Andrew's git / gitweb.git / http-fetch.c
?
http-fetch.con commit combine-diff: add safety check to --cc. (fd4b1d2)
   1#include "cache.h"
   2#include "commit.h"
   3#include "pack.h"
   4#include "fetch.h"
   5#include "http.h"
   6
   7#define PREV_BUF_SIZE 4096
   8#define RANGE_HEADER_SIZE 30
   9
  10static int got_alternates = -1;
  11
  12static struct curl_slist *no_pragma_header;
  13
  14struct alt_base
  15{
  16        char *base;
  17        int got_indices;
  18        struct packed_git *packs;
  19        struct alt_base *next;
  20};
  21
  22static struct alt_base *alt = NULL;
  23
  24enum object_request_state {
  25        WAITING,
  26        ABORTED,
  27        ACTIVE,
  28        COMPLETE,
  29};
  30
  31struct object_request
  32{
  33        unsigned char sha1[20];
  34        struct alt_base *repo;
  35        char *url;
  36        char filename[PATH_MAX];
  37        char tmpfile[PATH_MAX];
  38        int local;
  39        enum object_request_state state;
  40        CURLcode curl_result;
  41        char errorstr[CURL_ERROR_SIZE];
  42        long http_code;
  43        unsigned char real_sha1[20];
  44        SHA_CTX c;
  45        z_stream stream;
  46        int zret;
  47        int rename;
  48        struct active_request_slot *slot;
  49        struct object_request *next;
  50};
  51
  52struct alternates_request {
  53        char *base;
  54        char *url;
  55        struct buffer *buffer;
  56        struct active_request_slot *slot;
  57        int http_specific;
  58};
  59
  60static struct object_request *object_queue_head = NULL;
  61
  62static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
  63                               void *data)
  64{
  65        unsigned char expn[4096];
  66        size_t size = eltsize * nmemb;
  67        int posn = 0;
  68        struct object_request *obj_req = (struct object_request *)data;
  69        do {
  70                ssize_t retval = write(obj_req->local,
  71                                       ptr + posn, size - posn);
  72                if (retval < 0)
  73                        return posn;
  74                posn += retval;
  75        } while (posn < size);
  76
  77        obj_req->stream.avail_in = size;
  78        obj_req->stream.next_in = ptr;
  79        do {
  80                obj_req->stream.next_out = expn;
  81                obj_req->stream.avail_out = sizeof(expn);
  82                obj_req->zret = inflate(&obj_req->stream, Z_SYNC_FLUSH);
  83                SHA1_Update(&obj_req->c, expn,
  84                            sizeof(expn) - obj_req->stream.avail_out);
  85        } while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
  86        data_received++;
  87        return size;
  88}
  89
  90static void fetch_alternates(char *base);
  91
  92static void process_object_response(void *callback_data);
  93
  94static void start_object_request(struct object_request *obj_req)
  95{
  96        char *hex = sha1_to_hex(obj_req->sha1);
  97        char prevfile[PATH_MAX];
  98        char *url;
  99        char *posn;
 100        int prevlocal;
 101        unsigned char prev_buf[PREV_BUF_SIZE];
 102        ssize_t prev_read = 0;
 103        long prev_posn = 0;
 104        char range[RANGE_HEADER_SIZE];
 105        struct curl_slist *range_header = NULL;
 106        struct active_request_slot *slot;
 107
 108        snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
 109        unlink(prevfile);
 110        rename(obj_req->tmpfile, prevfile);
 111        unlink(obj_req->tmpfile);
 112
 113        if (obj_req->local != -1)
 114                error("fd leakage in start: %d", obj_req->local);
 115        obj_req->local = open(obj_req->tmpfile,
 116                              O_WRONLY | O_CREAT | O_EXCL, 0666);
 117        /* This could have failed due to the "lazy directory creation";
 118         * try to mkdir the last path component.
