forked from shibukawa/git4go
-
Notifications
You must be signed in to change notification settings - Fork 0
/
treecache.go
148 lines (137 loc) · 3.48 KB
/
treecache.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
138
139
140
141
142
143
144
145
146
147
148
package git4go
import (
"bytes"
"errors"
"fmt"
"strings"
)
type TreeCache struct {
children []*TreeCache
entryCount int
oid *Oid
name string
}
func (v *TreeCache) write(buffer *bytes.Buffer) {
buffer.WriteString(v.name)
buffer.WriteByte(0)
fmt.Fprintf(buffer, "%d %d\n", v.entryCount, len(v.children))
if v.entryCount != -1 {
buffer.Write(v.oid[:])
}
for _, child := range v.children {
child.write(buffer)
}
}
func (v *TreeCache) get(path string) *TreeCache {
current := v
for _, pathFragment := range strings.Split(path, "/") {
if pathFragment == "" {
continue
}
for _, child := range current.children {
if child.name == pathFragment {
current = child
continue
}
}
return nil
}
return current
}
func (v *TreeCache) invalidatePath(path string) {
v.entryCount--
current := v
for _, pathFragment := range strings.Split(path, "/") {
if pathFragment == "" {
continue
}
for _, child := range current.children {
if child.name == pathFragment {
current = child
current.entryCount--
continue
}
}
return /* we don't have that tree */
}
}
func readTreeInternal(buffer []byte, offset, bufferEnd int) (*TreeCache, int, error) {
nameEnd := findChar(buffer, 0, offset, bufferEnd)
if nameEnd == -1 || bufferEnd-nameEnd < 8 {
return nil, offset, errors.New("Corrupted TREE extension in index")
}
name := string(buffer[offset:nameEnd])
offset = nameEnd + 1
entryCount, newOffset := strtol32(buffer, offset, bufferEnd, 10)
childCount, newOffset := strtol32(buffer, newOffset, bufferEnd, 10)
if entryCount == -1 || childCount == -1 {
return nil, offset, errors.New("Corrupted TREE extension in index")
}
cache := &TreeCache{
name: name,
children: make([]*TreeCache, childCount),
entryCount: int(entryCount),
}
offset = newOffset
if entryCount > 0 {
if offset+GitOidRawSize > bufferEnd {
return nil, offset, errors.New("Corrupted TREE extension in index")
}
cache.oid = NewOidFromBytes(buffer[offset : offset+GitOidRawSize])
offset += GitOidRawSize
}
for i := 0; i < int(childCount); i++ {
child, newOffset, err := readTreeInternal(buffer, offset, bufferEnd)
if err != nil {
return nil, offset, err
}
offset = newOffset
cache.children[i] = child
}
return nil, offset, errors.New("Corrupted TREE extension in index")
}
func readTreeCache(buffer []byte, offset, extensionSize int) (*TreeCache, error) {
tree, newOffset, err := readTreeInternal(buffer, offset, offset+extensionSize)
if err != nil {
return nil, err
}
if newOffset < offset+extensionSize {
return tree, errors.New("Corrupted TREE extension in index (unexpected trailing data)")
}
return tree, nil
}
func readTreeCacheFromTreeRecursive(tree *Tree, cache *TreeCache) error {
cache.oid = tree.Id()
treeCount := 0
for _, entry := range tree.Entries {
if entry.Filemode == FilemodeTree {
treeCount++
}
}
cache.children = make([]*TreeCache, treeCount)
entryCount := 0
for i, entry := range tree.Entries {
if entry.Filemode != FilemodeTree {
entryCount++
continue
}
childCache := &TreeCache{
name: entry.Name,
}
childTree, err := tree.Owner().LookupTree(entry.Id)
if err != nil {
return err
}
err = readTreeCacheFromTreeRecursive(childTree, childCache)
if err != nil {
return err
}
cache.entryCount += childCache.entryCount
cache.children[i] = childCache
}
return nil
}
func createTreeCacheFromTree(tree *Tree) error {
cache := &TreeCache{}
return readTreeCacheFromTreeRecursive(tree, cache)
}