receive-pack.c: use a reference transaction for updating the refs
[git/mingw.git] / transport-helper.c
blob84c616f180bebc730d05f306906558dd0abad2a4
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"
10 #include "string-list.h"
11 #include "thread-utils.h"
12 #include "sigchain.h"
13 #include "argv-array.h"
14 #include "refs.h"
16 static int debug;
18 struct helper_data {
19 const char *name;
20 struct child_process *helper;
21 FILE *out;
22 unsigned fetch : 1,
23 import : 1,
24 bidi_import : 1,
25 export : 1,
26 option : 1,
27 push : 1,
28 connect : 1,
29 signed_tags : 1,
30 check_connectivity : 1,
31 no_disconnect_req : 1,
32 no_private_update : 1;
33 char *export_marks;
34 char *import_marks;
35 /* These go from remote name (as in "list") to private name */
36 struct refspec *refspecs;
37 int refspec_nr;
38 /* Transport options for fetch-pack/send-pack (should one of
39 * those be invoked).
41 struct git_transport_options transport_options;
44 static void sendline(struct helper_data *helper, struct strbuf *buffer)
46 if (debug)
47 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
48 if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
49 != buffer->len)
50 die_errno("Full write to remote helper failed");
53 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
55 strbuf_reset(buffer);
56 if (debug)
57 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
58 if (strbuf_getline(buffer, helper, '\n') == EOF) {
59 if (debug)
60 fprintf(stderr, "Debug: Remote helper quit.\n");
61 return 1;
64 if (debug)
65 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
66 return 0;
69 static int recvline(struct helper_data *helper, struct strbuf *buffer)
71 return recvline_fh(helper->out, buffer, helper->name);
74 static void write_constant(int fd, const char *str)
76 if (debug)
77 fprintf(stderr, "Debug: Remote helper: -> %s", str);
78 if (write_in_full(fd, str, strlen(str)) != strlen(str))
79 die_errno("Full write to remote helper failed");
82 static const char *remove_ext_force(const char *url)
84 if (url) {
85 const char *colon = strchr(url, ':');
86 if (colon && colon[1] == ':')
87 return colon + 2;
89 return url;
92 static void do_take_over(struct transport *transport)
94 struct helper_data *data;
95 data = (struct helper_data *)transport->data;
96 transport_take_over(transport, data->helper);
97 fclose(data->out);
98 free(data);
101 static struct child_process *get_helper(struct transport *transport)
103 struct helper_data *data = transport->data;
104 struct strbuf buf = STRBUF_INIT;
105 struct child_process *helper;
106 const char **refspecs = NULL;
107 int refspec_nr = 0;
108 int refspec_alloc = 0;
109 int duped;
110 int code;
111 char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
112 const char *helper_env[] = {
113 git_dir_buf,
114 NULL
118 if (data->helper)
119 return data->helper;
121 helper = xcalloc(1, sizeof(*helper));
122 helper->in = -1;
123 helper->out = -1;
124 helper->err = 0;
125 argv_array_pushf(&helper->args, "git-remote-%s", data->name);
126 argv_array_push(&helper->args, transport->remote->name);
127 argv_array_push(&helper->args, remove_ext_force(transport->url));
128 helper->git_cmd = 0;
129 helper->silent_exec_failure = 1;
131 snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
132 helper->env = helper_env;
134 code = start_command(helper);
135 if (code < 0 && errno == ENOENT)
136 die("Unable to find remote helper for '%s'", data->name);
137 else if (code != 0)
138 exit(code);
140 data->helper = helper;
141 data->no_disconnect_req = 0;
144 * Open the output as FILE* so strbuf_getline() can be used.
145 * Do this with duped fd because fclose() will close the fd,
146 * and stuff like taking over will require the fd to remain.
