Andrew's git - gitweb.git/blob

5821c9e5e90e5951f760fbfad25544251c2ead28
   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 *pragma_header;
  33static struct curl_slist *no_pragma_header;
  34static struct curl_slist *no_range_header;
  35static char curl_errorstr[CURL_ERROR_SIZE];
  36
  37struct alt_base
  38{
  39        char *base;
  40        int got_indices;
  41        struct packed_git *packs;
  42        struct alt_base *next;
  43};
  44
  45static struct alt_base *alt = NULL;
  46
  47enum transfer_state {
  48        WAITING,
  49        ABORTED,
  50        ACTIVE,
  51        COMPLETE,
  52};
  53
  54struct transfer_request
  55{
  56        unsigned char sha1[20];
  57        struct alt_base *repo;
  58        char *url;
  59        char filename[PATH_MAX];
  60        char tmpfile[PATH_MAX];
  61        int local;
  62        enum transfer_state state;
  63        CURLcode curl_result;
  64        char errorstr[CURL_ERROR_SIZE];
  65        long http_code;
  66        unsigned char real_sha1[20];
  67        SHA_CTX c;
  68        z_stream stream;
  69        int zret;
  70        int rename;
  71        struct active_request_slot *slot;
  72        struct transfer_request *next;
  73};
  74
  75struct active_request_slot
  76{
  77        CURL *curl;
  78        FILE *local;
  79        int in_use;
  80        int done;
  81        CURLcode curl_result;
  82        struct active_request_slot *next;
  83};
  84
  85static struct transfer_request *request_queue_head = NULL;
  86static struct active_request_slot *active_queue_head = NULL;
  87
  88static int curl_ssl_verify;
  89static char *ssl_cert;
  90static char *ssl_key;
  91static char *ssl_capath;
  92static char *ssl_cainfo;
  93
  94struct buffer
  95{
  96        size_t posn;
  97        size_t size;
  98        void *buffer;
  99};
 100
 101static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
 102                            struct buffer *buffer)
 103{
 104        size_t size = eltsize * nmemb;
 105        if (size > buffer->size - buffer->posn)
 106                size = buffer->size - buffer->posn;
 107        memcpy(buffer->buffer + buffer->posn, ptr, size);
 108        buffer->posn += size;
 109        data_received++;
 110        return size;
 111}
 112
 113static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 114                               void *data)
 115{
 116        unsigned char expn[4096];
 117        size_t size = eltsize * nmemb;
 118        int posn = 0;
 119        struct transfer_request *request = (struct transfer_request *)data;
 120        do {
 121                ssize_t retval = write(request->local,
 122                                       ptr + posn, size - posn);
 123                if (retval < 0)
 124                        return posn;
 125                posn += retval;
 126        } while (posn < size);
 127
 128        request->stream.avail_in = size;
 129        request->stream.next_in = ptr;
 130        do {
 131                request->stream.next_out = expn;
 132                request->stream.avail_out = sizeof(expn);
 133                request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
 134                SHA1_Update(&request->c, expn,
 135                            sizeof(expn) - request->stream.avail_out);
 136        } while (request->stream.avail_in && request->zret == Z_OK);
 137        data_received++;
 138        return size;
 139}
 140
 141#ifdef USE_CURL_MULTI
 142void process_curl_messages();
 143void process_request_queue();
 144#endif
 145
 146struct active_request_slot *get_active_slot()
 147{
 148        struct active_request_slot *slot = active_queue_head;
 149        struct active_request_slot *newslot;
 150
 151#ifdef USE_CURL_MULTI
 152        int num_transfers;
 153
 154        /* Wait for a slot to open up if the queue is full */
 155        while (active_requests >= max_requests) {
 156                curl_multi_perform(curlm, &num_transfers);
 157                if (num_transfers < active_requests) {
 158                        process_curl_messages();
 159                }
 160        }
 161#endif
 162
 163        while (slot != NULL && slot->in_use) {
 164                slot = slot->next;
 165        }