 119         */
 120        if (obj_req->local < 0 && errno == ENOENT) {
 121                char *dir = strrchr(obj_req->tmpfile, '/');
 122                if (dir) {
 123                        *dir = 0;
 124                        mkdir(obj_req->tmpfile, 0777);
 125                        *dir = '/';
 126                }
 127                obj_req->local = open(obj_req->tmpfile,
 128                                      O_WRONLY | O_CREAT | O_EXCL, 0666);
 129        }
 130
 131        if (obj_req->local < 0) {
 132                obj_req->state = ABORTED;
 133                error("Couldn't create temporary file %s for %s: %s\n",
 134                      obj_req->tmpfile, obj_req->filename, strerror(errno));
 135                return;
 136        }
 137
 138        memset(&obj_req->stream, 0, sizeof(obj_req->stream));
 139
 140        inflateInit(&obj_req->stream);
 141
 142        SHA1_Init(&obj_req->c);
 143
 144        url = xmalloc(strlen(obj_req->repo->base) + 50);
 145        obj_req->url = xmalloc(strlen(obj_req->repo->base) + 50);
 146        strcpy(url, obj_req->repo->base);
 147        posn = url + strlen(obj_req->repo->base);
 148        strcpy(posn, "objects/");
 149        posn += 8;
 150        memcpy(posn, hex, 2);
 151        posn += 2;
 152        *(posn++) = '/';
 153        strcpy(posn, hex + 2);
 154        strcpy(obj_req->url, url);
 155
 156        /* If a previous temp file is present, process what was already
 157           fetched. */
 158        prevlocal = open(prevfile, O_RDONLY);
 159        if (prevlocal != -1) {
 160                do {
 161                        prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 162                        if (prev_read>0) {
 163                                if (fwrite_sha1_file(prev_buf,
 164                                                     1,
 165                                                     prev_read,
 166                                                     obj_req) == prev_read) {
 167                                        prev_posn += prev_read;
 168                                } else {
 169                                        prev_read = -1;
 170                                }
 171                        }
 172                } while (prev_read > 0);
 173                close(prevlocal);
 174        }
 175        unlink(prevfile);
 176
 177        /* Reset inflate/SHA1 if there was an error reading the previous temp
 178           file; also rewind to the beginning of the local file. */
 179        if (prev_read == -1) {
 180                memset(&obj_req->stream, 0, sizeof(obj_req->stream));
 181                inflateInit(&obj_req->stream);
 182                SHA1_Init(&obj_req->c);
 183                if (prev_posn>0) {
 184                        prev_posn = 0;
 185                        lseek(obj_req->local, SEEK_SET, 0);
 186                        ftruncate(obj_req->local, 0);
 187                }
 188        }
 189
 190        slot = get_active_slot();
 191        slot->callback_func = process_object_response;
 192        slot->callback_data = obj_req;
 193        obj_req->slot = slot;
 194
 195        curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
 196        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 197        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->errorstr);
 198        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 199        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 200
 201        /* If we have successfully processed data from a previous fetch
 202           attempt, only fetch the data we don't already have. */
 203        if (prev_posn>0) {
 204                if (get_verbosely)
 205                        fprintf(stderr,
 206                                "Resuming fetch of object %s at byte %ld\n",
 207                                hex, prev_posn);
 208                sprintf(range, "Range: bytes=%ld-", prev_posn);
 209                range_header = curl_slist_append(range_header, range);
 210                curl_easy_setopt(slot->curl,
 211                                 CURLOPT_HTTPHEADER, range_header);
 212        }
 213
 214        /* Try to get the request started, abort the request on error */
 215        obj_req->state = ACTIVE;
 216        if (!start_active_slot(slot)) {
 217                obj_req->state = ABORTED;
 218                obj_req->slot = NULL;
 219                close(obj_req->local); obj_req->local = -1;
 220                free(obj_req->url);
 221                return;
 222        }
 223        
 224}
 225
 226static void finish_object_request(struct object_request *obj_req)
 227{
 228        struct stat st;
 229
 230        fchmod(obj_req->local, 0444);
 231        close(obj_req->local); obj_req->local = -1;
 232
 233        if (obj_req->http_code == 416) {
 234                fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 235        } else if (obj_req->curl_result != CURLE_OK) {
 236                if (stat(obj_req->tmpfile, &st) == 0)
 237                        if (st.st_size == 0)
 238                                unlink(obj_req->tmpfile);
 239                return;
 240        }
 241
