fetch and pull: learn --progress
[gitweb.git] / http-fetch.c
index 5821c9e5e90e5951f760fbfad25544251c2ead28..ffd0ad7e295d7341776bb7b6407602cdb2997ef3 100644 (file)
 #include "cache.h"
-#include "commit.h"
-#include "pack.h"
-#include "fetch.h"
-
-#include <curl/curl.h>
-#include <curl/easy.h>
-
-#if LIBCURL_VERSION_NUM >= 0x070908
-#define USE_CURL_MULTI
-#define DEFAULT_MAX_REQUESTS 5
-#endif
-
-#if LIBCURL_VERSION_NUM < 0x070704
-#define curl_global_cleanup() do { /* nothing */ } while(0)
-#endif
-#if LIBCURL_VERSION_NUM < 0x070800
-#define curl_global_init(a) do { /* nothing */ } while(0)
-#endif
-
-#define PREV_BUF_SIZE 4096
-#define RANGE_HEADER_SIZE 30
-
-static int active_requests = 0;
-static int data_received;
-
-#ifdef USE_CURL_MULTI
-static int max_requests = DEFAULT_MAX_REQUESTS;
-static CURLM *curlm;
-#endif
-static CURL *curl_default;
-static struct curl_slist *pragma_header;
-static struct curl_slist *no_pragma_header;
-static struct curl_slist *no_range_header;
-static char curl_errorstr[CURL_ERROR_SIZE];
-
-struct alt_base
-{
-       char *base;
-       int got_indices;
-       struct packed_git *packs;
-       struct alt_base *next;
-};
-
-static struct alt_base *alt = NULL;
-
-enum transfer_state {
-       WAITING,
-       ABORTED,
-       ACTIVE,
-       COMPLETE,
-};
-
-struct transfer_request
-{
-       unsigned char sha1[20];
-       struct alt_base *repo;
-       char *url;
-       char filename[PATH_MAX];
-       char tmpfile[PATH_MAX];
-       int local;
-       enum transfer_state state;
-       CURLcode curl_result;
-       char errorstr[CURL_ERROR_SIZE];
-       long http_code;
-       unsigned char real_sha1[20];
-       SHA_CTX c;
-       z_stream stream;
-       int zret;
-       int rename;
-       struct active_request_slot *slot;
-       struct transfer_request *next;
-};
-
-struct active_request_slot
-{
-       CURL *curl;
-       FILE *local;
-       int in_use;
-       int done;
-       CURLcode curl_result;
-       struct active_request_slot *next;
-};
-
-static struct transfer_request *request_queue_head = NULL;
-static struct active_request_slot *active_queue_head = NULL;
-
-static int curl_ssl_verify;
-static char *ssl_cert;
-static char *ssl_key;
-static char *ssl_capath;
-static char *ssl_cainfo;
-
-struct buffer
-{
-        size_t posn;
-        size_t size;
-        void *buffer;
-};
-
-static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
-                            struct buffer *buffer)
-{
-        size_t size = eltsize * nmemb;
-        if (size > buffer->size - buffer->posn)
-                size = buffer->size - buffer->posn;
-        memcpy(buffer->buffer + buffer->posn, ptr, size);
-        buffer->posn += size;
-       data_received++;
-        return size;
-}
-
-static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
-                              void *data)
-{
-       unsigned char expn[4096];
-       size_t size = eltsize * nmemb;
-       int posn = 0;
-       struct transfer_request *request = (struct transfer_request *)data;
-       do {
-               ssize_t retval = write(request->local,
-                                      ptr + posn, size - posn);
-               if (retval < 0)
-                       return posn;
-               posn += retval;
-       } while (posn < size);
-
-       request->stream.avail_in = size;
-       request->stream.next_in = ptr;
-       do {
-               request->stream.next_out = expn;
-               request->stream.avail_out = sizeof(expn);
-               request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
-               SHA1_Update(&request->c, expn,
-                           sizeof(expn) - request->stream.avail_out);
-       } while (request->stream.avail_in && request->zret == Z_OK);
-       data_received++;
-       return size;
-}
-
-#ifdef USE_CURL_MULTI
-void process_curl_messages();
-void process_request_queue();
-#endif
-
-struct active_request_slot *get_active_slot()
-{
-       struct active_request_slot *slot = active_queue_head;
-       struct active_request_slot *newslot;
-
-#ifdef USE_CURL_MULTI
-       int num_transfers;
-