 166        if (slot == NULL) {
 167                newslot = xmalloc(sizeof(*newslot));
 168                newslot->curl = curl_easy_duphandle(curl_default);
 169                newslot->in_use = 0;
 170                newslot->next = NULL;
 171
 172                slot = active_queue_head;
 173                if (slot == NULL) {
 174                        active_queue_head = newslot;
 175                } else {
 176                        while (slot->next != NULL) {
 177                                slot = slot->next;
 178                        }
 179                        slot->next = newslot;
 180                }
 181                slot = newslot;
 182        }
 183
 184        active_requests++;
 185        slot->in_use = 1;
 186        slot->done = 0;
 187        slot->local = NULL;
 188        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 189        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
 190        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 191
 192        return slot;
 193}
 194
 195int start_active_slot(struct active_request_slot *slot)
 196{
 197#ifdef USE_CURL_MULTI
 198        CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 199
 200        if (curlm_result != CURLM_OK &&
 201            curlm_result != CURLM_CALL_MULTI_PERFORM) {
 202                active_requests--;
 203                slot->in_use = 0;
 204                return 0;
 205        }
 206#endif
 207        return 1;
 208}
 209
 210void run_active_slot(struct active_request_slot *slot)
 211{
 212#ifdef USE_CURL_MULTI
 213        int num_transfers;
 214        long last_pos = 0;
 215        long current_pos;
 216        fd_set readfds;
 217        fd_set writefds;
 218        fd_set excfds;
 219        int max_fd;
 220        struct timeval select_timeout;
 221        CURLMcode curlm_result;
 222
 223        while (!slot->done) {
 224                data_received = 0;
 225                do {
 226                        curlm_result = curl_multi_perform(curlm,
 227                                                          &num_transfers);
 228                } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 229                if (num_transfers < active_requests) {
 230                        process_curl_messages();
 231                        process_request_queue();
 232                }
 233
 234                if (!data_received && slot->local != NULL) {
 235                        current_pos = ftell(slot->local);
 236                        if (current_pos > last_pos)
 237                                data_received++;
 238                        last_pos = current_pos;
 239                }
 240
 241                if (!slot->done && !data_received) {
 242                        max_fd = 0;
 243                        FD_ZERO(&readfds);
 244                        FD_ZERO(&writefds);
 245                        FD_ZERO(&excfds);
 246                        select_timeout.tv_sec = 0;
 247                        select_timeout.tv_usec = 50000;
 248                        select(max_fd, &readfds, &writefds,
 249                               &excfds, &select_timeout);
 250                }
 251        }
 252#else
 253        slot->curl_result = curl_easy_perform(slot->curl);
 254        active_requests--;
 255#endif
 256}
 257
 258void start_request(struct transfer_request *request)
 259{
 260        char *hex = sha1_to_hex(request->sha1);
 261        char prevfile[PATH_MAX];
 262        char *url;
 263        char *posn;
 264        int prevlocal;
 265        unsigned char prev_buf[PREV_BUF_SIZE];
 266        ssize_t prev_read = 0;
 267        long prev_posn = 0;
 268        char range[RANGE_HEADER_SIZE];
 269        struct curl_slist *range_header = NULL;
 270        struct active_request_slot *slot;
 271
 272        snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
 273        unlink(prevfile);
 274        rename(request->tmpfile, prevfile);
 275        unlink(request->tmpfile);
 276
 277        request->local = open(request->tmpfile,
 278                              O_WRONLY | O_CREAT | O_EXCL, 0666);
 279        /* This could have failed due to the "lazy directory creation";
 280         * try to mkdir the last path component.