 242        inflateEnd(&obj_req->stream);
 243        SHA1_Final(obj_req->real_sha1, &obj_req->c);
 244        if (obj_req->zret != Z_STREAM_END) {
 245                unlink(obj_req->tmpfile);
 246                return;
 247        }
 248        if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
 249                unlink(obj_req->tmpfile);
 250                return;
 251        }
 252        obj_req->rename =
 253                move_temp_to_file(obj_req->tmpfile, obj_req->filename);
 254
 255        if (obj_req->rename == 0)
 256                pull_say("got %s\n", sha1_to_hex(obj_req->sha1));
 257}
 258
 259static void process_object_response(void *callback_data)
 260{
 261        struct object_request *obj_req =
 262                (struct object_request *)callback_data;
 263
 264        obj_req->curl_result = obj_req->slot->curl_result;
 265        obj_req->http_code = obj_req->slot->http_code;
 266        obj_req->slot = NULL;
 267        obj_req->state = COMPLETE;
 268
 269        /* Use alternates if necessary */
 270        if (obj_req->http_code == 404 ||
 271            obj_req->curl_result == CURLE_FILE_COULDNT_READ_FILE) {
 272                fetch_alternates(alt->base);
 273                if (obj_req->repo->next != NULL) {
 274                        obj_req->repo =
 275                                obj_req->repo->next;
 276                        close(obj_req->local);
 277                        obj_req->local = -1;
 278                        start_object_request(obj_req);
 279                        return;
 280                }
 281        }
 282
 283        finish_object_request(obj_req);
 284}
 285
 286static void release_object_request(struct object_request *obj_req)
 287{
 288        struct object_request *entry = object_queue_head;
 289
 290        if (obj_req->local != -1)
 291                error("fd leakage in release: %d", obj_req->local);
 292        if (obj_req == object_queue_head) {
 293                object_queue_head = obj_req->next;
 294        } else {
 295                while (entry->next != NULL && entry->next != obj_req)
 296                        entry = entry->next;
 297                if (entry->next == obj_req)
 298                        entry->next = entry->next->next;
 299        }
 300
 301        free(obj_req->url);
 302        free(obj_req);
 303}
 304
 305#ifdef USE_CURL_MULTI
 306void fill_active_slots(void)
 307{
 308        struct object_request *obj_req = object_queue_head;
 309        struct active_request_slot *slot = active_queue_head;
 310        int num_transfers;
 311
 312        while (active_requests < max_requests && obj_req != NULL) {
 313                if (obj_req->state == WAITING) {
 314                        if (has_sha1_file(obj_req->sha1))
 315                                release_object_request(obj_req);
 316                        else
 317                                start_object_request(obj_req);
 318                        curl_multi_perform(curlm, &num_transfers);
 319                }
 320                obj_req = obj_req->next;
 321        }
 322
 323        while (slot != NULL) {
 324                if (!slot->in_use && slot->curl != NULL) {
 325                        curl_easy_cleanup(slot->curl);
 326                        slot->curl = NULL;
 327                }
 328                slot = slot->next;
 329        }                               
 330}
 331#endif
 332
 333void prefetch(unsigned char *sha1)
 334{
 335        struct object_request *newreq;
 336        struct object_request *tail;
 337        char *filename = sha1_file_name(sha1);
 338
 339        newreq = xmalloc(sizeof(*newreq));
 340        memcpy(newreq->sha1, sha1, 20);
 341        newreq->repo = alt;
 342        newreq->url = NULL;
 343        newreq->local = -1;
 344        newreq->state = WAITING;
 345        snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 346        snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 347                 "%s.temp", filename);
 348        newreq->next = NULL;
 349
 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        }
 359
 360#ifdef USE_CURL_MULTI
 361        fill_active_slots();
 362        step_active_slots();
 363#endif
 364}
 365
 366static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 367{
 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
 376        FILE *indexfile;
 377        struct active_request_slot *slot;
 378        struct slot_results results;
 379
 380        if (has_pack_index(sha1))
 381                return 0;
 382
 383        if (get_verbosely)
 384                fprintf(stderr, "Getting index for pack %s\n", hex);
 385        
 386        url = xmalloc(strlen(repo->base) + 64);
 387        sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 388        
 389        filename = sha1_pack_index_name(sha1);
 390        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 391        indexfile = fopen(tmpfile, "a");
 392        if (!indexfile)
 393                return error("Unable to open local file %s for pack index",
 394                             filename);
 395
 396        slot = get_active_slot();
 397        slot->results = &results;
