Documentation: merge: add a section about fast-forward
[git/gsoc2010-gitweb.git] / transport-helper.c
blob11f3d7ec52893dcdee127d8493f1897c6c091b31
1 #include "cache.h"
2 #include "transport.h"
3 #include "quote.h"
4 #include "run-command.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "quote.h"
9 #include "remote.h"
11 struct helper_data
13 const char *name;
14 struct child_process *helper;
15 FILE *out;
16 unsigned fetch : 1,
17 import : 1,
18 option : 1,
19 push : 1;
20 /* These go from remote name (as in "list") to private name */
21 struct refspec *refspecs;
22 int refspec_nr;
25 static struct child_process *get_helper(struct transport *transport)
27 struct helper_data *data = transport->data;
28 struct strbuf buf = STRBUF_INIT;
29 struct child_process *helper;
30 const char **refspecs = NULL;
31 int refspec_nr = 0;
32 int refspec_alloc = 0;
34 if (data->helper)
35 return data->helper;
37 helper = xcalloc(1, sizeof(*helper));
38 helper->in = -1;
39 helper->out = -1;
40 helper->err = 0;
41 helper->argv = xcalloc(4, sizeof(*helper->argv));
42 strbuf_addf(&buf, "remote-%s", data->name);
43 helper->argv[0] = strbuf_detach(&buf, NULL);
44 helper->argv[1] = transport->remote->name;
45 helper->argv[2] = transport->url;
46 helper->git_cmd = 1;
47 if (start_command(helper))
48 die("Unable to run helper: git %s", helper->argv[0]);
49 data->helper = helper;
51 write_str_in_full(helper->in, "capabilities\n");
53 data->out = xfdopen(helper->out, "r");
54 while (1) {
55 if (strbuf_getline(&buf, data->out, '\n') == EOF)
56 exit(128); /* child died, message supplied already */
58 if (!*buf.buf)
59 break;
60 if (!strcmp(buf.buf, "fetch"))
61 data->fetch = 1;
62 if (!strcmp(buf.buf, "option"))
63 data->option = 1;
64 if (!strcmp(buf.buf, "push"))
65 data->push = 1;
66 if (!strcmp(buf.buf, "import"))
67 data->import = 1;
68 if (!data->refspecs && !prefixcmp(buf.buf, "refspec ")) {
69 ALLOC_GROW(refspecs,
70 refspec_nr + 1,
71 refspec_alloc);
72 refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
75 if (refspecs) {
76 int i;
77 data->refspec_nr = refspec_nr;
78 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
79 for (i = 0; i < refspec_nr; i++) {
80 free((char *)refspecs[i]);
82 free(refspecs);
84 strbuf_release(&buf);
85 return data->helper;
88 static int disconnect_helper(struct transport *transport)
90 struct helper_data *data = transport->data;
91 if (data->helper) {
92 write_str_in_full(data->helper->in, "\n");
93 close(data->helper->in);
94 fclose(data->out);
95 finish_command(data->helper);
96 free((char *)data->helper->argv[0]);
97 free(data->helper->argv);
98 free(data->helper);
99 data->helper = NULL;
101 return 0;
104 static const char *unsupported_options[] = {
105 TRANS_OPT_UPLOADPACK,
106 TRANS_OPT_RECEIVEPACK,
107 TRANS_OPT_THIN,
108 TRANS_OPT_KEEP
110 static const char *boolean_options[] = {
111 TRANS_OPT_THIN,
112 TRANS_OPT_KEEP,
113 TRANS_OPT_FOLLOWTAGS
116 static int set_helper_option(struct transport *transport,
117 const char *name, const char *value)
119 struct helper_data *data = transport->data;
120 struct child_process *helper = get_helper(transport);
121 struct strbuf buf = STRBUF_INIT;
122 int i, ret, is_bool = 0;
124 if (!data->option)
125 return 1;
127 for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
128 if (!strcmp(name, unsupported_options[i]))
129 return 1;
132 for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
133 if (!strcmp(name, boolean_options[i])) {
134 is_bool = 1;
135 break;
139 strbuf_addf(&buf, "option %s ", name);
140 if (is_bool)
141 strbuf_addstr(&buf, value ? "true" : "false");
142 else
143 quote_c_style(value, &buf, NULL, 0);
144 strbuf_addch(&buf, '\n');
146 if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
147 die_errno("cannot send option to %s", data->name);
149 strbuf_reset(&buf);
150 if (strbuf_getline(&buf, data->out, '\n') == EOF)
151 exit(128); /* child died, message supplied already */
153 if (!strcmp(buf.buf, "ok"))
154 ret = 0;
155 else if (!prefixcmp(buf.buf, "error")) {
156 ret = -1;
157 } else if (!strcmp(buf.buf, "unsupported"))
158 ret = 1;
159 else {
160 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
161 ret = 1;
163 strbuf_release(&buf);
164 return ret;
167 static void standard_options(struct transport *t)
169 char buf[16];
170 int n;
171 int v = t->verbose;
172 int no_progress = v < 0 || (!t->progress && !isatty(1));