-       /* Wait for a slot to open up if the queue is full */
-       while (active_requests >= max_requests) {
-               curl_multi_perform(curlm, &num_transfers);
-               if (num_transfers < active_requests) {
-                       process_curl_messages();
-               }
-       }
-#endif
-
-       while (slot != NULL && slot->in_use) {
-               slot = slot->next;
-       }
-       if (slot == NULL) {
-               newslot = xmalloc(sizeof(*newslot));
-               newslot->curl = curl_easy_duphandle(curl_default);
-               newslot->in_use = 0;
-               newslot->next = NULL;
-
-               slot = active_queue_head;
-               if (slot == NULL) {
-                       active_queue_head = newslot;
-               } else {
-                       while (slot->next != NULL) {
-                               slot = slot->next;
-                       }
-                       slot->next = newslot;
-               }
-               slot = newslot;
-       }
-
-       active_requests++;
-       slot->in_use = 1;
-       slot->done = 0;
-       slot->local = NULL;
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
-       curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-
-       return slot;
-}
-
-int start_active_slot(struct active_request_slot *slot)
-{
-#ifdef USE_CURL_MULTI
-       CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
-
-       if (curlm_result != CURLM_OK &&
-           curlm_result != CURLM_CALL_MULTI_PERFORM) {
-               active_requests--;
-               slot->in_use = 0;
-               return 0;
-       }
-#endif
-       return 1;
-}
-
-void run_active_slot(struct active_request_slot *slot)
-{
-#ifdef USE_CURL_MULTI
-       int num_transfers;
-       long last_pos = 0;
-       long current_pos;
-       fd_set readfds;
-       fd_set writefds;
-       fd_set excfds;
-       int max_fd;
-       struct timeval select_timeout;
-       CURLMcode curlm_result;
-
-       while (!slot->done) {
-               data_received = 0;
-               do {
-                       curlm_result = curl_multi_perform(curlm,
-                                                         &num_transfers);
-               } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
-               if (num_transfers < active_requests) {
-                       process_curl_messages();
-                       process_request_queue();
-               }
-
-               if (!data_received && slot->local != NULL) {
-                       current_pos = ftell(slot->local);
-                       if (current_pos > last_pos)
-                               data_received++;
-                       last_pos = current_pos;
-               }
-
-               if (!slot->done && !data_received) {
-                       max_fd = 0;
-                       FD_ZERO(&readfds);
-                       FD_ZERO(&writefds);
-                       FD_ZERO(&excfds);
-                       select_timeout.tv_sec = 0;
-                       select_timeout.tv_usec = 50000;
-                       select(max_fd, &readfds, &writefds,
-                              &excfds, &select_timeout);
-               }
-       }
-#else
-       slot->curl_result = curl_easy_perform(slot->curl);
-       active_requests--;
-#endif
-}
-
-void start_request(struct transfer_request *request)
-{
-       char *hex = sha1_to_hex(request->sha1);
-       char prevfile[PATH_MAX];
-       char *url;
-       char *posn;
-       int prevlocal;
-       unsigned char prev_buf[PREV_BUF_SIZE];
-       ssize_t prev_read = 0;
-       long prev_posn = 0;
-       char range[RANGE_HEADER_SIZE];
-       struct curl_slist *range_header = NULL;
-       struct active_request_slot *slot;
-
-       snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
-       unlink(prevfile);
-       rename(request->tmpfile, prevfile);
-       unlink(request->tmpfile);
-
-       request->local = open(request->tmpfile,
-                             O_WRONLY | O_CREAT | O_EXCL, 0666);
-       /* This could have failed due to the "lazy directory creation";
-        * try to mkdir the last path component.
