/
metadata_utils.go
143 lines (133 loc) · 3.79 KB
/
metadata_utils.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
package antbird
import (
"crypto/md5"
"encoding/hex"
"fmt"
"io"
"os"
"strconv"
"syscall"
"github.com/kshlm/gogfapi/gfapi"
"github.com/openstack/swift/go/hummingbird"
)
const METADATA_CHUNK_SIZE = 65536
func GetXAttr(volume *gfapi.Volume, fileNameOrFd interface{}, attr string, value []byte) (int64, error) {
var err error
var ret int64
switch v := fileNameOrFd.(type) {
case string:
ret, err = volume.Getxattr(v, attr, value)
case *gfapi.File:
ret, err = v.Getxattr(attr, value)
case gfapi.Fd:
ret, err = v.Fgetxattr(attr, value)
}
return ret, err
}
func RawReadMetadata(volume *gfapi.Volume, fileNameOrFd interface{}) ([]byte, error) {
var pickledMetadata []byte
var offset, length int64
var err error
offset = 0
for index := 0; ; index += 1 {
var metadataName string
// get name of next xattr
if index == 0 {
metadataName = "user.swift.metadata"
} else {
metadataName = "user.swift.metadata" + strconv.Itoa(index)
}
// get size of xattr
length, err = GetXAttr(volume, fileNameOrFd, metadataName, nil)
if err != nil || length <= 0 {
if err.(syscall.Errno) == syscall.ENODATA && index == 0 {
// xattr does not exist
return nil, err
}
break
}
// grow buffer to hold xattr
for int64(cap(pickledMetadata)) < offset+length {
pickledMetadata = append(pickledMetadata, 0)
}
pickledMetadata = pickledMetadata[0 : offset+length]
if _, err := GetXAttr(volume, fileNameOrFd, metadataName, pickledMetadata[offset:]); err != nil {
return nil, err
}
if index == 0 && length < METADATA_CHUNK_SIZE {
// all metadata is retrieved as single xattr
break
}
offset += length
}
return pickledMetadata, nil
}
func ReadMetadata(volume *gfapi.Volume, fileNameOrFd interface{}) (map[string]string, error) {
pickledMetadata, err := RawReadMetadata(volume, fileNameOrFd)
if err != nil {
return nil, err
}
v, err := hummingbird.PickleLoads(pickledMetadata)
if err != nil {
return nil, err
}
if v, ok := v.(map[interface{}]interface{}); ok {
metadata := make(map[string]string, len(v))
for mk, mv := range v {
var mks, mvs string
if mks, ok = mk.(string); !ok {
return nil, fmt.Errorf("Metadata key not string: %v", mk)
} else if mvs, ok = mv.(string); !ok {
return nil, fmt.Errorf("Metadata value not string: %v", mv)
}
metadata[mks] = mvs
}
return metadata, nil
}
return nil, fmt.Errorf("Unpickled metadata not correct type")
}
func RawWriteMetadata(volume *gfapi.Volume, file interface{}, buf []byte) error {
var err error
for index := 0; len(buf) > 0; index++ {
var metadataName string
if index == 0 {
metadataName = "user.swift.metadata"
} else {
metadataName = "user.swift.metadata" + strconv.Itoa(index)
}
writelen := METADATA_CHUNK_SIZE
if len(buf) < writelen {
writelen = len(buf)
}
switch v := file.(type) {
case string:
err = volume.Setxattr(v, metadataName, buf[0:writelen], 0)
case *gfapi.File:
err = v.Setxattr(metadataName, buf[0:writelen], 0)
case gfapi.Fd:
err = v.Fsetxattr(metadataName, buf[0:writelen], 0)
}
if err != nil {
return err
}
buf = buf[writelen:len(buf)]
}
return nil
}
func WriteMetadata(volume *gfapi.Volume, file interface{}, v map[string]string) error {
return RawWriteMetadata(volume, file, hummingbird.PickleDumps(v))
}
func GenerateObjectMetadata(file *gfapi.File, stat os.FileInfo) (map[string]string, error) {
ts := float64(float64(stat.ModTime().UnixNano()) / 1000000000)
hash := md5.New()
io.Copy(hash, file)
file.Seek(int64(os.SEEK_SET), 0)
metadata := map[string]string{
"name": file.Name(),
"X-Timestamp": strconv.FormatFloat(ts, 'f', 5, 64),
"Content-Type": "application/octet-stream",
"Content-Length": strconv.FormatInt(stat.Size(), 10),
"ETag": hex.EncodeToString(hash.Sum(nil)),
}
return metadata, nil
}