 398        curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 399        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 400        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 401        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 402        slot->local = indexfile;
 403
 404        /* If there is data present from a previous transfer attempt,
 405           resume where it left off */
 406        prev_posn = ftell(indexfile);
 407        if (prev_posn>0) {
 408                if (get_verbosely)
 409                        fprintf(stderr,
 410                                "Resuming fetch of index for pack %s at byte %ld\n",
 411                                hex, prev_posn);
 412                sprintf(range, "Range: bytes=%ld-", prev_posn);
 413                range_header = curl_slist_append(range_header, range);
 414                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 415        }
 416
 417        if (start_active_slot(slot)) {
 418                run_active_slot(slot);
 419                if (results.curl_result != CURLE_OK) {
 420                        fclose(indexfile);
 421                        return error("Unable to get pack index %s\n%s", url,
 422                                     curl_errorstr);
 423                }
 424        } else {
 425                fclose(indexfile);
 426                return error("Unable to start request");
 427        }
 428
 429        fclose(indexfile);
 430
 431        return move_temp_to_file(tmpfile, filename);
 432}
 433
 434static int setup_index(struct alt_base *repo, unsigned char *sha1)
 435{
 436        struct packed_git *new_pack;
 437        if (has_pack_file(sha1))
 438                return 0; // don't list this as something we can get
 439
 440        if (fetch_index(repo, sha1))
 441                return -1;
 442
 443        new_pack = parse_pack_index(sha1);
 444        new_pack->next = repo->packs;
 445        repo->packs = new_pack;
 446        return 0;
 447}
 448
 449static void process_alternates_response(void *callback_data)
 450{
 451        struct alternates_request *alt_req =
 452                (struct alternates_request *)callback_data;
 453        struct active_request_slot *slot = alt_req->slot;
 454        struct alt_base *tail = alt;
 455        char *base = alt_req->base;
 456        static const char null_byte = '\0';
 457        char *data;
 458        int i = 0;
 459
 460        if (alt_req->http_specific) {
 461                if (slot->curl_result != CURLE_OK ||
 462                    !alt_req->buffer->posn) {
 463
 464                        /* Try reusing the slot to get non-http alternates */
 465                        alt_req->http_specific = 0;
 466                        sprintf(alt_req->url, "%s/objects/info/alternates",
 467                                base);
 468                        curl_easy_setopt(slot->curl, CURLOPT_URL,
 469                                         alt_req->url);
 470                        active_requests++;
 471                        slot->in_use = 1;
 472                        if (start_active_slot(slot)) {
 473                                return;
 474                        } else {
 475                                got_alternates = -1;
 476                                slot->in_use = 0;
 477                                return;
 478                        }
 479                }
 480        } else if (slot->curl_result != CURLE_OK) {
 481                if (slot->http_code != 404 &&
 482                    slot->curl_result != CURLE_FILE_COULDNT_READ_FILE) {
 483                        got_alternates = -1;
 484                        return;
 485                }
 486        }
 487
 488        fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
 489        alt_req->buffer->posn--;
 490        data = alt_req->buffer->buffer;
 491
 492        while (i < alt_req->buffer->posn) {
 493                int posn = i;
 494                while (posn < alt_req->buffer->posn && data[posn] != '\n')
 495                        posn++;
 496                if (data[posn] == '\n') {
 497                        int okay = 0;
 498                        int serverlen = 0;
 499                        struct alt_base *newalt;
 500                        char *target = NULL;
 501                        if (data[i] == '/') {
 502                                serverlen = strchr(base + 8, '/') - base;
 503                                okay = 1;
 504                        } else if (!memcmp(data + i, "../", 3)) {
 505                                i += 3;
 506                                serverlen = strlen(base);
 507                                while (i + 2 < posn && 
 508                                       !memcmp(data + i, "../", 3)) {
 509                                        do {
 510                                                serverlen--;
 511                                        } while (serverlen &&
 512                                                 base[serverlen - 1] != '/');
 513                                        i += 3;
 514                                }
 515                                // If the server got removed, give up.
