aboutsummaryrefslogtreecommitdiff
path: root/src/index/txindex.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/index/txindex.cpp')
-rw-r--r--src/index/txindex.cpp219
1 files changed, 218 insertions, 1 deletions
diff --git a/src/index/txindex.cpp b/src/index/txindex.cpp
index 328039977f..e106b9b420 100644
--- a/src/index/txindex.cpp
+++ b/src/index/txindex.cpp
@@ -3,15 +3,232 @@
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <index/txindex.h>
+#include <init.h>
+#include <ui_interface.h>
#include <util.h>
#include <validation.h>
+#include <boost/thread.hpp>
+
+constexpr char DB_BEST_BLOCK = 'B';
+constexpr char DB_TXINDEX = 't';
+constexpr char DB_TXINDEX_BLOCK = 'T';
+
std::unique_ptr<TxIndex> g_txindex;
+struct CDiskTxPos : public CDiskBlockPos
+{
+ unsigned int nTxOffset; // after header
+
+ ADD_SERIALIZE_METHODS;
+
+ template <typename Stream, typename Operation>
+ inline void SerializationOp(Stream& s, Operation ser_action) {
+ READWRITEAS(CDiskBlockPos, *this);
+ READWRITE(VARINT(nTxOffset));
+ }
+
+ CDiskTxPos(const CDiskBlockPos &blockIn, unsigned int nTxOffsetIn) : CDiskBlockPos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
+ }
+
+ CDiskTxPos() {
+ SetNull();
+ }
+
+ void SetNull() {
+ CDiskBlockPos::SetNull();
+ nTxOffset = 0;
+ }
+};
+
+/**
+ * Access to the txindex database (indexes/txindex/)
+ *
+ * The database stores a block locator of the chain the database is synced to
+ * so that the TxIndex can efficiently determine the point it last stopped at.
+ * A locator is used instead of a simple hash of the chain tip because blocks
+ * and block index entries may not be flushed to disk until after this database
+ * is updated.
+ */
+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"), 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()) {
+ boost::this_thread::interruption_point();
+ 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"), 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);
@@ -38,7 +255,7 @@ bool TxIndex::WriteBlock(const CBlock& block, const CBlockIndex* pindex)
return m_db->WriteTxs(vPos);
}
-BaseIndexDB& TxIndex::GetDB() const { return *m_db; }
+BaseIndex::DB& TxIndex::GetDB() const { return *m_db; }
bool TxIndex::FindTx(const uint256& tx_hash, uint256& block_hash, CTransactionRef& tx) const
{
generated by cgit v1.2.3 (git 2.26.2) at 2024-07-02 20:49:46 +0000