Andrew's git / gitweb.git / http-fetch.c
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http-fetch.con commit [PATCH] Don't fetch objects that exist in the local repository (11f0daf)
   1#include "cache.h"
   2#include "commit.h"
   3#include "pack.h"
   4#include "fetch.h"
   5
   6#include <curl/curl.h>
   7#include <curl/easy.h>
   8
   9#if LIBCURL_VERSION_NUM >= 0x070908
  10#define USE_CURL_MULTI
  11#define DEFAULT_MAX_REQUESTS 5
  12#endif
  13
  14#if LIBCURL_VERSION_NUM < 0x070704
  15#define curl_global_cleanup() do { /* nothing */ } while(0)
  16#endif
  17#if LIBCURL_VERSION_NUM < 0x070800
  18#define curl_global_init(a) do { /* nothing */ } while(0)
  19#endif
  20
  21#define PREV_BUF_SIZE 4096
  22#define RANGE_HEADER_SIZE 30
  23
  24static int active_requests = 0;
  25static int data_received;
  26
  27#ifdef USE_CURL_MULTI
  28static int max_requests = DEFAULT_MAX_REQUESTS;
  29static CURLM *curlm;
  30#endif
  31static CURL *curl_default;
  32static struct curl_slist *no_pragma_header;
  33static struct curl_slist *no_range_header;
  34static char curl_errorstr[CURL_ERROR_SIZE];
  35
  36struct alt_base
  37{
  38        char *base;
  39        int got_indices;
  40        struct packed_git *packs;
  41        struct alt_base *next;
  42};
  43
  44static struct alt_base *alt = NULL;
  45
  46enum transfer_state {
  47        WAITING,
  48        ABORTED,
  49        ACTIVE,
  50        COMPLETE,
  51};
  52
  53struct transfer_request
  54{
  55        unsigned char sha1[20];
  56        struct alt_base *repo;
  57        char *url;
  58        char filename[PATH_MAX];
  59        char tmpfile[PATH_MAX];
  60        int local;
  61        enum transfer_state state;
  62        CURLcode curl_result;
  63        char errorstr[CURL_ERROR_SIZE];
  64        long http_code;
  65        unsigned char real_sha1[20];
  66        SHA_CTX c;
  67        z_stream stream;
  68        int zret;
  69        int rename;
  70        struct active_request_slot *slot;
  71        struct transfer_request *next;
  72};
  73
  74struct active_request_slot
  75{
  76        CURL *curl;
  77        FILE *local;
  78        int in_use;
  79        int done;
  80        CURLcode curl_result;
  81        struct active_request_slot *next;
  82};
  83
  84static struct transfer_request *request_queue_head = NULL;
  85static struct active_request_slot *active_queue_head = NULL;
  86
  87static int curl_ssl_verify;
  88static char *ssl_cert;
  89static char *ssl_key;
  90static char *ssl_capath;
  91static char *ssl_cainfo;
  92
  93struct buffer
  94{
  95        size_t posn;
  96        size_t size;
  97        void *buffer;
  98};
  99
 100static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
 101                            struct buffer *buffer)
 102{
 103        size_t size = eltsize * nmemb;
 104        if (size > buffer->size - buffer->posn)
 105                size = buffer->size - buffer->posn;
 106        memcpy(buffer->buffer + buffer->posn, ptr, size);
 107        buffer->posn += size;
 108        data_received++;
 109        return size;
 110}
 111
 112static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 113                               void *data)
 114{
 115        unsigned char expn[4096];
 116        size_t size = eltsize * nmemb;
 117        int posn = 0;
 118        struct transfer_request *request = (struct transfer_request *)data;
 119        do {
 120                ssize_t retval = write(request->local,
 121                                       ptr + posn, size - posn);
 122                if (retval < 0)
 123                        return posn;
 124                posn += retval;
 125        } while (posn < size);
 126
 127        request->stream.avail_in = size;
 128        request->stream.next_in = ptr;
 129        do {
 130                request->stream.next_out = expn;
 131                request->stream.avail_out = sizeof(expn);
 132                request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
 133                SHA1_Update(&request->c, expn,
 134                            sizeof(expn) - request->stream.avail_out);
 135        } while (request->stream.avail_in && request->zret == Z_OK);
 136        data_received++;
 137        return size;
 138}
 139
 140int relink_or_rename(char *old, char *new) {
 141        int ret;
 142
 143        ret = link(old, new);
 144        if (ret < 0) {
 145                /* Same Coda hack as in write_sha1_file(sha1_file.c) */
 146                ret = errno;
 147                if (ret == EXDEV && !rename(old, new))
 148                        return 0;
 149        }
 150        unlink(old);
 151        if (ret) {
 152                if (ret != EEXIST)
 153                        return ret;
 154        }
 155
 156        return 0;
 157}
 158
 159#ifdef USE_CURL_MULTI
 160void process_curl_messages();
 161void process_request_queue();
 162#endif
 163
 164struct active_request_slot *get_active_slot()
 165{
 166        struct active_request_slot *slot = active_queue_head;
 167        struct active_request_slot *newslot;
 168
 169#ifdef USE_CURL_MULTI
 170        int num_transfers;
 171
 172        /* Wait for a slot to open up if the queue is full */
 173        while (active_requests >= max_requests) {
