From ca24edfbc1941ed0a3c9586416dae4e84794eb66 Mon Sep 17 00:00:00 2001 From: Andrew Chow Date: Thu, 14 May 2020 21:17:01 -0400 Subject: [PATCH] walletdb: Handle cursor internally Instead of returning a Dbc (BDB cursor object) and having the caller deal with the cursor, make BerkeleyBatch handle the cursor internally. This prepares BerkeleyBatch to work with other database systems as Dbc objects are BDB specific. --- src/wallet/bdb.cpp | 51 +++++++++++++++++++++++++---------------- src/wallet/bdb.h | 6 +++-- src/wallet/walletdb.cpp | 28 +++++++++++----------- 3 files changed, 50 insertions(+), 35 deletions(-) diff --git a/src/wallet/bdb.cpp b/src/wallet/bdb.cpp index 7ed9c88122a..eb62d6664ee 100644 --- a/src/wallet/bdb.cpp +++ b/src/wallet/bdb.cpp @@ -335,7 +335,7 @@ void BerkeleyEnvironment::CheckpointLSN(const std::string& strFile) } -BerkeleyBatch::BerkeleyBatch(BerkeleyDatabase& database, const char* pszMode, bool fFlushOnCloseIn) : pdb(nullptr), activeTxn(nullptr) +BerkeleyBatch::BerkeleyBatch(BerkeleyDatabase& database, const char* pszMode, bool fFlushOnCloseIn) : pdb(nullptr), activeTxn(nullptr), m_cursor(nullptr) { fReadOnly = (!strchr(pszMode, '+') && !strchr(pszMode, 'w')); fFlushOnClose = fFlushOnCloseIn; @@ -442,6 +442,7 @@ void BerkeleyBatch::Close() activeTxn->abort(); activeTxn = nullptr; pdb = nullptr; + CloseCursor(); if (fFlushOnClose) Flush(); @@ -528,17 +529,15 @@ bool BerkeleyBatch::Rewrite(BerkeleyDatabase& database, const char* pszSkip) fSuccess = false; } - Dbc* pcursor = db.GetCursor(); - if (pcursor) + if (db.StartCursor()) { while (fSuccess) { CDataStream ssKey(SER_DISK, CLIENT_VERSION); CDataStream ssValue(SER_DISK, CLIENT_VERSION); - int ret1 = db.ReadAtCursor(pcursor, ssKey, ssValue); - if (ret1 == DB_NOTFOUND) { - pcursor->close(); + bool complete; + bool ret1 = db.ReadAtCursor(ssKey, ssValue, complete); + if (complete) { break; - } else if (ret1 != 0) { - pcursor->close(); + } else if (!ret1) { fSuccess = false; break; } @@ -556,6 +555,8 @@ bool BerkeleyBatch::Rewrite(BerkeleyDatabase& database, const char* pszSkip) if (ret2 > 0) fSuccess = false; } + db.CloseCursor(); + } if (fSuccess) { db.Close(); env->CloseDb(strFile); @@ -738,27 +739,30 @@ void BerkeleyDatabase::ReloadDbEnv() } } -Dbc* BerkeleyBatch::GetCursor() +bool BerkeleyBatch::StartCursor() { + assert(!m_cursor); if (!pdb) - return nullptr; - Dbc* pcursor = nullptr; - int ret = pdb->cursor(nullptr, &pcursor, 0); - if (ret != 0) - return nullptr; - return pcursor; + return false; + int ret = pdb->cursor(nullptr, &m_cursor, 0); + return ret == 0; } -int BerkeleyBatch::ReadAtCursor(Dbc* pcursor, CDataStream& ssKey, CDataStream& ssValue) +bool BerkeleyBatch::ReadAtCursor(CDataStream& ssKey, CDataStream& ssValue, bool& complete) { + complete = false; + if (m_cursor == nullptr) return false; // Read at cursor SafeDbt datKey; SafeDbt datValue; - int ret = pcursor->get(datKey, datValue, DB_NEXT); + int ret = m_cursor->get(datKey, datValue, DB_NEXT); + if (ret == DB_NOTFOUND) { + complete = true; + } if (ret != 0) - return ret; + return false; else if (datKey.get_data() == nullptr || datValue.get_data() == nullptr) - return 99999; + return false; // Convert to streams ssKey.SetType(SER_DISK); @@ -767,7 +771,14 @@ int BerkeleyBatch::ReadAtCursor(Dbc* pcursor, CDataStream& ssKey, CDataStream& s ssValue.SetType(SER_DISK); ssValue.clear(); ssValue.write((char*)datValue.get_data(), datValue.get_size()); - return 0; + return true; +} + +void BerkeleyBatch::CloseCursor() +{ + if (!m_cursor) return; + m_cursor->close(); + m_cursor = nullptr; } bool BerkeleyBatch::TxnBegin() diff --git a/src/wallet/bdb.h b/src/wallet/bdb.h index 5ed364344b4..aac5bc016e5 100644 --- a/src/wallet/bdb.h +++ b/src/wallet/bdb.h @@ -211,6 +211,7 @@ protected: Db* pdb; std::string strFile; DbTxn* activeTxn; + Dbc* m_cursor; bool fReadOnly; bool fFlushOnClose; BerkeleyEnvironment *env; @@ -323,8 +324,9 @@ public: return (ret == 0); } - Dbc* GetCursor(); - int ReadAtCursor(Dbc* pcursor, CDataStream& ssKey, CDataStream& ssValue); + bool StartCursor(); + bool ReadAtCursor(CDataStream& ssKey, CDataStream& ssValue, bool& complete); + void CloseCursor(); bool TxnBegin(); bool TxnCommit(); bool TxnAbort(); diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp index 2f6c2b883ac..027fc7397b3 100644 --- a/src/wallet/walletdb.cpp +++ b/src/wallet/walletdb.cpp @@ -699,8 +699,7 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet) } // Get cursor - Dbc* pcursor = m_batch.GetCursor(); - if (!pcursor) + if (!m_batch.StartCursor()) { pwallet->WalletLogPrintf("Error getting wallet database cursor\n"); return DBErrors::CORRUPT; @@ -711,11 +710,14 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet) // Read next record CDataStream ssKey(SER_DISK, CLIENT_VERSION); CDataStream ssValue(SER_DISK, CLIENT_VERSION); - int ret = m_batch.ReadAtCursor(pcursor, ssKey, ssValue); - if (ret == DB_NOTFOUND) + bool complete; + bool ret = m_batch.ReadAtCursor(ssKey, ssValue, complete); + if (complete) { break; - else if (ret != 0) + } + else if (!ret) { + m_batch.CloseCursor(); pwallet->WalletLogPrintf("Error reading next record from wallet database\n"); return DBErrors::CORRUPT; } @@ -742,10 +744,10 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet) if (!strErr.empty()) pwallet->WalletLogPrintf("%s\n", strErr); } - pcursor->close(); } catch (...) { result = DBErrors::CORRUPT; } + m_batch.CloseCursor(); // Set the active ScriptPubKeyMans for (auto spk_man_pair : wss.m_active_external_spks) { @@ -849,8 +851,7 @@ DBErrors WalletBatch::FindWalletTx(std::vector& vTxHash, std::list& vTxHash, std::list& vTxHash, std::list> vWtx.back(); } } - pcursor->close(); } catch (...) { result = DBErrors::CORRUPT; } + m_batch.CloseCursor(); return result; }