/
utils.go
59 lines (51 loc) · 1.61 KB
/
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
package backend
import (
"bytes"
"context"
"io"
"github.com/restic/restic/internal/restic"
)
// LoadAll reads all data stored in the backend for the handle into the given
// buffer, which is truncated. If the buffer is not large enough or nil, a new
// one is allocated.
func LoadAll(ctx context.Context, buf []byte, be restic.Backend, h restic.Handle) ([]byte, error) {
err := be.Load(ctx, h, 0, 0, func(rd io.Reader) error {
// make sure this is idempotent, in case an error occurs this function may be called multiple times!
wr := bytes.NewBuffer(buf[:0])
_, cerr := io.Copy(wr, rd)
if cerr != nil {
return cerr
}
buf = wr.Bytes()
return nil
})
if err != nil {
return nil, err
}
return buf, nil
}
// LimitedReadCloser wraps io.LimitedReader and exposes the Close() method.
type LimitedReadCloser struct {
io.Closer
io.LimitedReader
}
// LimitReadCloser returns a new reader wraps r in an io.LimitedReader, but also
// exposes the Close() method.
func LimitReadCloser(r io.ReadCloser, n int64) *LimitedReadCloser {
return &LimitedReadCloser{Closer: r, LimitedReader: io.LimitedReader{R: r, N: n}}
}
// DefaultLoad implements Backend.Load using lower-level openReader func
func DefaultLoad(ctx context.Context, h restic.Handle, length int, offset int64,
openReader func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error),
fn func(rd io.Reader) error) error {
rd, err := openReader(ctx, h, length, offset)
if err != nil {
return err
}
err = fn(rd)
if err != nil {
_ = rd.Close() // ignore secondary errors closing the reader
return err
}
return rd.Close()
}