forked from troubling/hummingbird
-
Notifications
You must be signed in to change notification settings - Fork 0
/
swiftobject.go
89 lines (82 loc) · 2.36 KB
/
swiftobject.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
package common
import (
"fmt"
"strconv"
"github.com/troubling/hummingbird/common/fs"
"github.com/troubling/hummingbird/common/pickle"
)
const SWIFT_OBJECT_METADATA_CHUNK_SIZE = 65536
func SwiftObjectRawReadMetadata(fileNameOrFd interface{}) ([]byte, error) {
var pickledMetadata []byte
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 := fs.Getxattr(fileNameOrFd, metadataName, nil)
if err != nil || length <= 0 {
break
}
// grow buffer to hold xattr
for cap(pickledMetadata) < offset+length {
pickledMetadata = append(pickledMetadata, 0)
}
pickledMetadata = pickledMetadata[0 : offset+length]
if _, err := fs.Getxattr(fileNameOrFd, metadataName, pickledMetadata[offset:]); err != nil {
return nil, err
}
offset += length
}
return pickledMetadata, nil
}
func SwiftObjectReadMetadata(fileNameOrFd interface{}) (map[string]string, error) {
pickledMetadata, err := SwiftObjectRawReadMetadata(fileNameOrFd)
if err != nil {
return nil, err
}
v, err := pickle.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: %T %v", mk, mk)
} else if mvs, ok = mv.(string); !ok {
return nil, fmt.Errorf("Metadata value not string: %T %v", mv, mv)
}
metadata[mks] = mvs
}
return metadata, nil
}
return nil, fmt.Errorf("Unpickled metadata not correct type: %T", v)
}
func SwiftObjectRawWriteMetadata(fd uintptr, buf []byte) 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 := SWIFT_OBJECT_METADATA_CHUNK_SIZE
if len(buf) < writelen {
writelen = len(buf)
}
if _, err := fs.Setxattr(fd, metadataName, buf[0:writelen]); err != nil {
return err
}
buf = buf[writelen:]
}
return nil
}
func SwiftObjectWriteMetadata(fd uintptr, v map[string]string) error {
return SwiftObjectRawWriteMetadata(fd, pickle.PickleDumps(v))
}