 174                curl_multi_perform(curlm, &num_transfers);
 175                if (num_transfers < active_requests) {
 176                        process_curl_messages();
 177                }
 178        }
 179#endif
 180
 181        while (slot != NULL && slot->in_use) {
 182                slot = slot->next;
 183        }
 184        if (slot == NULL) {
 185                newslot = xmalloc(sizeof(*newslot));
 186                newslot->curl = curl_easy_duphandle(curl_default);
 187                newslot->in_use = 0;
 188                newslot->next = NULL;
 189
 190                slot = active_queue_head;
 191                if (slot == NULL) {
 192                        active_queue_head = newslot;
 193                } else {
 194                        while (slot->next != NULL) {
 195                                slot = slot->next;
 196                        }
 197                        slot->next = newslot;
 198                }
 199                slot = newslot;
 200        }
 201
 202        active_requests++;
 203        slot->in_use = 1;
 204        slot->done = 0;
 205        slot->local = NULL;
 206        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 207        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
 208        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 209
 210        return slot;
 211}
 212
 213int start_active_slot(struct active_request_slot *slot)
 214{
 215#ifdef USE_CURL_MULTI
 216        CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 217
 218        if (curlm_result != CURLM_OK &&
 219            curlm_result != CURLM_CALL_MULTI_PERFORM) {
 220                active_requests--;
 221                slot->in_use = 0;
 222                return 0;
 223        }
 224#endif
 225        return 1;
 226}
 227
 228void run_active_slot(struct active_request_slot *slot)
 229{
 230#ifdef USE_CURL_MULTI
 231        int num_transfers;
 232        long last_pos = 0;
 233        long current_pos;
 234        fd_set readfds;
 235        fd_set writefds;
 236        fd_set excfds;
 237        int max_fd;
 238        struct timeval select_timeout;
 239        CURLMcode curlm_result;
 240
 241        while (!slot->done) {
 242                data_received = 0;
 243                do {
 244                        curlm_result = curl_multi_perform(curlm,
 245                                                          &num_transfers);
 246                } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 247                if (num_transfers < active_requests) {
 248                        process_curl_messages();
 249                        process_request_queue();
 250                }
 251
 252                if (!data_received && slot->local != NULL) {
 253                        current_pos = ftell(slot->local);
 254                        if (current_pos > last_pos)
 255                                data_received++;
 256                        last_pos = current_pos;
 257                }
 258
 259                if (!slot->done && !data_received) {
 260                        max_fd = 0;
 261                        FD_ZERO(&readfds);
 262                        FD_ZERO(&writefds);
 263                        FD_ZERO(&excfds);
 264                        select_timeout.tv_sec = 0;
 265                        select_timeout.tv_usec = 50000;
 266                        select(max_fd, &readfds, &writefds,
 267                               &excfds, &select_timeout);
 268                }
 269        }
 270#else
 271        slot->curl_result = curl_easy_perform(slot->curl);
 272        active_requests--;
 273#endif
 274}
 275
 276void start_request(struct transfer_request *request)
 277{
 278        char *hex = sha1_to_hex(request->sha1);
 279        char prevfile[PATH_MAX];
 280        char *url;
 281        char *posn;
 282        int prevlocal;
 283        unsigned char prev_buf[PREV_BUF_SIZE];
 284        ssize_t prev_read = 0;
 285        long prev_posn = 0;
 286        char range[RANGE_HEADER_SIZE];
 287        struct curl_slist *range_header = NULL;
 288        struct active_request_slot *slot;
 289
 290        snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
 291        unlink(prevfile);
 292        rename(request->tmpfile, prevfile);
 293        unlink(request->tmpfile);
 294
 295        request->local = open(request->tmpfile,
 296                              O_WRONLY | O_CREAT | O_EXCL, 0666);
 297        if (request->local < 0) {
 298                request->state = ABORTED;
 299                error("Couldn't create temporary file %s for %s: %s\n",
 300                      request->tmpfile, request->filename, strerror(errno));
 301                return;
 302        }
 303
 304        memset(&request->stream, 0, sizeof(request->stream));
 305
 306        inflateInit(&request->stream);
 307
 308        SHA1_Init(&request->c);
 309
 310        url = xmalloc(strlen(request->repo->base) + 50);
 311        request->url = xmalloc(strlen(request->repo->base) + 50);
 312        strcpy(url, request->repo->base);
 313        posn = url + strlen(request->repo->base);
 314        strcpy(posn, "objects/");
 315        posn += 8;
 316        memcpy(posn, hex, 2);
 317        posn += 2;
