git / moonbite-core / src/index/txindex.cpp · raw

// Copyright (c) 2017-2019 The Bitcoin Core developers// Distributed under the MIT software license, see the accompanying// file COPYING or http://www.opensource.org/licenses/mit-license.php.#include <index/disktxpos.h>#include <index/txindex.h>#include <node/ui_interface.h>#include <shutdown.h>#include <util/system.h>#include <util/translation.h>#include <validation.h>constexpr char DB_BEST_BLOCK = 'B';constexpr char DB_TXINDEX = 't';constexpr char DB_TXINDEX_BLOCK = 'T';std::unique_ptr<TxIndex> g_txindex;/** Access to the txindex database (indexes/txindex/) */class TxIndex::DB : public BaseIndex::DB{public:    explicit DB(size_t n_cache_size, bool f_memory = false, bool f_wipe = false);    /// Read the disk location of the transaction data with the given hash. Returns false if the    /// transaction hash is not indexed.    bool ReadTxPos(const uint256& txid, CDiskTxPos& pos) const;    /// Write a batch of transaction positions to the DB.    bool WriteTxs(const std::vector<std::pair<uint256, CDiskTxPos>>& v_pos);    /// Migrate txindex data from the block tree DB, where it may be for older nodes that have not    /// been upgraded yet to the new database.    bool MigrateData(CBlockTreeDB& block_tree_db, const CBlockLocator& best_locator);};TxIndex::DB::DB(size_t n_cache_size, bool f_memory, bool f_wipe) :    BaseIndex::DB(GetDataDir() / "indexes" / "txindex", n_cache_size, f_memory, f_wipe){}bool TxIndex::DB::ReadTxPos(const uint256 &txid, CDiskTxPos& pos) const{    return Read(std::make_pair(DB_TXINDEX, txid), pos);}bool TxIndex::DB::WriteTxs(const std::vector<std::pair<uint256, CDiskTxPos>>& v_pos){    CDBBatch batch(*this);    for (const auto& tuple : v_pos) {        batch.Write(std::make_pair(DB_TXINDEX, tuple.first), tuple.second);    }    return WriteBatch(batch);}/* * Safely persist a transfer of data from the old txindex database to the new one, and compact the * range of keys updated. This is used internally by MigrateData. */static void WriteTxIndexMigrationBatches(CDBWrapper& newdb, CDBWrapper& olddb,                                         CDBBatch& batch_newdb, CDBBatch& batch_olddb,                                         const std::pair<unsigned char, uint256>& begin_key,                                         const std::pair<unsigned char, uint256>& end_key){    // Sync new DB changes to disk before deleting from old DB.    newdb.WriteBatch(batch_newdb, /*fSync=*/ true);    olddb.WriteBatch(batch_olddb);    olddb.CompactRange(begin_key, end_key);    batch_newdb.Clear();    batch_olddb.Clear();}bool TxIndex::DB::MigrateData(CBlockTreeDB& block_tree_db, const CBlockLocator& best_locator){    // The prior implementation of txindex was always in sync with block index    // and presence was indicated with a boolean DB flag. If the flag is set,    // this means the txindex from a previous version is valid and in sync with    // the chain tip. The first step of the migration is to unset the flag and    // write the chain hash to a separate key, DB_TXINDEX_BLOCK. After that, the    // index entries are copied over in batches to the new database. Finally,    // DB_TXINDEX_BLOCK is erased from the old database and the block hash is    // written to the new database.    //    // Unsetting the boolean flag ensures that if the node is downgraded to a    // previous version, it will not see a corrupted, partially migrated index    // -- it will see that the txindex is disabled. When the node is upgraded    // again, the migration will pick up where it left off and sync to the block    // with hash DB_TXINDEX_BLOCK.    bool f_legacy_flag = false;    block_tree_db.ReadFlag("txindex", f_legacy_flag);    if (f_legacy_flag) {        if (!block_tree_db.Write(DB_TXINDEX_BLOCK, best_locator)) {            return error("%s: cannot write block indicator", __func__);        }        if (!block_tree_db.WriteFlag("txindex", false)) {            return error("%s: cannot write block index db flag", __func__);        }    }    CBlockLocator locator;    if (!block_tree_db.Read(DB_TXINDEX_BLOCK, locator)) {        return true;    }    int64_t count = 0;    LogPrintf("Upgrading txindex database... [0%%]\n");    uiInterface.ShowProgress(_("Upgrading txindex database").translated, 0, true);    int report_done = 0;    const size_t batch_size = 1 << 24; // 16 MiB    CDBBatch batch_newdb(*this);    CDBBatch batch_olddb(block_tree_db);    std::pair<unsigned char, uint256> key;    std::pair<unsigned char, uint256> begin_key{DB_TXINDEX, uint256()};    std::pair<unsigned char, uint256> prev_key = begin_key;    bool interrupted = false;    std::unique_ptr<CDBIterator> cursor(block_tree_db.NewIterator());    for (cursor->Seek(begin_key); cursor->Valid(); cursor->Next()) {        if (ShutdownRequested()) {            interrupted = true;            break;        }        if (!cursor->GetKey(key)) {            return error("%s: cannot get key from valid cursor", __func__);        }        if (key.first != DB_TXINDEX) {            break;        }        // Log progress every 10%.        