174 set_helper_option(t, "progress", !no_progress ? "true" : "false");
176 n = snprintf(buf, sizeof(buf), "%d", v + 1);
177 if (n >= sizeof(buf))
178 die("impossibly large verbosity value");
179 set_helper_option(t, "verbosity", buf);
182 static int release_helper(struct transport *transport)
184 struct helper_data *data = transport->data;
185 free_refspec(data->refspec_nr, data->refspecs);
186 data->refspecs = NULL;
187 disconnect_helper(transport);
188 free(transport->data);
189 return 0;
192 static int fetch_with_fetch(struct transport *transport,
193 int nr_heads, struct ref **to_fetch)
195 struct helper_data *data = transport->data;
196 int i;
197 struct strbuf buf = STRBUF_INIT;
199 standard_options(transport);
201 for (i = 0; i < nr_heads; i++) {
202 const struct ref *posn = to_fetch[i];
203 if (posn->status & REF_STATUS_UPTODATE)
204 continue;
206 strbuf_addf(&buf, "fetch %s %s\n",
207 sha1_to_hex(posn->old_sha1), posn->name);
210 strbuf_addch(&buf, '\n');
211 if (write_in_full(data->helper->in, buf.buf, buf.len) != buf.len)
212 die_errno("cannot send fetch to %s", data->name);
214 while (1) {
215 strbuf_reset(&buf);
216 if (strbuf_getline(&buf, data->out, '\n') == EOF)
217 exit(128); /* child died, message supplied already */
219 if (!prefixcmp(buf.buf, "lock ")) {
220 const char *name = buf.buf + 5;
221 if (transport->pack_lockfile)
222 warning("%s also locked %s", data->name, name);
223 else
224 transport->pack_lockfile = xstrdup(name);
226 else if (!buf.len)
227 break;
228 else
229 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
231 strbuf_release(&buf);
232 return 0;
235 static int get_importer(struct transport *transport, struct child_process *fastimport)
237 struct child_process *helper = get_helper(transport);
238 memset(fastimport, 0, sizeof(*fastimport));
239 fastimport->in = helper->out;
240 fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
241 fastimport->argv[0] = "fast-import";
242 fastimport->argv[1] = "--quiet";
244 fastimport->git_cmd = 1;
245 return start_command(fastimport);
248 static int fetch_with_import(struct transport *transport,
249 int nr_heads, struct ref **to_fetch)
251 struct child_process fastimport;
252 struct child_process *helper = get_helper(transport);
253 struct helper_data *data = transport->data;
254 int i;
255 struct ref *posn;
256 struct strbuf buf = STRBUF_INIT;
258 if (get_importer(transport, &fastimport))
259 die("Couldn't run fast-import");
261 for (i = 0; i < nr_heads; i++) {
262 posn = to_fetch[i];
263 if (posn->status & REF_STATUS_UPTODATE)
264 continue;
266 strbuf_addf(&buf, "import %s\n", posn->name);
267 write_in_full(helper->in, buf.buf, buf.len);
268 strbuf_reset(&buf);
270 disconnect_helper(transport);
271 finish_command(&fastimport);
272 free(fastimport.argv);
273 fastimport.argv = NULL;
275 for (i = 0; i < nr_heads; i++) {
276 char *private;
277 posn = to_fetch[i];
278 if (posn->status & REF_STATUS_UPTODATE)
279 continue;
280 if (data->refspecs)
281 private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
282 else
283 private = strdup(posn->name);
284 read_ref(private, posn->old_sha1);
285 free(private);
287 strbuf_release(&buf);
288 return 0;
291 static int fetch(struct transport *transport,
292 int nr_heads, struct ref **to_fetch)
294 struct helper_data *data = transport->data;
295 int i, count;
297 count = 0;
298 for (i = 0; i < nr_heads; i++)
299 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
300 count++;
302 if (!count)
303 return 0;
305 if (data->fetch)
306 return fetch_with_fetch(transport, nr_heads, to_fetch);
308 if (data->import)
309 return fetch_with_import(transport, nr_heads, to_fetch);
311 return -1;
314 static int push_refs(struct transport *transport,
315 struct ref *remote_refs, int flags)
317 int force_all = flags & TRANSPORT_PUSH_FORCE;
318 int mirror = flags & TRANSPORT_PUSH_MIRROR;
319 struct helper_data *data = transport->data;
320 struct strbuf buf = STRBUF_INIT;
321 struct child_process *helper;
322 struct ref *ref;
324 if (!remote_refs)
325 return 0;
327 helper = get_helper(transport);
328 if (!data->push)
329 return 1;
331 for (ref = remote_refs; ref; ref = ref->next) {
332 if (ref->peer_ref)
333 hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
334 else if (!mirror)
335 continue;
337 ref->deletion = is_null_sha1(ref->new_sha1);
338 if (!ref->deletion &&
