From 1ebf50b6dada3bace0ed3e02266f326096c98831 Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Wed, 7 Oct 2015 17:12:24 -0700 Subject: [PATCH] Encapsulate CLevelDB iterators cleanly Conflicts: src/leveldb.cpp src/leveldb.h src/txdb.cpp --- src/leveldbwrapper.cpp | 9 +++++- src/leveldbwrapper.h | 64 +++++++++++++++++++++++++++++++++++++++--- src/txdb.cpp | 59 +++++++++++++------------------------- 3 files changed, 88 insertions(+), 44 deletions(-) diff --git a/src/leveldbwrapper.cpp b/src/leveldbwrapper.cpp index 22658b092..2a3e777c9 100644 --- a/src/leveldbwrapper.cpp +++ b/src/leveldbwrapper.cpp @@ -91,7 +91,14 @@ bool CLevelDBWrapper::WriteBatch(CLevelDBBatch& batch, bool fSync) bool CLevelDBWrapper::IsEmpty() { - boost::scoped_ptr it(NewIterator()); + boost::scoped_ptr it(NewIterator()); it->SeekToFirst(); return !(it->Valid()); } + +CLevelDBIterator::~CLevelDBIterator() { delete piter; } +bool CLevelDBIterator::Valid() { return piter->Valid(); } +void CLevelDBIterator::SeekToFirst() { piter->SeekToFirst(); } +void CLevelDBIterator::SeekToLast() { piter->SeekToLast(); } +void CLevelDBIterator::Next() { piter->Next(); } +void CLevelDBIterator::Prev() { piter->Prev(); } diff --git a/src/leveldbwrapper.h b/src/leveldbwrapper.h index 2bcef7daf..daa0f78ce 100644 --- a/src/leveldbwrapper.h +++ b/src/leveldbwrapper.h @@ -60,7 +60,64 @@ public: batch.Delete(slKey); } }; + +class CLevelDBIterator +{ +private: + leveldb::Iterator *piter; +public: + CLevelDBIterator(leveldb::Iterator *piterIn) : piter(piterIn) {} + ~CLevelDBIterator(); + + bool Valid(); + + void SeekToFirst(); + void SeekToLast(); + + template void Seek(const K& key) { + CDataStream ssKey(SER_DISK, CLIENT_VERSION); + ssKey.reserve(ssKey.GetSerializeSize(key)); + ssKey << key; + leveldb::Slice slKey(&ssKey[0], ssKey.size()); + piter->Seek(slKey); + } + + void Next(); + void Prev(); + + template bool GetKey(K& key) { + leveldb::Slice slKey = piter->key(); + try { + CDataStream ssKey(slKey.data(), slKey.data() + slKey.size(), SER_DISK, CLIENT_VERSION); + ssKey >> key; + } catch(std::exception &e) { + return false; + } + return true; + } + + unsigned int GetKeySize() { + return piter->key().size(); + } + + template bool GetValue(V& value) { + leveldb::Slice slValue = piter->value(); + try { + CDataStream ssValue(slValue.data(), slValue.data() + slValue.size(), SER_DISK, CLIENT_VERSION); + ssValue >> value; + } catch(std::exception &e) { + return false; + } + return true; + } + + unsigned int GetValueSize() { + return piter->value().size(); + } + +}; + class CLevelDBWrapper { private: @@ -169,11 +226,10 @@ public: return WriteBatch(batch, true); } - // not exactly clean encapsulation, but it's easiest for now - leveldb::Iterator* NewIterator() + CLevelDBIterator *NewIterator() + { + return new CLevelDBIterator(pdb->NewIterator(iteroptions)); { - return pdb->NewIterator(iteroptions); - } /** * Return true if the database managed by this class contains no entries. diff --git a/src/txdb.cpp b/src/txdb.cpp index 297777781..29b49745c 100644 --- a/src/txdb.cpp +++ b/src/txdb.cpp @@ -162,8 +162,8 @@ bool CCoinsViewDB::GetStats(CCoinsStats &stats) const { /* It seems that there are no "const iterators" for LevelDB. Since we only need read operations on it, use a const-cast to get around that restriction. */ - boost::scoped_ptr pcursor(const_cast(&db)->NewIterator()); - pcursor->SeekToFirst(); + boost::scoped_ptr pcursor(const_cast(&db)->NewIterator()); + pcursor->Seek('c'); CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION); stats.hashBlock = GetBestBlock(); @@ -171,22 +171,10 @@ bool CCoinsViewDB::GetStats(CCoinsStats &stats) const { CAmount nTotalAmount = 0; while (pcursor->Valid()) { boost::this_thread::interruption_point(); - try { - leveldb::Slice slKey = pcursor->key(); - CDataStream ssKey(slKey.data(), slKey.data()+slKey.size(), SER_DISK, CLIENT_VERSION); - char chType; - ssKey >> chType; - if (chType == DB_COINS) { - leveldb::Slice slValue = pcursor->value(); - CDataStream ssValue(slValue.data(), slValue.data()+slValue.size(), SER_DISK, CLIENT_VERSION); - CCoins coins; - ssValue >> coins; - uint256 txhash; - ssKey >> txhash; - ss << txhash; - ss << VARINT(coins.nVersion); - ss << (coins.fCoinBase ? 'c' : 'n'); - ss << VARINT(coins.nHeight); + std::pair key; + CCoins coins; + if (pcursor->GetKey(key) && key.first == 'c') { + if (pcursor->GetValue(coins)) { stats.nTransactions++; for (unsigned int i=0; iGetKeySize(); ss << VARINT(0); + } else { + return error("CCoinsViewDB::GetStats() : unable to read value"); } - pcursor->Next(); - } catch (const std::exception& e) { - return error("%s: Deserialize or I/O error - %s", __func__, e.what()); + } else { + break; } + pcursor->Next(); } { LOCK(cs_main); @@ -261,24 +251,15 @@ bool CBlockTreeDB::LoadBlockIndexGuts() { boost::scoped_ptr pcursor(NewIterator()); - CDataStream ssKeySet(SER_DISK, CLIENT_VERSION); - ssKeySet << make_pair(DB_BLOCK_INDEX, uint256()); - pcursor->Seek(ssKeySet.str()); + pcursor->Seek(make_pair('b', uint256(0))); // Load mapBlockIndex while (pcursor->Valid()) { boost::this_thread::interruption_point(); - try { - leveldb::Slice slKey = pcursor->key(); - CDataStream ssKey(slKey.data(), slKey.data()+slKey.size(), SER_DISK, CLIENT_VERSION); - char chType; - ssKey >> chType; - if (chType == DB_BLOCK_INDEX) { - leveldb::Slice slValue = pcursor->value(); - CDataStream ssValue(slValue.data(), slValue.data()+slValue.size(), SER_DISK, CLIENT_VERSION); - CDiskBlockIndex diskindex; - ssValue >> diskindex; - + std::pair key; + if (pcursor->GetKey(key) && key.first == 'b') { + CDiskBlockIndex diskindex; + if (pcursor->GetValue(diskindex)) { // Construct block index object CBlockIndex* pindexNew = InsertBlockIndex(diskindex.GetBlockHash()); pindexNew->pprev = InsertBlockIndex(diskindex.hashPrev); @@ -309,10 +290,10 @@ bool CBlockTreeDB::LoadBlockIndexGuts() pcursor->Next(); } else { - break; // if shutdown requested or finished loading block index + return error("LoadBlockIndex() : failed to read value"); } - } catch (const std::exception& e) { - return error("%s: Deserialize or I/O error - %s", __func__, e.what()); + } else { + break; } }