if (++count % 256 == 0) {            // Since txids are uniformly random and traversed in increasing order, the high 16 bits            // of the hash can be used to estimate the current progress.            const uint256& txid = key.second;            uint32_t high_nibble =                (static_cast<uint32_t>(*(txid.begin() + 0)) << 8) +                (static_cast<uint32_t>(*(txid.begin() + 1)) << 0);            int percentage_done = (int)(high_nibble * 100.0 / 65536.0 + 0.5);            uiInterface.ShowProgress(_("Upgrading txindex database").translated, percentage_done, true);            if (report_done < percentage_done/10) {                LogPrintf("Upgrading txindex database... [%d%%]\n", percentage_done);                report_done = percentage_done/10;            }        }        CDiskTxPos value;        if (!cursor->GetValue(value)) {            return error("%s: cannot parse txindex record", __func__);        }        batch_newdb.Write(key, value);        batch_olddb.Erase(key);        if (batch_newdb.SizeEstimate() > batch_size || batch_olddb.SizeEstimate() > batch_size) {            // NOTE: it's OK to delete the key pointed at by the current DB cursor while iterating            // because LevelDB iterators are guaranteed to provide a consistent view of the            // underlying data, like a lightweight snapshot.            WriteTxIndexMigrationBatches(*this, block_tree_db,                                         batch_newdb, batch_olddb,                                         prev_key, key);            prev_key = key;        }    }    // If these final DB batches complete the migration, write the best block    // hash marker to the new database and delete from the old one. This signals    // that the former is fully caught up to that point in the blockchain and    // that all txindex entries have been removed from the latter.    if (!interrupted) {        batch_olddb.Erase(DB_TXINDEX_BLOCK);        batch_newdb.Write(DB_BEST_BLOCK, locator);    }    WriteTxIndexMigrationBatches(*this, block_tree_db,                                 batch_newdb, batch_olddb,                                 begin_key, key);    if (interrupted) {        LogPrintf("[CANCELLED].\n");        return false;    }    uiInterface.ShowProgress("", 100, false);    LogPrintf("[DONE].\n");    return true;}TxIndex::TxIndex(size_t n_cache_size, bool f_memory, bool f_wipe)    : m_db(MakeUnique<TxIndex::DB>(n_cache_size, f_memory, f_wipe)){}TxIndex::~TxIndex() {}bool TxIndex::Init(){    LOCK(cs_main);    // Attempt to migrate txindex from the old database to the new one. Even if    // chain_tip is null, the node could be reindexing and we still want to    // delete txindex records in the old database.    if (!m_db->MigrateData(*pblocktree, ::ChainActive().GetLocator())) {        return false;    }    return BaseIndex::Init();}bool TxIndex::WriteBlock(const CBlock& block, const CBlockIndex* pindex){    // Exclude genesis block transaction because outputs are not spendable.    if (pindex->nHeight == 0) return true;    CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));    std::vector<std::pair<uint256, CDiskTxPos>> vPos;    vPos.reserve(block.vtx.size());    for (const auto& tx : block.vtx) {        vPos.emplace_back(tx->GetHash(), pos);        pos.nTxOffset += ::GetSerializeSize(*tx, CLIENT_VERSION);    }    return m_db->WriteTxs(vPos);}BaseIndex::DB& TxIndex::GetDB() const { return *m_db; }bool TxIndex::FindTx(const uint256& tx_hash, uint256& block_hash, CTransactionRef& tx) const{    CDiskTxPos postx;    if (!m_db->ReadTxPos(tx_hash, postx)) {        return false;    }    CAutoFile file(OpenBlockFile(postx, true), SER_DISK, CLIENT_VERSION);    if (file.IsNull()) {        return error("%s: OpenBlockFile failed", __func__);    }    CBlockHeader header;    try {        file >> header;        if (fseek(file.Get(), postx.nTxOffset, SEEK_CUR)) {            return error("%s: fseek(...) failed", __func__);        }        file >> tx;    } catch (const std::exception& e) {        return error("%s: Deserialize or I/O error - %s", __func__, e.what());    }    if (tx->GetHash() != tx_hash) {        return error("%s: txid mismatch", __func__);    }    block_hash = header.GetHash();    return true;}