-        */
-       if (request->local < 0 && errno == ENOENT) {
-               char *dir = strrchr(request->tmpfile, '/');
-               if (dir) {
-                       *dir = 0;
-                       mkdir(request->tmpfile, 0777);
-                       *dir = '/';
-               }
-               request->local = open(request->tmpfile,
-                                     O_WRONLY | O_CREAT | O_EXCL, 0666);
-       }
-
-       if (request->local < 0) {
-               request->state = ABORTED;
-               error("Couldn't create temporary file %s for %s: %s\n",
-                     request->tmpfile, request->filename, strerror(errno));
-               return;
-       }
-
-       memset(&request->stream, 0, sizeof(request->stream));
-
-       inflateInit(&request->stream);
-
-       SHA1_Init(&request->c);
-
-       url = xmalloc(strlen(request->repo->base) + 50);
-       request->url = xmalloc(strlen(request->repo->base) + 50);
-       strcpy(url, request->repo->base);
-       posn = url + strlen(request->repo->base);
-       strcpy(posn, "objects/");
-       posn += 8;
-       memcpy(posn, hex, 2);
-       posn += 2;
-       *(posn++) = '/';
-       strcpy(posn, hex + 2);
-       strcpy(request->url, url);
-
-       /* If a previous temp file is present, process what was already
-          fetched. */
-       prevlocal = open(prevfile, O_RDONLY);
-       if (prevlocal != -1) {
-               do {
-                       prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
-                       if (prev_read>0) {
-                               if (fwrite_sha1_file(prev_buf,
-                                                    1,
-                                                    prev_read,
-                                                    request) == prev_read) {
-                                       prev_posn += prev_read;
-                               } else {
-                                       prev_read = -1;
-                               }
-                       }
-               } while (prev_read > 0);
-               close(prevlocal);
-       }
-       unlink(prevfile);
-
-       /* Reset inflate/SHA1 if there was an error reading the previous temp
-          file; also rewind to the beginning of the local file. */
-       if (prev_read == -1) {
-               memset(&request->stream, 0, sizeof(request->stream));
-               inflateInit(&request->stream);
-               SHA1_Init(&request->c);
-               if (prev_posn>0) {
-                       prev_posn = 0;
-                       lseek(request->local, SEEK_SET, 0);
-                       ftruncate(request->local, 0);
-               }
-       }
-
-       slot = get_active_slot();
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
-       curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
-
-       /* If we have successfully processed data from a previous fetch
-          attempt, only fetch the data we don't already have. */
-       if (prev_posn>0) {
-               if (get_verbosely)
-                       fprintf(stderr,
-                               "Resuming fetch of object %s at byte %ld\n",
-                               hex, prev_posn);
-               sprintf(range, "Range: bytes=%ld-", prev_posn);
-               range_header = curl_slist_append(range_header, range);
-               curl_easy_setopt(slot->curl,
-                                CURLOPT_HTTPHEADER, range_header);
-       }
-
-       /* Try to get the request started, abort the request on error */
-       if (!start_active_slot(slot)) {
-               request->state = ABORTED;
-               close(request->local);
-               free(request->url);
-               return;
-       }
-       
-       request->slot = slot;
-       request->state = ACTIVE;
-}
-
-void finish_request(struct transfer_request *request)
-{
-       fchmod(request->local, 0444);
-       close(request->local);
-
-       if (request->http_code == 416) {
-               fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
-       } else if (request->curl_result != CURLE_OK) {
-               return;
-       }
-
-       inflateEnd(&request->stream);
-       SHA1_Final(request->real_sha1, &request->c);
-       if (request->zret != Z_STREAM_END) {
-               unlink(request->tmpfile);
-               return;
-       }
-       if (memcmp(request->sha1, request->real_sha1, 20)) {
-               unlink(request->tmpfile);
-               return;
-       }
-       request->rename =
-               move_temp_to_file(request->tmpfile, request->filename);
-
-       if (request->rename == 0)
-               pull_say("got %s\n", sha1_to_hex(request->sha1));
-}
-
-void release_request(struct transfer_request *request)
-{
-       struct transfer_request *entry = request_queue_head;
-
-       if (request == request_queue_head) {
-               request_queue_head = request->next;
