github.com/bamzi/go-ethereum@v1.6.7-0.20170704111104-138f26c93af1/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/ethereum/go-ethereum/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  	lock sync.RWMutex
    32  }
    33  
    34  func NewMemDatabase() (*MemDatabase, error) {
    35  	return &MemDatabase{
    36  		db: make(map[string][]byte),
    37  	}, nil
    38  }
    39  
    40  func (db *MemDatabase) Put(key []byte, value []byte) error {
    41  	db.lock.Lock()
    42  	defer db.lock.Unlock()
    43  
    44  	db.db[string(key)] = common.CopyBytes(value)
    45  	return nil
    46  }
    47  
    48  func (db *MemDatabase) Get(key []byte) ([]byte, error) {
    49  	db.lock.RLock()
    50  	defer db.lock.RUnlock()
    51  
    52  	if entry, ok := db.db[string(key)]; ok {
    53  		return entry, nil
    54  	}
    55  	return nil, errors.New("not found")
    56  }
    57  
    58  func (db *MemDatabase) Keys() [][]byte {
    59  	db.lock.RLock()
    60  	defer db.lock.RUnlock()
    61  
    62  	keys := [][]byte{}
    63  	for key := range db.db {
    64  		keys = append(keys, []byte(key))
    65  	}
    66  	return keys
    67  }
    68  
    69  /*
    70  func (db *MemDatabase) GetKeys() []*common.Key {
    71  	data, _ := db.Get([]byte("KeyRing"))
    72  
    73  	return []*common.Key{common.NewKeyFromBytes(data)}
    74  }
    75  */
    76  
    77  func (db *MemDatabase) Delete(key []byte) error {
    78  	db.lock.Lock()
    79  	defer db.lock.Unlock()
    80  
    81  	delete(db.db, string(key))
    82  	return nil
    83  }
    84  
    85  func (db *MemDatabase) Close() {}
    86  
    87  func (db *MemDatabase) NewBatch() Batch {
    88  	return &memBatch{db: db}
    89  }
    90  
    91  type kv struct{ k, v []byte }
    92  
    93  type memBatch struct {
    94  	db     *MemDatabase
    95  	writes []kv
    96  	lock   sync.RWMutex
    97  }
    98  
    99  func (b *memBatch) Put(key, value []byte) error {
   100  	b.lock.Lock()
   101  	defer b.lock.Unlock()
   102  
   103  	b.writes = append(b.writes, kv{common.CopyBytes(key), common.CopyBytes(value)})
   104  	return nil
   105  }
   106  
   107  func (b *memBatch) Write() error {
   108  	b.lock.RLock()
   109  	defer b.lock.RUnlock()
   110  
   111  	b.db.lock.Lock()
   112  	defer b.db.lock.Unlock()
   113  
   114  	for _, kv := range b.writes {
   115  		b.db.db[string(kv.k)] = kv.v
   116  	}
   117  	return nil
   118  }