 318        *(posn++) = '/';
 319        strcpy(posn, hex + 2);
 320        strcpy(request->url, url);
 321
 322        /* If a previous temp file is present, process what was already
 323           fetched. */
 324        prevlocal = open(prevfile, O_RDONLY);
 325        if (prevlocal != -1) {
 326                do {
 327                        prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 328                        if (prev_read>0) {
 329                                if (fwrite_sha1_file(prev_buf,
 330                                                     1,
 331                                                     prev_read,
 332                                                     request) == prev_read) {
 333                                        prev_posn += prev_read;
 334                                } else {
 335                                        prev_read = -1;
 336                                }
 337                        }
 338                } while (prev_read > 0);
 339                close(prevlocal);
 340        }
 341        unlink(prevfile);
 342
 343        /* Reset inflate/SHA1 if there was an error reading the previous temp
 344           file; also rewind to the beginning of the local file. */
 345        if (prev_read == -1) {
 346                memset(&request->stream, 0, sizeof(request->stream));
 347                inflateInit(&request->stream);
 348                SHA1_Init(&request->c);
 349                if (prev_posn>0) {
 350                        prev_posn = 0;
 351                        lseek(request->local, SEEK_SET, 0);
 352                        ftruncate(request->local, 0);
 353                }
 354        }
 355
 356        slot = get_active_slot();
 357        curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
 358        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 359        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
 360        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 361
 362        /* If we have successfully processed data from a previous fetch
 363           attempt, only fetch the data we don't already have. */
 364        if (prev_posn>0) {
 365                if (get_verbosely)
 366                        fprintf(stderr,
 367                                "Resuming fetch of object %s at byte %ld\n",
 368                                hex, prev_posn);
 369                sprintf(range, "Range: bytes=%ld-", prev_posn);
 370                range_header = curl_slist_append(range_header, range);
 371                curl_easy_setopt(slot->curl,
 372                                 CURLOPT_HTTPHEADER, range_header);
 373        }
 374
 375        /* Try to get the request started, abort the request on error */
 376        if (!start_active_slot(slot)) {
 377                request->state = ABORTED;
 378                close(request->local);
 379                free(request->url);
 380                return;
 381        }
 382        
 383        request->slot = slot;
 384        request->state = ACTIVE;
 385}
 386
 387void finish_request(struct transfer_request *request)
 388{
 389        fchmod(request->local, 0444);
 390        close(request->local);
 391
 392        if (request->http_code == 416) {
 393                fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 394        } else if (request->curl_result != CURLE_OK) {
 395                return;
 396        }
 397
 398        inflateEnd(&request->stream);
 399        SHA1_Final(request->real_sha1, &request->c);
 400        if (request->zret != Z_STREAM_END) {
 401                unlink(request->tmpfile);
 402                return;
 403        }
 404        if (memcmp(request->sha1, request->real_sha1, 20)) {
 405                unlink(request->tmpfile);
 406                return;
 407        }
 408        request->rename =
 409                relink_or_rename(request->tmpfile, request->filename);
 410
 411        if (request->rename == 0)
 412                pull_say("got %s\n", sha1_to_hex(request->sha1));
 413}
 414
 415void release_request(struct transfer_request *request)
 416{
 417        struct transfer_request *entry = request_queue_head;
 418
 419        if (request == request_queue_head) {
 420                request_queue_head = request->next;
 421        } else {
 422                while (entry->next != NULL && entry->next != request)
 423                        entry = entry->next;
 424                if (entry->next == request)
 425                        entry->next = entry->next->next;
 426        }
 427
 428        free(request->url);
 429        free(request);
 430}
 431
 432#ifdef USE_CURL_MULTI
 433void process_curl_messages()
 434{
 435        int num_messages;
 436        struct active_request_slot *slot;
 437        struct transfer_request *request = NULL;
 438        CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 439
 440        while (curl_message != NULL) {
 441                if (curl_message->msg == CURLMSG_DONE) {
 442                        slot = active_queue_head;
 443                        while (slot != NULL &&
 444                               slot->curl != curl_message->easy_handle)
 445                                slot = slot->next;