-       } else {
-               while (entry->next != NULL && entry->next != request)
-                       entry = entry->next;
-               if (entry->next == request)
-                       entry->next = entry->next->next;
-       }
-
-       free(request->url);
-       free(request);
-}
-
-#ifdef USE_CURL_MULTI
-void process_curl_messages()
-{
-       int num_messages;
-       struct active_request_slot *slot;
-       struct transfer_request *request = NULL;
-       CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
-
-       while (curl_message != NULL) {
-               if (curl_message->msg == CURLMSG_DONE) {
-                       slot = active_queue_head;
-                       while (slot != NULL &&
-                              slot->curl != curl_message->easy_handle)
-                               slot = slot->next;
-                       if (slot != NULL) {
-                               curl_multi_remove_handle(curlm, slot->curl);
-                               active_requests--;
-                               slot->done = 1;
-                               slot->in_use = 0;
-                               slot->curl_result = curl_message->data.result;
-                               request = request_queue_head;
-                               while (request != NULL &&
-                                      request->slot != slot)
-                                       request = request->next;
-                       } else {
-                               fprintf(stderr, "Received DONE message for unknown request!\n");
-                       }
-                       if (request != NULL) {
-                               request->curl_result =
-                                       curl_message->data.result;
-                               curl_easy_getinfo(slot->curl,
-                                                 CURLINFO_HTTP_CODE,
-                                                 &request->http_code);
-                               request->slot = NULL;
-
-                               /* Use alternates if necessary */
-                               if (request->http_code == 404 &&
-                                   request->repo->next != NULL) {
-                                       request->repo = request->repo->next;
-                                       start_request(request);
-                               } else {
-                                       finish_request(request);
-                                       request->state = COMPLETE;
-                               }
-                       }
-               } else {
-                       fprintf(stderr, "Unknown CURL message received: %d\n",
-                               (int)curl_message->msg);
-               }
-               curl_message = curl_multi_info_read(curlm, &num_messages);
-       }
-}
-
-void process_request_queue()
-{
-       struct transfer_request *request = request_queue_head;
-       int num_transfers;
-
-       while (active_requests < max_requests && request != NULL) {
-               if (request->state == WAITING) {
-                       if (has_sha1_file(request->sha1))
-                               release_request(request);
-                       else
-                               start_request(request);
-                       curl_multi_perform(curlm, &num_transfers);
-               }
-               request = request->next;
-       }
-}
-#endif
-
-void prefetch(unsigned char *sha1)
-{
-       struct transfer_request *newreq;
-       struct transfer_request *tail;
-       char *filename = sha1_file_name(sha1);
-
-       newreq = xmalloc(sizeof(*newreq));
-       memcpy(newreq->sha1, sha1, 20);
-       newreq->repo = alt;
-       newreq->url = NULL;
-       newreq->local = -1;
-       newreq->state = WAITING;
-       snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
-       snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
-                "%s.temp", filename);
-       newreq->next = NULL;
-
-       if (request_queue_head == NULL) {
-               request_queue_head = newreq;
-       } else {
-               tail = request_queue_head;
-               while (tail->next != NULL) {
-                       tail = tail->next;
-               }
-               tail->next = newreq;
-       }
-#ifdef USE_CURL_MULTI
-       process_request_queue();
-       process_curl_messages();
-#endif
-}
-
-static int got_alternates = 0;
-
-static int fetch_index(struct alt_base *repo, unsigned char *sha1)
-{
-       char *hex = sha1_to_hex(sha1);
-       char *filename;
-       char *url;
-       char tmpfile[PATH_MAX];
-       long prev_posn = 0;
-       char range[RANGE_HEADER_SIZE];
-       struct curl_slist *range_header = NULL;
-
-       FILE *indexfile;
-       struct active_request_slot *slot;
-
-       if (has_pack_index(sha1))
-               return 0;
-
-       if (get_verbosely)
