-
Notifications
You must be signed in to change notification settings - Fork 0
/
engine.go
146 lines (130 loc) · 2.68 KB
/
engine.go
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
135
136
137
138
139
140
141
142
143
144
145
146
package engine
import (
"errors"
"time"
"github.com/machinly/bitcask/engine/dbfile"
"github.com/machinly/bitcask/engine/index"
"github.com/machinly/bitcask/engine/record"
)
type Engine interface {
Put(key, value string) error
Get(key string) (string, error)
Delete(key string) error
ListKeys() ([]string, error)
Merge() error
Sync() bool
Close() bool
}
type bitcask struct {
index map[string]index.Set
dbFile dbfile.DBFile
}
func OpenBitcaskEngine(dirName string) (Engine, error) {
dbFile, err := dbfile.OpenDBFile(dirName)
if err != nil {
return nil, err
}
bc := &bitcask{
index: make(map[string]index.Set),
dbFile: dbFile,
}
err = bc.buildIndex()
if err != nil {
return nil, err
}
return bc, nil
}
func (c *bitcask) buildIndex() error {
index := make(map[string]index.Set)
deleteList := make([]string, 0)
for _, fileName := range c.dbFile.FileList() {
pos := int64(0)
}
for k, v := range index {
if v.ValueSize == 0 {
deleteList = append(deleteList, k)
}
}
for _, k := range deleteList {
delete(index, k)
}
c.index = index
return nil
}
func (c *bitcask) Put(key string, value string) error {
r, err := record.NewRecord(key, value)
if err != nil {
return err
}
buf, err := r.ToBytes()
if err != nil {
return err
}
fileName, ret, err := c.dbFile.Write(buf)
if err != nil {
return err
}
c.index[key] = index.Set{
fileId: fileName,
valuePosition: r.ValueRelativePosition() + ret,
valueSize: r.ValueSize(),
tstamp: time.Now().Unix(),
}
return nil
}
func (c *bitcask) Get(key string) (string, error) {
vSet, ok := c.index[key]
if !ok || vSet.ValueSize == 0 {
return "", errors.New("key not found")
}
buf := make([]byte, vSet.valueSize)
n, err := c.dbFile.Read(vSet.FileId, vSet.ValuePosition, buf)
if err != nil {
return "", err
}
if int64(n) != vSet.valueSize {
return "", errors.New("read size not equal to value size")
}
return string(buf), nil
}
func (c *bitcask) Delete(key string) error {
_, ok := c.index[key]
if !ok {
return errors.New("key not found")
}
delete(c.index, key)
r, err := record.NewDeleteRecord(key)
if err != nil {
return err
}
buf, err := r.ToBytes()
_, _, err = c.dbFile.Write(buf)
if err != nil {
return err
}
return nil
}
func (c *bitcask) ListKeys() ([]string, error) {
result := make([]string, 0, len(c.index))
for k := range c.index {
result = append(result, k)
}
return result, nil
}
func (c *bitcask) Merge() error {
panic("not implemented")
}
func (c *bitcask) Sync() bool {
err := c.dbFile.Sync()
if err != nil {
return false
}
return true
}
func (c *bitcask) Close() bool {
err := c.dbFile.Close()
if err != nil {
return false
}
return true
}