/
layer.go
69 lines (57 loc) · 1.72 KB
/
layer.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
// Copyright 2021 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package static
import (
"bytes"
"io"
"io/ioutil"
"sync"
v1 "github.com/google/go-containerregistry/pkg/v1"
"github.com/google/go-containerregistry/pkg/v1/types"
)
// NewLayer returns a layer containing the given bytes, with the given mediaType.
//
// Contents will not be compressed.
func NewLayer(b []byte, mt types.MediaType) v1.Layer {
return &staticLayer{b: b, mt: mt}
}
type staticLayer struct {
b []byte
mt types.MediaType
once sync.Once
h v1.Hash
}
func (l *staticLayer) Digest() (v1.Hash, error) {
var err error
// Only calculate digest the first time we're asked.
l.once.Do(func() {
l.h, _, err = v1.SHA256(bytes.NewReader(l.b))
})
return l.h, err
}
func (l *staticLayer) DiffID() (v1.Hash, error) {
return l.Digest()
}
func (l *staticLayer) Compressed() (io.ReadCloser, error) {
return ioutil.NopCloser(bytes.NewReader(l.b)), nil
}
func (l *staticLayer) Uncompressed() (io.ReadCloser, error) {
return ioutil.NopCloser(bytes.NewReader(l.b)), nil
}
func (l *staticLayer) Size() (int64, error) {
return int64(len(l.b)), nil
}
func (l *staticLayer) MediaType() (types.MediaType, error) {
return l.mt, nil
}