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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
|
// Package common implements the git pack protocol with a pluggable transport.
// This is a low-level package to implement new transports. Use a concrete
// implementation instead (e.g. http, file, ssh).
//
// A simple example of usage can be found in the file package.
package common
import (
"bufio"
"context"
"errors"
"fmt"
"io"
stdioutil "io/ioutil"
"strings"
"time"
"gopkg.in/src-d/go-git.v4/plumbing/format/pktline"
"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/capability"
"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/sideband"
"gopkg.in/src-d/go-git.v4/plumbing/transport"
"gopkg.in/src-d/go-git.v4/utils/ioutil"
)
const (
readErrorSecondsTimeout = 10
)
var (
ErrTimeoutExceeded = errors.New("timeout exceeded")
)
// Commander creates Command instances. This is the main entry point for
// transport implementations.
type Commander interface {
// Command creates a new Command for the given git command and
// endpoint. cmd can be git-upload-pack or git-receive-pack. An
// error should be returned if the endpoint is not supported or the
// command cannot be created (e.g. binary does not exist, connection
// cannot be established).
Command(cmd string, ep *transport.Endpoint, auth transport.AuthMethod) (Command, error)
}
// Command is used for a single command execution.
// This interface is modeled after exec.Cmd and ssh.Session in the standard
// library.
type Command interface {
// StderrPipe returns a pipe that will be connected to the command's
// standard error when the command starts. It should not be called after
// Start.
StderrPipe() (io.Reader, error)
// StdinPipe returns a pipe that will be connected to the command's
// standard input when the command starts. It should not be called after
// Start. The pipe should be closed when no more input is expected.
StdinPipe() (io.WriteCloser, error)
// StdoutPipe returns a pipe that will be connected to the command's
// standard output when the command starts. It should not be called after
// Start.
StdoutPipe() (io.Reader, error)
// Start starts the specified command. It does not wait for it to
// complete.
Start() error
// Close closes the command and releases any resources used by it. It
// will block until the command exits.
Close() error
}
// CommandKiller expands the Command interface, enableing it for being killed.
type CommandKiller interface {
// Kill and close the session whatever the state it is. It will block until
// the command is terminated.
Kill() error
}
type client struct {
cmdr Commander
}
// NewClient creates a new client using the given Commander.
func NewClient(runner Commander) transport.Transport {
return &client{runner}
}
// NewUploadPackSession creates a new UploadPackSession.
func (c *client) NewUploadPackSession(ep *transport.Endpoint, auth transport.AuthMethod) (
transport.UploadPackSession, error) {
return c.newSession(transport.UploadPackServiceName, ep, auth)
}
// NewReceivePackSession creates a new ReceivePackSession.
func (c *client) NewReceivePackSession(ep *transport.Endpoint, auth transport.AuthMethod) (
transport.ReceivePackSession, error) {
return c.newSession(transport.ReceivePackServiceName, ep, auth)
}
type session struct {
Stdin io.WriteCloser
Stdout io.Reader
Command Command
isReceivePack bool
advRefs *packp.AdvRefs
packRun bool
finished bool
firstErrLine chan string
}
func (c *client) newSession(s string, ep *transport.Endpoint, auth transport.AuthMethod) (*session, error) {
cmd, err := c.cmdr.Command(s, ep, auth)
if err != nil {
return nil, err
}
stdin, err := cmd.StdinPipe()
if err != nil {
return nil, err
}
stdout, err := cmd.StdoutPipe()
if err != nil {
return nil, err
}
stderr, err := cmd.StderrPipe()
if err != nil {
return nil, err
}
if err := cmd.Start(); err != nil {
return nil, err
}
return &session{
Stdin: stdin,
Stdout: stdout,
Command: cmd,
firstErrLine: c.listenFirstError(stderr),
isReceivePack: s == transport.ReceivePackServiceName,
}, nil
}
func (c *client) listenFirstError(r io.Reader) chan string {
if r == nil {
return nil
}
errLine := make(chan string, 1)
go func() {
s := bufio.NewScanner(r)
if s.Scan() {
errLine <- s.Text()
} else {
close(errLine)
}
_, _ = io.Copy(stdioutil.Discard, r)
}()
return errLine
}
// AdvertisedReferences retrieves the advertised references from the server.
func (s *session) AdvertisedReferences() (*packp.AdvRefs, error) {
if s.advRefs != nil {
return s.advRefs, nil
}
ar := packp.NewAdvRefs()
if err := ar.Decode(s.Stdout); err != nil {
if err := s.handleAdvRefDecodeError(err); err != nil {
return nil, err
}
}
transport.FilterUnsupportedCapabilities(ar.Capabilities)
s.advRefs = ar
return ar, nil
}
func (s *session) handleAdvRefDecodeError(err error) error {
// If repository is not found, we get empty stdout and server writes an
// error to stderr.
if err == packp.ErrEmptyInput {
s.finished = true
if err := s.checkNotFoundError(); err != nil {
return err
}
return io.ErrUnexpectedEOF
}
// For empty (but existing) repositories, we get empty advertised-references
// message. But valid. That is, it includes at least a flush.
if err == packp.ErrEmptyAdvRefs {
// Empty repositories are valid for git-receive-pack.
if s.isReceivePack {
return nil
}
if err := s.finish(); err != nil {
return err
}
return transport.ErrEmptyRemoteRepository
}
// Some server sends the errors as normal content (git protocol), so when
// we try to decode it fails, we need to check the content of it, to detect
// not found errors
if uerr, ok := err.(*packp.ErrUnexpectedData); ok {
if isRepoNotFoundError(string(uerr.Data)) {
return transport.ErrRepositoryNotFound
}
}
return err
}
// UploadPack performs a request to the server to fetch a packfile. A reader is
// returned with the packfile content. The reader must be closed after reading.
func (s *session) UploadPack(ctx context.Context, req *packp.UploadPackRequest) (*packp.UploadPackResponse, error) {
if req.IsEmpty
|