 281         */
 282        if (request->local < 0 && errno == ENOENT) {
 283                char *dir = strrchr(request->tmpfile, '/');
 284                if (dir) {
 285                        *dir = 0;
 286                        mkdir(request->tmpfile, 0777);
 287                        *dir = '/';
 288                }
 289                request->local = open(request->tmpfile,
 290                                      O_WRONLY | O_CREAT | O_EXCL, 0666);
 291        }
 292
 293        if (request->local < 0) {
 294                request->state = ABORTED;
 295                error("Couldn't create temporary file %s for %s: %s\n",
 296                      request->tmpfile, request->filename, strerror(errno));
 297                return;
 298        }
 299
 300        memset(&request->stream, 0, sizeof(request->stream));
 301
 302        inflateInit(&request->stream);
 303
 304        SHA1_Init(&request->c);
 305
 306        url = xmalloc(strlen(request->repo->base) + 50);
 307        request->url = xmalloc(strlen(request->repo->base) + 50);
 308        strcpy(url, request->repo->base);
 309        posn = url + strlen(request->repo->base);
 310        strcpy(posn, "objects/");
 311        posn += 8;
 312        memcpy(posn, hex, 2);
 313        posn += 2;
 314        *(posn++) = '/';
 315        strcpy(posn, hex + 2);
 316        strcpy(request->url, url);
 317
 318        /* If a previous temp file is present, process what was already
 319           fetched. */
 320        prevlocal = open(prevfile, O_RDONLY);
 321        if (prevlocal != -1) {
 322                do {
 323                        prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 324                        if (prev_read>0) {
 325                                if (fwrite_sha1_file(prev_buf,
 326                                                     1,
 327                                                     prev_read,
 328                                                     request) == prev_read) {
 329                                        prev_posn += prev_read;
 330                                } else {
 331                                        prev_read = -1;
 332                                }
 333                        }
 334                } while (prev_read > 0);
 335                close(prevlocal);
 336        }
 337        unlink(prevfile);
 338
 339        /* Reset inflate/SHA1 if there was an error reading the previous temp
 340           file; also rewind to the beginning of the local file. */
 341        if (prev_read == -1) {
 342                memset(&request->stream, 0, sizeof(request->stream));
 343                inflateInit(&request->stream);
 344                SHA1_Init(&request->c);
 345                if (prev_posn>0) {
 346                        prev_posn = 0;
 347                        lseek(request->local, SEEK_SET, 0);
 348                        ftruncate(request->local, 0);
 349                }
 350        }
 351
 352        slot = get_active_slot();
 353        curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
 354        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 355        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
 356        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 357        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 358
 359        /* If we have successfully processed data from a previous fetch
 360           attempt, only fetch the data we don't already have. */
 361        if (prev_posn>0) {
 362                if (get_verbosely)
 363                        fprintf(stderr,
 364                                "Resuming fetch of object %s at byte %ld\n",
 365                                hex, prev_posn);
 366                sprintf(range, "Range: bytes=%ld-", prev_posn);
 367                range_header = curl_slist_append(range_header, range);
 368                curl_easy_setopt(slot->curl,
 369                                 CURLOPT_HTTPHEADER, range_header);
 370        }
 371
 372        /* Try to get the request started, abort the request on error */
 373        if (!start_active_slot(slot)) {
 374                request->state = ABORTED;
 375                close(request->local);
 376                free(request->url);
 377                return;
 378        }
 379        
 380        request->slot = slot;
 381        request->state = ACTIVE;
 382}
 383
 384void finish_request(struct transfer_request *request)
 385{
 386        fchmod(request->local, 0444);
 387        close(request->local);
 388
 389        if (request->http_code == 416) {
 390                fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 391        } else if (request->curl_result != CURLE_OK) {
 392                return;
 393        }
 394
 395        inflateEnd(&request->stream);
 396        SHA1_Final(request->real_sha1, &request->c);
 397        if (request->zret != Z_STREAM_END) {
 398                unlink(request->tmpfile);
 399                return;
 400        }
 401        if (memcmp(request->sha1, request->real_sha1, 20)) {
 402                unlink(request->tmpfile);
 403                return;
 404        }
 405        request->rename =
 406                move_temp_to_file(request->tmpfile, request->filename);
 407
 408        if (request->rename == 0)
 409                pull_say("got %s\n", sha1_to_hex(request->sha1));
 410}
 411
 412void release_request(struct transfer_request *request)
 413{
 414        struct transfer_request *entry = request_queue_head;
 415
 416        if (request == request_queue_head) {
