Windows: boost startup by avoiding a static dependency on shell32.dll
[git/dscho.git] / http-walker.c
blob700bc13112d65dfe8cf89af17522e28cf0d76e26
1 #include "cache.h"
2 #include "commit.h"
3 #include "walker.h"
4 #include "http.h"
6 struct alt_base
8         char *base;
9         int got_indices;
10         struct packed_git *packs;
11         struct alt_base *next;
14 enum object_request_state {
15         WAITING,
16         ABORTED,
17         ACTIVE,
18         COMPLETE,
21 struct object_request
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;
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;
40 struct walker_data {
41         const char *url;
42         int got_alternates;
43         struct alt_base *alt;
46 static struct object_request *object_queue_head;
48 static void fetch_alternates(struct walker *walker, const char *base);
50 static void process_object_response(void *callback_data);
52 static void start_object_request(struct walker *walker,
53                                  struct object_request *obj_req)
55         struct active_request_slot *slot;
56         struct http_object_request *req;
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;
65         slot = req->slot;
66         slot->callback_func = process_object_response;
67         slot->callback_data = obj_req;
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         }
78 static void finish_object_request(struct object_request *obj_req)
80         if (finish_http_object_request(obj_req->req))
81                 return;
83         if (obj_req->req->rename == 0)
84                 walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1));
87 static void process_object_response(void *callback_data)
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;
95         process_http_object_request(obj_req->req);
96         obj_req->state = COMPLETE;
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         }
110         finish_object_request(obj_req);
113 static void release_object_request(struct object_request *obj_req)
115         struct object_request *entry = object_queue_head;
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         }
128         free(obj_req);
131 #ifdef USE_CURL_MULTI
132 static int fill_active_slot(struct walker *walker)
134         struct object_request *obj_req;
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;
148 #endif
150 static void prefetch(struct walker *walker, unsigned char *sha1)
152         struct object_request *newreq;
153         struct object_request *tail;
154         struct walker_data *data = walker->data;
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;
164         http_is_verbose = walker->get_verbosely;
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         }
175 #ifdef USE_CURL_MULTI
176         fill_active_slots();
177         step_active_slots();
178 #endif
181 static void process_alternates_response(void *callback_data)
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;
194         if (alt_req->http_specific) {
195                 if (slot->curl_result != CURLE_OK ||
196                     !alt_req->buffer->len) {
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         }
223         fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
224         alt_req->buffer->len--;
225         data = alt_req->buffer->buf;
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;
306                                 while (tail->next != NULL)
307                                         tail = tail->next;
308                                 tail->next = newalt;
309                         }
310                 }
311                 i = posn + 1;
312         }
314         cdata->got_alternates = 1;
317 static void fetch_alternates(struct walker *walker, const char *base)
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;
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
336         /* Nothing to do if they've already been fetched */
337         if (cdata->got_alternates == 1)
338                 return;
340         /* Start the fetch */
341         cdata->got_alternates = 0;
343         if (walker->get_verbosely)
344                 fprintf(stderr, "Getting alternates list for %s\n", base);
346         url = xmalloc(strlen(base) + 31);
347         sprintf(url, "%s/objects/info/http-alternates", base);
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;
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);
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;
368         if (start_active_slot(slot))
369                 run_active_slot(slot);
370         else
371                 cdata->got_alternates = -1;
373         strbuf_release(&buffer);
374         free(url);
377 static int fetch_indices(struct walker *walker, struct alt_base *repo)
379         int ret;
381         if (repo->got_indices)
382                 return 0;
384         if (walker->get_verbosely)
385                 fprintf(stderr, "Getting pack list for %s\n", repo->base);
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         }
398         return ret;
401 static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
403         struct packed_git *target;
404         int ret;
405         struct slot_results results;
406         struct http_pack_request *preq;
408         if (fetch_indices(walker, repo))
409                 return -1;
410         target = find_sha1_pack(sha1, repo->packs);
411         if (!target)
412                 return -1;
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         }
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;
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         }
439         ret = finish_http_pack_request(preq);
440         release_http_pack_request(preq);
441         if (ret)
442                 return ret;
444         return 0;
446 abort:
447         return -1;
450 static void abort_object_request(struct object_request *obj_req)
452         release_object_request(obj_req);
455 static int fetch_object(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
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;
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);
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         }
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
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);
489         req = obj_req->req;
491         if (req->localfile != -1) {
492                 close(req->localfile);
493                 req->localfile = -1;
494         }
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         }
516         release_http_object_request(req);
517         release_object_request(obj_req);
518         return ret;
521 static int fetch(struct walker *walker, unsigned char *sha1)
523         struct walker_data *data = walker->data;
524         struct alt_base *altbase = data->alt;
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);
538 static int fetch_ref(struct walker *walker, struct ref *ref)
540         struct walker_data *data = walker->data;
541         return http_fetch_ref(data->alt->base, ref);
544 static void cleanup(struct walker *walker)
546         http_cleanup();
549 struct walker *get_http_walker(const char *url, struct remote *remote)
551         char *s;
552         struct walker_data *data = xmalloc(sizeof(struct walker_data));
553         struct walker *walker = xmalloc(sizeof(struct walker));
555         http_init(remote);
557         data->alt = xmalloc(sizeof(*data->alt));
558         data->alt->base = xmalloc(strlen(url) + 1);
559         strcpy(data->alt->base, url);
560         for (s = data->alt->base + strlen(data->alt->base) - 1; *s == '/'; --s)
561                 *s = 0;
563         data->alt->got_indices = 0;
564         data->alt->packs = NULL;
565         data->alt->next = NULL;
566         data->got_alternates = -1;
568         walker->corrupt_object_found = 0;
569         walker->fetch = fetch;
570         walker->fetch_ref = fetch_ref;
571         walker->prefetch = prefetch;
572         walker->cleanup = cleanup;
573         walker->data = data;
575 #ifdef USE_CURL_MULTI
576         add_fill_function(walker, (int (*)(void *)) fill_active_slot);
577 #endif
579         return walker;