1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
package storage
import (
"fmt"
"os"
"path/filepath"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/util"
"github.com/syndtr/goleveldb/leveldb"
)
type LevelDbNeedleMap struct {
dbFileName string
db *leveldb.DB
baseNeedleMapper
}
func NewLevelDbNeedleMap(dbFileName string, indexFile *os.File) (m *LevelDbNeedleMap, err error) {
m = &LevelDbNeedleMap{dbFileName: dbFileName}
m.indexFile = indexFile
if !isLevelDbFresh(dbFileName, indexFile) {
glog.V(1).Infof("Start to Generate %s from %s", dbFileName, indexFile.Name())
generateLevelDbFile(dbFileName, indexFile)
glog.V(1).Infof("Finished Generating %s from %s", dbFileName, indexFile.Name())
}
glog.V(1).Infof("Opening %s...", dbFileName)
if m.db, err = leveldb.OpenFile(dbFileName, nil); err != nil {
return
}
glog.V(1).Infof("Loading %s...", indexFile.Name())
nm, indexLoadError := LoadNeedleMap(indexFile)
if indexLoadError != nil {
return nil, indexLoadError
}
m.mapMetric = nm.mapMetric
return
}
func isLevelDbFresh(dbFileName string, indexFile *os.File) bool {
// normally we always write to index file first
dbLogFile, err := os.Open(filepath.Join(dbFileName, "LOG"))
if err != nil {
return false
}
defer dbLogFile.Close()
dbStat, dbStatErr := dbLogFile.Stat()
indexStat, indexStatErr := indexFile.Stat()
if dbStatErr != nil || indexStatErr != nil {
glog.V(0).Infof("Can not stat file: %v and %v", dbStatErr, indexStatErr)
return false
}
return dbStat.ModTime().After(indexStat.ModTime())
}
func generateLevelDbFile(dbFileName string, indexFile *os.File) error {
db, err := leveldb.OpenFile(dbFileName, nil)
if err != nil {
return err
}
defer db.Close()
return WalkIndexFile(indexFile, func(key uint64, offset, size uint32) error {
if offset > 0 {
levelDbWrite(db, key, offset, size)
} else {
levelDbDelete(db, key)
}
return nil
})
}
func (m *LevelDbNeedleMap) Get(key uint64) (element *NeedleValue, ok bool) {
bytes := make([]byte, 8)
util.Uint64toBytes(bytes, key)
data, err := m.db.Get(bytes, nil)
if err != nil || len(data) != 8 {
return nil, false
}
offset := util.BytesToUint32(data[0:4])
size := util.BytesToUint32(data[4:8])
return &NeedleValue{Key: Key(key), Offset: offset, Size: size}, true
}
func (m *LevelDbNeedleMap) Put(key uint64, offset uint32, size uint32) error {
var oldSize uint32
if oldNeedle, ok := m.Get(key); ok {
oldSize = oldNeedle.Size
}
m.logPut(key, oldSize, size)
// write to index file first
if err := m.appendToIndexFile(key, offset, size); err != nil {
return fmt.Errorf("cannot write to indexfile %s: %v", m.indexFile.Name(), err)
}
return levelDbWrite(m.db, key, offset, size)
}
func levelDbWrite(db *leveldb.DB,
key uint64, offset uint32, size uint32) error {
bytes := make([]byte, 16)
util.Uint64toBytes(bytes[0:8], key)
util.Uint32toBytes(bytes[8:12], offset)
util.Uint32toBytes(bytes[12:16], size)
if err := db.Put(bytes[0:8], bytes[8:16], nil); err != nil {
return fmt.Errorf("failed to write leveldb: %v", err)
}
return nil
}
func levelDbDelete(db *leveldb.DB, key uint64) error {
bytes := make([]byte, 8)
util.Uint64toBytes(bytes, key)
return db.Delete(bytes, nil)
}
func (m *LevelDbNeedleMap) Delete(key uint64) error {
if oldNeedle, ok := m.Get(key); ok {
m.logDelete(oldNeedle.Size)
}
// write to index file first
if err := m.appendToIndexFile(key, 0, 0); err != nil {
return err
}
return levelDbDelete(m.db, key)
}
func (m *LevelDbNeedleMap) Close() {
m.db.Close()
}
func (m *LevelDbNeedleMap) Destroy() error {
m.Close()
os.Remove(m.indexFile.Name())
return os.Remove(m.dbFileName)
}
|