 446                        if (slot != NULL) {
 447                                curl_multi_remove_handle(curlm, slot->curl);
 448                                active_requests--;
 449                                slot->done = 1;
 450                                slot->in_use = 0;
 451                                slot->curl_result = curl_message->data.result;
 452                                request = request_queue_head;
 453                                while (request != NULL &&
 454                                       request->slot != slot)
 455                                        request = request->next;
 456                        } else {
 457                                fprintf(stderr, "Received DONE message for unknown request!\n");
 458                        }
 459                        if (request != NULL) {
 460                                request->curl_result =
 461                                        curl_message->data.result;
 462                                curl_easy_getinfo(slot->curl,
 463                                                  CURLINFO_HTTP_CODE,
 464                                                  &request->http_code);
 465                                request->slot = NULL;
 466
 467                                /* Use alternates if necessary */
 468                                if (request->http_code == 404 &&
 469                                    request->repo->next != NULL) {
 470                                        request->repo = request->repo->next;
 471                                        start_request(request);
 472                                } else {
 473                                        finish_request(request);
 474                                        request->state = COMPLETE;
 475                                }
 476                        }
 477                } else {
 478                        fprintf(stderr, "Unknown CURL message received: %d\n",
 479                                (int)curl_message->msg);
 480                }
 481                curl_message = curl_multi_info_read(curlm, &num_messages);
 482        }
 483}
 484
 485void process_request_queue()
 486{
 487        struct transfer_request *request = request_queue_head;
 488        int num_transfers;
 489
 490        while (active_requests < max_requests && request != NULL) {
 491                if (request->state == WAITING) {
 492                        if (has_sha1_file(request->sha1))
 493                                release_request(request);
 494                        else
 495                                start_request(request);
 496                        curl_multi_perform(curlm, &num_transfers);
 497                }
 498                request = request->next;
 499        }
 500}
 501#endif
 502
 503void prefetch(unsigned char *sha1)
 504{
 505        struct transfer_request *newreq;
 506        struct transfer_request *tail;
 507        char *filename = sha1_file_name(sha1);
 508
 509        newreq = xmalloc(sizeof(*newreq));
 510        memcpy(newreq->sha1, sha1, 20);
 511        newreq->repo = alt;
 512        newreq->url = NULL;
 513        newreq->local = -1;
 514        newreq->state = WAITING;
 515        snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 516        snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 517                 "%s.temp", filename);
 518        newreq->next = NULL;
 519
 520        if (request_queue_head == NULL) {
 521                request_queue_head = newreq;
 522        } else {
 523                tail = request_queue_head;
 524                while (tail->next != NULL) {
 525                        tail = tail->next;
 526                }
 527                tail->next = newreq;
 528        }
 529#ifdef USE_CURL_MULTI
 530        process_request_queue();
 531        process_curl_messages();
 532#endif
 533}
 534
 535static int got_alternates = 0;
 536
 537static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 538{
 539        char *hex = sha1_to_hex(sha1);
 540        char *filename;
 541        char *url;
 542        char tmpfile[PATH_MAX];
 543        int ret;
 544        long prev_posn = 0;
 545        char range[RANGE_HEADER_SIZE];
 546        struct curl_slist *range_header = NULL;
 547
 548        FILE *indexfile;
 549        struct active_request_slot *slot;
 550
 551        if (has_pack_index(sha1))
 552                return 0;
 553
 554        if (get_verbosely)
 555                fprintf(stderr, "Getting index for pack %s\n", hex);
 556        
 557        url = xmalloc(strlen(repo->base) + 64);
 558        sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 559        
 560        filename = sha1_pack_index_name(sha1);
 561        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 562        indexfile = fopen(tmpfile, "a");
 563        if (!indexfile)
 564                return error("Unable to open local file %s for pack index",
 565                             filename);
 566
 567        slot = get_active_slot();
 568        curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 569        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 570        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 571        slot->local = indexfile;