 417                request_queue_head = request->next;
 418        } else {
 419                while (entry->next != NULL && entry->next != request)
 420                        entry = entry->next;
 421                if (entry->next == request)
 422                        entry->next = entry->next->next;
 423        }
 424
 425        free(request->url);
 426        free(request);
 427}
 428
 429#ifdef USE_CURL_MULTI
 430void process_curl_messages()
 431{
 432        int num_messages;
 433        struct active_request_slot *slot;
 434        struct transfer_request *request = NULL;
 435        CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 436
 437        while (curl_message != NULL) {
 438                if (curl_message->msg == CURLMSG_DONE) {
 439                        slot = active_queue_head;
 440                        while (slot != NULL &&
 441                               slot->curl != curl_message->easy_handle)
 442                                slot = slot->next;
 443                        if (slot != NULL) {
 444                                curl_multi_remove_handle(curlm, slot->curl);
 445                                active_requests--;
 446                                slot->done = 1;
 447                                slot->in_use = 0;
 448                                slot->curl_result = curl_message->data.result;
 449                                request = request_queue_head;
 450                                while (request != NULL &&
 451                                       request->slot != slot)
 452                                        request = request->next;
 453                        } else {
 454                                fprintf(stderr, "Received DONE message for unknown request!\n");
 455                        }
 456                        if (request != NULL) {
 457                                request->curl_result =
 458                                        curl_message->data.result;
 459                                curl_easy_getinfo(slot->curl,
 460                                                  CURLINFO_HTTP_CODE,
 461                                                  &request->http_code);
 462                                request->slot = NULL;
 463
 464                                /* Use alternates if necessary */
 465                                if (request->http_code == 404 &&
 466                                    request->repo->next != NULL) {
 467                                        request->repo = request->repo->next;
 468                                        start_request(request);
 469                                } else {
 470                                        finish_request(request);
 471                                        request->state = COMPLETE;
 472                                }
 473                        }
 474                } else {
 475                        fprintf(stderr, "Unknown CURL message received: %d\n",
 476                                (int)curl_message->msg);
 477                }
 478                curl_message = curl_multi_info_read(curlm, &num_messages);
 479        }
 480}
 481
 482void process_request_queue()
 483{
 484        struct transfer_request *request = request_queue_head;
 485        int num_transfers;
 486
 487        while (active_requests < max_requests && request != NULL) {
 488                if (request->state == WAITING) {
 489                        if (has_sha1_file(request->sha1))
 490                                release_request(request);
 491                        else
 492                                start_request(request);
 493                        curl_multi_perform(curlm, &num_transfers);
 494                }
 495                request = request->next;
 496        }
 497}
 498#endif
 499
 500void prefetch(unsigned char *sha1)
 501{
 502        struct transfer_request *newreq;
 503        struct transfer_request *tail;
 504        char *filename = sha1_file_name(sha1);
 505
 506        newreq = xmalloc(sizeof(*newreq));
 507        memcpy(newreq->sha1, sha1, 20);
 508        newreq->repo = alt;
 509        newreq->url = NULL;
 510        newreq->local = -1;
 511        newreq->state = WAITING;
 512        snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 513        snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 514                 "%s.temp", filename);
 515        newreq->next = NULL;
 516
 517        if (request_queue_head == NULL) {
 518                request_queue_head = newreq;
 519        } else {
 520                tail = request_queue_head;
 521                while (tail->next != NULL) {
 522                        tail = tail->next;
 523                }
 524                tail->next = newreq;
 525        }
 526#ifdef USE_CURL_MULTI
 527        process_request_queue();
 528        process_curl_messages();
 529#endif
 530}
 531
 532static int got_alternates = 0;
 533
 534static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 535{
 536        char *hex = sha1_to_hex(sha1);
 537        char *filename;
 538        char *url;
 539        char tmpfile[PATH_MAX];
 540        long prev_posn = 0;
 541        char range[RANGE_HEADER_SIZE];
 542        struct curl_slist *range_header = NULL;
 543
 544        FILE *indexfile;
 545        struct active_request_slot *slot;
 546
 547        if (has_pack_index(sha1))
 548                return 0;
 549
 550        if (get_verbosely)
 551                fprintf(stderr, "Getting index for pack %s\n", hex);
 552        
 553        url = xmalloc(strlen(repo->base) + 64);