148 duped = dup(helper->out);
149 if (duped < 0)
150 die_errno("Can't dup helper output fd");
151 data->out = xfdopen(duped, "r");
153 write_constant(helper->in, "capabilities\n");
155 while (1) {
156 const char *capname;
157 int mandatory = 0;
158 if (recvline(data, &buf))
159 exit(128);
161 if (!*buf.buf)
162 break;
164 if (*buf.buf == '*') {
165 capname = buf.buf + 1;
166 mandatory = 1;
167 } else
168 capname = buf.buf;
170 if (debug)
171 fprintf(stderr, "Debug: Got cap %s\n", capname);
172 if (!strcmp(capname, "fetch"))
173 data->fetch = 1;
174 else if (!strcmp(capname, "option"))
175 data->option = 1;
176 else if (!strcmp(capname, "push"))
177 data->push = 1;
178 else if (!strcmp(capname, "import"))
179 data->import = 1;
180 else if (!strcmp(capname, "bidi-import"))
181 data->bidi_import = 1;
182 else if (!strcmp(capname, "export"))
183 data->export = 1;
184 else if (!strcmp(capname, "check-connectivity"))
185 data->check_connectivity = 1;
186 else if (!data->refspecs && starts_with(capname, "refspec ")) {
187 ALLOC_GROW(refspecs,
188 refspec_nr + 1,
189 refspec_alloc);
190 refspecs[refspec_nr++] = xstrdup(capname + strlen("refspec "));
191 } else if (!strcmp(capname, "connect")) {
192 data->connect = 1;
193 } else if (!strcmp(capname, "signed-tags")) {
194 data->signed_tags = 1;
195 } else if (starts_with(capname, "export-marks ")) {
196 data->export_marks = xstrdup(capname + strlen("export-marks "));
197 } else if (starts_with(capname, "import-marks")) {
198 data->import_marks = xstrdup(capname + strlen("import-marks "));
199 } else if (starts_with(capname, "no-private-update")) {
200 data->no_private_update = 1;
201 } else if (mandatory) {
202 die("Unknown mandatory capability %s. This remote "
203 "helper probably needs newer version of Git.",
204 capname);
207 if (refspecs) {
208 int i;
209 data->refspec_nr = refspec_nr;
210 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
211 for (i = 0; i < refspec_nr; i++)
212 free((char *)refspecs[i]);
213 free(refspecs);
214 } else if (data->import || data->bidi_import || data->export) {
215 warning("This remote helper should implement refspec capability.");
217 strbuf_release(&buf);
218 if (debug)
219 fprintf(stderr, "Debug: Capabilities complete.\n");
220 return data->helper;
223 static int disconnect_helper(struct transport *transport)
225 struct helper_data *data = transport->data;
226 int res = 0;
228 if (data->helper) {
229 if (debug)
230 fprintf(stderr, "Debug: Disconnecting.\n");
231 if (!data->no_disconnect_req) {
233 * Ignore write errors; there's nothing we can do,
234 * since we're about to close the pipe anyway. And the
235 * most likely error is EPIPE due to the helper dying
236 * to report an error itself.
238 sigchain_push(SIGPIPE, SIG_IGN);
239 xwrite(data->helper->in, "\n", 1);
240 sigchain_pop(SIGPIPE);
242 close(data->helper->in);
243 close(data->helper->out);
244 fclose(data->out);
245 res = finish_command(data->helper);
246 free(data->helper);
247 data->helper = NULL;
249 return res;
252 static const char *unsupported_options[] = {
253 TRANS_OPT_UPLOADPACK,
254 TRANS_OPT_RECEIVEPACK,
255 TRANS_OPT_THIN,
256 TRANS_OPT_KEEP
259 static const char *boolean_options[] = {
260 TRANS_OPT_THIN,
261 TRANS_OPT_KEEP,
262 TRANS_OPT_FOLLOWTAGS
265 static int set_helper_option(struct transport *transport,
266 const char *name, const char *value)
268 struct helper_data *data = transport->data;
269 struct strbuf buf = STRBUF_INIT;
270 int i, ret, is_bool = 0;
272 get_helper(transport);
274 if (!data->option)
275 return 1;
277 for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
278 if (!strcmp(name, unsupported_options[i]))
279 return 1;
282 for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
283 if (!strcmp(name, boolean_options[i])) {
284 is_bool = 1;
285 break;
289 strbuf_addf(&buf, "option %s ", name);
290 if (is_bool)
291 strbuf_addstr(&buf, value ? "true" : "false");
292 else
293 quote_c_style(value, &buf, NULL, 0);
294 strbuf_addch(&buf, '\n');
296 sendline(data, &buf);
297 if (recvline(data, &buf))
298 exit(128);
300 if (!strcmp(buf.buf, "ok"))
301 ret = 0;
302 else if (starts_with(buf.buf, "error")) {
303 ret = -1;
304 } else if (!strcmp(buf.buf, "unsupported"))
305 ret = 1;
306 else {
307 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
308 ret = 1;
310 strbuf_release(&buf);
311 return ret;
314 static void standard_options(struct transport *t)
316 char buf[16];
317 int n;
318 int v = t->verbose;
320 set_helper_option(t, "progress", t->progress ? "true" : "false");
322 n = snprintf(buf, sizeof(buf), "%d", v + 1);
323 if (n >= sizeof(buf))
324 die("impossibly large verbosity value");
325 set_helper_option(t, "verbosity", buf);
328 static int release_helper(struct transport *transport)
330 int res = 0;
331 struct helper_data *data = transport->data;
332 free_refspec(data->refspec_nr, data->refspecs);
333 data->refspecs = NULL;
334 res = disconnect_helper(transport);
335 free(transport->data);
336 return res;
339 static int fetch_with_fetch(struct transport *transport,
340 int nr_heads, struct ref **to_fetch)
342 struct helper_data *data = transport->data;
343 int i;
344 struct strbuf buf = STRBUF_INIT;
346 standard_options(transport);
347 if (data->check_connectivity &&
348 data->transport_options.check_self_contained_and_connected)
349 set_helper_option(transport, "check-connectivity", "true");