 572
 573        /* If there is data present from a previous transfer attempt,
 574           resume where it left off */
 575        prev_posn = ftell(indexfile);
 576        if (prev_posn>0) {
 577                if (get_verbosely)
 578                        fprintf(stderr,
 579                                "Resuming fetch of index for pack %s at byte %ld\n",
 580                                hex, prev_posn);
 581                sprintf(range, "Range: bytes=%ld-", prev_posn);
 582                range_header = curl_slist_append(range_header, range);
 583                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 584        }
 585
 586        if (start_active_slot(slot)) {
 587                run_active_slot(slot);
 588                if (slot->curl_result != CURLE_OK) {
 589                        fclose(indexfile);
 590                        return error("Unable to get pack index %s\n%s", url,
 591                                     curl_errorstr);
 592                }
 593        } else {
 594                return error("Unable to start request");
 595        }
 596
 597        fclose(indexfile);
 598
 599        ret = relink_or_rename(tmpfile, filename);
 600        if (ret)
 601                return error("unable to write index filename %s: %s",
 602                             filename, strerror(ret));
 603
 604        return 0;
 605}
 606
 607static int setup_index(struct alt_base *repo, unsigned char *sha1)
 608{
 609        struct packed_git *new_pack;
 610        if (has_pack_file(sha1))
 611                return 0; // don't list this as something we can get
 612
 613        if (fetch_index(repo, sha1))
 614                return -1;
 615
 616        new_pack = parse_pack_index(sha1);
 617        new_pack->next = repo->packs;
 618        repo->packs = new_pack;
 619        return 0;
 620}
 621
 622static int fetch_alternates(char *base)
 623{
 624        int ret = 0;
 625        struct buffer buffer;
 626        char *url;
 627        char *data;
 628        int i = 0;
 629        int http_specific = 1;
 630        struct alt_base *tail = alt;
 631
 632        struct active_request_slot *slot;
 633        if (got_alternates)
 634                return 0;
 635        data = xmalloc(4096);
 636        buffer.size = 4095;
 637        buffer.posn = 0;
 638        buffer.buffer = data;
 639
 640        if (get_verbosely)
 641                fprintf(stderr, "Getting alternates list\n");
 642        
 643        url = xmalloc(strlen(base) + 31);
 644        sprintf(url, "%s/objects/info/http-alternates", base);
 645
 646        slot = get_active_slot();
 647        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 648        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 649        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 650        if (start_active_slot(slot)) {
 651                run_active_slot(slot);
 652                if (slot->curl_result != CURLE_OK || !buffer.posn) {
 653                        http_specific = 0;
 654
 655                        sprintf(url, "%s/objects/info/alternates", base);
 656
 657                        slot = get_active_slot();
 658                        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 659                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 660                                         fwrite_buffer);
 661                        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 662                        if (start_active_slot(slot)) {
 663                                run_active_slot(slot);
 664                                if (slot->curl_result != CURLE_OK) {
 665                                        return 0;
 666                                }
 667                        }
 668                }
 669        } else {
 670                return 0;
 671        }
 672
 673        data[buffer.posn] = '\0';
 674
 675        while (i < buffer.posn) {
 676                int posn = i;
 677                while (posn < buffer.posn && data[posn] != '\n')
 678                        posn++;
 679                if (data[posn] == '\n') {
 680                        int okay = 0;
 681                        int serverlen = 0;
 682                        struct alt_base *newalt;
 683                        char *target = NULL;
 684                        if (data[i] == '/') {
 685                                serverlen = strchr(base + 8, '/') - base;
 686                                okay = 1;
 687                        } else if (!memcmp(data + i, "../", 3)) {
 688                                i += 3;
 689                                serverlen = strlen(base);
 690                                while (i + 2 < posn && 
 691                                       !memcmp(data + i, "../", 3)) {
 692                                        do {
 693                                                serverlen--;
 694                                        } while (serverlen &&
 695                                                 base[serverlen - 1] != '/');
 696                                        i += 3;
 697                                }
 698                                // If the server got removed, give up.