-               fprintf(stderr, "Getting index for pack %s\n", hex);
-       
-       url = xmalloc(strlen(repo->base) + 64);
-       sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
-       
-       filename = sha1_pack_index_name(sha1);
-       snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-       indexfile = fopen(tmpfile, "a");
-       if (!indexfile)
-               return error("Unable to open local file %s for pack index",
-                            filename);
-
-       slot = get_active_slot();
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
-       slot->local = indexfile;
-
-       /* If there is data present from a previous transfer attempt,
-          resume where it left off */
-       prev_posn = ftell(indexfile);
-       if (prev_posn>0) {
-               if (get_verbosely)
-                       fprintf(stderr,
-                               "Resuming fetch of index for pack %s at byte %ld\n",
-                               hex, prev_posn);
-               sprintf(range, "Range: bytes=%ld-", prev_posn);
-               range_header = curl_slist_append(range_header, range);
-               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
-       }
-
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (slot->curl_result != CURLE_OK) {
-                       fclose(indexfile);
-                       return error("Unable to get pack index %s\n%s", url,
-                                    curl_errorstr);
-               }
-       } else {
-               return error("Unable to start request");
-       }
-
-       fclose(indexfile);
-
-       return move_temp_to_file(tmpfile, filename);
-}
-
-static int setup_index(struct alt_base *repo, unsigned char *sha1)
-{
-       struct packed_git *new_pack;
-       if (has_pack_file(sha1))
-               return 0; // don't list this as something we can get
-
-       if (fetch_index(repo, sha1))
-               return -1;
-
-       new_pack = parse_pack_index(sha1);
-       new_pack->next = repo->packs;
-       repo->packs = new_pack;
-       return 0;
-}
-
-static int fetch_alternates(char *base)
-{
-       int ret = 0;
-       struct buffer buffer;
-       char *url;
-       char *data;
-       int i = 0;
-       int http_specific = 1;
-       struct alt_base *tail = alt;
-
-       struct active_request_slot *slot;
-       if (got_alternates)
-               return 0;
-       data = xmalloc(4096);
-       buffer.size = 4095;
-       buffer.posn = 0;
-       buffer.buffer = data;
-
-       if (get_verbosely)
-               fprintf(stderr, "Getting alternates list\n");
-       
-       url = xmalloc(strlen(base) + 31);
-       sprintf(url, "%s/objects/info/http-alternates", base);
-
-       slot = get_active_slot();
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (slot->curl_result != CURLE_OK || !buffer.posn) {
-                       http_specific = 0;
-
-                       sprintf(url, "%s/objects/info/alternates", base);
-
-                       slot = get_active_slot();
-                       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-                       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
-                                        fwrite_buffer);
-                       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-                       if (start_active_slot(slot)) {
-                               run_active_slot(slot);
-                               if (slot->curl_result != CURLE_OK) {
-                                       return 0;
-                               }
-                       }
-               }
-       } else {
-               return 0;
-       }
-
-       data[buffer.posn] = '\0';
-
-       while (i < buffer.posn) {
-               int posn = i;
-               while (posn < buffer.posn && data[posn] != '\n')
-                       posn++;
-               if (data[posn] == '\n') {
-                       int okay = 0;
-                       int serverlen = 0;
-                       struct alt_base *newalt;
-                       char *target = NULL;
-                       if (data[i] == '/') {
-                               serverlen = strchr(base + 8, '/') - base;
-                               okay = 1;
-                       } else if (!memcmp(data + i, "../", 3)) {
-                               i += 3;
-                               serverlen = strlen(base);
-                               while (i + 2 < posn && 
-                                      !memcmp(data + i, "../", 3)) {
-                                       do {
-                                               serverlen--;
-                                       } while (serverlen &&
-                                                base[serverlen - 1] != '/');
-                                       i += 3;
-                               }
-                               // If the server got removed, give up.