351 if (transport->cloning)
352 set_helper_option(transport, "cloning", "true");
354 if (data->transport_options.update_shallow)
355 set_helper_option(transport, "update-shallow", "true");
357 for (i = 0; i < nr_heads; i++) {
358 const struct ref *posn = to_fetch[i];
359 if (posn->status & REF_STATUS_UPTODATE)
360 continue;
362 strbuf_addf(&buf, "fetch %s %s\n",
363 sha1_to_hex(posn->old_sha1), posn->name);
366 strbuf_addch(&buf, '\n');
367 sendline(data, &buf);
369 while (1) {
370 if (recvline(data, &buf))
371 exit(128);
373 if (starts_with(buf.buf, "lock ")) {
374 const char *name = buf.buf + 5;
375 if (transport->pack_lockfile)
376 warning("%s also locked %s", data->name, name);
377 else
378 transport->pack_lockfile = xstrdup(name);
380 else if (data->check_connectivity &&
381 data->transport_options.check_self_contained_and_connected &&
382 !strcmp(buf.buf, "connectivity-ok"))
383 data->transport_options.self_contained_and_connected = 1;
384 else if (!buf.len)
385 break;
386 else
387 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
389 strbuf_release(&buf);
390 return 0;
393 static int get_importer(struct transport *transport, struct child_process *fastimport)
395 struct child_process *helper = get_helper(transport);
396 struct helper_data *data = transport->data;
397 int cat_blob_fd, code;
398 memset(fastimport, 0, sizeof(*fastimport));
399 fastimport->in = helper->out;
400 argv_array_push(&fastimport->args, "fast-import");
401 argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
403 if (data->bidi_import) {
404 cat_blob_fd = xdup(helper->in);
405 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
407 fastimport->git_cmd = 1;
409 code = start_command(fastimport);
410 return code;
413 static int get_exporter(struct transport *transport,
414 struct child_process *fastexport,
415 struct string_list *revlist_args)
417 struct helper_data *data = transport->data;
418 struct child_process *helper = get_helper(transport);
419 int i;
421 memset(fastexport, 0, sizeof(*fastexport));
423 /* we need to duplicate helper->in because we want to use it after
424 * fastexport is done with it. */
425 fastexport->out = dup(helper->in);
426 argv_array_push(&fastexport->args, "fast-export");
427 argv_array_push(&fastexport->args, "--use-done-feature");
428 argv_array_push(&fastexport->args, data->signed_tags ?
429 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
430 if (data->export_marks)
431 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
432 if (data->import_marks)
433 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
435 for (i = 0; i < revlist_args->nr; i++)
436 argv_array_push(&fastexport->args, revlist_args->items[i].string);
438 fastexport->git_cmd = 1;
439 return start_command(fastexport);
442 static int fetch_with_import(struct transport *transport,
443 int nr_heads, struct ref **to_fetch)
445 struct child_process fastimport;
446 struct helper_data *data = transport->data;
447 int i;
448 struct ref *posn;
449 struct strbuf buf = STRBUF_INIT;
451 get_helper(transport);
453 if (get_importer(transport, &fastimport))
454 die("Couldn't run fast-import");
456 for (i = 0; i < nr_heads; i++) {
457 posn = to_fetch[i];
458 if (posn->status & REF_STATUS_UPTODATE)
459 continue;
461 strbuf_addf(&buf, "import %s\n", posn->name);
462 sendline(data, &buf);
463 strbuf_reset(&buf);
466 write_constant(data->helper->in, "\n");
468 * remote-helpers that advertise the bidi-import capability are required to
469 * buffer the complete batch of import commands until this newline before
470 * sending data to fast-import.
471 * These helpers read back data from fast-import on their stdin, which could
472 * be mixed with import commands, otherwise.
475 if (finish_command(&fastimport))
476 die("Error while running fast-import");
479 * The fast-import stream of a remote helper that advertises
480 * the "refspec" capability writes to the refs named after the
481 * right hand side of the first refspec matching each ref we
482 * were fetching.
484 * (If no "refspec" capability was specified, for historical
485 * reasons we default to the equivalent of *:*.)
487 * Store the result in to_fetch[i].old_sha1. Callers such
488 * as "git fetch" can use the value to write feedback to the
489 * terminal, populate FETCH_HEAD, and determine what new value
490 * should be written to peer_ref if the update is a
491 * fast-forward or this is a forced update.
493 for (i = 0; i < nr_heads; i++) {
494 char *private;
495 posn = to_fetch[i];
496 if (posn->status & REF_STATUS_UPTODATE)
497 continue;
498 if (data->refspecs)
499 private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
500 else
501 private = xstrdup(posn->name);
502 if (private) {
503 read_ref(private, posn->old_sha1);
504 free(private);
507 strbuf_release(&buf);
508 return 0;
511 static int process_connect_service(struct transport *transport,
512 const char *name, const char *exec)
514 struct helper_data *data = transport->data;
515 struct strbuf cmdbuf = STRBUF_INIT;
516 struct child_process *helper;
517 int r, duped, ret = 0;
518 FILE *input;
520 helper = get_helper(transport);
523 * Yes, dup the pipe another time, as we need unbuffered version
524 * of input pipe as FILE*. fclose() closes the underlying fd and
525 * stream buffering only can be changed before first I/O operation
526 * on it.
