github.com/turingchain2020/turingchain@v1.1.21/common/db/go_mem_db.go (about)

     1  // Copyright Turing Corp. 2018 All Rights Reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package db
     6  
     7  import (
     8  	"bytes"
     9  
    10  	log "github.com/turingchain2020/turingchain/common/log/log15"
    11  	"github.com/turingchain2020/turingchain/types"
    12  	"github.com/syndtr/goleveldb/leveldb/comparer"
    13  	"github.com/syndtr/goleveldb/leveldb/memdb"
    14  	"github.com/syndtr/goleveldb/leveldb/util"
    15  )
    16  
    17  var mlog = log.New("module", "db.memdb")
    18  
    19  // memdb 应该无需区分同步与异步操作
    20  
    21  func init() {
    22  	dbCreator := func(name string, dir string, cache int) (DB, error) {
    23  		return NewGoMemDB(name, dir, cache)
    24  	}
    25  	registerDBCreator(memDBBackendStr, dbCreator, false)
    26  }
    27  
    28  //GoMemDB db
    29  type GoMemDB struct {
    30  	BaseDB
    31  	db *memdb.DB
    32  }
    33  
    34  //NewGoMemDB new
    35  func NewGoMemDB(name string, dir string, cache int) (*GoMemDB, error) {
    36  	return &GoMemDB{
    37  		db: memdb.New(comparer.DefaultComparer, 0),
    38  	}, nil
    39  }
    40  
    41  //Get get
    42  func (db *GoMemDB) Get(key []byte) ([]byte, error) {
    43  	v, err := db.db.Get(key)
    44  	if err != nil {
    45  		return nil, ErrNotFoundInDb
    46  	}
    47  	return cloneByte(v), nil
    48  }
    49  
    50  //Set set
    51  func (db *GoMemDB) Set(key []byte, value []byte) error {
    52  	err := db.db.Put(key, value)
    53  	if err != nil {
    54  		llog.Error("Set", "error", err)
    55  		return err
    56  	}
    57  	return nil
    58  }
    59  
    60  //SetSync 设置同步
    61  func (db *GoMemDB) SetSync(key []byte, value []byte) error {
    62  	err := db.db.Put(key, value)
    63  	if err != nil {
    64  		llog.Error("SetSync", "error", err)
    65  		return err
    66  	}
    67  	return nil
    68  }
    69  
    70  //Delete 删除
    71  func (db *GoMemDB) Delete(key []byte) error {
    72  	err := db.db.Delete(key)
    73  	if err != nil {
    74  		llog.Error("Delete", "error", err)
    75  		return err
    76  	}
    77  	return nil
    78  }
    79  
    80  //DeleteSync 删除同步
    81  func (db *GoMemDB) DeleteSync(key []byte) error {
    82  	err := db.db.Delete(key)
    83  	if err != nil {
    84  		llog.Error("DeleteSync", "error", err)
    85  		return err
    86  	}
    87  	return nil
    88  }
    89  
    90  //DB db
    91  func (db *GoMemDB) DB() *memdb.DB {
    92  	return db.db
    93  }
    94  
    95  //Close 关闭
    96  func (db *GoMemDB) Close() {
    97  }
    98  
    99  //Print 打印
   100  func (db *GoMemDB) Print() {
   101  	it := db.db.NewIterator(nil)
   102  	for it.Next() {
   103  		mlog.Info("Print", "key", string(it.Key()), "value", string(it.Value()))
   104  	}
   105  }
   106  
   107  //Stats ...
   108  func (db *GoMemDB) Stats() map[string]string {
   109  	//TODO
   110  	return nil
   111  }
   112  
   113  //Iterator 迭代器
   114  func (db *GoMemDB) Iterator(start []byte, end []byte, reverse bool) Iterator {
   115  	if end == nil {
   116  		end = bytesPrefix(start)
   117  	}
   118  	if bytes.Equal(end, types.EmptyValue) {
   119  		end = nil
   120  	}
   121  	r := &util.Range{Start: start, Limit: end}
   122  	it := db.db.NewIterator(r)
   123  	base := itBase{start, end, reverse}
   124  	return &goLevelDBIt{it, base}
   125  }
   126  
   127  type kv struct{ k, v []byte }
   128  type memBatch struct {
   129  	db     *GoMemDB
   130  	writes []kv
   131  	size   int
   132  	len    int
   133  }
   134  
   135  //NewBatch new
   136  func (db *GoMemDB) NewBatch(sync bool) Batch {
   137  	return &memBatch{db: db}
   138  }
   139  
   140  func (b *memBatch) Set(key, value []byte) {
   141  	b.writes = append(b.writes, kv{cloneByte(key), cloneByte(value)})
   142  	b.size += len(value)
   143  	b.size += len(key)
   144  	b.len += len(value)
   145  }
   146  
   147  func (b *memBatch) Delete(key []byte) {
   148  	b.writes = append(b.writes, kv{cloneByte(key), nil})
   149  	b.size += len(key)
   150  	b.len++
   151  }
   152  
   153  func (b *memBatch) Write() error {
   154  	var err error
   155  	for _, kv := range b.writes {
   156  		if kv.v == nil {
   157  			err = b.db.Delete(kv.k)
   158  		} else {
   159  			err = b.db.Set(kv.k, kv.v)
   160  		}
   161  	}
   162  	return err
   163  }
   164  
   165  func (b *memBatch) ValueSize() int {
   166  	return b.size
   167  }
   168  
   169  //ValueLen  batch数量
   170  func (b *memBatch) ValueLen() int {
   171  	return b.len
   172  }
   173  
   174  func (b *memBatch) Reset() {
   175  	//重置batch自己的buf，不能调用db reset，将直接清空db历史数据
   176  	b.writes = b.writes[:0]
   177  	b.size = 0
   178  	b.len = 0
   179  }
   180  
   181  func (b *memBatch) UpdateWriteSync(sync bool) {
   182  }