Fix config key miscount in url.*.insteadOf
[git/dscho.git] / http-walker.c
blob7bda34d91498c3959569327ea2132851230999e7
1 #include "cache.h"
2 #include "commit.h"
3 #include "pack.h"
4 #include "walker.h"
5 #include "http.h"
7 #define PREV_BUF_SIZE 4096
8 #define RANGE_HEADER_SIZE 30
10 struct alt_base
12         char *base;
13         int got_indices;
14         struct packed_git *packs;
15         struct alt_base *next;
18 enum object_request_state {
19         WAITING,
20         ABORTED,
21         ACTIVE,
22         COMPLETE,
25 struct object_request
27         struct walker *walker;
28         unsigned char sha1[20];
29         struct alt_base *repo;
30         char *url;
31         char filename[PATH_MAX];
32         char tmpfile[PATH_MAX];
33         int local;
34         enum object_request_state state;
35         CURLcode curl_result;
36         char errorstr[CURL_ERROR_SIZE];
37         long http_code;
38         unsigned char real_sha1[20];
39         SHA_CTX c;
40         z_stream stream;
41         int zret;
42         int rename;
43         struct active_request_slot *slot;
44         struct object_request *next;
47 struct alternates_request {
48         struct walker *walker;
49         const char *base;
50         char *url;
51         struct strbuf *buffer;
52         struct active_request_slot *slot;
53         int http_specific;
56 struct walker_data {
57         const char *url;
58         int got_alternates;
59         struct alt_base *alt;
60         struct curl_slist *no_pragma_header;
63 static struct object_request *object_queue_head;
65 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
66                                void *data)
68         unsigned char expn[4096];
69         size_t size = eltsize * nmemb;
70         int posn = 0;
71         struct object_request *obj_req = (struct object_request *)data;
72         do {
73                 ssize_t retval = xwrite(obj_req->local,
74                                        (char *) ptr + posn, size - posn);
75                 if (retval < 0)
76                         return posn;
77                 posn += retval;
78         } while (posn < size);
80         obj_req->stream.avail_in = size;
81         obj_req->stream.next_in = ptr;
82         do {
83                 obj_req->stream.next_out = expn;
84                 obj_req->stream.avail_out = sizeof(expn);
85                 obj_req->zret = inflate(&obj_req->stream, Z_SYNC_FLUSH);
86                 SHA1_Update(&obj_req->c, expn,
87                             sizeof(expn) - obj_req->stream.avail_out);
88         } while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
89         data_received++;
90         return size;
93 static void fetch_alternates(struct walker *walker, const char *base);
95 static void process_object_response(void *callback_data);
97 static void start_object_request(struct walker *walker,
98                                  struct object_request *obj_req)
100         char *hex = sha1_to_hex(obj_req->sha1);
101         char prevfile[PATH_MAX];
102         char *url;
103         char *posn;
104         int prevlocal;
105         unsigned char prev_buf[PREV_BUF_SIZE];
106         ssize_t prev_read = 0;
107         long prev_posn = 0;
108         char range[RANGE_HEADER_SIZE];
109         struct curl_slist *range_header = NULL;
110         struct active_request_slot *slot;
111         struct walker_data *data = walker->data;
113         snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
114         unlink(prevfile);
115         rename(obj_req->tmpfile, prevfile);
116         unlink(obj_req->tmpfile);
118         if (obj_req->local != -1)
119                 error("fd leakage in start: %d", obj_req->local);
120         obj_req->local = open(obj_req->tmpfile,
121                               O_WRONLY | O_CREAT | O_EXCL, 0666);
122         /* This could have failed due to the "lazy directory creation";
123          * try to mkdir the last path component.