 554        sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 555        
 556        filename = sha1_pack_index_name(sha1);
 557        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 558        indexfile = fopen(tmpfile, "a");
 559        if (!indexfile)
 560                return error("Unable to open local file %s for pack index",
 561                             filename);
 562
 563        slot = get_active_slot();
 564        curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 565        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 566        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 567        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 568        slot->local = indexfile;
 569
 570        /* If there is data present from a previous transfer attempt,
 571           resume where it left off */
 572        prev_posn = ftell(indexfile);
 573        if (prev_posn>0) {
 574                if (get_verbosely)
 575                        fprintf(stderr,
 576                                "Resuming fetch of index for pack %s at byte %ld\n",
 577                                hex, prev_posn);
 578                sprintf(range, "Range: bytes=%ld-", prev_posn);
 579                range_header = curl_slist_append(range_header, range);
 580                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 581        }
 582
 583        if (start_active_slot(slot)) {
 584                run_active_slot(slot);
 585                if (slot->curl_result != CURLE_OK) {
 586                        fclose(indexfile);
 587                        return error("Unable to get pack index %s\n%s", url,
 588                                     curl_errorstr);
 589                }
 590        } else {
 591                return error("Unable to start request");
 592        }
 593
 594        fclose(indexfile);
 595
 596        return move_temp_to_file(tmpfile, filename);
 597}
 598
 599static int setup_index(struct alt_base *repo, unsigned char *sha1)
 600{
 601        struct packed_git *new_pack;
 602        if (has_pack_file(sha1))
 603                return 0; // don't list this as something we can get
 604
 605        if (fetch_index(repo, sha1))
 606                return -1;
 607
 608        new_pack = parse_pack_index(sha1);
 609        new_pack->next = repo->packs;
 610        repo->packs = new_pack;
 611        return 0;
 612}
 613
 614static int fetch_alternates(char *base)
 615{
 616        int ret = 0;
 617        struct buffer buffer;
 618        char *url;
 619        char *data;
 620        int i = 0;
 621        int http_specific = 1;
 622        struct alt_base *tail = alt;
 623
 624        struct active_request_slot *slot;
 625        if (got_alternates)
 626                return 0;
 627        data = xmalloc(4096);
 628        buffer.size = 4095;
 629        buffer.posn = 0;
 630        buffer.buffer = data;
 631
 632        if (get_verbosely)
 633                fprintf(stderr, "Getting alternates list\n");
 634        
 635        url = xmalloc(strlen(base) + 31);
 636        sprintf(url, "%s/objects/info/http-alternates", base);
 637
 638        slot = get_active_slot();
 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        if (start_active_slot(slot)) {
 643                run_active_slot(slot);
 644                if (slot->curl_result != CURLE_OK || !buffer.posn) {
 645                        http_specific = 0;
 646
 647                        sprintf(url, "%s/objects/info/alternates", base);
 648
 649                        slot = get_active_slot();
 650                        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 651                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 652                                         fwrite_buffer);
 653                        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 654                        if (start_active_slot(slot)) {
 655                                run_active_slot(slot);
 656                                if (slot->curl_result != CURLE_OK) {
 657                                        return 0;
 658                                }
 659                        }
 660                }
 661        } else {
 662                return 0;
 663        }
 664
 665        data[buffer.posn] = '\0';
 666
 667        while (i < buffer.posn) {
 668                int posn = i;
 669                while (posn < buffer.posn && data[posn] != '\n')
 670                        posn++;
 671                if (data[posn] == '\n') {
 672                        int okay = 0;
 673                        int serverlen = 0;
 674                        struct alt_base *newalt;
 675                        char *target = NULL;
 676                        if (data[i] == '/') {
 677                                serverlen = strchr(base + 8, '/') - base;
 678                                okay = 1;
 679                        } else if (!memcmp(data + i, "../", 3)) {
 680                                i += 3;
 681                                serverlen = strlen(base);
 682                                while (i + 2 < posn && 
 683                                       !memcmp(data + i, "../", 3)) {
 684                                        do {
 685                                                serverlen--;
 686                                        } while (serverlen &&
 687                                                 base[serverlen - 1] != '/');
 688                                        i += 3;
 689                                }
 690                                // If the server got removed, give up.