528 duped = dup(helper->out);
529 if (duped < 0)
530 die_errno("Can't dup helper output fd");
531 input = xfdopen(duped, "r");
532 setvbuf(input, NULL, _IONBF, 0);
535 * Handle --upload-pack and friends. This is fire and forget...
536 * just warn if it fails.
538 if (strcmp(name, exec)) {
539 r = set_helper_option(transport, "servpath", exec);
540 if (r > 0)
541 warning("Setting remote service path not supported by protocol.");
542 else if (r < 0)
543 warning("Invalid remote service path.");
546 if (data->connect)
547 strbuf_addf(&cmdbuf, "connect %s\n", name);
548 else
549 goto exit;
551 sendline(data, &cmdbuf);
552 if (recvline_fh(input, &cmdbuf, name))
553 exit(128);
555 if (!strcmp(cmdbuf.buf, "")) {
556 data->no_disconnect_req = 1;
557 if (debug)
558 fprintf(stderr, "Debug: Smart transport connection "
559 "ready.\n");
560 ret = 1;
561 } else if (!strcmp(cmdbuf.buf, "fallback")) {
562 if (debug)
563 fprintf(stderr, "Debug: Falling back to dumb "
564 "transport.\n");
565 } else
566 die("Unknown response to connect: %s",
567 cmdbuf.buf);
569 exit:
570 fclose(input);
571 return ret;
574 static int process_connect(struct transport *transport,
575 int for_push)
577 struct helper_data *data = transport->data;
578 const char *name;
579 const char *exec;
581 name = for_push ? "git-receive-pack" : "git-upload-pack";
582 if (for_push)
583 exec = data->transport_options.receivepack;
584 else
585 exec = data->transport_options.uploadpack;
587 return process_connect_service(transport, name, exec);
590 static int connect_helper(struct transport *transport, const char *name,
591 const char *exec, int fd[2])
593 struct helper_data *data = transport->data;
595 /* Get_helper so connect is inited. */
596 get_helper(transport);
597 if (!data->connect)
598 die("Operation not supported by protocol.");
600 if (!process_connect_service(transport, name, exec))
601 die("Can't connect to subservice %s.", name);
603 fd[0] = data->helper->out;
604 fd[1] = data->helper->in;
605 return 0;
608 static int fetch(struct transport *transport,
609 int nr_heads, struct ref **to_fetch)
611 struct helper_data *data = transport->data;
612 int i, count;
614 if (process_connect(transport, 0)) {
615 do_take_over(transport);
616 return transport->fetch(transport, nr_heads, to_fetch);
619 count = 0;
620 for (i = 0; i < nr_heads; i++)
621 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
622 count++;
624 if (!count)
625 return 0;
627 if (data->fetch)
628 return fetch_with_fetch(transport, nr_heads, to_fetch);
630 if (data->import)
631 return fetch_with_import(transport, nr_heads, to_fetch);
633 return -1;
636 static int push_update_ref_status(struct strbuf *buf,
637 struct ref **ref,
638 struct ref *remote_refs)
640 char *refname, *msg;
641 int status, forced = 0;
643 if (starts_with(buf->buf, "ok ")) {
644 status = REF_STATUS_OK;
645 refname = buf->buf + 3;
646 } else if (starts_with(buf->buf, "error ")) {
647 status = REF_STATUS_REMOTE_REJECT;
648 refname = buf->buf + 6;
649 } else
650 die("expected ok/error, helper said '%s'", buf->buf);
652 msg = strchr(refname, ' ');
653 if (msg) {
654 struct strbuf msg_buf = STRBUF_INIT;
655 const char *end;
657 *msg++ = '\0';
658 if (!unquote_c_style(&msg_buf, msg, &end))
659 msg = strbuf_detach(&msg_buf, NULL);
660 else
661 msg = xstrdup(msg);
662 strbuf_release(&msg_buf);
664 if (!strcmp(msg, "no match")) {
665 status = REF_STATUS_NONE;
666 free(msg);
667 msg = NULL;
669 else if (!strcmp(msg, "up to date")) {
670 status = REF_STATUS_UPTODATE;
671 free(msg);
672 msg = NULL;
674 else if (!strcmp(msg, "non-fast forward")) {
675 status = REF_STATUS_REJECT_NONFASTFORWARD;
676 free(msg);
677 msg = NULL;
679 else if (!strcmp(msg, "already exists")) {
680 status = REF_STATUS_REJECT_ALREADY_EXISTS;
681 free(msg);
682 msg = NULL;
684 else if (!strcmp(msg, "fetch first")) {
685 status = REF_STATUS_REJECT_FETCH_FIRST;
686 free(msg);
687 msg = NULL;
689 else if (!strcmp(msg, "needs force")) {
690 status = REF_STATUS_REJECT_NEEDS_FORCE;
691 free(msg);
692 msg = NULL;
694 else if (!strcmp(msg, "stale info")) {
695 status = REF_STATUS_REJECT_STALE;
696 free(msg);
697 msg = NULL;
699 else if (!strcmp(msg, "forced update")) {
700 forced = 1;
701 free(msg);
702 msg = NULL;
706 if (*ref)
707 *ref = find_ref_by_name(*ref, refname);
708 if (!*ref)
709 *ref = find_ref_by_name(remote_refs, refname);
710 if (!*ref) {
711 warning("helper reported unexpected status of %s", refname);
712 return 1;
715 if ((*ref)->status != REF_STATUS_NONE) {
717 * Earlier, the ref was marked not to be pushed, so ignore the ref
718 * status reported by the remote helper if the latter is 'no match'.
