github.com/edxfund/masterchain@v1.8.16-0.20190112084457-6ad8bdd0f74a/ethdb/memory_database.go (about) 1 // Copyright 2014 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 ethdb 18 19 import ( 20 "errors" 21 "sync" 22 23 "github.com/EDXFund/MasterChain/common" 24 ) 25 26 /* 27 * This is a test memory database. Do not use for any production it does not get persisted 28 */ 29 type MemDatabase struct { 30 db map[string][]byte 31 32 lock sync.RWMutex 33 } 34 35 func NewMemDatabase() *MemDatabase { 36 return &MemDatabase{ 37 db: make(map[string][]byte), 38 } 39 } 40 41 func NewMemDatabaseWithCap(size int) *MemDatabase { 42 return &MemDatabase{ 43 db: make(map[string][]byte, size), 44 } 45 } 46 47 func (db *MemDatabase) Put(key []byte, value []byte) error { 48 db.lock.Lock() 49 defer db.lock.Unlock() 50 51 db.db[string(key)] = common.CopyBytes(value) 52 return nil 53 } 54 55 func (db *MemDatabase) Has(key []byte) (bool, error) { 56 db.lock.RLock() 57 defer db.lock.RUnlock() 58 59 _, ok := db.db[string(key)] 60 return ok, nil 61 } 62 63 func (db *MemDatabase) Get(key []byte) ([]byte, error) { 64 db.lock.RLock() 65 defer db.lock.RUnlock() 66 67 if entry, ok := db.db[string(key)]; ok { 68 return common.CopyBytes(entry), nil 69 } 70 return nil, errors.New("not found") 71 } 72 73 func (db *MemDatabase) Keys() [][]byte { 74 db.lock.RLock() 75 defer db.lock.RUnlock() 76 77 keys := [][]byte{} 78 for key := range db.db { 79 keys = append(keys, []byte(key)) 80 } 81 return keys 82 } 83 84 func (db *MemDatabase) Delete(key []byte) error { 85 db.lock.Lock() 86 defer db.lock.Unlock() 87 88 delete(db.db, string(key)) 89 return nil 90 } 91 92 func (db *MemDatabase) Close() {} 93 94 func (db *MemDatabase) NewBatch() Batch { 95 return &memBatch{db: db} 96 } 97 98 func (db *MemDatabase) Len() int { return len(db.db) } 99 100 type kv struct { 101 k, v []byte 102 del bool 103 } 104 105 type memBatch struct { 106 db *MemDatabase 107 writes []kv 108 size int 109 } 110 111 func (b *memBatch) Put(key, value []byte) error { 112 b.writes = append(b.writes, kv{common.CopyBytes(key), common.CopyBytes(value), false}) 113 b.size += len(value) 114 return nil 115 } 116 117 func (b *memBatch) Delete(key []byte) error { 118 b.writes = append(b.writes, kv{common.CopyBytes(key), nil, true}) 119 b.size += 1 120 return nil 121 } 122 123 func (b *memBatch) Write() error { 124 b.db.lock.Lock() 125 defer b.db.lock.Unlock() 126 127 for _, kv := range b.writes { 128 if kv.del { 129 delete(b.db.db, string(kv.k)) 130 continue 131 } 132 b.db.db[string(kv.k)] = kv.v 133 } 134 return nil 135 } 136 137 func (b *memBatch) ValueSize() int { 138 return b.size 139 } 140 141 func (b *memBatch) Reset() { 142 b.writes = b.writes[:0] 143 b.size = 0 144 }