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 object
import (
"bytes"
"fmt"
"sort"
"codeberg.org/lindenii/furgit/objecttype"
"codeberg.org/lindenii/furgit/oid"
)
// FileMode represents the mode of a file in a Git tree.
type FileMode uint32
const (
FileModeDir FileMode = 0o40000
FileModeRegular FileMode = 0o100644
FileModeExecutable FileMode = 0o100755
FileModeSymlink FileMode = 0o120000
FileModeGitlink FileMode = 0o160000
)
// TreeEntry represents a single entry in a tree.
type TreeEntry struct {
Mode FileMode
Name []byte
ID oid.ObjectID
}
// Tree represents a Git tree object.
type Tree struct {
Entries []TreeEntry
}
// ObjectType returns TypeTree.
func (tree *Tree) ObjectType() objecttype.Type {
_ = tree
return objecttype.TypeTree
}
// Entry looks up a tree entry by name.
func (tree *Tree) Entry(name []byte) *TreeEntry {
if len(tree.Entries) == 0 {
return nil
}
if e := tree.entry(name, true); e != nil {
return e
}
return tree.entry(name, false)
}
func (tree *Tree) entry(name []byte, searchIsTree bool) *TreeEntry {
low, high := 0, len(tree.Entries)-1
for low <= high {
mid := low + (high-low)/2
entry := &tree.Entries[mid]
cmp := TreeEntryNameCompare(entry.Name, entry.Mode, name, searchIsTree)
if cmp == 0 {
if bytes.Equal(entry.Name, name) {
return entry
}
return nil
}
if cmp < 0 {
low = mid + 1
} else {
high = mid - 1
}
}
return nil
}
// InsertEntry inserts a tree entry while preserving Git ordering.
func (tree *Tree) InsertEntry(newEntry TreeEntry) error {
if tree.entry(newEntry.Name, true) != nil || tree.entry(newEntry.Name, false) != nil {
return fmt.Errorf("object: tree: entry %q already exists", newEntry.Name)
}
newIsTree := newEntry.Mode == FileModeDir
insertAt := sort.Search(len(tree.Entries), func(i int) bool {
return TreeEntryNameCompare(tree.Entries[i].Name, tree.Entries[i].Mode, newEntry.Name, newIsTree) >= 0
})
tree.Entries = append(tree.Entries, TreeEntry{})
copy(tree.Entries[insertAt+1:], tree.Entries[insertAt:])
tree.Entries[insertAt] = newEntry
return nil
}
// RemoveEntry removes a tree entry by name.
func (tree *Tree) RemoveEntry(name []byte) error {
if len(tree.Entries) == 0 {
return fmt.Errorf("object: tree: entry %q not found", name)
}
for i := range tree.Entries {
if bytes.Equal(tree.Entries[i].Name, name) {
copy(tree.Entries[i:], tree.Entries[i+1:])
tree.Entries = tree.Entries[:len(tree.Entries)-1]
return nil
}
}
return fmt.Errorf("object: tree: entry %q not found", name)
}
// TreeEntryNameCompare compares names using Git tree ordering rules.
func TreeEntryNameCompare(entryName []byte, entryMode FileMode, searchName []byte, searchIsTree bool) int {
isEntryTree := entryMode == FileModeDir
entryLen := len(entryName)
if isEntryTree {
entryLen++
}
searchLen := len(searchName)
if searchIsTree {
searchLen++
}
n := entryLen
if searchLen < n {
n = searchLen
}
for i := 0; i < n; i++ {
var ec, sc byte
if i < len(entryName) {
ec = entryName[i]
} else {
ec = '/'
}
if i < len(searchName) {
sc = searchName[i]
} else {
sc = '/'
}
if ec < sc {
return -1
}
if ec > sc {
return 1
}
}
if entryLen < searchLen {
return -1
}
if entryLen > searchLen {
return 1
}
return 0
}
|
