enums: omit trailing comma for portability
[git/git.git] / http-walker.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "walker.h"
4 #include "http.h"
5
6 struct alt_base
7 {
8 char *base;
9 int got_indices;
10 struct packed_git *packs;
11 struct alt_base *next;
12 };
13
14 enum object_request_state {
15 WAITING,
16 ABORTED,
17 ACTIVE,
18 COMPLETE
19 };
20
21 struct object_request
22 {
23 struct walker *walker;
24 unsigned char sha1[20];
25 struct alt_base *repo;
26 enum object_request_state state;
27 struct http_object_request *req;
28 struct object_request *next;
29 };
30
31 struct alternates_request {
32 struct walker *walker;
33 const char *base;
34 char *url;
35 struct strbuf *buffer;
36 struct active_request_slot *slot;
37 int http_specific;
38 };
39
40 struct walker_data {
41 const char *url;
42 int got_alternates;
43 struct alt_base *alt;
44 };
45
46 static struct object_request *object_queue_head;
47
48 static void fetch_alternates(struct walker *walker, const char *base);
49
50 static void process_object_response(void *callback_data);
51
52 static void start_object_request(struct walker *walker,
53 struct object_request *obj_req)
54 {
55 struct active_request_slot *slot;
56 struct http_object_request *req;
57
58 req = new_http_object_request(obj_req->repo->base, obj_req->sha1);
59 if (req == NULL) {
60 obj_req->state = ABORTED;
61 return;
62 }
63 obj_req->req = req;
64
65 slot = req->slot;
66 slot->callback_func = process_object_response;
67 slot->callback_data = obj_req;
68
69 /* Try to get the request started, abort the request on error */
70 obj_req->state = ACTIVE;
71 if (!start_active_slot(slot)) {
72 obj_req->state = ABORTED;
73 release_http_object_request(req);
74 return;
75 }
76 }
77
78 static void finish_object_request(struct object_request *obj_req)
79 {
80 if (finish_http_object_request(obj_req->req))
81 return;
82
83 if (obj_req->req->rename == 0)
84 walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1));
85 }
86
87 static void process_object_response(void *callback_data)
88 {
89 struct object_request *obj_req =
90 (struct object_request *)callback_data;
91 struct walker *walker = obj_req->walker;
92 struct walker_data *data = walker->data;
93 struct alt_base *alt = data->alt;
94
95 process_http_object_request(obj_req->req);
96 obj_req->state = COMPLETE;
97
98 /* Use alternates if necessary */
99 if (missing_target(obj_req->req)) {
100 fetch_alternates(walker, alt->base);
101 if (obj_req->repo->next != NULL) {
102 obj_req->repo =
103 obj_req->repo->next;
104 release_http_object_request(obj_req->req);
105 start_object_request(walker, obj_req);
106 return;
107 }
108 }
109
110 finish_object_request(obj_req);
111 }
112
113 static void release_object_request(struct object_request *obj_req)
114 {
115 struct object_request *entry = object_queue_head;
116
117 if (obj_req->req !=NULL && obj_req->req->localfile != -1)
118 error("fd leakage in release: %d", obj_req->req->localfile);
119 if (obj_req == object_queue_head) {
120 object_queue_head = obj_req->next;
121 } else {
122 while (entry->next != NULL && entry->next != obj_req)
123 entry = entry->next;
124 if (entry->next == obj_req)
125 entry->next = entry->next->next;
126 }
127
128 free(obj_req);
129 }
130
131 #ifdef USE_CURL_MULTI
132 static int fill_active_slot(struct walker *walker)
133 {
134 struct object_request *obj_req;
135
136 for (obj_req = object_queue_head; obj_req; obj_req = obj_req->next) {
137 if (obj_req->state == WAITING) {