720 if (status == REF_STATUS_NONE)
721 return 1;
724 (*ref)->status = status;
725 (*ref)->forced_update |= forced;
726 (*ref)->remote_status = msg;
727 return !(status == REF_STATUS_OK);
730 static int push_update_refs_status(struct helper_data *data,
731 struct ref *remote_refs,
732 int flags)
734 struct strbuf buf = STRBUF_INIT;
735 struct ref *ref = remote_refs;
736 int ret = 0;
738 for (;;) {
739 char *private;
741 if (recvline(data, &buf)) {
742 ret = 1;
743 break;
746 if (!buf.len)
747 break;
749 if (push_update_ref_status(&buf, &ref, remote_refs))
750 continue;
752 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
753 continue;
755 /* propagate back the update to the remote namespace */
756 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
757 if (!private)
758 continue;
759 update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
760 free(private);
762 strbuf_release(&buf);
763 return ret;
766 static int push_refs_with_push(struct transport *transport,
767 struct ref *remote_refs, int flags)
769 int force_all = flags & TRANSPORT_PUSH_FORCE;
770 int mirror = flags & TRANSPORT_PUSH_MIRROR;
771 struct helper_data *data = transport->data;
772 struct strbuf buf = STRBUF_INIT;
773 struct ref *ref;
774 struct string_list cas_options = STRING_LIST_INIT_DUP;
775 struct string_list_item *cas_option;
777 get_helper(transport);
778 if (!data->push)
779 return 1;
781 for (ref = remote_refs; ref; ref = ref->next) {
782 if (!ref->peer_ref && !mirror)
783 continue;
785 /* Check for statuses set by set_ref_status_for_push() */
786 switch (ref->status) {
787 case REF_STATUS_REJECT_NONFASTFORWARD:
788 case REF_STATUS_REJECT_STALE:
789 case REF_STATUS_REJECT_ALREADY_EXISTS:
790 case REF_STATUS_UPTODATE:
791 continue;
792 default:
793 ; /* do nothing */
796 if (force_all)
797 ref->force = 1;
799 strbuf_addstr(&buf, "push ");
800 if (!ref->deletion) {
801 if (ref->force)
802 strbuf_addch(&buf, '+');
803 if (ref->peer_ref)
804 strbuf_addstr(&buf, ref->peer_ref->name);
805 else
806 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
808 strbuf_addch(&buf, ':');
809 strbuf_addstr(&buf, ref->name);
810 strbuf_addch(&buf, '\n');
813 * The "--force-with-lease" options without explicit
814 * values to expect have already been expanded into
815 * the ref->old_sha1_expect[] field; we can ignore
816 * transport->smart_options->cas altogether and instead
817 * can enumerate them from the refs.
