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
|
package fsutil
import (
"context"
"os"
"strings"
"github.com/tonistiigi/fsutil/types"
"golang.org/x/sync/errgroup"
)
// Everything below is copied from containerd/fs. TODO: remove duplication @dmcgowan
// Const redefined because containerd/fs doesn't build on !linux
// ChangeKind is the type of modification that
// a change is making.
type ChangeKind int
const (
// ChangeKindAdd represents an addition of
// a file
ChangeKindAdd ChangeKind = iota
// ChangeKindModify represents a change to
// an existing file
ChangeKindModify
// ChangeKindDelete represents a delete of
// a file
ChangeKindDelete
)
// ChangeFunc is the type of function called for each change
// computed during a directory changes calculation.
type ChangeFunc func(ChangeKind, string, os.FileInfo, error) error
type currentPath struct {
path string
stat *types.Stat
// fullPath string
}
// doubleWalkDiff walks both directories to create a diff
func doubleWalkDiff(ctx context.Context, changeFn ChangeFunc, a, b walkerFn, filter FilterFunc) (err error) {
g, ctx := errgroup.WithContext(ctx)
var (
c1 = make(chan *currentPath, 128)
c2 = make(chan *currentPath, 128)
f1, f2 *currentPath
rmdir string
)
g.Go(func() error {
defer close(c1)
return a(ctx, c1)
})
g.Go(func() error {
defer close(c2)
return b(ctx, c2)
})
g.Go(func() error {
loop0:
for c1 != nil || c2 != nil {
if f1 == nil && c1 != nil {
f1, err = nextPath(ctx, c1)
if err != nil {
return err
}
if f1 == nil {
c1 = nil
}
}
if f2 == nil && c2 != nil {
f2, err = nextPath(ctx, c2)
if err != nil {
return err
}
if f2 == nil {
c2 = nil
}
}
if f1 == nil && f2 == nil {
continue
}
var f *types.Stat
var f2copy *currentPath
if f2 != nil {
statCopy := *f2.stat
if filter != nil {
filter(f2.path, &statCopy)
}
f2copy = ¤tPath{path: f2.path, stat: &statCopy}
}
k, p := pathChange(f1, f2copy)
switch k {
case ChangeKindAdd:
if rmdir != "" {
rmdir = ""
}
f = f2.stat
f2 = nil
case ChangeKindDelete:
// Check if this file is already removed by being
// under of a removed directory
if rmdir != "" && strings.HasPrefix(f1.path, rmdir) {
f1 = nil
continue
} else if rmdir == "" && f1.stat.IsDir() {
rmdir = f1.path + string(os.PathSeparator)
} else if rmdir != "" {
rmdir = ""
}
f1 = nil
case ChangeKindModify:
same, err := sameFile(f1, f2copy)
if err != nil {
return err
}
if f1.stat.IsDir() && !f2copy.stat.IsDir() {
rmdir = f1.path + string(os.PathSeparator)
} else if rmdir != "" {
rmdir = ""
}
f = f2.stat
f1 = nil
f2 = nil
if same {
continue loop0
}
}
if err := changeFn(k, p, &StatInfo{f}, nil); err != nil {
return err
}
}
return nil
})
return g.Wait()
}
func pathChange(lower, upper *currentPath) (ChangeKind, string) {
if lower == nil {
if upper == nil {
panic("cannot compare nil paths")
}
return ChangeKindAdd, upper.path
}
if upper == nil {
return ChangeKindDelete, lower.path
}
switch i := ComparePath(lower.path, upper.path); {
case i < 0:
// File in lower that is not in upper
return ChangeKindDelete, lower.path
case i > 0:
// File in upper that is not in lower
return ChangeKindAdd, upper.path
default:
return ChangeKindModify, upper.path
}
}
func sameFile(f1, f2 *currentPath) (same bool, retErr error) {
// If not a directory also check size, modtime, and content
if !f1.stat.IsDir() {
if f1.stat.Size_ != f2.stat.Size_ {
return false, nil
}
if f1.stat.ModTime != f2.stat.ModTime {
return false, nil
}
}
return compareStat(f1.stat, f2.stat)
}
// compareStat returns whether the stats are equivalent,
// whether the files are considered the same file, and
// an error
func compareStat(ls1, ls2 *types.Stat) (bool, error) {
return ls1.Mode == ls2.Mode && ls1.Uid == ls2.Uid && ls1.Gid == ls2.Gid && ls1.Devmajor == ls2.Devmajor && ls1.Devminor == ls2.Devminor && ls1.Linkname == ls2.Linkname, nil
}
func nextPath(ctx context.Context, pathC <-chan *currentPath) (*currentPath, error) {
select {
case <-ctx.Done():
return nil, ctx.Err()
case p := <-pathC:
return p, nil
}
}
|
