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| author | MarcoFalke <falke.marco@gmail.com> | 2021-06-23 18:32:28 +0200 |
|---|---|---|
| committer | MarcoFalke <falke.marco@gmail.com> | 2021-06-23 18:32:35 +0200 |
| commit | 7317e14a44c6efc545e6fb9bcedee7174e93a8fa (patch) | |
| tree | 7acfd04611c899e41816f8506fd060f63d46ab78 /src/txdb.cpp | |
| parent | c0e30933e0d319eda6aa8a7f01df32fbb0c3ead8 (diff) | |
| parent | 7ad414f4bfa74595ee5726e66f3527045c02a977 (diff) | |
Merge bitcoin/bitcoin#22263: refactor: wrap CCoinsViewCursor in unique_ptr
7ad414f4bfa74595ee5726e66f3527045c02a977 doc: add comment about CCoinsViewDBCursor constructor (James O'Beirne)
0f8a5a4dd530549d37c43da52c923ac3b2af1a03 move-only(ish): don't expose CCoinsViewDBCursor (James O'Beirne)
615c1adfb07b9b466173166dc2e53ace540e4b32 refactor: wrap CCoinsViewCursor in unique_ptr (James O'Beirne)
Pull request description:
I tripped over this one for a few hours at the beginning of the week, so I've sort of got a personal vendetta against `CCoinsView::Cursor()` returning a raw pointer.
Specifically in the case of CCoinsViewDB, if a raw cursor is allocated and not freed, a cryptic leveldb assertion failure occurs on CCoinsViewDB destruction (`Assertion 'dummy_versions_.next_ == &dummy_versions_' failed.`).
This is a pretty simple change.
Related to: https://github.com/bitcoin/bitcoin/issues/21766
See also: https://github.com/google/leveldb/issues/142#issuecomment-414418135
ACKs for top commit:
MarcoFalke:
review ACK 7ad414f4bfa74595ee5726e66f3527045c02a977 🔎
jonatack:
re-ACK 7ad414f4bfa74595ee5726e66f3527045c02a977 modulo suggestion
ryanofsky:
Code review ACK 7ad414f4bfa74595ee5726e66f3527045c02a977. Two new commits look good and thanks for clarifying constructor comment
Tree-SHA512: 6471d03e2de674d84b1ea0d31e25f433d52aa1aa4996f7b4aab1bd02b6bc340b15e64cc8ea07bbefefa3b5da35384ca5400cc230434e787c30931b8574c672f9
Diffstat (limited to 'src/txdb.cpp')
| -rw-r--r-- | src/txdb.cpp | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/src/txdb.cpp b/src/txdb.cpp index 762f71feb1..4b76bee5ab 100644 --- a/src/txdb.cpp +++ b/src/txdb.cpp @@ -168,9 +168,34 @@ bool CBlockTreeDB::ReadLastBlockFile(int &nFile) { return Read(DB_LAST_BLOCK, nFile); } -CCoinsViewCursor *CCoinsViewDB::Cursor() const +/** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */ +class CCoinsViewDBCursor: public CCoinsViewCursor { - CCoinsViewDBCursor *i = new CCoinsViewDBCursor(const_cast<CDBWrapper&>(*m_db).NewIterator(), GetBestBlock()); +public: + // Prefer using CCoinsViewDB::Cursor() since we want to perform some + // cache warmup on instantiation. + CCoinsViewDBCursor(CDBIterator* pcursorIn, const uint256&hashBlockIn): + CCoinsViewCursor(hashBlockIn), pcursor(pcursorIn) {} + ~CCoinsViewDBCursor() {} + + bool GetKey(COutPoint &key) const override; + bool GetValue(Coin &coin) const override; + unsigned int GetValueSize() const override; + + bool Valid() const override; + void Next() override; + +private: + std::unique_ptr<CDBIterator> pcursor; + std::pair<char, COutPoint> keyTmp; + + friend class CCoinsViewDB; +}; + +std::unique_ptr<CCoinsViewCursor> CCoinsViewDB::Cursor() const +{ + auto i = std::make_unique<CCoinsViewDBCursor>( + const_cast<CDBWrapper&>(*m_db).NewIterator(), GetBestBlock()); /* 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. */ |