124          */
125         if (obj_req->local < 0 && errno == ENOENT) {
126                 char *dir = strrchr(obj_req->tmpfile, '/');
127                 if (dir) {
128                         *dir = 0;
129                         mkdir(obj_req->tmpfile, 0777);
130                         *dir = '/';
131                 }
132                 obj_req->local = open(obj_req->tmpfile,
133                                       O_WRONLY | O_CREAT | O_EXCL, 0666);
134         }
136         if (obj_req->local < 0) {
137                 obj_req->state = ABORTED;
138                 error("Couldn't create temporary file %s for %s: %s",
139                       obj_req->tmpfile, obj_req->filename, strerror(errno));
140                 return;
141         }
143         memset(&obj_req->stream, 0, sizeof(obj_req->stream));
145         inflateInit(&obj_req->stream);
147         SHA1_Init(&obj_req->c);
149         url = xmalloc(strlen(obj_req->repo->base) + 51);
150         obj_req->url = xmalloc(strlen(obj_req->repo->base) + 51);
151         strcpy(url, obj_req->repo->base);
152         posn = url + strlen(obj_req->repo->base);
153         strcpy(posn, "/objects/");
154         posn += 9;
155         memcpy(posn, hex, 2);
156         posn += 2;
157         *(posn++) = '/';
158         strcpy(posn, hex + 2);
159         strcpy(obj_req->url, url);
161         /* If a previous temp file is present, process what was already
162            fetched. */
163         prevlocal = open(prevfile, O_RDONLY);
164         if (prevlocal != -1) {
165                 do {
166                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
167                         if (prev_read>0) {
168                                 if (fwrite_sha1_file(prev_buf,
169                                                      1,
170                                                      prev_read,
171                                                      obj_req) == prev_read) {
172                                         prev_posn += prev_read;
173                                 } else {
174                                         prev_read = -1;
175                                 }
176                         }
177                 } while (prev_read > 0);
178                 close(prevlocal);
179         }
180         unlink(prevfile);
182         /* Reset inflate/SHA1 if there was an error reading the previous temp
183            file; also rewind to the beginning of the local file. */
184         if (prev_read == -1) {
185                 memset(&obj_req->stream, 0, sizeof(obj_req->stream));
186                 inflateInit(&obj_req->stream);
187                 SHA1_Init(&obj_req->c);
188                 if (prev_posn>0) {
189                         prev_posn = 0;
190                         lseek(obj_req->local, 0, SEEK_SET);
191                         ftruncate(obj_req->local, 0);
192                 }
193         }
195         slot = get_active_slot();
196         slot->callback_func = process_object_response;
197         slot->callback_data = obj_req;
198         obj_req->slot = slot;
200         curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
201         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
202         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->errorstr);
203         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
204         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
206         /* If we have successfully processed data from a previous fetch
207            attempt, only fetch the data we don't already have. */
208         if (prev_posn>0) {
209                 if (walker->get_verbosely)
210                         fprintf(stderr,
211                                 "Resuming fetch of object %s at byte %ld\n",
212                                 hex, prev_posn);
213                 sprintf(range, "Range: bytes=%ld-", prev_posn);
214                 range_header = curl_slist_append(range_header, range);
215                 curl_easy_setopt(slot->curl,
216                                  CURLOPT_HTTPHEADER, range_header);
217         }
219         /* Try to get the request started, abort the request on error */
220         obj_req->state = ACTIVE;
221         if (!start_active_slot(slot)) {
222                 obj_req->state = ABORTED;
223                 obj_req->slot = NULL;
224                 close(obj_req->local); obj_req->local = -1;
225                 free(obj_req->url);
226                 return;
227         }
230 static void finish_object_request(struct object_request *obj_req)
232         struct stat st;
234         fchmod(obj_req->local, 0444);
235         close(obj_req->local); obj_req->local = -1;
237         if (obj_req->http_code == 416) {
238                 fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
239         } else if (obj_req->curl_result != CURLE_OK) {
240                 if (stat(obj_req->tmpfile, &st) == 0)
241                         if (st.st_size == 0)
242                                 unlink(obj_req->tmpfile);
243                 return;
244         }
246         inflateEnd(&obj_req->stream);
247         SHA1_Final(obj_req->real_sha1, &obj_req->c);
248         if (obj_req->zret != Z_STREAM_END) {
249                 unlink(obj_req->tmpfile);
250                 return;
251         }
252         if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
253                 unlink(obj_req->tmpfile);
254                 return;