138 if (has_sha1_file(obj_req->sha1))
139 obj_req->state = COMPLETE;
140 else {
141 start_object_request(walker, obj_req);
142 return 1;
143 }
144 }
145 }
146 return 0;
147 }
148 #endif
149
150 static void prefetch(struct walker *walker, unsigned char *sha1)
151 {
152 struct object_request *newreq;
153 struct object_request *tail;
154 struct walker_data *data = walker->data;
155
156 newreq = xmalloc(sizeof(*newreq));
157 newreq->walker = walker;
158 hashcpy(newreq->sha1, sha1);
159 newreq->repo = data->alt;
160 newreq->state = WAITING;
161 newreq->req = NULL;
162 newreq->next = NULL;
163
164 http_is_verbose = walker->get_verbosely;
165
166 if (object_queue_head == NULL) {
167 object_queue_head = newreq;
168 } else {
169 tail = object_queue_head;
170 while (tail->next != NULL)
171 tail = tail->next;
172 tail->next = newreq;
173 }
174
175 #ifdef USE_CURL_MULTI
176 fill_active_slots();
177 step_active_slots();
178 #endif
179 }
180
181 static void process_alternates_response(void *callback_data)
182 {
183 struct alternates_request *alt_req =
184 (struct alternates_request *)callback_data;
185 struct walker *walker = alt_req->walker;
186 struct walker_data *cdata = walker->data;
187 struct active_request_slot *slot = alt_req->slot;
188 struct alt_base *tail = cdata->alt;
189 const char *base = alt_req->base;
190 static const char null_byte = '\0';
191 char *data;
192 int i = 0;
193
194 if (alt_req->http_specific) {
195 if (slot->curl_result != CURLE_OK ||
196 !alt_req->buffer->len) {
197
198 /* Try reusing the slot to get non-http alternates */
199 alt_req->http_specific = 0;
200 sprintf(alt_req->url, "%s/objects/info/alternates",
201 base);
202 curl_easy_setopt(slot->curl, CURLOPT_URL,
203 alt_req->url);
204 active_requests++;
205 slot->in_use = 1;
206 if (slot->finished != NULL)
207 (*slot->finished) = 0;
208 if (!start_active_slot(slot)) {
209 cdata->got_alternates = -1;
210 slot->in_use = 0;
211 if (slot->finished != NULL)
212 (*slot->finished) = 1;
213 }
214 return;
215 }
216 } else if (slot->curl_result != CURLE_OK) {
217 if (!missing_target(slot)) {
218 cdata->got_alternates = -1;
219 return;
220 }
221 }
222
223 fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
224 alt_req->buffer->len--;
225 data = alt_req->buffer->buf;
226
227 while (i < alt_req->buffer->len) {
228 int posn = i;
229 while (posn < alt_req->buffer->len && data[posn] != '\n')
230 posn++;
231 if (data[posn] == '\n') {
232 int okay = 0;
233 int serverlen = 0;
234 struct alt_base *newalt;
235 char *target = NULL;
236 if (data[i] == '/') {
237 /*
238 * This counts
239 * http://git.host/pub/scm/linux.git/
240 * -----------here^
241 * so memcpy(dst, base, serverlen) will
242 * copy up to "...git.host".
243 */
244 const char *colon_ss = strstr(base,"://");
245 if (colon_ss) {
246 serverlen = (strchr(colon_ss + 3, '/')
247 - base);
248 okay = 1;
249 }
250 } else if (!memcmp(data + i, "../", 3)) {
251 /*
252 * Relative URL; chop the corresponding
253 * number of subpath from base (and ../
254 * from data), and concatenate the result.
255 *
256 * The code first drops ../ from data, and
257 * then drops one ../ from data and one path
258 * from base. IOW, one extra ../ is dropped
259 * from data than path is dropped from base.
260 *
261 * This is not wrong. The alternate in
262 * http://git.host/pub/scm/linux.git/
263 * to borrow from
264 * http://git.host/pub/scm/linus.git/
265 * is ../../linus.git/objects/. You need
266 * two ../../ to borrow from your direct
267 * neighbour.
