Fast implementation of Git in pure Go
codeberg.org/lindenii/furgit
git
go
object/id: Empty tree
+56
-1
+11
-1
object/id/algorithms.go
+11
-1
object/id/algorithms.go
···
24
24
packHashID uint32
25
25
sum func([]byte) ObjectID
26
26
new func() hash.Hash
27
+
emptyTree ObjectID
27
28
}
28
29
29
30
//nolint:gochecknoglobals
···
69
70
)
70
71
71
72
func init() { //nolint:gochecknoinits
73
+
emptyTreeInput := []byte("tree 0\x00")
74
+
72
75
for algo := Algorithm(0); int(algo) < len(algorithmTable); algo++ {
73
-
info := algorithmTable[algo]
76
+
info := &algorithmTable[algo]
74
77
if info.name == "" {
75
78
continue
76
79
}
77
80
81
+
info.emptyTree = info.sum(emptyTreeInput)
78
82
algorithmByName[info.name] = algo
79
83
supportedAlgorithms = append(supportedAlgorithms, algo)
80
84
}
···
133
137
}
134
138
135
139
return newFn(), nil
140
+
}
141
+
142
+
// EmptyTree returns the object ID of an empty tree ("tree 0\x00") for this
143
+
// algorithm.
144
+
func (algo Algorithm) EmptyTree() ObjectID {
145
+
return algo.info().emptyTree
136
146
}
137
147
138
148
func (algo Algorithm) info() algorithmDetails {
+45
object/id/objectid_test.go
+45
object/id/objectid_test.go
···
182
182
t.Fatalf("sha1 and sha256 should differ")
183
183
}
184
184
}
185
+
186
+
func TestAlgorithmEmptyTree(t *testing.T) {
187
+
t.Parallel()
188
+
189
+
tests := []struct {
190
+
name string
191
+
algo objectid.Algorithm
192
+
want string
193
+
}{
194
+
{
195
+
name: "sha1",
196
+
algo: objectid.AlgorithmSHA1,
197
+
want: "4b825dc642cb6eb9a060e54bf8d69288fbee4904",
198
+
},
199
+
{
200
+
name: "sha256",
201
+
algo: objectid.AlgorithmSHA256,
202
+
want: "6ef19b41225c5369f1c104d45d8d85efa9b057b53b14b4b9b939dd74decc5321",
203
+
},
204
+
}
205
+
206
+
for _, tt := range tests {
207
+
t.Run(tt.name, func(t *testing.T) {
208
+
t.Parallel()
209
+
210
+
got := tt.algo.EmptyTree()
211
+
if got.Algorithm() != tt.algo {
212
+
t.Fatalf("EmptyTree() algorithm = %v, want %v", got.Algorithm(), tt.algo)
213
+
}
214
+
215
+
if got.String() != tt.want {
216
+
t.Fatalf("EmptyTree() = %q, want %q", got.String(), tt.want)
217
+
}
218
+
})
219
+
}
220
+
}
221
+
222
+
func TestUnknownAlgorithmEmptyTree(t *testing.T) {
223
+
t.Parallel()
224
+
225
+
got := objectid.AlgorithmUnknown.EmptyTree()
226
+
if got != (objectid.ObjectID{}) {
227
+
t.Fatalf("EmptyTree() for unknown algorithm = %#v, want zero value", got)
228
+
}
229
+
}