255         }
256         obj_req->rename =
257                 move_temp_to_file(obj_req->tmpfile, obj_req->filename);
259         if (obj_req->rename == 0)
260                 walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1));
263 static void process_object_response(void *callback_data)
265         struct object_request *obj_req =
266                 (struct object_request *)callback_data;
267         struct walker *walker = obj_req->walker;
268         struct walker_data *data = walker->data;
269         struct alt_base *alt = data->alt;
271         obj_req->curl_result = obj_req->slot->curl_result;
272         obj_req->http_code = obj_req->slot->http_code;
273         obj_req->slot = NULL;
274         obj_req->state = COMPLETE;
276         /* Use alternates if necessary */
277         if (missing_target(obj_req)) {
278                 fetch_alternates(walker, alt->base);
279                 if (obj_req->repo->next != NULL) {
280                         obj_req->repo =
281                                 obj_req->repo->next;
282                         close(obj_req->local);
283                         obj_req->local = -1;
284                         start_object_request(walker, obj_req);
285                         return;
286                 }
287         }
289         finish_object_request(obj_req);
292 static void release_object_request(struct object_request *obj_req)
294         struct object_request *entry = object_queue_head;
296         if (obj_req->local != -1)
297                 error("fd leakage in release: %d", obj_req->local);
298         if (obj_req == object_queue_head) {
299                 object_queue_head = obj_req->next;
300         } else {
301                 while (entry->next != NULL && entry->next != obj_req)
302                         entry = entry->next;
303                 if (entry->next == obj_req)
304                         entry->next = entry->next->next;
305         }
307         free(obj_req->url);
308         free(obj_req);
311 #ifdef USE_CURL_MULTI
312 static int fill_active_slot(struct walker *walker)
314         struct object_request *obj_req;
316         for (obj_req = object_queue_head; obj_req; obj_req = obj_req->next) {
317                 if (obj_req->state == WAITING) {
318                         if (has_sha1_file(obj_req->sha1))
319                                 obj_req->state = COMPLETE;
320                         else {
321                                 start_object_request(walker, obj_req);
322                                 return 1;
323                         }
324                 }
325         }
326         return 0;
328 #endif
330 static void prefetch(struct walker *walker, unsigned char *sha1)
332         struct object_request *newreq;
333         struct object_request *tail;
334         struct walker_data *data = walker->data;
335         char *filename = sha1_file_name(sha1);
337         newreq = xmalloc(sizeof(*newreq));
338         newreq->walker = walker;
339         hashcpy(newreq->sha1, sha1);
340         newreq->repo = data->alt;
341         newreq->url = NULL;
342         newreq->local = -1;
343         newreq->state = WAITING;
344         snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
345         snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
346                  "%s.temp", filename);
347         newreq->slot = NULL;
348         newreq->next = NULL;
350         if (object_queue_head == NULL) {
351                 object_queue_head = newreq;
352         } else {
353                 tail = object_queue_head;
354                 while (tail->next != NULL) {
355                         tail = tail->next;
356                 }
357                 tail->next = newreq;
358         }
360 #ifdef USE_CURL_MULTI
361         fill_active_slots();
362         step_active_slots();
363 #endif
366 static int fetch_index(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
368         char *hex = sha1_to_hex(sha1);
369         char *filename;
370         char *url;
371         char tmpfile[PATH_MAX];
372         long prev_posn = 0;
373         char range[RANGE_HEADER_SIZE];
374         struct curl_slist *range_header = NULL;
375         struct walker_data *data = walker->data;
377         FILE *indexfile;
378         struct active_request_slot *slot;
379         struct slot_results results;
381         if (has_pack_index(sha1))
382                 return 0;
384         if (walker->get_verbosely)
385                 fprintf(stderr, "Getting index for pack %s\n", hex);
387         url = xmalloc(strlen(repo->base) + 64);
388         sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
390         filename = sha1_pack_index_name(sha1);
391         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
392         indexfile = fopen(tmpfile, "a");
393         if (!indexfile)
394                 return error("Unable to open local file %s for pack index",
395                              tmpfile);
397         slot = get_active_slot();
398         slot->results = &results;
399         curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
400         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
401         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
402         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
403         slot->local = indexfile;
405         /* If there is data present from a previous transfer attempt,
406            resume where it left off */