 691                                okay = strchr(base, ':') - base + 3 < 
 692                                        serverlen;
 693                        } else if (http_specific) {
 694                                char *colon = strchr(data + i, ':');
 695                                char *slash = strchr(data + i, '/');
 696                                if (colon && slash && colon < data + posn &&
 697                                    slash < data + posn && colon < slash) {
 698                                        okay = 1;
 699                                }
 700                        }
 701                        // skip 'objects' at end
 702                        if (okay) {
 703                                target = xmalloc(serverlen + posn - i - 6);
 704                                strncpy(target, base, serverlen);
 705                                strncpy(target + serverlen, data + i,
 706                                        posn - i - 7);
 707                                target[serverlen + posn - i - 7] = '\0';
 708                                if (get_verbosely)
 709                                        fprintf(stderr, 
 710                                                "Also look at %s\n", target);
 711                                newalt = xmalloc(sizeof(*newalt));
 712                                newalt->next = NULL;
 713                                newalt->base = target;
 714                                newalt->got_indices = 0;
 715                                newalt->packs = NULL;
 716                                while (tail->next != NULL)
 717                                        tail = tail->next;
 718                                tail->next = newalt;
 719                                ret++;
 720                        }
 721                }
 722                i = posn + 1;
 723        }
 724        got_alternates = 1;
 725        
 726        return ret;
 727}
 728
 729static int fetch_indices(struct alt_base *repo)
 730{
 731        unsigned char sha1[20];
 732        char *url;
 733        struct buffer buffer;
 734        char *data;
 735        int i = 0;
 736
 737        struct active_request_slot *slot;
 738
 739        if (repo->got_indices)
 740                return 0;
 741
 742        data = xmalloc(4096);
 743        buffer.size = 4096;
 744        buffer.posn = 0;
 745        buffer.buffer = data;
 746
 747        if (get_verbosely)
 748                fprintf(stderr, "Getting pack list\n");
 749        
 750        url = xmalloc(strlen(repo->base) + 21);
 751        sprintf(url, "%s/objects/info/packs", repo->base);
 752
 753        slot = get_active_slot();
 754        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 755        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 756        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 757        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 758        if (start_active_slot(slot)) {
 759                run_active_slot(slot);
 760                if (slot->curl_result != CURLE_OK)
 761                        return error("%s", curl_errorstr);
 762        } else {
 763                return error("Unable to start request");
 764        }
 765
 766        while (i < buffer.posn) {
 767                switch (data[i]) {
 768                case 'P':
 769                        i++;
 770                        if (i + 52 < buffer.posn &&
 771                            !strncmp(data + i, " pack-", 6) &&
 772                            !strncmp(data + i + 46, ".pack\n", 6)) {
 773                                get_sha1_hex(data + i + 6, sha1);
 774                                setup_index(repo, sha1);
 775                                i += 51;
 776                                break;
 777                        }
 778                default:
 779                        while (data[i] != '\n')
 780                                i++;
 781                }
 782                i++;
 783        }
 784
 785        repo->got_indices = 1;
 786        return 0;
 787}
 788
 789static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 790{
 791        char *url;
 792        struct packed_git *target;
 793        struct packed_git **lst;
 794        FILE *packfile;
 795        char *filename;
 796        char tmpfile[PATH_MAX];
 797        int ret;
 798        long prev_posn = 0;
 799        char range[RANGE_HEADER_SIZE];
 800        struct curl_slist *range_header = NULL;
 801
 802        struct active_request_slot *slot;
 803
 804        if (fetch_indices(repo))
 805                return -1;
 806        target = find_sha1_pack(sha1, repo->packs);
 807        if (!target)
 808                return -1;
 809
 810        if (get_verbosely) {
 811                fprintf(stderr, "Getting pack %s\n",
 812                        sha1_to_hex(target->sha1));
 813                fprintf(stderr, " which contains %s\n",
 814                        sha1_to_hex(sha1));
 815        }
 816
 817        url = xmalloc(strlen(repo->base) + 65);
 818        sprintf(url, "%s/objects/pack/pack-%s.pack",
 819                repo->base, sha1_to_hex(target->sha1));
 820
 821        filename = sha1_pack_name(target->sha1);
 822        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 823        packfile = fopen(tmpfile, "a");
 824        if (!packfile)
 825                return error("Unable to open local file %s for pack",
