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
|
package compression
import (
"compress/gzip"
"context"
"io"
"github.com/containerd/containerd/content"
"github.com/containerd/containerd/images"
ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
)
func (c gzipType) Compress(ctx context.Context, comp Config) (compressorFunc Compressor, finalize Finalizer) {
return func(dest io.Writer, _ string) (io.WriteCloser, error) {
return gzipWriter(comp)(dest)
}, nil
}
func (c gzipType) Decompress(ctx context.Context, cs content.Store, desc ocispecs.Descriptor) (io.ReadCloser, error) {
return decompress(ctx, cs, desc)
}
func (c gzipType) NeedsConversion(ctx context.Context, cs content.Store, desc ocispecs.Descriptor) (bool, error) {
esgz, err := EStargz.Is(ctx, cs, desc.Digest)
if err != nil {
return false, err
}
if !images.IsLayerType(desc.MediaType) {
return false, nil
}
ct, err := FromMediaType(desc.MediaType)
if err != nil {
return false, err
}
if ct == Gzip && !esgz {
return false, nil
}
return true, nil
}
func (c gzipType) NeedsComputeDiffBySelf(comp Config) bool {
// we allow compressing it with a customized compression level that containerd differ doesn't support so we compress it by self.
return comp.Level != nil
}
func (c gzipType) OnlySupportOCITypes() bool {
return false
}
func (c gzipType) MediaType() string {
return ocispecs.MediaTypeImageLayerGzip
}
func (c gzipType) String() string {
return "gzip"
}
func gzipWriter(comp Config) func(io.Writer) (io.WriteCloser, error) {
return func(dest io.Writer) (io.WriteCloser, error) {
level := gzip.DefaultCompression
if comp.Level != nil {
level = *comp.Level
}
return gzip.NewWriterLevel(dest, level)
}
}
|
