
1053                 }
1054                 fIsEncrypted = true;
1055             }
1056             else if (strType == "defaultkey")
1057             {
1058                 ssValue >> pwallet->vchDefaultKey;
1059             }
1060             else if (strType == "pool")
1061             {
1062                 int64 nIndex;
1063                 ssKey >> nIndex;
1064                 pwallet->setKeyPool.insert(nIndex);
1065             }
1066             else if (strType == "version")
1067             {
1068                 ssValue >> nFileVersion;
1069                 if (nFileVersion == 10300)
1070                     nFileVersion = 300;
1071             }
1072             else if (strType == "cscript")
1073             {
1074                 uint160 hash;
1075                 ssKey >> hash;
1076                 CScript script;
1077                 ssValue >> script;
1078                 if (!pwallet->LoadCScript(script))
1079                 {
1080                     printf("Error reading wallet database: LoadCScript failed\n");
1081                     return DB_CORRUPT;
1082                 }
1083             }
1084         }
1085         pcursor->close();
1086     }
1087
1088     BOOST_FOREACH(uint256 hash, vWalletUpgrade)
1089         WriteTx(hash, pwallet->mapWallet[hash]);
1090
1091     printf("nFileVersion = %d\n", nFileVersion);
1092
1093
1094     // Rewrite encrypted wallets of versions 0.4.0 and 0.5.0rc:
1095     if (fIsEncrypted && (nFileVersion == 40000 || nFileVersion == 50000))
1096         return DB_NEED_REWRITE;
1097
1098     if (nFileVersion < CLIENT_VERSION) // Update
1099         WriteVersion(CLIENT_VERSION);
1100
1101     return DB_LOAD_OK;
1102 }
1103
1104 void ThreadFlushWalletDB(void* parg)
1105 {
1106     const string& strFile = ((const string*)parg)[0];
1107     static bool fOneThread;
1108     if (fOneThread)
1109         return;
1110     fOneThread = true;
1111     if (!GetBoolArg("-flushwallet", true))
1112         return;
1113
1114     unsigned int nLastSeen = nWalletDBUpdated;
1115     unsigned int nLastFlushed = nWalletDBUpdated;
1116     int64 nLastWalletUpdate = GetTime();
1117     while (!fShutdown)
1118     {
1119         Sleep(500);
1120
1121         if (nLastSeen != nWalletDBUpdated)
1122         {
1123             nLastSeen = nWalletDBUpdated;
1124             nLastWalletUpdate = GetTime();
1125         }
1126
1127         if (nLastFlushed != nWalletDBUpdated && GetTime() - nLastWalletUpdate >= 2)
1128         {
1129             TRY_LOCK(cs_db,lockDb);
1130             if (lockDb)
1131             {
1132                 // Don't do this if any databases are in use
1133                 int nRefCount = 0;
1134                 map<string, int>::iterator mi = mapFileUseCount.begin();
1135                 while (mi != mapFileUseCount.end())
1136                 {
1137                     nRefCount += (*mi).second;
1138                     mi++;
1139                 }
1140
1141                 if (nRefCount == 0 && !fShutdown)
1142                 {
1143                     map<string, int>::iterator mi = mapFileUseCount.find(strFile);
1144                     if (mi != mapFileUseCount.end())
1145                     {
1146                         printf("%s ", DateTimeStrFormat("%x %H:%M:%S", GetTime()).c_str());
1147                         printf("Flushing wallet.dat\n");
1148                         nLastFlushed = nWalletDBUpdated;
1149                         int64 nStart = GetTimeMillis();
1150
1151                         // Flush wallet.dat so it's self contained
1152                         CloseDb(strFile);
1153                         dbenv.txn_checkpoint(0, 0, 0);
1154                         dbenv.lsn_reset(strFile.c_str(), 0);
1155
1156                         mapFileUseCount.erase(mi++);
1157                         printf("Flushed wallet.dat %"PRI64d"ms\n", GetTimeMillis() - nStart);
1158                     }
1159                 }
1160             }
1161         }
1162     }
1163 }
1164
1165 bool BackupWallet(const CWallet& wallet, const string& strDest)
1166 {
1167     if (!wallet.fFileBacked)
1168         return false;
1169     while (!fShutdown)
1170     {
1171         {
1172             LOCK(cs_db);
1173             if (!mapFileUseCount.count(wallet.strWalletFile) || mapFileUseCount[wallet.strWalletFile] == 0)
1174             {
1175                 // Flush log data to the dat file
1176                 CloseDb(wallet.strWalletFile);
1177                 dbenv.txn_checkpoint(0, 0, 0);
1178                 dbenv.lsn_reset(wallet.strWalletFile.c_str(), 0);
1179                 mapFileUseCount.erase(wallet.strWalletFile);
1180
1181                 // Copy wallet.dat
1182                 filesystem::path pathSrc = GetDataDir() / wallet.strWalletFile;
1183                 filesystem::path pathDest(strDest);
1184                 if (filesystem::is_directory(pathDest))
1185                     pathDest /= wallet.strWalletFile;
1186
1187                 try {
1188 #if BOOST_VERSION >= 104000
1189                     filesystem::copy_file(pathSrc, pathDest, filesystem::copy_option::overwrite_if_exists);
1190 #else
1191                     filesystem::copy_file(pathSrc, pathDest);
1192 #endif
1193                     printf("copied wallet.dat to %s\n", pathDest.string().c_str());
1194                     return true;
1195                 } catch(const filesystem::filesystem_error &e) {
1196                     printf("error copying wallet.dat to %s - %s\n", pathDest.string().c_str(), e.what());
1197                     return false;
1198                 }
1199             }
1200         }
1201         Sleep(100);
1202     }
1203     return false;
1204 }