268 */
269 i += 3;
270 serverlen = strlen(base);
271 while (i + 2 < posn &&
272 !memcmp(data + i, "../", 3)) {
273 do {
274 serverlen--;
275 } while (serverlen &&
276 base[serverlen - 1] != '/');
277 i += 3;
278 }
279 /* If the server got removed, give up. */
280 okay = strchr(base, ':') - base + 3 <
281 serverlen;
282 } else if (alt_req->http_specific) {
283 char *colon = strchr(data + i, ':');
284 char *slash = strchr(data + i, '/');
285 if (colon && slash && colon < data + posn &&
286 slash < data + posn && colon < slash) {
287 okay = 1;
288 }
289 }
290 /* skip "objects\n" at end */
291 if (okay) {
292 target = xmalloc(serverlen + posn - i - 6);
293 memcpy(target, base, serverlen);
294 memcpy(target + serverlen, data + i,
295 posn - i - 7);
296 target[serverlen + posn - i - 7] = 0;
297 if (walker->get_verbosely)
298 fprintf(stderr,
299 "Also look at %s\n", target);
300 newalt = xmalloc(sizeof(*newalt));
301 newalt->next = NULL;
302 newalt->base = target;
303 newalt->got_indices = 0;
304 newalt->packs = NULL;
305
306 while (tail->next != NULL)
307 tail = tail->next;
308 tail->next = newalt;
309 }
310 }
311 i = posn + 1;
312 }
313
314 cdata->got_alternates = 1;
315 }
316
317 static void fetch_alternates(struct walker *walker, const char *base)
318 {
319 struct strbuf buffer = STRBUF_INIT;
320 char *url;
321 struct active_request_slot *slot;
322 struct alternates_request alt_req;
323 struct walker_data *cdata = walker->data;
324
325 /*
326 * If another request has already started fetching alternates,
327 * wait for them to arrive and return to processing this request's
328 * curl message
329 */
330 #ifdef USE_CURL_MULTI
331 while (cdata->got_alternates == 0) {
332 step_active_slots();
333 }
334 #endif
335
336 /* Nothing to do if they've already been fetched */
337 if (cdata->got_alternates == 1)
338 return;
339
340 /* Start the fetch */
341 cdata->got_alternates = 0;
342
343 if (walker->get_verbosely)
344 fprintf(stderr, "Getting alternates list for %s\n", base);
345
346 url = xmalloc(strlen(base) + 31);
347 sprintf(url, "%s/objects/info/http-alternates", base);
348
349 /*
350 * Use a callback to process the result, since another request
351 * may fail and need to have alternates loaded before continuing
352 */
353 slot = get_active_slot();
354 slot->callback_func = process_alternates_response;
355 alt_req.walker = walker;
356 slot->callback_data = &alt_req;
357
358 curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
359 curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
360 curl_easy_setopt(slot->curl, CURLOPT_URL, url);
361
362 alt_req.base = base;
363 alt_req.url = url;
364 alt_req.buffer = &buffer;
365 alt_req.http_specific = 1;
366 alt_req.slot = slot;
367
368 if (start_active_slot(slot))
369 run_active_slot(slot);
370 else
371 cdata->got_alternates = -1;
372
373 strbuf_release(&buffer);
374 free(url);
375 }
376
377 static int fetch_indices(struct walker *walker, struct alt_base *repo)
378 {
379 int ret;
380
381 if (repo->got_indices)
382 return 0;
383
384 if (walker->get_verbosely)
385 fprintf(stderr, "Getting pack list for %s\n", repo->base);
386
387 switch (http_get_info_packs(repo->base, &repo->packs)) {
388 case HTTP_OK:
389 case HTTP_MISSING_TARGET:
390 repo->got_indices = 1;
391 ret = 0;
392 break;
393 default:
394 repo->got_indices = 0;
395 ret = -1;
396 }
397
398 return ret;
399 }
400
401 static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
402 {
403 struct packed_git *target;
404 int ret;
405 struct slot_results results;
406 struct http_pack_request *preq;
407
408 if (fetch_indices(walker, repo))
409 return -1;
410 target = find_sha1_pack(sha1, repo->packs);
411 if (!target)
412 return -1;
413
414 if (walker->get_verbosely) {
415 fprintf(stderr, "Getting pack %s\n",
416 sha1_to_hex(target->sha1));
417 fprintf(stderr, " which contains %s\n",
418 sha1_to_hex(sha1));
419 }
420
421 preq = new_http_pack_request(target, repo->base);
422 if (preq == NULL)
423 goto abort;
424 preq->lst = &repo->packs;
425 preq->slot->results = &results;
426
427 if (start_active_slot(preq->slot)) {
428 run_active_slot(preq->slot);
429 if (results.curl_result != CURLE_OK) {
430 error("Unable to get pack file %s\n%s", preq->url,
431 curl_errorstr);
432 goto abort;
433 }
434 } else {
435 error("Unable to start request");
436 goto abort;
437 }
438
439 ret = finish_http_pack_request(preq);
440 release_http_pack_request(preq);
441 if (ret)
442 return ret;
443
444 return 0;
445
446 abort:
447 return -1;
448 }
449
450 static void abort_object_request(struct object_request *obj_req)
451 {
452 release_object_request(obj_req);
453 }
454
455 static int fetch_object(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
456 {
457 char *hex = sha1_to_hex(sha1);
458 int ret = 0;
459 struct object_request *obj_req = object_queue_head;
460 struct http_object_request *req;
461
462 while (obj_req != NULL && hashcmp(obj_req->sha1, sha1))
463 obj_req = obj_req->next;
464 if (obj_req == NULL)
465 return error("Couldn't find request for %s in the queue", hex);
466
467 if (has_sha1_file(obj_req->sha1)) {
468 if (obj_req->req != NULL)
469 abort_http_object_request(obj_req->req);
470 abort_object_request(obj_req);
471 return 0;
472 }
473
474 #ifdef USE_CURL_MULTI
475 while (obj_req->state == WAITING)
476 step_active_slots();
477 #else
478 start_object_request(walker, obj_req);
479 #endif
480
481 /*
482 * obj_req->req might change when fetching alternates in the callback
483 * process_object_response; therefore, the "shortcut" variable, req,
484 * is used only after we're done with slots.