407         prev_posn = ftell(indexfile);
408         if (prev_posn>0) {
409                 if (walker->get_verbosely)
410                         fprintf(stderr,
411                                 "Resuming fetch of index for pack %s at byte %ld\n",
412                                 hex, prev_posn);
413                 sprintf(range, "Range: bytes=%ld-", prev_posn);
414                 range_header = curl_slist_append(range_header, range);
415                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
416         }
418         if (start_active_slot(slot)) {
419                 run_active_slot(slot);
420                 if (results.curl_result != CURLE_OK) {
421                         fclose(indexfile);
422                         return error("Unable to get pack index %s\n%s", url,
423                                      curl_errorstr);
424                 }
425         } else {
426                 fclose(indexfile);
427                 return error("Unable to start request");
428         }
430         fclose(indexfile);
432         return move_temp_to_file(tmpfile, filename);
435 static int setup_index(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
437         struct packed_git *new_pack;
438         if (has_pack_file(sha1))
439                 return 0; /* don't list this as something we can get */
441         if (fetch_index(walker, repo, sha1))
442                 return -1;
444         new_pack = parse_pack_index(sha1);
445         new_pack->next = repo->packs;
446         repo->packs = new_pack;
447         return 0;
450 static void process_alternates_response(void *callback_data)
452         struct alternates_request *alt_req =
453                 (struct alternates_request *)callback_data;
454         struct walker *walker = alt_req->walker;
455         struct walker_data *cdata = walker->data;
456         struct active_request_slot *slot = alt_req->slot;
457         struct alt_base *tail = cdata->alt;
458         const char *base = alt_req->base;
459         static const char null_byte = '\0';
460         char *data;
461         int i = 0;
463         if (alt_req->http_specific) {
464                 if (slot->curl_result != CURLE_OK ||
465                     !alt_req->buffer->len) {
467                         /* Try reusing the slot to get non-http alternates */
468                         alt_req->http_specific = 0;
469                         sprintf(alt_req->url, "%s/objects/info/alternates",
470                                 base);
471                         curl_easy_setopt(slot->curl, CURLOPT_URL,
472                                          alt_req->url);
473                         active_requests++;
474                         slot->in_use = 1;
475                         if (slot->finished != NULL)
476                                 (*slot->finished) = 0;
477                         if (!start_active_slot(slot)) {
478                                 cdata->got_alternates = -1;
479                                 slot->in_use = 0;
480                                 if (slot->finished != NULL)
481                                         (*slot->finished) = 1;
482                         }
483                         return;
484                 }
485         } else if (slot->curl_result != CURLE_OK) {
486                 if (!missing_target(slot)) {
487                         cdata->got_alternates = -1;
488                         return;
489                 }
490         }
492         fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
493         alt_req->buffer->len--;
494         data = alt_req->buffer->buf;
496         while (i < alt_req->buffer->len) {
497                 int posn = i;
498                 while (posn < alt_req->buffer->len && data[posn] != '\n')
499                         posn++;
500                 if (data[posn] == '\n') {
501                         int okay = 0;
502                         int serverlen = 0;
503                         struct alt_base *newalt;
504                         char *target = NULL;
505                         if (data[i] == '/') {
506                                 /* This counts
507                                  * http://git.host/pub/scm/linux.git/
508                                  * -----------here^
509                                  * so memcpy(dst, base, serverlen) will
510                                  * copy up to "...git.host".
511                                  */
512                                 const char *colon_ss = strstr(base,"://");
513                                 if (colon_ss) {
514                                         serverlen = (strchr(colon_ss + 3, '/')
515                                                      - base);
516                                         okay = 1;
517                                 }
518                         } else if (!memcmp(data + i, "../", 3)) {
519                                 /* Relative URL; chop the corresponding
520                                  * number of subpath from base (and ../
521                                  * from data), and concatenate the result.
522                                  *
523                                  * The code first drops ../ from data, and
524                                  * then drops one ../ from data and one path
525                                  * from base.  IOW, one extra ../ is dropped
526                                  * from data than path is dropped from base.
