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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
// Copyright 2019 Google LLC
//
// 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
//
// https://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 builder
import (
"bytes"
"context"
"encoding/json"
"io"
"io/ioutil"
"log"
"sync"
)
type Build struct {
SHA256 string `json:"sha256"`
MD5 string `json:"md5"`
}
// LocalCache implements the structure used for local caching of
// manifests and layer uploads.
type LocalCache struct {
// Manifest cache
mmtx sync.RWMutex
mcache map[string]string
// Layer cache
lmtx sync.RWMutex
lcache map[string]Build
}
func NewCache() LocalCache {
return LocalCache{
mcache: make(map[string]string),
lcache: make(map[string]Build),
}
}
// Retrieve a cached manifest if the build is cacheable and it exists.
func (c *LocalCache) manifestFromLocalCache(key string) (string, bool) {
c.mmtx.RLock()
path, ok := c.mcache[key]
c.mmtx.RUnlock()
if !ok {
return "", false
}
return path, true
}
// Adds the result of a manifest build to the local cache, if the
// manifest is considered cacheable.
func (c *LocalCache) localCacheManifest(key, path string) {
c.mmtx.Lock()
c.mcache[key] = path
c.mmtx.Unlock()
}
// Retrieve a cached build from the local cache.
func (c *LocalCache) buildFromLocalCache(key string) (*Build, bool) {
c.lmtx.RLock()
b, ok := c.lcache[key]
c.lmtx.RUnlock()
return &b, ok
}
// Add a build result to the local cache.
func (c *LocalCache) localCacheBuild(key string, b Build) {
c.lmtx.Lock()
c.lcache[key] = b
c.lmtx.Unlock()
}
// Retrieve a manifest from the cache(s). First the local cache is
// checked, then the GCS-bucket cache.
func manifestFromCache(ctx context.Context, s *State, key string) (json.RawMessage, bool) {
// path, cached := s.Cache.manifestFromLocalCache(key)
// if cached {
// return path, true
// }
// TODO: local cache?
obj := s.Bucket.Object("manifests/" + key)
// Probe whether the file exists before trying to fetch it.
_, err := obj.Attrs(ctx)
if err != nil {
return nil, false
}
r, err := obj.NewReader(ctx)
if err != nil {
log.Printf("Failed to retrieve manifest '%s' from cache: %s\n", key, err)
return nil, false
}
defer r.Close()
m, err := ioutil.ReadAll(r)
if err != nil {
log.Printf("Failed to read cached manifest for '%s': %s\n", key, err)
}
// TODO: locally cache manifest, but the cache needs to be changed
log.Printf("Retrieved manifest for sha1:%s from GCS\n", key)
return json.RawMessage(m), true
}
// Add a manifest to the bucket & local caches
func cacheManifest(ctx context.Context, s *State, key string, m json.RawMessage) {
// go s.Cache.localCacheManifest(key, path)
// TODO local cache
obj := s.Bucket.Object("manifests/" + key)
w := obj.NewWriter(ctx)
r := bytes.NewReader([]byte(m))
size, err := io.Copy(w, r)
if err != nil {
log.Printf("failed to cache manifest sha1:%s: %s\n", key, err)
return
}
if err = w.Close(); err != nil {
log.Printf("failed to cache manifest sha1:%s: %s\n", key, err)
return
}
log.Printf("Cached manifest sha1:%s (%v bytes written)\n", key, size)
}
// Retrieve a build from the cache, first checking the local cache
// followed by the bucket cache.
func buildFromCache(ctx context.Context, s *State, key string) (*Build, bool) {
build, cached := s.Cache.buildFromLocalCache(key)
if cached {
return build, true
}
obj := s.Bucket.Object("builds/" + key)
_, err := obj.Attrs(ctx)
if err != nil {
return nil, false
}
r, err := obj.NewReader(ctx)
if err != nil {
log.Printf("Failed to retrieve build '%s' from cache: %s\n", key, err)
return nil, false
}
defer r.Close()
jb := bytes.NewBuffer([]byte{})
_, err = io.Copy(jb, r)
if err != nil {
log.Printf("Failed to read build '%s' from cache: %s\n", key, err)
return nil, false
}
var b Build
err = json.Unmarshal(jb.Bytes(), &build)
if err != nil {
log.Printf("Failed to unmarshal build '%s' from cache: %s\n", key, err)
return nil, false
}
go s.Cache.localCacheBuild(key, b)
return &b, true
}
func cacheBuild(ctx context.Context, s *State, key string, build Build) {
go s.Cache.localCacheBuild(key, build)
obj := s.Bucket.Object("builds/" + key)
j, _ := json.Marshal(&build)
w := obj.NewWriter(ctx)
_, err := io.Copy(w, bytes.NewReader(j))
if err != nil {
log.Printf("failed to cache build '%s': %s\n", key, err)
return
}
}
|