 516                                okay = strchr(base, ':') - base + 3 < 
 517                                        serverlen;
 518                        } else if (alt_req->http_specific) {
 519                                char *colon = strchr(data + i, ':');
 520                                char *slash = strchr(data + i, '/');
 521                                if (colon && slash && colon < data + posn &&
 522                                    slash < data + posn && colon < slash) {
 523                                        okay = 1;
 524                                }
 525                        }
 526                        // skip 'objects' at end
 527                        if (okay) {
 528                                target = xmalloc(serverlen + posn - i - 6);
 529                                strncpy(target, base, serverlen);
 530                                strncpy(target + serverlen, data + i,
 531                                        posn - i - 7);
 532                                target[serverlen + posn - i - 7] = '\0';
 533                                if (get_verbosely)
 534                                        fprintf(stderr, 
 535                                                "Also look at %s\n", target);
 536                                newalt = xmalloc(sizeof(*newalt));
 537                                newalt->next = NULL;
 538                                newalt->base = target;
 539                                newalt->got_indices = 0;
 540                                newalt->packs = NULL;
 541                                while (tail->next != NULL)
 542                                        tail = tail->next;
 543                                tail->next = newalt;
 544                        }
 545                }
 546                i = posn + 1;
 547        }
 548
 549        got_alternates = 1;
 550}
 551
 552static void fetch_alternates(char *base)
 553{
 554        struct buffer buffer;
 555        char *url;
 556        char *data;
 557        struct active_request_slot *slot;
 558        struct alternates_request alt_req;
 559
 560        /* If another request has already started fetching alternates,
 561           wait for them to arrive and return to processing this request's
 562           curl message */
 563#ifdef USE_CURL_MULTI
 564        while (got_alternates == 0) {
 565                step_active_slots();
 566        }
 567#endif
 568
 569        /* Nothing to do if they've already been fetched */
 570        if (got_alternates == 1)
 571                return;
 572
 573        /* Start the fetch */
 574        got_alternates = 0;
 575
 576        data = xmalloc(4096);
 577        buffer.size = 4096;
 578        buffer.posn = 0;
 579        buffer.buffer = data;
 580
 581        if (get_verbosely)
 582                fprintf(stderr, "Getting alternates list for %s\n", base);
 583        
 584        url = xmalloc(strlen(base) + 31);
 585        sprintf(url, "%s/objects/info/http-alternates", base);
 586
 587        /* Use a callback to process the result, since another request
 588           may fail and need to have alternates loaded before continuing */
 589        slot = get_active_slot();
 590        slot->callback_func = process_alternates_response;
 591        slot->callback_data = &alt_req;
 592
 593        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 594        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 595        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 596
 597        alt_req.base = base;
 598        alt_req.url = url;
 599        alt_req.buffer = &buffer;
 600        alt_req.http_specific = 1;
 601        alt_req.slot = slot;
 602
 603        if (start_active_slot(slot))
 604                run_active_slot(slot);
 605        else
 606                got_alternates = -1;
 607
 608        free(data);
 609        free(url);
 610}
 611
 612static int fetch_indices(struct alt_base *repo)
 613{
 614        unsigned char sha1[20];
 615        char *url;
 616        struct buffer buffer;
 617        char *data;
 618        int i = 0;
 619
 620        struct active_request_slot *slot;
 621        struct slot_results results;
 622
 623        if (repo->got_indices)
 624                return 0;
 625
 626        data = xmalloc(4096);
 627        buffer.size = 4096;