 826                             filename);
 827
 828        slot = get_active_slot();
 829        curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
 830        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 831        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 832        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 833        slot->local = packfile;
 834
 835        /* If there is data present from a previous transfer attempt,
 836           resume where it left off */
 837        prev_posn = ftell(packfile);
 838        if (prev_posn>0) {
 839                if (get_verbosely)
 840                        fprintf(stderr,
 841                                "Resuming fetch of pack %s at byte %ld\n",
 842                                sha1_to_hex(target->sha1), prev_posn);
 843                sprintf(range, "Range: bytes=%ld-", prev_posn);
 844                range_header = curl_slist_append(range_header, range);
 845                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 846        }
 847
 848        if (start_active_slot(slot)) {
 849                run_active_slot(slot);
 850                if (slot->curl_result != CURLE_OK) {
 851                        fclose(packfile);
 852                        return error("Unable to get pack file %s\n%s", url,
 853                                     curl_errorstr);
 854                }
 855        } else {
 856                return error("Unable to start request");
 857        }
 858
 859        fclose(packfile);
 860
 861        ret = move_temp_to_file(tmpfile, filename);
 862        if (ret)
 863                return ret;
 864
 865        lst = &repo->packs;
 866        while (*lst != target)
 867                lst = &((*lst)->next);
 868        *lst = (*lst)->next;
 869
 870        if (verify_pack(target, 0))
 871                return -1;
 872        install_packed_git(target);
 873
 874        return 0;
 875}
 876
 877static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 878{
 879        char *hex = sha1_to_hex(sha1);
 880        int ret;
 881        struct transfer_request *request = request_queue_head;
 882
 883        while (request != NULL && memcmp(request->sha1, sha1, 20))
 884                request = request->next;
 885        if (request == NULL)
 886                return error("Couldn't find request for %s in the queue", hex);
 887
 888        if (has_sha1_file(request->sha1)) {
 889                release_request(request);
 890                return 0;
 891        }
 892
 893#ifdef USE_CURL_MULTI
 894        int num_transfers;
 895        while (request->state == WAITING) {
 896                curl_multi_perform(curlm, &num_transfers);
 897                if (num_transfers < active_requests) {
 898                        process_curl_messages();
 899                        process_request_queue();
 900                }
 901        }
 902#else
 903        start_request(request);
 904#endif
 905
 906        while (request->state == ACTIVE) {
 907                run_active_slot(request->slot);
 908#ifndef USE_CURL_MULTI
 909                request->curl_result = request->slot->curl_result;
 910                curl_easy_getinfo(request->slot->curl,
 911                                  CURLINFO_HTTP_CODE,
 912                                  &request->http_code);
 913                request->slot = NULL;
 914
 915                /* Use alternates if necessary */
 916                if (request->http_code == 404 &&
 917                    request->repo->next != NULL) {
 918                        request->repo = request->repo->next;
 919                        start_request(request);
 920                } else {
 921                        finish_request(request);
 922                        request->state = COMPLETE;
 923                }
 924#endif
 925        }
 926
 927        if (request->state == ABORTED) {
 928                release_request(request);
 929                return error("Request for %s aborted", hex);
 930        }
 931
 932        if (request->curl_result != CURLE_OK && request->http_code != 416) {
 933                ret = error("%s", request->errorstr);
 934                release_request(request);
 935                return ret;
 936        }
 937
 938        if (request->zret != Z_STREAM_END) {
 939                ret = error("File %s (%s) corrupt\n", hex, request->url);
 940                release_request(request);
 941                return ret;
 942        }
 943
 944        if (memcmp(request->sha1, request->real_sha1, 20)) {
 945                release_request(request);
 946                return error("File %s has bad hash\n", hex);
 947        }
 948
 949        if (request->rename < 0) {
 950                ret = error("unable to write sha1 filename %s: %s",
 951                            request->filename,
 952                            strerror(request->rename));
 953                release_request(request);
 954                return ret;
 955        }
 956
 957        release_request(request);
 958        return 0;
 959}
 960
 961int fetch(unsigned char *sha1)
 962{
 963        struct alt_base *altbase = alt;
 964
 965        if (!fetch_object(altbase, sha1))
 966                return 0;
 967        while (altbase) {
 968                if (!fetch_pack(altbase, sha1))
 969                        return 0;
 970                altbase = altbase->next;
 971        }