 699                                okay = strchr(base, ':') - base + 3 < 
 700                                        serverlen;
 701                        } else if (http_specific) {
 702                                char *colon = strchr(data + i, ':');
 703                                char *slash = strchr(data + i, '/');
 704                                if (colon && slash && colon < data + posn &&
 705                                    slash < data + posn && colon < slash) {
 706                                        okay = 1;
 707                                }
 708                        }
 709                        // skip 'objects' at end
 710                        if (okay) {
 711                                target = xmalloc(serverlen + posn - i - 6);
 712                                strncpy(target, base, serverlen);
 713                                strncpy(target + serverlen, data + i,
 714                                        posn - i - 7);
 715                                target[serverlen + posn - i - 7] = '\0';
 716                                if (get_verbosely)
 717                                        fprintf(stderr, 
 718                                                "Also look at %s\n", target);
 719                                newalt = xmalloc(sizeof(*newalt));
 720                                newalt->next = NULL;
 721                                newalt->base = target;
 722                                newalt->got_indices = 0;
 723                                newalt->packs = NULL;
 724                                while (tail->next != NULL)
 725                                        tail = tail->next;
 726                                tail->next = newalt;
 727                                ret++;
 728                        }
 729                }
 730                i = posn + 1;
 731        }
 732        got_alternates = 1;
 733        
 734        return ret;
 735}
 736
 737static int fetch_indices(struct alt_base *repo)
 738{
 739        unsigned char sha1[20];
 740        char *url;
 741        struct buffer buffer;
 742        char *data;
 743        int i = 0;
 744
 745        struct active_request_slot *slot;
 746
 747        if (repo->got_indices)
 748                return 0;
 749
 750        data = xmalloc(4096);
 751        buffer.size = 4096;
 752        buffer.posn = 0;
 753        buffer.buffer = data;
 754
 755        if (get_verbosely)
 756                fprintf(stderr, "Getting pack list\n");
 757        
 758        url = xmalloc(strlen(repo->base) + 21);
 759        sprintf(url, "%s/objects/info/packs", repo->base);
 760
 761        slot = get_active_slot();
 762        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 763        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 764        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 765        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 766        if (start_active_slot(slot)) {
 767                run_active_slot(slot);
 768                if (slot->curl_result != CURLE_OK)
 769                        return error("%s", curl_errorstr);
 770        } else {
 771                return error("Unable to start request");
 772        }
 773
 774        while (i < buffer.posn) {
 775                switch (data[i]) {
 776                case 'P':
 777                        i++;
 778                        if (i + 52 < buffer.posn &&
 779                            !strncmp(data + i, " pack-", 6) &&
 780                            !strncmp(data + i + 46, ".pack\n", 6)) {
 781                                get_sha1_hex(data + i + 6, sha1);
 782                                setup_index(repo, sha1);
 783                                i += 51;
 784                                break;
 785                        }
 786                default:
 787                        while (data[i] != '\n')
 788                                i++;
 789                }
 790                i++;
 791        }
 792
 793        repo->got_indices = 1;
 794        return 0;
 795}
 796
 797static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 798{
 799        char *url;
 800        struct packed_git *target;
 801        struct packed_git **lst;
 802        FILE *packfile;
 803        char *filename;
 804        char tmpfile[PATH_MAX];
 805        int ret;
 806        long prev_posn = 0;
 807        char range[RANGE_HEADER_SIZE];
 808        struct curl_slist *range_header = NULL;
 809
 810        struct active_request_slot *slot;
 811
 812        if (fetch_indices(repo))
 813                return -1;
 814        target = find_sha1_pack(sha1, repo->packs);
 815        if (!target)
 816                return -1;
 817
 818        if (get_verbosely) {
 819                fprintf(stderr, "Getting pack %s\n",
 820                        sha1_to_hex(target->sha1));
 821                fprintf(stderr, " which contains %s\n",
 822                        sha1_to_hex(sha1));
 823        }
 824
 825        url = xmalloc(strlen(repo->base) + 65);
 826        sprintf(url, "%s/objects/pack/pack-%s.pack",
 827                repo->base, sha1_to_hex(target->sha1));
 828
 829        filename = sha1_pack_name(target->sha1);
 830        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 831        packfile = fopen(tmpfile, "a");
 832        if (!packfile)
