blob: 7883752cc9573deb7c20b27a79e2b198f159807c (
plain)
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
|
package exif
import (
"io"
"github.com/dsoprea/go-logging"
"github.com/dsoprea/go-utility/v2/filesystem"
)
type ExifBlobSeeker interface {
GetReadSeeker(initialOffset int64) (rs io.ReadSeeker, err error)
}
// ExifReadSeeker knows how to retrieve data from the EXIF blob relative to the
// beginning of the blob (so, absolute position (0) is the first byte of the
// EXIF data).
type ExifReadSeeker struct {
rs io.ReadSeeker
}
func NewExifReadSeeker(rs io.ReadSeeker) *ExifReadSeeker {
return &ExifReadSeeker{
rs: rs,
}
}
func NewExifReadSeekerWithBytes(exifData []byte) *ExifReadSeeker {
sb := rifs.NewSeekableBufferWithBytes(exifData)
edbs := NewExifReadSeeker(sb)
return edbs
}
// Fork creates a new ReadSeeker instead that wraps a BouncebackReader to
// maintain its own position in the stream.
func (edbs *ExifReadSeeker) GetReadSeeker(initialOffset int64) (rs io.ReadSeeker, err error) {
defer func() {
if state := recover(); state != nil {
err = log.Wrap(state.(error))
}
}()
br, err := rifs.NewBouncebackReader(edbs.rs)
log.PanicIf(err)
_, err = br.Seek(initialOffset, io.SeekStart)
log.PanicIf(err)
return br, nil
}
|
