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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
package core
import (
"errors"
"io"
"strings"
)
const (
refPrefix = "refs/"
refHeadPrefix = refPrefix + "heads/"
refTagPrefix = refPrefix + "tags/"
refRemotePrefix = refPrefix + "remotes/"
refNotePrefix = refPrefix + "notes/"
symrefPrefix = "ref: "
maxResolveRecursion = 1024
)
var (
ErrMaxResolveRecursion = errors.New("max. recursion level reached")
ErrReferenceNotFound = errors.New("reference not found")
)
// ReferenceType reference type's
type ReferenceType int8
const (
InvalidReference ReferenceType = 0
HashReference ReferenceType = 1
SymbolicReference ReferenceType = 2
)
// ReferenceName reference name's
type ReferenceName string
// AsRemote returns a new remote reference name using current one as base
func (r ReferenceName) AsRemote(remote string) ReferenceName {
return ReferenceName(refRemotePrefix + remote + "/" + r.alias())
}
func (r ReferenceName) String() string {
return string(r)
}
func (r ReferenceName) alias() string {
parts := strings.Split(string(r), "/")
return parts[len(parts)-1]
}
const (
HEAD ReferenceName = "HEAD"
)
// Reference is a representation of git reference
type Reference struct {
t ReferenceType
n ReferenceName
h Hash
target ReferenceName
}
// NewReferenceFromStrings creates a reference from name and target as string,
// the resulting reference can be a SymbolicReference or a HashReference base
// on the target provided
func NewReferenceFromStrings(name, target string) *Reference {
n := ReferenceName(name)
if strings.HasPrefix(target, symrefPrefix) {
target := ReferenceName(target[len(symrefPrefix):])
return NewSymbolicReference(n, target)
}
return NewHashReference(n, NewHash(target))
}
// NewSymbolicReference creates a new SymbolicReference reference
func NewSymbolicReference(n, target ReferenceName) *Reference {
return &Reference{
t: SymbolicReference,
n: n,
target: target,
}
}
// NewHashReference creates a new HashReference reference
func NewHashReference(n ReferenceName, h Hash) *Reference {
return &Reference{
t: HashReference,
n: n,
h: h,
}
}
// Type return the type of a reference
func (r *Reference) Type() ReferenceType {
return r.t
}
// Name return the name of a reference
func (r *Reference) Name() ReferenceName {
return r.n
}
// Hash return the hash of a hash reference
func (r *Reference) Hash() Hash {
return r.h
}
// Target return the target of a symbolic reference
func (r *Reference) Target() ReferenceName {
return r.target
}
// IsBranch check if a reference is a branch
func (r *Reference) IsBranch() bool {
return strings.HasPrefix(string(r.n), refHeadPrefix) || r.n == HEAD
}
// IsNote check if a reference is a note
func (r *Reference) IsNote() bool {
return strings.HasPrefix(string(r.n), refNotePrefix)
}
// IsRemote check if a reference is a remote
func (r *Reference) IsRemote() bool {
return strings.HasPrefix(string(r.n), refRemotePrefix)
}
// IsTag check if a reference is a tag
func (r *Reference) IsTag() bool {
return strings.HasPrefix(string(r.n), refTagPrefix)
}
// Strings dump a reference as a [2]string
func (r *Reference) Strings() [2]string {
var o [2]string
o[0] = r.Name().String()
switch r.Type() {
case HashReference:
o[1] = r.Hash().String()
case SymbolicReference:
o[1] = symrefPrefix + r.Target().String()
}
return o
}
// ReferenceSliceIter implements ReferenceIter. It iterates over a series of
// references stored in a slice and yields each one in turn when Next() is
// called.
//
// The ReferenceSliceIter must be closed with a call to Close() when it is no
// longer needed.
type ReferenceSliceIter struct {
series []*Reference
pos int
}
// NewReferenceSliceIter returns a reference iterator for the given slice of
// objects.
func NewReferenceSliceIter(series []*Reference) *ReferenceSliceIter {
return &ReferenceSliceIter{
series: series,
}
}
// Next returns the next reference from the iterator. If the iterator has
// reached the end it will return io.EOF as an error.
func (iter *ReferenceSliceIter) Next() (*Reference, error) {
if iter.pos >= len(iter.series) {
return nil, io.EOF
}
obj := iter.series[iter.pos]
iter.pos++
return obj, nil
}
// ForEach call the cb function for each reference contained on this iter until
// an error happends or the end of the iter is reached. If ErrStop is sent
// the iteration is stop but no error is returned
func (iter *ReferenceSliceIter) ForEach(cb func(*Reference) error) error {
for _, r := range iter.series {
if err := cb(r); err != nil {
if err == ErrStop {
return nil
}
return nil
}
}
return nil
}
// Close releases any resources used by the iterator.
func (iter *ReferenceSliceIter) Close() {
iter.pos = len(iter.series)
}
func ResolveReference(s ReferenceStorage, n ReferenceName) (*Reference, error) {
r, err := s.Get(n)
if err != nil || r == nil {
return r, err
}
return resolveReference(s, r, 0)
}
func resolveReference(s ReferenceStorage, r *Reference, recursion int) (*Reference, error) {
if r.Type() != SymbolicReference {
return r, nil
}
if recursion > maxResolveRecursion {
return nil, ErrMaxResolveRecursion
}
t, err := s.Get(r.Target())
if err != nil {
return nil, err
}
recursion++
return resolveReference(s, t, recursion)
}
|