 628        buffer.posn = 0;
 629        buffer.buffer = data;
 630
 631        if (get_verbosely)
 632                fprintf(stderr, "Getting pack list for %s\n", repo->base);
 633        
 634        url = xmalloc(strlen(repo->base) + 21);
 635        sprintf(url, "%s/objects/info/packs", repo->base);
 636
 637        slot = get_active_slot();
 638        slot->results = &results;
 639        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 640        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 641        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 642        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 643        if (start_active_slot(slot)) {
 644                run_active_slot(slot);
 645                if (results.curl_result != CURLE_OK) {
 646                        if (results.http_code == 404 ||
 647                            results.curl_result == CURLE_FILE_COULDNT_READ_FILE) {
 648                                repo->got_indices = 1;
 649                                free(buffer.buffer);
 650                                return 0;
 651                        } else {
 652                                repo->got_indices = 0;
 653                                free(buffer.buffer);
 654                                return error("%s", curl_errorstr);
 655                        }
 656                }
 657        } else {
 658                repo->got_indices = 0;
 659                free(buffer.buffer);
 660                return error("Unable to start request");
 661        }
 662
 663        data = buffer.buffer;
 664        while (i < buffer.posn) {
 665                switch (data[i]) {
 666                case 'P':
 667                        i++;
 668                        if (i + 52 <= buffer.posn &&
 669                            !strncmp(data + i, " pack-", 6) &&
 670                            !strncmp(data + i + 46, ".pack\n", 6)) {
 671                                get_sha1_hex(data + i + 6, sha1);
 672                                setup_index(repo, sha1);
 673                                i += 51;
 674                                break;
 675                        }
 676                default:
 677                        while (i < buffer.posn && data[i] != '\n')
 678                                i++;
 679                }
 680                i++;
 681        }
 682
 683        free(buffer.buffer);
 684        repo->got_indices = 1;
 685        return 0;
 686}
 687
 688static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 689{
 690        char *url;
 691        struct packed_git *target;
 692        struct packed_git **lst;
 693        FILE *packfile;
 694        char *filename;
 695        char tmpfile[PATH_MAX];
 696        int ret;
 697        long prev_posn = 0;
 698        char range[RANGE_HEADER_SIZE];
 699        struct curl_slist *range_header = NULL;
 700
 701        struct active_request_slot *slot;
 702        struct slot_results results;
 703
 704        if (fetch_indices(repo))
 705                return -1;
 706        target = find_sha1_pack(sha1, repo->packs);
 707        if (!target)
 708                return -1;
 709
 710        if (get_verbosely) {
 711                fprintf(stderr, "Getting pack %s\n",
 712                        sha1_to_hex(target->sha1));
 713                fprintf(stderr, " which contains %s\n",
 714                        sha1_to_hex(sha1));
 715        }
 716
 717        url = xmalloc(strlen(repo->base) + 65);
 718        sprintf(url, "%s/objects/pack/pack-%s.pack",
 719                repo->base, sha1_to_hex(target->sha1));
 720
 721        filename = sha1_pack_name(target->sha1);
 722        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 723        packfile = fopen(tmpfile, "a");
 724        if (!packfile)
 725                return error("Unable to open local file %s for pack",
 726                             filename);
 727
 728        slot = get_active_slot();
 729        slot->results = &results;
 730        curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
 731        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 732        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 733        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 734        slot->local = packfile;
 735
 736        /* If there is data present from a previous transfer attempt,