 833                return error("Unable to open local file %s for pack",
 834                             filename);
 835
 836        slot = get_active_slot();
 837        curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
 838        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 839        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 840        slot->local = packfile;
 841
 842        /* If there is data present from a previous transfer attempt,
 843           resume where it left off */
 844        prev_posn = ftell(packfile);
 845        if (prev_posn>0) {
 846                if (get_verbosely)
 847                        fprintf(stderr,
 848                                "Resuming fetch of pack %s at byte %ld\n",
 849                                sha1_to_hex(target->sha1), prev_posn);
 850                sprintf(range, "Range: bytes=%ld-", prev_posn);
 851                range_header = curl_slist_append(range_header, range);
 852                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 853        }
 854
 855        if (start_active_slot(slot)) {
 856                run_active_slot(slot);
 857                if (slot->curl_result != CURLE_OK) {
 858                        fclose(packfile);
 859                        return error("Unable to get pack file %s\n%s", url,
 860                                     curl_errorstr);
 861                }
 862        } else {
 863                return error("Unable to start request");
 864        }
 865
 866        fclose(packfile);
 867
 868        ret = relink_or_rename(tmpfile, filename);
 869        if (ret)
 870                return error("unable to write pack filename %s: %s",
 871                             filename, strerror(ret));
 872
 873        lst = &repo->packs;
 874        while (*lst != target)
 875                lst = &((*lst)->next);
 876        *lst = (*lst)->next;
 877
 878        if (verify_pack(target, 0))
 879                return -1;
 880        install_packed_git(target);
 881
 882        return 0;
 883}
 884
 885static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 886{
 887        char *hex = sha1_to_hex(sha1);
 888        int ret;
 889        struct transfer_request *request = request_queue_head;
 890
 891        while (request != NULL && memcmp(request->sha1, sha1, 20))
 892                request = request->next;
 893        if (request == NULL)
 894                return error("Couldn't find request for %s in the queue", hex);
 895
 896        if (has_sha1_file(request->sha1)) {
 897                release_request(request);
 898                return 0;
 899        }
 900
 901#ifdef USE_CURL_MULTI
 902        int num_transfers;
 903        while (request->state == WAITING) {
 904                curl_multi_perform(curlm, &num_transfers);
 905                if (num_transfers < active_requests) {
 906                        process_curl_messages();
 907                        process_request_queue();
 908                }
 909        }
 910#else
 911        start_request(request);
 912#endif
 913
 914        while (request->state == ACTIVE) {
 915                run_active_slot(request->slot);
 916#ifndef USE_CURL_MULTI
 917                request->curl_result = request->slot->curl_result;
 918                curl_easy_getinfo(request->slot->curl,
 919                                  CURLINFO_HTTP_CODE,
 920                                  &request->http_code);
 921                request->slot = NULL;
 922
 923                /* Use alternates if necessary */
 924                if (request->http_code == 404 &&
 925                    request->repo->next != NULL) {
 926                        request->repo = request->repo->next;
 927                        start_request(request);
 928                } else {
 929                        finish_request(request);
 930                        request->state = COMPLETE;
 931                }
 932#endif
 933        }
 934
 935        if (request->state == ABORTED) {
 936                release_request(request);
 937                return error("Request for %s aborted", hex);
 938        }
 939
 940        if (request->curl_result != CURLE_OK && request->http_code != 416) {
 941                ret = error("%s", request->errorstr);
 942                release_request(request);
 943                return ret;
 944        }
 945
 946        if (request->zret != Z_STREAM_END) {
 947                ret = error("File %s (%s) corrupt\n", hex, request->url);
 948                release_request(request);
 949                return ret;
 950        }
 951
 952        if (memcmp(request->sha1, request->real_sha1, 20)) {
 953                release_request(request);
 954                return error("File %s has bad hash\n", hex);
 955        }
 956
 957        if (request->rename < 0) {
 958                ret = error("unable to write sha1 filename %s: %s",
 959                            request->filename,
 960                            strerror(request->rename));
 961                release_request(request);
 962                return ret;
 963        }
 964
 965        release_request(request);
 966        return 0;
 967}
 968
 969int fetch(unsigned char *sha1)
 970{
 971        struct alt_base *altbase = alt;
 972
 973        if (!fetch_object(altbase, sha1))
 974                return 0;
 975        while (altbase) {
 976                if (!fetch_pack(altbase, sha1))
