From 9e5f03b6c487175cc5aa1224e5e12fd573f483a7 Mon Sep 17 00:00:00 2001 From: Felix Lange Date: Tue, 27 Jun 2017 15:57:06 +0200 Subject: core/state: access trie through Database interface, track errors (#14589) With this commit, core/state's access to the underlying key/value database is mediated through an interface. Database errors are tracked in StateDB and returned by CommitTo or the new Error method. Motivation for this change: We can remove the light client's duplicated copy of core/state. The light client now supports node iteration, so tracing and storage enumeration can work with the light client (not implemented in this commit). --- core/state/database.go | 154 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 core/state/database.go (limited to 'core/state/database.go') diff --git a/core/state/database.go b/core/state/database.go new file mode 100644 index 000000000..946625e76 --- /dev/null +++ b/core/state/database.go @@ -0,0 +1,154 @@ +// Copyright 2017 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package state + +import ( + "fmt" + "sync" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/ethdb" + "github.com/ethereum/go-ethereum/trie" + lru "github.com/hashicorp/golang-lru" +) + +// Trie cache generation limit after which to evic trie nodes from memory. +var MaxTrieCacheGen = uint16(120) + +const ( + // Number of past tries to keep. This value is chosen such that + // reasonable chain reorg depths will hit an existing trie. + maxPastTries = 12 + + // Number of codehash->size associations to keep. + codeSizeCacheSize = 100000 +) + +// Database wraps access to tries and contract code. +type Database interface { + // Accessing tries: + // OpenTrie opens the main account trie. + // OpenStorageTrie opens the storage trie of an account. + OpenTrie(root common.Hash) (Trie, error) + OpenStorageTrie(addrHash, root common.Hash) (Trie, error) + // Accessing contract code: + ContractCode(addrHash, codeHash common.Hash) ([]byte, error) + ContractCodeSize(addrHash, codeHash common.Hash) (int, error) + // CopyTrie returns an independent copy of the given trie. + CopyTrie(Trie) Trie +} + +// Trie is a Ethereum Merkle Trie. +type Trie interface { + TryGet(key []byte) ([]byte, error) + TryUpdate(key, value []byte) error + TryDelete(key []byte) error + CommitTo(trie.DatabaseWriter) (common.Hash, error) + Hash() common.Hash + NodeIterator(startKey []byte) trie.NodeIterator + GetKey([]byte) []byte // TODO(fjl): remove this when SecureTrie is removed +} + +// NewDatabase creates a backing store for state. The returned database is safe for +// concurrent use and retains cached trie nodes in memory. +func NewDatabase(db ethdb.Database) Database { + csc, _ := lru.New(codeSizeCacheSize) + return &cachingDB{db: db, codeSizeCache: csc} +} + +type cachingDB struct { + db ethdb.Database + mu sync.Mutex + pastTries []*trie.SecureTrie + codeSizeCache *lru.Cache +} + +func (db *cachingDB) OpenTrie(root common.Hash) (Trie, error) { + db.mu.Lock() + defer db.mu.Unlock() + + for i := len(db.pastTries) - 1; i >= 0; i-- { + if db.pastTries[i].Hash() == root { + return cachedTrie{db.pastTries[i].Copy(), db}, nil + } + } + tr, err := trie.NewSecure(root, db.db, MaxTrieCacheGen) + if err != nil { + return nil, err + } + return cachedTrie{tr, db}, nil +} + +func (db *cachingDB) pushTrie(t *trie.SecureTrie) { + db.mu.Lock() + defer db.mu.Unlock() + + if len(db.pastTries) >= maxPastTries { + copy(db.pastTries, db.pastTries[1:]) + db.pastTries[len(db.pastTries)-1] = t + } else { + db.pastTries = append(db.pastTries, t) + } +} + +func (db *cachingDB) OpenStorageTrie(addrHash, root common.Hash) (Trie, error) { + return trie.NewSecure(root, db.db, 0) +} + +func (db *cachingDB) CopyTrie(t Trie) Trie { + switch t := t.(type) { + case cachedTrie: + return cachedTrie{t.SecureTrie.Copy(), db} + case *trie.SecureTrie: + return t.Copy() + default: + panic(fmt.Errorf("unknown trie type %T", t)) + } +} + +func (db *cachingDB) ContractCode(addrHash, codeHash common.Hash) ([]byte, error) { + code, err := db.db.Get(codeHash[:]) + if err == nil { + db.codeSizeCache.Add(codeHash, len(code)) + } + return code, err +} + +func (db *cachingDB) ContractCodeSize(addrHash, codeHash common.Hash) (int, error) { + if cached, ok := db.codeSizeCache.Get(codeHash); ok { + return cached.(int), nil + } + code, err := db.ContractCode(addrHash, codeHash) + if err == nil { + db.codeSizeCache.Add(codeHash, len(code)) + } + return len(code), err +} + +// cachedTrie inserts its trie into a cachingDB on commit. +type cachedTrie struct { + *trie.SecureTrie + db *cachingDB +} + +func (m cachedTrie) CommitTo(dbw trie.DatabaseWriter) (common.Hash, error) { + root, err := m.SecureTrie.CommitTo(dbw) + if err == nil { + m.db.pushTrie(m.SecureTrie) + } + return root, err +} -- cgit