339 !hashcmp(ref->old_sha1, ref->new_sha1)) {
340 ref->status = REF_STATUS_UPTODATE;
341 continue;
344 if (force_all)
345 ref->force = 1;
347 strbuf_addstr(&buf, "push ");
348 if (!ref->deletion) {
349 if (ref->force)
350 strbuf_addch(&buf, '+');
351 if (ref->peer_ref)
352 strbuf_addstr(&buf, ref->peer_ref->name);
353 else
354 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
356 strbuf_addch(&buf, ':');
357 strbuf_addstr(&buf, ref->name);
358 strbuf_addch(&buf, '\n');
360 if (buf.len == 0)
361 return 0;
363 transport->verbose = flags & TRANSPORT_PUSH_VERBOSE ? 1 : 0;
364 standard_options(transport);
366 if (flags & TRANSPORT_PUSH_DRY_RUN) {
367 if (set_helper_option(transport, "dry-run", "true") != 0)
368 die("helper %s does not support dry-run", data->name);
371 strbuf_addch(&buf, '\n');
372 if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
373 exit(128);
375 ref = remote_refs;
376 while (1) {
377 char *refname, *msg;
378 int status;
380 strbuf_reset(&buf);
381 if (strbuf_getline(&buf, data->out, '\n') == EOF)
382 exit(128); /* child died, message supplied already */
383 if (!buf.len)
384 break;
386 if (!prefixcmp(buf.buf, "ok ")) {
387 status = REF_STATUS_OK;
388 refname = buf.buf + 3;
389 } else if (!prefixcmp(buf.buf, "error ")) {
390 status = REF_STATUS_REMOTE_REJECT;
391 refname = buf.buf + 6;
392 } else
393 die("expected ok/error, helper said '%s'\n", buf.buf);
395 msg = strchr(refname, ' ');
396 if (msg) {
397 struct strbuf msg_buf = STRBUF_INIT;
398 const char *end;
400 *msg++ = '\0';
401 if (!unquote_c_style(&msg_buf, msg, &end))
402 msg = strbuf_detach(&msg_buf, NULL);
403 else
404 msg = xstrdup(msg);
405 strbuf_release(&msg_buf);
407 if (!strcmp(msg, "no match")) {
408 status = REF_STATUS_NONE;
409 free(msg);
410 msg = NULL;
412 else if (!strcmp(msg, "up to date")) {
413 status = REF_STATUS_UPTODATE;
414 free(msg);
415 msg = NULL;
417 else if (!strcmp(msg, "non-fast forward")) {
418 status = REF_STATUS_REJECT_NONFASTFORWARD;
419 free(msg);
420 msg = NULL;
424 if (ref)
425 ref = find_ref_by_name(ref, refname);
426 if (!ref)
427 ref = find_ref_by_name(remote_refs, refname);
428 if (!ref) {
429 warning("helper reported unexpected status of %s", refname);
430 continue;
433 ref->status = status;
434 ref->remote_status = msg;
436 strbuf_release(&buf);
437 return 0;
440 static int has_attribute(const char *attrs, const char *attr) {
441 int len;
442 if (!attrs)
443 return 0;
445 len = strlen(attr);
446 for (;;) {
447 const char *space = strchrnul(attrs, ' ');
448 if (len == space - attrs && !strncmp(attrs, attr, len))
449 return 1;
450 if (!*space)
451 return 0;
452 attrs = space + 1;
456 static struct ref *get_refs_list(struct transport *transport, int for_push)
458 struct helper_data *data = transport->data;
459 struct child_process *helper;
460 struct ref *ret = NULL;
461 struct ref **tail = &ret;
462 struct ref *posn;
463 struct strbuf buf = STRBUF_INIT;
465 helper = get_helper(transport);
467 if (data->push && for_push)
468 write_str_in_full(helper->in, "list for-push\n");
469 else
470 write_str_in_full(helper->in, "list\n");
472 while (1) {
473 char *eov, *eon;
474 if (strbuf_getline(&buf, data->out, '\n') == EOF)
475 exit(128); /* child died, message supplied already */
477 if (!*buf.buf)
478 break;
480 eov = strchr(buf.buf, ' ');
481 if (!eov)
482 die("Malformed response in ref list: %s", buf.buf);
483 eon = strchr(eov + 1, ' ');
484 *eov = '\0';
485 if (eon)
486 *eon = '\0';
487 *tail = alloc_ref(eov + 1);
488 if (buf.buf[0] == '@')
489 (*tail)->symref = xstrdup(buf.buf + 1);
490 else if (buf.buf[0] != '?')
491 get_sha1_hex(buf.buf, (*tail)->old_sha1);
492 if (eon) {
493 if (has_attribute(eon + 1, "unchanged")) {
494 (*tail)->status |= REF_STATUS_UPTODATE;
495 read_ref((*tail)->name, (*tail)->old_sha1);
498 tail = &((*tail)->next);
500 strbuf_release(&buf);
502 for (posn = ret; posn; posn = posn->next)
503 resolve_remote_symref(posn, ret);
505 return ret;
508 int transport_helper_init(struct transport *transport, const char *name)
510 struct helper_data *data = xcalloc(sizeof(*data), 1);
511 data->name = name;
513 transport->data = data;
514 transport->set_option = set_helper_option;
515 transport->get_refs_list = get_refs_list;
516 transport->fetch = fetch;
517 transport->push_refs = push_refs;
518 transport->disconnect = release_helper;
519 return 0;