819 if (ref->expect_old_sha1) {
820 struct strbuf cas = STRBUF_INIT;
821 strbuf_addf(&cas, "%s:%s",
822 ref->name, sha1_to_hex(ref->old_sha1_expect));
823 string_list_append(&cas_options, strbuf_detach(&cas, NULL));
826 if (buf.len == 0) {
827 string_list_clear(&cas_options, 0);
828 return 0;
831 standard_options(transport);
832 for_each_string_list_item(cas_option, &cas_options)
833 set_helper_option(transport, "cas", cas_option->string);
835 if (flags & TRANSPORT_PUSH_DRY_RUN) {
836 if (set_helper_option(transport, "dry-run", "true") != 0)
837 die("helper %s does not support dry-run", data->name);
840 strbuf_addch(&buf, '\n');
841 sendline(data, &buf);
842 strbuf_release(&buf);
844 return push_update_refs_status(data, remote_refs, flags);
847 static int push_refs_with_export(struct transport *transport,
848 struct ref *remote_refs, int flags)
850 struct ref *ref;
851 struct child_process *helper, exporter;
852 struct helper_data *data = transport->data;
853 struct string_list revlist_args = STRING_LIST_INIT_DUP;
854 struct strbuf buf = STRBUF_INIT;
856 if (!data->refspecs)
857 die("remote-helper doesn't support push; refspec needed");
859 if (flags & TRANSPORT_PUSH_DRY_RUN) {
860 if (set_helper_option(transport, "dry-run", "true") != 0)
861 die("helper %s does not support dry-run", data->name);
864 if (flags & TRANSPORT_PUSH_FORCE) {
865 if (set_helper_option(transport, "force", "true") != 0)
866 warning("helper %s does not support 'force'", data->name);
869 helper = get_helper(transport);
871 write_constant(helper->in, "export\n");
873 for (ref = remote_refs; ref; ref = ref->next) {
874 char *private;
875 unsigned char sha1[20];
877 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
878 if (private && !get_sha1(private, sha1)) {
879 strbuf_addf(&buf, "^%s", private);
880 string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
881 hashcpy(ref->old_sha1, sha1);
883 free(private);
885 if (ref->peer_ref) {
886 if (strcmp(ref->name, ref->peer_ref->name)) {
887 if (!ref->deletion) {
888 const char *name;
889 int flag;
891 /* Follow symbolic refs (mainly for HEAD). */
892 name = resolve_ref_unsafe(ref->peer_ref->name, sha1, 1, &flag);
893 if (!name || !(flag & REF_ISSYMREF))
894 name = ref->peer_ref->name;
896 strbuf_addf(&buf, "%s:%s", name, ref->name);
897 } else
898 strbuf_addf(&buf, ":%s", ref->name);
900 string_list_append(&revlist_args, "--refspec");
901 string_list_append(&revlist_args, buf.buf);
902 strbuf_release(&buf);
904 if (!ref->deletion)
905 string_list_append(&revlist_args, ref->peer_ref->name);
909 if (get_exporter(transport, &exporter, &revlist_args))
910 die("Couldn't run fast-export");
912 string_list_clear(&revlist_args, 1);
914 if (finish_command(&exporter))
915 die("Error while running fast-export");
916 if (push_update_refs_status(data, remote_refs, flags))
917 return 1;
919 if (data->export_marks) {
920 strbuf_addf(&buf, "%s.tmp", data->export_marks);
921 rename(buf.buf, data->export_marks);
922 strbuf_release(&buf);
925 return 0;
928 static int push_refs(struct transport *transport,
929 struct ref *remote_refs, int flags)
931 struct helper_data *data = transport->data;
933 if (process_connect(transport, 1)) {
934 do_take_over(transport);
935 return transport->push_refs(transport, remote_refs, flags);
938 if (!remote_refs) {
939 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
940 "Perhaps you should specify a branch such as 'master'.\n");
941 return 0;
944 if (data->push)
945 return push_refs_with_push(transport, remote_refs, flags);
947 if (data->export)
948 return push_refs_with_export(transport, remote_refs, flags);
950 return -1;
954 static int has_attribute(const char *attrs, const char *attr) {
955 int len;
956 if (!attrs)
957 return 0;
959 len = strlen(attr);
960 for (;;) {
961 const char *space = strchrnul(attrs, ' ');
962 if (len == space - attrs && !strncmp(attrs, attr, len))
963 return 1;
964 if (!*space)
965 return 0;
966 attrs = space + 1;
970 static struct ref *get_refs_list(struct transport *transport, int for_push)
972 struct helper_data *data = transport->data;
973 struct child_process *helper;
974 struct ref *ret = NULL;
975 struct ref **tail = &ret;
976 struct ref *posn;
977 struct strbuf buf = STRBUF_INIT;
979 helper = get_helper(transport);
981 if (process_connect(transport, for_push)) {
982 do_take_over(transport);
983 return transport->get_refs_list(transport, for_push);
986 if (data->push && for_push)
987 write_str_in_full(helper->in, "list for-push\n");
988 else
989 write_str_in_full(helper->in, "list\n");
991 while (1) {
992 char *eov, *eon;
993 if (recvline(data, &buf))
994 exit(128);
996 if (!*buf.buf)
997 break;
999 eov = strchr(buf.buf, ' ');
1000 if (!eov)
1001 die("Malformed response in ref list: %s", buf.buf);
1002 eon = strchr(eov + 1, ' ');
1003 *eov = '\0';
1004 if (eon)
1005 *eon = '\0';
1006 *tail = alloc_ref(eov + 1);
1007 if (buf.buf[0] == '@')
1008 (*tail)->symref = xstrdup(buf.buf + 1);
1009 else if (buf.buf[0] != '?')
