github.com/samgwo/go-ethereum@v1.8.2-0.20180302101319-49bcb5fbd55e/swarm/storage/database.go (about) 1 // Copyright 2016 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 package storage 18 19 // this is a clone of an earlier state of the ethereum ethdb/database 20 // no need for queueing/caching 21 22 import ( 23 "fmt" 24 25 "github.com/ethereum/go-ethereum/compression/rle" 26 "github.com/syndtr/goleveldb/leveldb" 27 "github.com/syndtr/goleveldb/leveldb/iterator" 28 "github.com/syndtr/goleveldb/leveldb/opt" 29 ) 30 31 const openFileLimit = 128 32 33 type LDBDatabase struct { 34 db *leveldb.DB 35 comp bool 36 } 37 38 func NewLDBDatabase(file string) (*LDBDatabase, error) { 39 // Open the db 40 db, err := leveldb.OpenFile(file, &opt.Options{OpenFilesCacheCapacity: openFileLimit}) 41 if err != nil { 42 return nil, err 43 } 44 45 database := &LDBDatabase{db: db, comp: false} 46 47 return database, nil 48 } 49 50 func (self *LDBDatabase) Put(key []byte, value []byte) { 51 if self.comp { 52 value = rle.Compress(value) 53 } 54 55 err := self.db.Put(key, value, nil) 56 if err != nil { 57 fmt.Println("Error put", err) 58 } 59 } 60 61 func (self *LDBDatabase) Get(key []byte) ([]byte, error) { 62 dat, err := self.db.Get(key, nil) 63 if err != nil { 64 return nil, err 65 } 66 67 if self.comp { 68 return rle.Decompress(dat) 69 } 70 71 return dat, nil 72 } 73 74 func (self *LDBDatabase) Delete(key []byte) error { 75 return self.db.Delete(key, nil) 76 } 77 78 func (self *LDBDatabase) LastKnownTD() []byte { 79 data, _ := self.Get([]byte("LTD")) 80 81 if len(data) == 0 { 82 data = []byte{0x0} 83 } 84 85 return data 86 } 87 88 func (self *LDBDatabase) NewIterator() iterator.Iterator { 89 return self.db.NewIterator(nil, nil) 90 } 91 92 func (self *LDBDatabase) Write(batch *leveldb.Batch) error { 93 return self.db.Write(batch, nil) 94 } 95 96 func (self *LDBDatabase) Close() { 97 // Close the leveldb database 98 self.db.Close() 99 }