 737           resume where it left off */
 738        prev_posn = ftell(packfile);
 739        if (prev_posn>0) {
 740                if (get_verbosely)
 741                        fprintf(stderr,
 742                                "Resuming fetch of pack %s at byte %ld\n",
 743                                sha1_to_hex(target->sha1), prev_posn);
 744                sprintf(range, "Range: bytes=%ld-", prev_posn);
 745                range_header = curl_slist_append(range_header, range);
 746                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 747        }
 748
 749        if (start_active_slot(slot)) {
 750                run_active_slot(slot);
 751                if (results.curl_result != CURLE_OK) {
 752                        fclose(packfile);
 753                        return error("Unable to get pack file %s\n%s", url,
 754                                     curl_errorstr);
 755                }
 756        } else {
 757                fclose(packfile);
 758                return error("Unable to start request");
 759        }
 760
 761        fclose(packfile);
 762
 763        ret = move_temp_to_file(tmpfile, filename);
 764        if (ret)
 765                return ret;
 766
 767        lst = &repo->packs;
 768        while (*lst != target)
 769                lst = &((*lst)->next);
 770        *lst = (*lst)->next;
 771
 772        if (verify_pack(target, 0))
 773                return -1;
 774        install_packed_git(target);
 775
 776        return 0;
 777}
 778
 779static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 780{
 781        char *hex = sha1_to_hex(sha1);
 782        int ret = 0;
 783        struct object_request *obj_req = object_queue_head;
 784
 785        while (obj_req != NULL && memcmp(obj_req->sha1, sha1, 20))
 786                obj_req = obj_req->next;
 787        if (obj_req == NULL)
 788                return error("Couldn't find request for %s in the queue", hex);
 789
 790        if (has_sha1_file(obj_req->sha1)) {
 791                release_object_request(obj_req);
 792                return 0;
 793        }
 794
 795#ifdef USE_CURL_MULTI
 796        while (obj_req->state == WAITING) {
 797                step_active_slots();
 798        }
 799#else
 800        start_object_request(obj_req);
 801#endif
 802
 803        while (obj_req->state == ACTIVE) {
 804                run_active_slot(obj_req->slot);
 805        }
 806        if (obj_req->local != -1) {
 807                close(obj_req->local); obj_req->local = -1;
 808        }
 809
 810        if (obj_req->state == ABORTED) {
 811                ret = error("Request for %s aborted", hex);
 812        } else if (obj_req->curl_result != CURLE_OK &&
 813                   obj_req->http_code != 416) {
 814                if (obj_req->http_code == 404 ||
 815                    obj_req->curl_result == CURLE_FILE_COULDNT_READ_FILE)
 816                        ret = -1; /* Be silent, it is probably in a pack. */
 817                else
 818                        ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
 819                                    obj_req->errorstr, obj_req->curl_result,
 820                                    obj_req->http_code, hex);
 821        } else if (obj_req->zret != Z_STREAM_END) {
 822                ret = error("File %s (%s) corrupt\n", hex, obj_req->url);
 823        } else if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
 824                ret = error("File %s has bad hash\n", hex);
 825        } else if (obj_req->rename < 0) {
 826                ret = error("unable to write sha1 filename %s: %s",
 827                            obj_req->filename,
 828                            strerror(obj_req->rename));
 829        }
 830
 831        release_object_request(obj_req);
 832        return ret;
 833}
 834
 835int fetch(unsigned char *sha1)
 836{
 837        struct alt_base *altbase = alt;
 838
 839        if (!fetch_object(altbase, sha1))
 840                return 0;
 841        while (altbase) {
 842                if (!fetch_pack(altbase, sha1))
 843                        return 0;
 844                fetch_alternates(alt->base);
 845                altbase = altbase->next;
 846        }
 847        return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
 848                     alt->base);
