forked from moby/buildkit
/
snapshotter.go
137 lines (118 loc) · 3.76 KB
/
snapshotter.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
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
package snapshot
import (
"context"
"sync"
"github.com/containerd/containerd/mount"
"github.com/containerd/containerd/snapshots"
digest "github.com/opencontainers/go-digest"
)
type Mountable interface {
// ID() string
Mount() ([]mount.Mount, error)
Release() error
}
type SnapshotterBase interface {
Mounts(ctx context.Context, key string) (Mountable, error)
Prepare(ctx context.Context, key, parent string, opts ...snapshots.Opt) error
View(ctx context.Context, key, parent string, opts ...snapshots.Opt) (Mountable, error)
Stat(ctx context.Context, key string) (snapshots.Info, error)
Update(ctx context.Context, info snapshots.Info, fieldpaths ...string) (snapshots.Info, error)
Usage(ctx context.Context, key string) (snapshots.Usage, error)
Commit(ctx context.Context, name, key string, opts ...snapshots.Opt) error
Remove(ctx context.Context, key string) error
Walk(ctx context.Context, fn func(context.Context, snapshots.Info) error) error
Close() error
}
// Snapshotter defines interface that any snapshot implementation should satisfy
type Snapshotter interface {
Blobmapper
SnapshotterBase
}
type Blobmapper interface {
GetBlob(ctx context.Context, key string) (digest.Digest, digest.Digest, error)
SetBlob(ctx context.Context, key string, diffID, blob digest.Digest) error
}
func FromContainerdSnapshotter(s snapshots.Snapshotter) SnapshotterBase {
return &fromContainerd{Snapshotter: s}
}
type fromContainerd struct {
snapshots.Snapshotter
}
func (s *fromContainerd) Mounts(ctx context.Context, key string) (Mountable, error) {
mounts, err := s.Snapshotter.Mounts(ctx, key)
if err != nil {
return nil, err
}
return &staticMountable{mounts}, nil
}
func (s *fromContainerd) Prepare(ctx context.Context, key, parent string, opts ...snapshots.Opt) error {
_, err := s.Snapshotter.Prepare(ctx, key, parent, opts...)
return err
}
func (s *fromContainerd) View(ctx context.Context, key, parent string, opts ...snapshots.Opt) (Mountable, error) {
mounts, err := s.Snapshotter.View(ctx, key, parent, opts...)
if err != nil {
return nil, err
}
return &staticMountable{mounts}, nil
}
type staticMountable struct {
mounts []mount.Mount
}
func (m *staticMountable) Mount() ([]mount.Mount, error) {
return m.mounts, nil
}
func (cm *staticMountable) Release() error {
return nil
}
// NewContainerdSnapshotter converts snapshotter to containerd snapshotter
func NewContainerdSnapshotter(s Snapshotter) (snapshots.Snapshotter, func() error) {
cs := &containerdSnapshotter{Snapshotter: s}
return cs, cs.release
}
type containerdSnapshotter struct {
mu sync.Mutex
releasers []func() error
Snapshotter
}
func (cs *containerdSnapshotter) release() error {
cs.mu.Lock()
defer cs.mu.Unlock()
var err error
for _, f := range cs.releasers {
if err1 := f(); err != nil && err == nil {
err = err1
}
}
return err
}
func (cs *containerdSnapshotter) returnMounts(mf Mountable) ([]mount.Mount, error) {
mounts, err := mf.Mount()
if err != nil {
return nil, err
}
cs.mu.Lock()
cs.releasers = append(cs.releasers, mf.Release)
cs.mu.Unlock()
return mounts, nil
}
func (cs *containerdSnapshotter) Mounts(ctx context.Context, key string) ([]mount.Mount, error) {
mf, err := cs.Snapshotter.Mounts(ctx, key)
if err != nil {
return nil, err
}
return cs.returnMounts(mf)
}
func (cs *containerdSnapshotter) Prepare(ctx context.Context, key, parent string, opts ...snapshots.Opt) ([]mount.Mount, error) {
if err := cs.Snapshotter.Prepare(ctx, key, parent, opts...); err != nil {
return nil, err
}
return cs.Mounts(ctx, key)
}
func (cs *containerdSnapshotter) View(ctx context.Context, key, parent string, opts ...snapshots.Opt) ([]mount.Mount, error) {
mf, err := cs.Snapshotter.View(ctx, key, parent, opts...)
if err != nil {
return nil, err
}
return cs.returnMounts(mf)
}