1010 get_sha1_hex(buf.buf, (*tail)->old_sha1);
1011 if (eon) {
1012 if (has_attribute(eon + 1, "unchanged")) {
1013 (*tail)->status |= REF_STATUS_UPTODATE;
1014 read_ref((*tail)->name, (*tail)->old_sha1);
1017 tail = &((*tail)->next);
1019 if (debug)
1020 fprintf(stderr, "Debug: Read ref listing.\n");
1021 strbuf_release(&buf);
1023 for (posn = ret; posn; posn = posn->next)
1024 resolve_remote_symref(posn, ret);
1026 return ret;
1029 int transport_helper_init(struct transport *transport, const char *name)
1031 struct helper_data *data = xcalloc(1, sizeof(*data));
1032 data->name = name;
1034 if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1035 debug = 1;
1037 transport->data = data;
1038 transport->set_option = set_helper_option;
1039 transport->get_refs_list = get_refs_list;
1040 transport->fetch = fetch;
1041 transport->push_refs = push_refs;
1042 transport->disconnect = release_helper;
1043 transport->connect = connect_helper;
1044 transport->smart_options = &(data->transport_options);
1045 return 0;
1049 * Linux pipes can buffer 65536 bytes at once (and most platforms can
1050 * buffer less), so attempt reads and writes with up to that size.
1052 #define BUFFERSIZE 65536
1053 /* This should be enough to hold debugging message. */
1054 #define PBUFFERSIZE 8192
1056 /* Print bidirectional transfer loop debug message. */
1057 __attribute__((format (printf, 1, 2)))
1058 static void transfer_debug(const char *fmt, ...)
1060 va_list args;
1061 char msgbuf[PBUFFERSIZE];
1062 static int debug_enabled = -1;
1064 if (debug_enabled < 0)
1065 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1066 if (!debug_enabled)
1067 return;
1069 va_start(args, fmt);
1070 vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1071 va_end(args);
1072 fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1075 /* Stream state: More data may be coming in this direction. */
1076 #define SSTATE_TRANSFERING 0
1078 * Stream state: No more data coming in this direction, flushing rest of
1079 * data.
1081 #define SSTATE_FLUSHING 1
1082 /* Stream state: Transfer in this direction finished. */
1083 #define SSTATE_FINISHED 2
1085 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1086 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1087 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1089 /* Unidirectional transfer. */
1090 struct unidirectional_transfer {
1091 /* Source */
1092 int src;
1093 /* Destination */
1094 int dest;
1095 /* Is source socket? */
1096 int src_is_sock;
1097 /* Is destination socket? */
1098 int dest_is_sock;
1099 /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1100 int state;
1101 /* Buffer. */
1102 char buf[BUFFERSIZE];
1103 /* Buffer used. */
1104 size_t bufuse;
1105 /* Name of source. */
1106 const char *src_name;
1107 /* Name of destination. */
1108 const char *dest_name;
1111 /* Closes the target (for writing) if transfer has finished. */
1112 static void udt_close_if_finished(struct unidirectional_transfer *t)
1114 if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1115 t->state = SSTATE_FINISHED;
1116 if (t->dest_is_sock)
1117 shutdown(t->dest, SHUT_WR);
1118 else
1119 close(t->dest);
1120 transfer_debug("Closed %s.", t->dest_name);
1125 * Tries to read read data from source into buffer. If buffer is full,
1126 * no data is read. Returns 0 on success, -1 on error.
1128 static int udt_do_read(struct unidirectional_transfer *t)
1130 ssize_t bytes;
1132 if (t->bufuse == BUFFERSIZE)
1133 return 0; /* No space for more. */
1135 transfer_debug("%s is readable", t->src_name);
1136 bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1137 if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1138 errno != EINTR) {
1139 error("read(%s) failed: %s", t->src_name, strerror(errno));
1140 return -1;
1141 } else if (bytes == 0) {
1142 transfer_debug("%s EOF (with %i bytes in buffer)",
1143 t->src_name, (int)t->bufuse);
1144 t->state = SSTATE_FLUSHING;
1145 } else if (bytes > 0) {
1146 t->bufuse += bytes;
1147 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1148 (int)bytes, t->src_name, (int)t->bufuse);
1150 return 0;
1153 /* Tries to write data from buffer into destination. If buffer is empty,
1154 * no data is written. Returns 0 on success, -1 on error.
1156 static int udt_do_write(struct unidirectional_transfer *t)
1158 ssize_t bytes;
1160 if (t->bufuse == 0)
1161 return 0; /* Nothing to write. */
1163 transfer_debug("%s is writable", t->dest_name);
1164 bytes = xwrite(t->dest, t->buf, t->bufuse);
1165 if (bytes < 0 && errno != EWOULDBLOCK) {
1166 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1167 return -1;
1168 } else if (bytes > 0) {
1169 t->bufuse -= bytes;
1170 if (t->bufuse)
1171 memmove(t->buf, t->buf + bytes, t->bufuse);
1172 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1173 (int)bytes, t->dest_name, (int)t->bufuse);
1175 return 0;
1179 /* State of bidirectional transfer loop. */
1180 struct bidirectional_transfer_state {
1181 /* Direction from program to git. */
1182 struct unidirectional_transfer ptg;
1183 /* Direction from git to program. */
1184 struct unidirectional_transfer gtp;
1187 static void *udt_copy_task_routine(void *udt)
1189 struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1190 while (t->state != SSTATE_FINISHED) {
1191 if (STATE_NEEDS_READING(t->state))
1192 if (udt_do_read(t))
1193 return NULL;
1194 if (STATE_NEEDS_WRITING(t->state))
1195 if (udt_do_write(t))
1196 return NULL;
1197 if (STATE_NEEDS_CLOSING(t->state))
1198 udt_close_if_finished(t);
1200 return udt; /* Just some non-NULL value. */
1203 #ifndef NO_PTHREADS
1206 * Join thread, with appropriate errors on failure. Name is name for the
1207 * thread (for error messages). Returns 0 on success, 1 on failure.