527                                  *
528                                  * This is not wrong.  The alternate in
529                                  *     http://git.host/pub/scm/linux.git/
530                                  * to borrow from
531                                  *     http://git.host/pub/scm/linus.git/
532                                  * is ../../linus.git/objects/.  You need
533                                  * two ../../ to borrow from your direct
534                                  * neighbour.
535                                  */
536                                 i += 3;
537                                 serverlen = strlen(base);
538                                 while (i + 2 < posn &&
539                                        !memcmp(data + i, "../", 3)) {
540                                         do {
541                                                 serverlen--;
542                                         } while (serverlen &&
543                                                  base[serverlen - 1] != '/');
544                                         i += 3;
545                                 }
546                                 /* If the server got removed, give up. */
547                                 okay = strchr(base, ':') - base + 3 <
548                                         serverlen;
549                         } else if (alt_req->http_specific) {
550                                 char *colon = strchr(data + i, ':');
551                                 char *slash = strchr(data + i, '/');
552                                 if (colon && slash && colon < data + posn &&
553                                     slash < data + posn && colon < slash) {
554                                         okay = 1;
555                                 }
556                         }
557                         /* skip "objects\n" at end */
558                         if (okay) {
559                                 target = xmalloc(serverlen + posn - i - 6);
560                                 memcpy(target, base, serverlen);
561                                 memcpy(target + serverlen, data + i,
562                                        posn - i - 7);
563                                 target[serverlen + posn - i - 7] = 0;
564                                 if (walker->get_verbosely)
565                                         fprintf(stderr,
566                                                 "Also look at %s\n", target);
567                                 newalt = xmalloc(sizeof(*newalt));
568                                 newalt->next = NULL;
569                                 newalt->base = target;
570                                 newalt->got_indices = 0;
571                                 newalt->packs = NULL;
573                                 while (tail->next != NULL)
574                                         tail = tail->next;
575                                 tail->next = newalt;
576                         }
577                 }
578                 i = posn + 1;
579         }
581         cdata->got_alternates = 1;
584 static void fetch_alternates(struct walker *walker, const char *base)
586         struct strbuf buffer = STRBUF_INIT;
587         char *url;
588         struct active_request_slot *slot;
589         struct alternates_request alt_req;
590         struct walker_data *cdata = walker->data;
592         /* If another request has already started fetching alternates,
593            wait for them to arrive and return to processing this request's
594            curl message */
595 #ifdef USE_CURL_MULTI
596         while (cdata->got_alternates == 0) {
597                 step_active_slots();
598         }
599 #endif
601         /* Nothing to do if they've already been fetched */
602         if (cdata->got_alternates == 1)
603                 return;
605         /* Start the fetch */
606         cdata->got_alternates = 0;
608         if (walker->get_verbosely)
609                 fprintf(stderr, "Getting alternates list for %s\n", base);
611         url = xmalloc(strlen(base) + 31);
612         sprintf(url, "%s/objects/info/http-alternates", base);
614         /* Use a callback to process the result, since another request
615            may fail and need to have alternates loaded before continuing */
616         slot = get_active_slot();
617         slot->callback_func = process_alternates_response;
618         alt_req.walker = walker;
619         slot->callback_data = &alt_req;
621         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
622         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
623         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
625         alt_req.base = base;
626         alt_req.url = url;
627         alt_req.buffer = &buffer;
628         alt_req.http_specific = 1;
629         alt_req.slot = slot;
631         if (start_active_slot(slot))
632                 run_active_slot(slot);
633         else
634                 cdata->got_alternates = -1;
636         strbuf_release(&buffer);
637         free(url);
640 static int fetch_indices(struct walker *walker, struct alt_base *repo)
642         unsigned char sha1[20];
643         char *url;
644         struct strbuf buffer = STRBUF_INIT;
645         char *data;
646         int i = 0;