485 */
486 while (obj_req->state == ACTIVE)
487 run_active_slot(obj_req->req->slot);
488
489 req = obj_req->req;
490
491 if (req->localfile != -1) {
492 close(req->localfile);
493 req->localfile = -1;
494 }
495
496 if (obj_req->state == ABORTED) {
497 ret = error("Request for %s aborted", hex);
498 } else if (req->curl_result != CURLE_OK &&
499 req->http_code != 416) {
500 if (missing_target(req))
501 ret = -1; /* Be silent, it is probably in a pack. */
502 else
503 ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
504 req->errorstr, req->curl_result,
505 req->http_code, hex);
506 } else if (req->zret != Z_STREAM_END) {
507 walker->corrupt_object_found++;
508 ret = error("File %s (%s) corrupt", hex, req->url);
509 } else if (hashcmp(obj_req->sha1, req->real_sha1)) {
510 ret = error("File %s has bad hash", hex);
511 } else if (req->rename < 0) {
512 ret = error("unable to write sha1 filename %s",
513 req->filename);
514 }
515
516 release_http_object_request(req);
517 release_object_request(obj_req);
518 return ret;
519 }
520
521 static int fetch(struct walker *walker, unsigned char *sha1)
522 {
523 struct walker_data *data = walker->data;
524 struct alt_base *altbase = data->alt;
525
526 if (!fetch_object(walker, altbase, sha1))
527 return 0;
528 while (altbase) {
529 if (!fetch_pack(walker, altbase, sha1))
530 return 0;
531 fetch_alternates(walker, data->alt->base);
532 altbase = altbase->next;
533 }
534 return error("Unable to find %s under %s", sha1_to_hex(sha1),
535 data->alt->base);
536 }
537
538 static int fetch_ref(struct walker *walker, struct ref *ref)
539 {
540 struct walker_data *data = walker->data;
541 return http_fetch_ref(data->alt->base, ref);
542 }
543
544 static void cleanup(struct walker *walker)
545 {
546 struct walker_data *data = walker->data;
547 struct alt_base *alt, *alt_next;
548
549 if (data) {
550 alt = data->alt;
551 while (alt) {
552 alt_next = alt->next;
553
554 free(alt->base);
555 free(alt);
556
557 alt = alt_next;
558 }
559 free(data);
560 walker->data = NULL;
561 }
562 }
563
564 struct walker *get_http_walker(const char *url)
565 {
566 char *s;
567 struct walker_data *data = xmalloc(sizeof(struct walker_data));
568 struct walker *walker = xmalloc(sizeof(struct walker));
569
570 data->alt = xmalloc(sizeof(*data->alt));
571 data->alt->base = xmalloc(strlen(url) + 1);
572 strcpy(data->alt->base, url);
573 for (s = data->alt->base + strlen(data->alt->base) - 1; *s == '/'; --s)
574 *s = 0;
575
576 data->alt->got_indices = 0;
577 data->alt->packs = NULL;
578 data->alt->next = NULL;
579 data->got_alternates = -1;
580
581 walker->corrupt_object_found = 0;
582 walker->fetch = fetch;
583 walker->fetch_ref = fetch_ref;
584 walker->prefetch = prefetch;
585 walker->cleanup = cleanup;
586 walker->data = data;
587
588 #ifdef USE_CURL_MULTI
589 add_fill_function(walker, (int (*)(void *)) fill_active_slot);
590 #endif
591
592 return walker;
593 }