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author | MarcoFalke <falke.marco@gmail.com> | 2021-06-23 18:32:28 +0200 |
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committer | MarcoFalke <falke.marco@gmail.com> | 2021-06-23 18:32:35 +0200 |
commit | 7317e14a44c6efc545e6fb9bcedee7174e93a8fa (patch) | |
tree | 7acfd04611c899e41816f8506fd060f63d46ab78 /src | |
parent | c0e30933e0d319eda6aa8a7f01df32fbb0c3ead8 (diff) | |
parent | 7ad414f4bfa74595ee5726e66f3527045c02a977 (diff) | |
download | bitcoin-7317e14a44c6efc545e6fb9bcedee7174e93a8fa.tar.xz |
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')
-rw-r--r-- | src/coins.cpp | 4 | ||||
-rw-r--r-- | src/coins.h | 6 | ||||
-rw-r--r-- | src/rpc/blockchain.cpp | 4 | ||||
-rw-r--r-- | src/test/fuzz/coins_view.cpp | 4 | ||||
-rw-r--r-- | src/txdb.cpp | 29 | ||||
-rw-r--r-- | src/txdb.h | 24 |
6 files changed, 37 insertions, 34 deletions
diff --git a/src/coins.cpp b/src/coins.cpp index d52851cadd..ce0b131de6 100644 --- a/src/coins.cpp +++ b/src/coins.cpp @@ -13,7 +13,7 @@ bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return f uint256 CCoinsView::GetBestBlock() const { return uint256(); } std::vector<uint256> CCoinsView::GetHeadBlocks() const { return std::vector<uint256>(); } bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; } -CCoinsViewCursor *CCoinsView::Cursor() const { return nullptr; } +std::unique_ptr<CCoinsViewCursor> CCoinsView::Cursor() const { return nullptr; } bool CCoinsView::HaveCoin(const COutPoint &outpoint) const { @@ -28,7 +28,7 @@ uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); } std::vector<uint256> CCoinsViewBacked::GetHeadBlocks() const { return base->GetHeadBlocks(); } void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; } bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); } -CCoinsViewCursor *CCoinsViewBacked::Cursor() const { return base->Cursor(); } +std::unique_ptr<CCoinsViewCursor> CCoinsViewBacked::Cursor() const { return base->Cursor(); } size_t CCoinsViewBacked::EstimateSize() const { return base->EstimateSize(); } CCoinsViewCache::CCoinsViewCache(CCoinsView *baseIn) : CCoinsViewBacked(baseIn), cachedCoinsUsage(0) {} diff --git a/src/coins.h b/src/coins.h index 816b4864a3..3151a260d9 100644 --- a/src/coins.h +++ b/src/coins.h @@ -180,7 +180,7 @@ public: virtual bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock); //! Get a cursor to iterate over the whole state - virtual CCoinsViewCursor *Cursor() const; + virtual std::unique_ptr<CCoinsViewCursor> Cursor() const; //! As we use CCoinsViews polymorphically, have a virtual destructor virtual ~CCoinsView() {} @@ -204,7 +204,7 @@ public: std::vector<uint256> GetHeadBlocks() const override; void SetBackend(CCoinsView &viewIn); bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) override; - CCoinsViewCursor *Cursor() const override; + std::unique_ptr<CCoinsViewCursor> Cursor() const override; size_t EstimateSize() const override; }; @@ -237,7 +237,7 @@ public: uint256 GetBestBlock() const override; void SetBestBlock(const uint256 &hashBlock); bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) override; - CCoinsViewCursor* Cursor() const override { + std::unique_ptr<CCoinsViewCursor> Cursor() const override { throw std::logic_error("CCoinsViewCache cursor iteration not supported."); } diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp index 63897e0e05..4d4d3fb7d0 100644 --- a/src/rpc/blockchain.cpp +++ b/src/rpc/blockchain.cpp @@ -2391,7 +2391,7 @@ static RPCHelpMan scantxoutset() LOCK(cs_main); CChainState& active_chainstate = chainman.ActiveChainstate(); active_chainstate.ForceFlushStateToDisk(); - pcursor = std::unique_ptr<CCoinsViewCursor>(active_chainstate.CoinsDB().Cursor()); + pcursor = active_chainstate.CoinsDB().Cursor(); CHECK_NONFATAL(pcursor); tip = active_chainstate.m_chain.Tip(); CHECK_NONFATAL(tip); @@ -2590,7 +2590,7 @@ UniValue CreateUTXOSnapshot(NodeContext& node, CChainState& chainstate, CAutoFil throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set"); } - pcursor = std::unique_ptr<CCoinsViewCursor>(chainstate.CoinsDB().Cursor()); + pcursor = chainstate.CoinsDB().Cursor(); tip = chainstate.m_blockman.LookupBlockIndex(stats.hashBlock); CHECK_NONFATAL(tip); } diff --git a/src/test/fuzz/coins_view.cpp b/src/test/fuzz/coins_view.cpp index 42f19d16c6..f452696689 100644 --- a/src/test/fuzz/coins_view.cpp +++ b/src/test/fuzz/coins_view.cpp @@ -183,8 +183,8 @@ FUZZ_TARGET_INIT(coins_view, initialize_coins_view) } { - const CCoinsViewCursor* coins_view_cursor = backend_coins_view.Cursor(); - assert(coins_view_cursor == nullptr); + std::unique_ptr<CCoinsViewCursor> coins_view_cursor = backend_coins_view.Cursor(); + assert(!coins_view_cursor); (void)backend_coins_view.EstimateSize(); (void)backend_coins_view.GetBestBlock(); (void)backend_coins_view.GetHeadBlocks(); 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. */ diff --git a/src/txdb.h b/src/txdb.h index 0cf7e2f1b8..845d80788f 100644 --- a/src/txdb.h +++ b/src/txdb.h @@ -60,7 +60,7 @@ public: uint256 GetBestBlock() const override; std::vector<uint256> GetHeadBlocks() const override; bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) override; - CCoinsViewCursor *Cursor() const override; + std::unique_ptr<CCoinsViewCursor> Cursor() const override; //! Attempt to update from an older database format. Returns whether an error occurred. bool Upgrade(); @@ -70,28 +70,6 @@ public: void ResizeCache(size_t new_cache_size) EXCLUSIVE_LOCKS_REQUIRED(cs_main); }; -/** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */ -class CCoinsViewDBCursor: public CCoinsViewCursor -{ -public: - ~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: - CCoinsViewDBCursor(CDBIterator* pcursorIn, const uint256 &hashBlockIn): - CCoinsViewCursor(hashBlockIn), pcursor(pcursorIn) {} - std::unique_ptr<CDBIterator> pcursor; - std::pair<char, COutPoint> keyTmp; - - friend class CCoinsViewDB; -}; - /** Access to the block database (blocks/index/) */ class CBlockTreeDB : public CDBWrapper { |