From daad2b25596a1cd25a570d9cb2a747a702e17901 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= Date: Thu, 10 Mar 2016 20:19:09 +0200 Subject: core: cache fresh headers and tds to avoid db trashing --- core/headerchain.go | 68 +++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 50 insertions(+), 18 deletions(-) (limited to 'core/headerchain.go') diff --git a/core/headerchain.go b/core/headerchain.go index 8528801a7..255139dde 100644 --- a/core/headerchain.go +++ b/core/headerchain.go @@ -43,11 +43,13 @@ type HeaderChain struct { chainDb ethdb.Database genesisHeader *types.Header - currentHeader *types.Header // Current head of the header chain (may be above the block chain!) - headerCache *lru.Cache // Cache for the most recent block headers - tdCache *lru.Cache // Cache for the most recent block total difficulties + currentHeader *types.Header // Current head of the header chain (may be above the block chain!) + currentHeaderHash common.Hash // Hash of the current head of the header chain (prevent recomputing all the time) - procInterrupt func() bool + headerCache *lru.Cache // Cache for the most recent block headers + tdCache *lru.Cache // Cache for the most recent block total difficulties + + procInterrupt func() bool rand *mrand.Rand getValidator getHeaderValidatorFn @@ -95,6 +97,7 @@ func NewHeaderChain(chainDb ethdb.Database, getValidator getHeaderValidatorFn, p hc.currentHeader = chead } } + hc.currentHeaderHash = hc.currentHeader.Hash() return hc, nil } @@ -109,12 +112,17 @@ func NewHeaderChain(chainDb ethdb.Database, getValidator getHeaderValidatorFn, p // in two scenarios: pure-header mode of operation (light clients), or properly // separated header/block phases (non-archive clients). func (hc *HeaderChain) WriteHeader(header *types.Header) (status WriteStatus, err error) { + // Cache some values to prevent constant recalculation + var ( + hash = header.Hash() + number = header.Number.Uint64() + ) // Calculate the total difficulty of the header ptd := hc.GetTd(header.ParentHash) if ptd == nil { return NonStatTy, ParentError(header.ParentHash) } - localTd := hc.GetTd(hc.currentHeader.Hash()) + localTd := hc.GetTd(hc.currentHeaderHash) externTd := new(big.Int).Add(header.Difficulty, ptd) // If the total difficulty is higher than our known, add it to the canonical chain @@ -122,34 +130,44 @@ func (hc *HeaderChain) WriteHeader(header *types.Header) (status WriteStatus, er // Please refer to http://www.cs.cornell.edu/~ie53/publications/btcProcFC.pdf if externTd.Cmp(localTd) > 0 || (externTd.Cmp(localTd) == 0 && mrand.Float64() < 0.5) { // Delete any canonical number assignments above the new head - for i := header.Number.Uint64() + 1; GetCanonicalHash(hc.chainDb, i) != (common.Hash{}); i++ { + for i := number + 1; GetCanonicalHash(hc.chainDb, i) != (common.Hash{}); i++ { DeleteCanonicalHash(hc.chainDb, i) } // Overwrite any stale canonical number assignments - head := hc.GetHeader(header.ParentHash) - for GetCanonicalHash(hc.chainDb, head.Number.Uint64()) != head.Hash() { - WriteCanonicalHash(hc.chainDb, head.Hash(), head.Number.Uint64()) - head = hc.GetHeader(head.ParentHash) + var ( + headHash = header.ParentHash + headHeader = hc.GetHeader(headHash) + headNumber = headHeader.Number.Uint64() + ) + for GetCanonicalHash(hc.chainDb, headNumber) != headHash { + WriteCanonicalHash(hc.chainDb, headHash, headNumber) + + headHash = headHeader.ParentHash + headHeader = hc.GetHeader(headHash) + headNumber = headHeader.Number.Uint64() } // Extend the canonical chain with the new header - if err := WriteCanonicalHash(hc.chainDb, header.Hash(), header.Number.Uint64()); err != nil { + if err := WriteCanonicalHash(hc.chainDb, hash, number); err != nil { glog.Fatalf("failed to insert header number: %v", err) } - if err := WriteHeadHeaderHash(hc.chainDb, header.Hash()); err != nil { + if err := WriteHeadHeaderHash(hc.chainDb, hash); err != nil { glog.Fatalf("failed to insert head header hash: %v", err) } - hc.currentHeader = types.CopyHeader(header) + hc.currentHeaderHash, hc.currentHeader = hash, types.CopyHeader(header) + status = CanonStatTy } else { status = SideStatTy } // Irrelevant of the canonical status, write the header itself to the database - if err := WriteTd(hc.chainDb, header.Hash(), externTd); err != nil { + if err := hc.WriteTd(hash, externTd); err != nil { glog.Fatalf("failed to write header total difficulty: %v", err) } if err := WriteHeader(hc.chainDb, header); err != nil { glog.Fatalf("failed to write header contents: %v", err) } + hc.headerCache.Add(hash, header) + return } @@ -285,10 +303,11 @@ func (hc *HeaderChain) GetBlockHashesFromHash(hash common.Hash, max uint64) []co // Iterate the headers until enough is collected or the genesis reached chain := make([]common.Hash, 0, max) for i := uint64(0); i < max; i++ { - if header = hc.GetHeader(header.ParentHash); header == nil { + next := header.ParentHash + if header = hc.GetHeader(next); header == nil { break } - chain = append(chain, header.Hash()) + chain = append(chain, next) if header.Number.Cmp(common.Big0) == 0 { break } @@ -312,6 +331,16 @@ func (hc *HeaderChain) GetTd(hash common.Hash) *big.Int { return td } +// WriteTd stores a block's total difficulty into the database, also caching it +// along the way. +func (hc *HeaderChain) WriteTd(hash common.Hash, td *big.Int) error { + if err := WriteTd(hc.chainDb, hash, td); err != nil { + return err + } + hc.tdCache.Add(hash, new(big.Int).Set(td)) + return nil +} + // GetHeader retrieves a block header from the database by hash, caching it if // found. func (hc *HeaderChain) GetHeader(hash common.Hash) *types.Header { @@ -324,7 +353,7 @@ func (hc *HeaderChain) GetHeader(hash common.Hash) *types.Header { return nil } // Cache the found header for next time and return - hc.headerCache.Add(header.Hash(), header) + hc.headerCache.Add(hash, header) return header } @@ -356,6 +385,7 @@ func (hc *HeaderChain) SetCurrentHeader(head *types.Header) { glog.Fatalf("failed to insert head header hash: %v", err) } hc.currentHeader = head + hc.currentHeaderHash = head.Hash() } // DeleteCallback is a callback function that is called by SetHead before @@ -390,7 +420,9 @@ func (hc *HeaderChain) SetHead(head uint64, delFn DeleteCallback) { if hc.currentHeader == nil { hc.currentHeader = hc.genesisHeader } - if err := WriteHeadHeaderHash(hc.chainDb, hc.currentHeader.Hash()); err != nil { + hc.currentHeaderHash = hc.currentHeader.Hash() + + if err := WriteHeadHeaderHash(hc.chainDb, hc.currentHeaderHash); err != nil { glog.Fatalf("failed to reset head header hash: %v", err) } } -- cgit v1.2.3