647         int ret = 0;
649         struct active_request_slot *slot;
650         struct slot_results results;
652         if (repo->got_indices)
653                 return 0;
655         if (walker->get_verbosely)
656                 fprintf(stderr, "Getting pack list for %s\n", repo->base);
658         url = xmalloc(strlen(repo->base) + 21);
659         sprintf(url, "%s/objects/info/packs", repo->base);
661         slot = get_active_slot();
662         slot->results = &results;
663         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
664         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
665         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
666         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
667         if (start_active_slot(slot)) {
668                 run_active_slot(slot);
669                 if (results.curl_result != CURLE_OK) {
670                         if (missing_target(&results)) {
671                                 repo->got_indices = 1;
672                                 goto cleanup;
673                         } else {
674                                 repo->got_indices = 0;
675                                 ret = error("%s", curl_errorstr);
676                                 goto cleanup;
677                         }
678                 }
679         } else {
680                 repo->got_indices = 0;
681                 ret = error("Unable to start request");
682                 goto cleanup;
683         }
685         data = buffer.buf;
686         while (i < buffer.len) {
687                 switch (data[i]) {
688                 case 'P':
689                         i++;
690                         if (i + 52 <= buffer.len &&
691                             !prefixcmp(data + i, " pack-") &&
692                             !prefixcmp(data + i + 46, ".pack\n")) {
693                                 get_sha1_hex(data + i + 6, sha1);
694                                 setup_index(walker, repo, sha1);
695                                 i += 51;
696                                 break;
697                         }
698                 default:
699                         while (i < buffer.len && data[i] != '\n')
700                                 i++;
701                 }
702                 i++;
703         }
705         repo->got_indices = 1;
706 cleanup:
707         strbuf_release(&buffer);
708         free(url);
709         return ret;
712 static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
714         char *url;
715         struct packed_git *target;
716         struct packed_git **lst;
717         FILE *packfile;
718         char *filename;
719         char tmpfile[PATH_MAX];
720         int ret;
721         long prev_posn = 0;
722         char range[RANGE_HEADER_SIZE];
723         struct curl_slist *range_header = NULL;
724         struct walker_data *data = walker->data;
726         struct active_request_slot *slot;
727         struct slot_results results;
729         if (fetch_indices(walker, repo))
730                 return -1;
731         target = find_sha1_pack(sha1, repo->packs);
732         if (!target)
733                 return -1;
735         if (walker->get_verbosely) {
736                 fprintf(stderr, "Getting pack %s\n",
737                         sha1_to_hex(target->sha1));
738                 fprintf(stderr, " which contains %s\n",
739                         sha1_to_hex(sha1));
740         }
742         url = xmalloc(strlen(repo->base) + 65);
743         sprintf(url, "%s/objects/pack/pack-%s.pack",
744                 repo->base, sha1_to_hex(target->sha1));
746         filename = sha1_pack_name(target->sha1);
747         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
748         packfile = fopen(tmpfile, "a");
749         if (!packfile)
750                 return error("Unable to open local file %s for pack",
751                              tmpfile);
753         slot = get_active_slot();
754         slot->results = &results;
755         curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
756         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
757         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
758         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
759         slot->local = packfile;
761         /* If there is data present from a previous transfer attempt,
762            resume where it left off */
763         prev_posn = ftell(packfile);
764         if (prev_posn>0) {
765                 if (walker->get_verbosely)
766                         fprintf(stderr,
767                                 "Resuming fetch of pack %s at byte %ld\n",
768                                 sha1_to_hex(target->sha1), prev_posn);
769                 sprintf(range, "Range: bytes=%ld-", prev_posn);
770                 range_header = curl_slist_append(range_header, range);
771                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
772         }
774         if (start_active_slot(slot)) {
775                 run_active_slot(slot);
776                 if (results.curl_result != CURLE_OK) {
777                         fclose(packfile);
778                         return error("Unable to get pack file %s\n%s", url,
779                                      curl_errorstr);
780                 }
781         } else {
