81 lines
2.2 KiB
Go
81 lines
2.2 KiB
Go
// Copyright 2014 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// go-ethereum is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package trie
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import (
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"github.com/ethereum/go-ethereum/compression/rle"
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"github.com/ethereum/go-ethereum/ethdb"
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"github.com/ethereum/go-ethereum/logger/glog"
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"github.com/syndtr/goleveldb/leveldb"
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)
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type Backend interface {
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Get([]byte) ([]byte, error)
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Put([]byte, []byte) error
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}
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type Cache struct {
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batch *leveldb.Batch
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store map[string][]byte
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backend Backend
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}
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func NewCache(backend Backend) *Cache {
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return &Cache{new(leveldb.Batch), make(map[string][]byte), backend}
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}
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func (self *Cache) Get(key []byte) []byte {
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data := self.store[string(key)]
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if data == nil {
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data, _ = self.backend.Get(key)
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}
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return data
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}
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func (self *Cache) Put(key []byte, data []byte) {
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// write the data to the ldb batch
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self.batch.Put(key, rle.Compress(data))
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self.store[string(key)] = data
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}
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// Flush flushes the trie to the backing layer. If this is a leveldb instance
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// we'll use a batched write, otherwise we'll use regular put.
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func (self *Cache) Flush() {
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if db, ok := self.backend.(*ethdb.LDBDatabase); ok {
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if err := db.LDB().Write(self.batch, nil); err != nil {
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glog.Fatal("db write err:", err)
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}
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} else {
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for k, v := range self.store {
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self.backend.Put([]byte(k), v)
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}
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}
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}
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func (self *Cache) Copy() *Cache {
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cache := NewCache(self.backend)
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for k, v := range self.store {
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cache.store[k] = v
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}
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return cache
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}
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func (self *Cache) Reset() {
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//self.store = make(map[string][]byte)
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}
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