 977                        return 0;
 978                altbase = altbase->next;
 979        }
 980        return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
 981                     alt->base);
 982}
 983
 984int fetch_ref(char *ref, unsigned char *sha1)
 985{
 986        char *url, *posn;
 987        char hex[42];
 988        struct buffer buffer;
 989        char *base = alt->base;
 990        struct active_request_slot *slot;
 991        buffer.size = 41;
 992        buffer.posn = 0;
 993        buffer.buffer = hex;
 994        hex[41] = '\0';
 995        
 996        url = xmalloc(strlen(base) + 6 + strlen(ref));
 997        strcpy(url, base);
 998        posn = url + strlen(base);
 999        strcpy(posn, "refs/");
1000        posn += 5;
1001        strcpy(posn, ref);
1002
1003        slot = get_active_slot();
1004        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
1005        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
1006        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
1007        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1008        if (start_active_slot(slot)) {
1009                run_active_slot(slot);
1010                if (slot->curl_result != CURLE_OK)
1011                        return error("Couldn't get %s for %s\n%s",
1012                                     url, ref, curl_errorstr);
1013        } else {
1014                return error("Unable to start request");
1015        }
1016
1017        hex[40] = '\0';
1018        get_sha1_hex(hex, sha1);
1019        return 0;
1020}
1021
1022int main(int argc, char **argv)
1023{
1024        char *commit_id;
1025        char *url;
1026        int arg = 1;
1027        struct active_request_slot *slot;
1028
1029        while (arg < argc && argv[arg][0] == '-') {
1030                if (argv[arg][1] == 't') {
1031                        get_tree = 1;
1032                } else if (argv[arg][1] == 'c') {
1033                        get_history = 1;
1034                } else if (argv[arg][1] == 'a') {
1035                        get_all = 1;
1036                        get_tree = 1;
1037                        get_history = 1;
1038                } else if (argv[arg][1] == 'v') {
1039                        get_verbosely = 1;
1040                } else if (argv[arg][1] == 'w') {
1041                        write_ref = argv[arg + 1];
1042                        arg++;
1043                } else if (!strcmp(argv[arg], "--recover")) {
1044                        get_recover = 1;
1045                }
1046                arg++;
1047        }
1048        if (argc < arg + 2) {
1049                usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
1050                return 1;
1051        }
1052        commit_id = argv[arg];
1053        url = argv[arg + 1];
1054
1055        curl_global_init(CURL_GLOBAL_ALL);
1056
1057#ifdef USE_CURL_MULTI
1058        char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1059        if (http_max_requests != NULL)
1060                max_requests = atoi(http_max_requests);
1061        if (max_requests < 1)
1062                max_requests = DEFAULT_MAX_REQUESTS;
1063
1064        curlm = curl_multi_init();
1065        if (curlm == NULL) {
1066                fprintf(stderr, "Error creating curl multi handle.\n");
1067                return 1;
1068        }
1069#endif
1070        no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1071        no_range_header = curl_slist_append(no_range_header, "Range:");
1072
1073        curl_default = curl_easy_init();
1074
1075        curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
1076        curl_easy_setopt(curl_default, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
1077#if LIBCURL_VERSION_NUM >= 0x070907
1078        curl_easy_setopt(curl_default, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
1079#endif
1080
1081        if ((ssl_cert = getenv("GIT_SSL_CERT")) != NULL) {
1082                curl_easy_setopt(curl_default, CURLOPT_SSLCERT, ssl_cert);
1083        }
1084#if LIBCURL_VERSION_NUM >= 0x070902
1085        if ((ssl_key = getenv("GIT_SSL_KEY")) != NULL) {
1086                curl_easy_setopt(curl_default, CURLOPT_SSLKEY, ssl_key);
1087        }
1088#endif
1089#if LIBCURL_VERSION_NUM >= 0x070908
1090        if ((ssl_capath = getenv("GIT_SSL_CAPATH")) != NULL) {
1091                curl_easy_setopt(curl_default, CURLOPT_CAPATH, ssl_capath);
1092        }
1093#endif
1094        if ((ssl_cainfo = getenv("GIT_SSL_CAINFO")) != NULL) {
1095                curl_easy_setopt(curl_default, CURLOPT_CAINFO, ssl_cainfo);
1096        }
1097        curl_easy_setopt(curl_default, CURLOPT_FAILONERROR, 1);
1098
1099        alt = xmalloc(sizeof(*alt));
1100        alt->base = url;
1101        alt->got_indices = 0;
1102        alt->packs = NULL;
1103        alt->next = NULL;
1104        fetch_alternates(alt->base);
1105
1106        if (pull(commit_id))
1107                return 1;
1108
1109        curl_slist_free_all(no_pragma_header);
1110        curl_slist_free_all(no_range_header);
1111        curl_easy_cleanup(curl_default);
1112        slot = active_queue_head;
1113        while (slot != NULL) {
1114                curl_easy_cleanup(slot->curl);
1115                slot = slot->next;
1116        }
1117#ifdef USE_CURL_MULTI
1118        curl_multi_cleanup(curlm);
1119#endif
1120        curl_global_cleanup();
1121        return 0;
1122}