1209 static int tloop_join(pthread_t thread, const char *name)
1211 int err;
1212 void *tret;
1213 err = pthread_join(thread, &tret);
1214 if (!tret) {
1215 error("%s thread failed", name);
1216 return 1;
1218 if (err) {
1219 error("%s thread failed to join: %s", name, strerror(err));
1220 return 1;
1222 return 0;
1226 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1227 * -1 on failure.
1229 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1231 pthread_t gtp_thread;
1232 pthread_t ptg_thread;
1233 int err;
1234 int ret = 0;
1235 err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1236 &s->gtp);
1237 if (err)
1238 die("Can't start thread for copying data: %s", strerror(err));
1239 err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1240 &s->ptg);
1241 if (err)
1242 die("Can't start thread for copying data: %s", strerror(err));
1244 ret |= tloop_join(gtp_thread, "Git to program copy");
1245 ret |= tloop_join(ptg_thread, "Program to git copy");
1246 return ret;
1248 #else
1250 /* Close the source and target (for writing) for transfer. */
1251 static void udt_kill_transfer(struct unidirectional_transfer *t)
1253 t->state = SSTATE_FINISHED;
1255 * Socket read end left open isn't a disaster if nobody
1256 * attempts to read from it (mingw compat headers do not
1257 * have SHUT_RD)...
1259 * We can't fully close the socket since otherwise gtp
1260 * task would first close the socket it sends data to
1261 * while closing the ptg file descriptors.
1263 if (!t->src_is_sock)
1264 close(t->src);
1265 if (t->dest_is_sock)
1266 shutdown(t->dest, SHUT_WR);
1267 else
1268 close(t->dest);
1272 * Join process, with appropriate errors on failure. Name is name for the
1273 * process (for error messages). Returns 0 on success, 1 on failure.
1275 static int tloop_join(pid_t pid, const char *name)
1277 int tret;
1278 if (waitpid(pid, &tret, 0) < 0) {
1279 error("%s process failed to wait: %s", name, strerror(errno));
1280 return 1;
1282 if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1283 error("%s process failed", name);
1284 return 1;
1286 return 0;
1290 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1291 * -1 on failure.
1293 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1295 pid_t pid1, pid2;
1296 int ret = 0;
1298 /* Fork thread #1: git to program. */
1299 pid1 = fork();
1300 if (pid1 < 0)
1301 die_errno("Can't start thread for copying data");
1302 else if (pid1 == 0) {
1303 udt_kill_transfer(&s->ptg);
1304 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1307 /* Fork thread #2: program to git. */
1308 pid2 = fork();
1309 if (pid2 < 0)
1310 die_errno("Can't start thread for copying data");
1311 else if (pid2 == 0) {
1312 udt_kill_transfer(&s->gtp);
1313 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1317 * Close both streams in parent as to not interfere with
1318 * end of file detection and wait for both tasks to finish.
1320 udt_kill_transfer(&s->gtp);
1321 udt_kill_transfer(&s->ptg);
1322 ret |= tloop_join(pid1, "Git to program copy");
1323 ret |= tloop_join(pid2, "Program to git copy");
1324 return ret;
1326 #endif
1329 * Copies data from stdin to output and from input to stdout simultaneously.
1330 * Additionally filtering through given filter. If filter is NULL, uses
1331 * identity filter.
1333 int bidirectional_transfer_loop(int input, int output)
1335 struct bidirectional_transfer_state state;
1337 /* Fill the state fields. */
1338 state.ptg.src = input;
1339 state.ptg.dest = 1;
1340 state.ptg.src_is_sock = (input == output);
1341 state.ptg.dest_is_sock = 0;
1342 state.ptg.state = SSTATE_TRANSFERING;
1343 state.ptg.bufuse = 0;
1344 state.ptg.src_name = "remote input";
1345 state.ptg.dest_name = "stdout";
1347 state.gtp.src = 0;
1348 state.gtp.dest = output;
1349 state.gtp.src_is_sock = 0;
1350 state.gtp.dest_is_sock = (input == output);
1351 state.gtp.state = SSTATE_TRANSFERING;
1352 state.gtp.bufuse = 0;
1353 state.gtp.src_name = "stdin";
1354 state.gtp.dest_name = "remote output";
1356 return tloop_spawnwait_tasks(&state);