 972        return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
 973                     alt->base);
 974}
 975
 976int fetch_ref(char *ref, unsigned char *sha1)
 977{
 978        char *url, *posn;
 979        char hex[42];
 980        struct buffer buffer;
 981        char *base = alt->base;
 982        struct active_request_slot *slot;
 983        buffer.size = 41;
 984        buffer.posn = 0;
 985        buffer.buffer = hex;
 986        hex[41] = '\0';
 987        
 988        url = xmalloc(strlen(base) + 6 + strlen(ref));
 989        strcpy(url, base);
 990        posn = url + strlen(base);
 991        strcpy(posn, "refs/");
 992        posn += 5;
 993        strcpy(posn, ref);
 994
 995        slot = get_active_slot();
 996        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 997        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 998        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 999        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1000        if (start_active_slot(slot)) {
1001                run_active_slot(slot);
1002                if (slot->curl_result != CURLE_OK)
1003                        return error("Couldn't get %s for %s\n%s",
1004                                     url, ref, curl_errorstr);
1005        } else {
1006                return error("Unable to start request");
1007        }
1008
1009        hex[40] = '\0';
1010        get_sha1_hex(hex, sha1);
1011        return 0;
1012}
1013
1014int main(int argc, char **argv)
1015{
1016        char *commit_id;
1017        char *url;
1018        int arg = 1;
1019        struct active_request_slot *slot;
1020
1021        while (arg < argc && argv[arg][0] == '-') {
1022                if (argv[arg][1] == 't') {
1023                        get_tree = 1;
1024                } else if (argv[arg][1] == 'c') {
1025                        get_history = 1;
1026                } else if (argv[arg][1] == 'a') {
1027                        get_all = 1;
1028                        get_tree = 1;
1029                        get_history = 1;
1030                } else if (argv[arg][1] == 'v') {
1031                        get_verbosely = 1;
1032                } else if (argv[arg][1] == 'w') {
1033                        write_ref = argv[arg + 1];
1034                        arg++;
1035                } else if (!strcmp(argv[arg], "--recover")) {
1036                        get_recover = 1;
1037                }
1038                arg++;
1039        }
1040        if (argc < arg + 2) {
1041                usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
1042                return 1;
1043        }
1044        commit_id = argv[arg];
1045        url = argv[arg + 1];
1046
1047        curl_global_init(CURL_GLOBAL_ALL);
1048
1049#ifdef USE_CURL_MULTI
1050        char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1051        if (http_max_requests != NULL)
1052                max_requests = atoi(http_max_requests);
1053        if (max_requests < 1)
1054                max_requests = DEFAULT_MAX_REQUESTS;
1055
1056        curlm = curl_multi_init();
1057        if (curlm == NULL) {
1058                fprintf(stderr, "Error creating curl multi handle.\n");
1059                return 1;
1060        }
1061#endif
1062        pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
1063        no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1064        no_range_header = curl_slist_append(no_range_header, "Range:");
1065
1066        curl_default = curl_easy_init();
1067
1068        curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
1069        curl_easy_setopt(curl_default, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
1070#if LIBCURL_VERSION_NUM >= 0x070907
1071        curl_easy_setopt(curl_default, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
1072#endif
1073
1074        if ((ssl_cert = getenv("GIT_SSL_CERT")) != NULL) {
1075                curl_easy_setopt(curl_default, CURLOPT_SSLCERT, ssl_cert);
1076        }
1077#if LIBCURL_VERSION_NUM >= 0x070902
1078        if ((ssl_key = getenv("GIT_SSL_KEY")) != NULL) {
1079                curl_easy_setopt(curl_default, CURLOPT_SSLKEY, ssl_key);
1080        }
1081#endif
1082#if LIBCURL_VERSION_NUM >= 0x070908
1083        if ((ssl_capath = getenv("GIT_SSL_CAPATH")) != NULL) {
1084                curl_easy_setopt(curl_default, CURLOPT_CAPATH, ssl_capath);
1085        }
1086#endif
1087        if ((ssl_cainfo = getenv("GIT_SSL_CAINFO")) != NULL) {
1088                curl_easy_setopt(curl_default, CURLOPT_CAINFO, ssl_cainfo);
1089        }
1090        curl_easy_setopt(curl_default, CURLOPT_FAILONERROR, 1);
1091
1092        alt = xmalloc(sizeof(*alt));
1093        alt->base = url;
1094        alt->got_indices = 0;
1095        alt->packs = NULL;
1096        alt->next = NULL;
1097        fetch_alternates(alt->base);
1098
1099        if (pull(commit_id))
1100                return 1;
1101
1102        curl_slist_free_all(pragma_header);
1103        curl_slist_free_all(no_pragma_header);
1104        curl_slist_free_all(no_range_header);
1105        curl_easy_cleanup(curl_default);
1106        slot = active_queue_head;
1107        while (slot != NULL) {
1108                curl_easy_cleanup(slot->curl);
1109                slot = slot->next;
1110        }
1111#ifdef USE_CURL_MULTI
1112        curl_multi_cleanup(curlm);
1113#endif
1114        curl_global_cleanup();
1115        return 0;
1116}