782                 fclose(packfile);
783                 return error("Unable to start request");
784         }
786         target->pack_size = ftell(packfile);
787         fclose(packfile);
789         ret = move_temp_to_file(tmpfile, filename);
790         if (ret)
791                 return ret;
793         lst = &repo->packs;
794         while (*lst != target)
795                 lst = &((*lst)->next);
796         *lst = (*lst)->next;
798         if (verify_pack(target, 0))
799                 return -1;
800         install_packed_git(target);
802         return 0;
805 static void abort_object_request(struct object_request *obj_req)
807         if (obj_req->local >= 0) {
808                 close(obj_req->local);
809                 obj_req->local = -1;
810         }
811         unlink(obj_req->tmpfile);
812         if (obj_req->slot) {
813                 release_active_slot(obj_req->slot);
814                 obj_req->slot = NULL;
815         }
816         release_object_request(obj_req);
819 static int fetch_object(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
821         char *hex = sha1_to_hex(sha1);
822         int ret = 0;
823         struct object_request *obj_req = object_queue_head;
825         while (obj_req != NULL && hashcmp(obj_req->sha1, sha1))
826                 obj_req = obj_req->next;
827         if (obj_req == NULL)
828                 return error("Couldn't find request for %s in the queue", hex);
830         if (has_sha1_file(obj_req->sha1)) {
831                 abort_object_request(obj_req);
832                 return 0;
833         }
835 #ifdef USE_CURL_MULTI
836         while (obj_req->state == WAITING) {
837                 step_active_slots();
838         }
839 #else
840         start_object_request(walker, obj_req);
841 #endif
843         while (obj_req->state == ACTIVE) {
844                 run_active_slot(obj_req->slot);
845         }
846         if (obj_req->local != -1) {
847                 close(obj_req->local); obj_req->local = -1;
848         }
850         if (obj_req->state == ABORTED) {
851                 ret = error("Request for %s aborted", hex);
852         } else if (obj_req->curl_result != CURLE_OK &&
853                    obj_req->http_code != 416) {
854                 if (missing_target(obj_req))
855                         ret = -1; /* Be silent, it is probably in a pack. */
856                 else
857                         ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
858                                     obj_req->errorstr, obj_req->curl_result,
859                                     obj_req->http_code, hex);
860         } else if (obj_req->zret != Z_STREAM_END) {
861                 walker->corrupt_object_found++;
862                 ret = error("File %s (%s) corrupt", hex, obj_req->url);
863         } else if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
864                 ret = error("File %s has bad hash", hex);
865         } else if (obj_req->rename < 0) {
866                 ret = error("unable to write sha1 filename %s",
867                             obj_req->filename);
868         }
870         release_object_request(obj_req);
871         return ret;
874 static int fetch(struct walker *walker, unsigned char *sha1)
876         struct walker_data *data = walker->data;
877         struct alt_base *altbase = data->alt;
879         if (!fetch_object(walker, altbase, sha1))
880                 return 0;
881         while (altbase) {
882                 if (!fetch_pack(walker, altbase, sha1))
883                         return 0;
884                 fetch_alternates(walker, data->alt->base);
885                 altbase = altbase->next;
886         }
887         return error("Unable to find %s under %s", sha1_to_hex(sha1),
888                      data->alt->base);
891 static int fetch_ref(struct walker *walker, char *ref, unsigned char *sha1)
893         struct walker_data *data = walker->data;
894         return http_fetch_ref(data->alt->base, ref, sha1);
897 static void cleanup(struct walker *walker)
899         struct walker_data *data = walker->data;
900         http_cleanup();
902         curl_slist_free_all(data->no_pragma_header);
905 struct walker *get_http_walker(const char *url, struct remote *remote)
907         char *s;
908         struct walker_data *data = xmalloc(sizeof(struct walker_data));
909         struct walker *walker = xmalloc(sizeof(struct walker));
911         http_init(remote);
913         data->no_pragma_header = curl_slist_append(NULL, "Pragma:");
915         data->alt = xmalloc(sizeof(*data->alt));
916         data->alt->base = xmalloc(strlen(url) + 1);
917         strcpy(data->alt->base, url);
918         for (s = data->alt->base + strlen(data->alt->base) - 1; *s == '/'; --s)
919                 *s = 0;
921         data->alt->got_indices = 0;
922         data->alt->packs = NULL;
923         data->alt->next = NULL;
924         data->got_alternates = -1;
926         walker->corrupt_object_found = 0;
927         walker->fetch = fetch;
928         walker->fetch_ref = fetch_ref;
929         walker->prefetch = prefetch;
930         walker->cleanup = cleanup;
931         walker->data = data;
933 #ifdef USE_CURL_MULTI
934         add_fill_function(walker, (int (*)(void *)) fill_active_slot);
935 #endif
937         return walker;