github.com/sberex/go-sberex@v1.8.2-0.20181113200658-ed96ac38f7d7/ethdb/memory_database.go (about)

     1  // This file is part of the go-sberex library. The go-sberex library is 
     2  // free software: you can redistribute it and/or modify it under the terms 
     3  // of the GNU Lesser General Public License as published by the Free 
     4  // Software Foundation, either version 3 of the License, or (at your option)
     5  // any later version.
     6  //
     7  // The go-sberex library is distributed in the hope that it will be useful, 
     8  // but WITHOUT ANY WARRANTY; without even the implied warranty of
     9  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser 
    10  // General Public License <http://www.gnu.org/licenses/> for more details.
    11  
    12  package ethdb
    13  
    14  import (
    15  	"errors"
    16  	"sync"
    17  
    18  	"github.com/Sberex/go-sberex/common"
    19  )
    20  
    21  /*
    22   * This is a test memory database. Do not use for any production it does not get persisted
    23   */
    24  type MemDatabase struct {
    25  	db   map[string][]byte
    26  	lock sync.RWMutex
    27  }
    28  
    29  func NewMemDatabase() (*MemDatabase, error) {
    30  	return &MemDatabase{
    31  		db: make(map[string][]byte),
    32  	}, nil
    33  }
    34  
    35  func NewMemDatabaseWithCap(size int) (*MemDatabase, error) {
    36  	return &MemDatabase{
    37  		db: make(map[string][]byte, size),
    38  	}, nil
    39  }
    40  
    41  func (db *MemDatabase) Put(key []byte, value []byte) error {
    42  	db.lock.Lock()
    43  	defer db.lock.Unlock()
    44  
    45  	db.db[string(key)] = common.CopyBytes(value)
    46  	return nil
    47  }
    48  
    49  func (db *MemDatabase) Has(key []byte) (bool, error) {
    50  	db.lock.RLock()
    51  	defer db.lock.RUnlock()
    52  
    53  	_, ok := db.db[string(key)]
    54  	return ok, nil
    55  }
    56  
    57  func (db *MemDatabase) Get(key []byte) ([]byte, error) {
    58  	db.lock.RLock()
    59  	defer db.lock.RUnlock()
    60  
    61  	if entry, ok := db.db[string(key)]; ok {
    62  		return common.CopyBytes(entry), nil
    63  	}
    64  	return nil, errors.New("not found")
    65  }
    66  
    67  func (db *MemDatabase) Keys() [][]byte {
    68  	db.lock.RLock()
    69  	defer db.lock.RUnlock()
    70  
    71  	keys := [][]byte{}
    72  	for key := range db.db {
    73  		keys = append(keys, []byte(key))
    74  	}
    75  	return keys
    76  }
    77  
    78  func (db *MemDatabase) Delete(key []byte) error {
    79  	db.lock.Lock()
    80  	defer db.lock.Unlock()
    81  
    82  	delete(db.db, string(key))
    83  	return nil
    84  }
    85  
    86  func (db *MemDatabase) Close() {}
    87  
    88  func (db *MemDatabase) NewBatch() Batch {
    89  	return &memBatch{db: db}
    90  }
    91  
    92  func (db *MemDatabase) Len() int { return len(db.db) }
    93  
    94  type kv struct{ k, v []byte }
    95  
    96  type memBatch struct {
    97  	db     *MemDatabase
    98  	writes []kv
    99  	size   int
   100  }
   101  
   102  func (b *memBatch) Put(key, value []byte) error {
   103  	b.writes = append(b.writes, kv{common.CopyBytes(key), common.CopyBytes(value)})
   104  	b.size += len(value)
   105  	return nil
   106  }
   107  
   108  func (b *memBatch) Write() error {
   109  	b.db.lock.Lock()
   110  	defer b.db.lock.Unlock()
   111  
   112  	for _, kv := range b.writes {
   113  		b.db.db[string(kv.k)] = kv.v
   114  	}
   115  	return nil
   116  }
   117  
   118  func (b *memBatch) ValueSize() int {
   119  	return b.size
   120  }
   121  
   122  func (b *memBatch) Reset() {
   123  	b.writes = b.writes[:0]
   124  	b.size = 0
   125  }