 849}
 850
 851static inline int needs_quote(int ch)
 852{
 853        switch (ch) {
 854        case '/': case '-': case '.':
 855        case 'A'...'Z': case 'a'...'z': case '0'...'9':
 856                return 0;
 857        default:
 858                return 1;
 859        }
 860}
 861
 862static inline int hex(int v)
 863{
 864        if (v < 10) return '0' + v;
 865        else return 'A' + v - 10;
 866}
 867
 868static char *quote_ref_url(const char *base, const char *ref)
 869{
 870        const char *cp;
 871        char *dp, *qref;
 872        int len, baselen, ch;
 873
 874        baselen = strlen(base);
 875        len = baselen + 6; /* "refs/" + NUL */
 876        for (cp = ref; (ch = *cp) != 0; cp++, len++)
 877                if (needs_quote(ch))
 878                        len += 2; /* extra two hex plus replacement % */
 879        qref = xmalloc(len);
 880        memcpy(qref, base, baselen);
 881        memcpy(qref + baselen, "refs/", 5);
 882        for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
 883                if (needs_quote(ch)) {
 884                        *dp++ = '%';
 885                        *dp++ = hex((ch >> 4) & 0xF);
 886                        *dp++ = hex(ch & 0xF);
 887                }
 888                else
 889                        *dp++ = ch;
 890        }
 891        *dp = 0;
 892
 893        return qref;
 894}
 895
 896int fetch_ref(char *ref, unsigned char *sha1)
 897{
 898        char *url;
 899        char hex[42];
 900        struct buffer buffer;
 901        char *base = alt->base;
 902        struct active_request_slot *slot;
 903        struct slot_results results;
 904        buffer.size = 41;
 905        buffer.posn = 0;
 906        buffer.buffer = hex;
 907        hex[41] = '\0';
 908        
 909        url = quote_ref_url(base, ref);
 910        slot = get_active_slot();
 911        slot->results = &results;
 912        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 913        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 914        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 915        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 916        if (start_active_slot(slot)) {
 917                run_active_slot(slot);
 918                if (results.curl_result != CURLE_OK)
 919                        return error("Couldn't get %s for %s\n%s",
 920                                     url, ref, curl_errorstr);
 921        } else {
 922                return error("Unable to start request");
 923        }
 924
 925        hex[40] = '\0';
 926        get_sha1_hex(hex, sha1);
 927        return 0;
 928}
 929
 930int main(int argc, char **argv)
 931{
 932        char *commit_id;
 933        char *url;
 934        int arg = 1;
 935        int rc = 0;
 936
 937        setup_git_directory();
 938
 939        while (arg < argc && argv[arg][0] == '-') {
 940                if (argv[arg][1] == 't') {
 941                        get_tree = 1;
 942                } else if (argv[arg][1] == 'c') {
 943                        get_history = 1;
 944                } else if (argv[arg][1] == 'a') {
 945                        get_all = 1;
 946                        get_tree = 1;
 947                        get_history = 1;
 948                } else if (argv[arg][1] == 'v') {
 949                        get_verbosely = 1;
 950                } else if (argv[arg][1] == 'w') {
 951                        write_ref = argv[arg + 1];
 952                        arg++;
 953                } else if (!strcmp(argv[arg], "--recover")) {
 954                        get_recover = 1;
 955                }
 956                arg++;
 957        }
 958        if (argc < arg + 2) {
 959                usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
 960                return 1;
 961        }
 962        commit_id = argv[arg];
 963        url = argv[arg + 1];
 964
 965        http_init();
 966
 967        no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 968
 969        alt = xmalloc(sizeof(*alt));
 970        alt->base = url;
 971        alt->got_indices = 0;
 972        alt->packs = NULL;
 973        alt->next = NULL;
 974
 975        if (pull(commit_id))
 976                rc = 1;
 977
 978        curl_slist_free_all(no_pragma_header);
 979
 980        http_cleanup();
 981
 982        return rc;
 983}