-                               okay = strchr(base, ':') - base + 3 < 
-                                       serverlen;
-                       } else if (http_specific) {
-                               char *colon = strchr(data + i, ':');
-                               char *slash = strchr(data + i, '/');
-                               if (colon && slash && colon < data + posn &&
-                                   slash < data + posn && colon < slash) {
-                                       okay = 1;
-                               }
-                       }
-                       // skip 'objects' at end
-                       if (okay) {
-                               target = xmalloc(serverlen + posn - i - 6);
-                               strncpy(target, base, serverlen);
-                               strncpy(target + serverlen, data + i,
-                                       posn - i - 7);
-                               target[serverlen + posn - i - 7] = '\0';
-                               if (get_verbosely)
-                                       fprintf(stderr, 
-                                               "Also look at %s\n", target);
-                               newalt = xmalloc(sizeof(*newalt));
-                               newalt->next = NULL;
-                               newalt->base = target;
-                               newalt->got_indices = 0;
-                               newalt->packs = NULL;
-                               while (tail->next != NULL)
-                                       tail = tail->next;
-                               tail->next = newalt;
-                               ret++;
-                       }
-               }
-               i = posn + 1;
-       }
-       got_alternates = 1;
-       
-       return ret;
-}
-
-static int fetch_indices(struct alt_base *repo)
-{
-       unsigned char sha1[20];
-       char *url;
-       struct buffer buffer;
-       char *data;
-       int i = 0;
-
-       struct active_request_slot *slot;
-
-       if (repo->got_indices)
-               return 0;
-
-       data = xmalloc(4096);
-       buffer.size = 4096;
-       buffer.posn = 0;
-       buffer.buffer = data;
-
-       if (get_verbosely)
-               fprintf(stderr, "Getting pack list\n");
-       
-       url = xmalloc(strlen(repo->base) + 21);
-       sprintf(url, "%s/objects/info/packs", repo->base);
-
-       slot = get_active_slot();
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (slot->curl_result != CURLE_OK)
-                       return error("%s", curl_errorstr);
-       } else {
-               return error("Unable to start request");
-       }
-
-       while (i < buffer.posn) {
-               switch (data[i]) {
-               case 'P':
-                       i++;
-                       if (i + 52 < buffer.posn &&
-                           !strncmp(data + i, " pack-", 6) &&
-                           !strncmp(data + i + 46, ".pack\n", 6)) {
-                               get_sha1_hex(data + i + 6, sha1);
-                               setup_index(repo, sha1);
-                               i += 51;
-                               break;
-                       }
-               default:
-                       while (data[i] != '\n')
-                               i++;
-               }
-               i++;
-       }
-
-       repo->got_indices = 1;
-       return 0;
-}
-
-static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
-{
-       char *url;
-       struct packed_git *target;
-       struct packed_git **lst;
-       FILE *packfile;
-       char *filename;
-       char tmpfile[PATH_MAX];
-       int ret;
-       long prev_posn = 0;
-       char range[RANGE_HEADER_SIZE];
-       struct curl_slist *range_header = NULL;
-
-       struct active_request_slot *slot;
-
-       if (fetch_indices(repo))
-               return -1;
-       target = find_sha1_pack(sha1, repo->packs);
-       if (!target)
-               return -1;
-
-       if (get_verbosely) {
-               fprintf(stderr, "Getting pack %s\n",
-                       sha1_to_hex(target->sha1));
-               fprintf(stderr, " which contains %s\n",
-                       sha1_to_hex(sha1));
-       }
-
-       url = xmalloc(strlen(repo->base) + 65);
-       sprintf(url, "%s/objects/pack/pack-%s.pack",
-               repo->base, sha1_to_hex(target->sha1));
-
-       filename = sha1_pack_name(target->sha1);
-       snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-       packfile = fopen(tmpfile, "a");
-       if (!packfile)
-               return error("Unable to open local file %s for pack",
-                            filename);
-
-       slot = get_active_slot();
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
-       slot->local = packfile;
-
-       /* If there is data present from a previous transfer attempt,
-          resume where it left off */
-       prev_posn = ftell(packfile);
-       if (prev_posn>0) {
-               if (get_verbosely)
-                       fprintf(stderr,
-                               "Resuming fetch of pack %s at byte %ld\n",
-                               sha1_to_hex(target->sha1), prev_posn);
-               sprintf(range, "Range: bytes=%ld-", prev_posn);
-               range_header = curl_slist_append(range_header, range);
-               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
-       }
-
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (slot->curl_result != CURLE_OK) {
-                       fclose(packfile);
-                       return error("Unable to get pack file %s\n%s", url,
-                                    curl_errorstr);
-               }
-       } else {
-               return error("Unable to start request");
-       }
-
-       fclose(packfile);
-
-       ret = move_temp_to_file(tmpfile, filename);
-       if (ret)
-               return ret;
-
-       lst = &repo->packs;
-       while (*lst != target)
-               lst = &((*lst)->next);
-       *lst = (*lst)->next;
-
-       if (verify_pack(target, 0))
-               return -1;
-       install_packed_git(target);
-
-       return 0;
-}
-
-static int fetch_object(struct alt_base *repo, unsigned char *sha1)
-{
-       char *hex = sha1_to_hex(sha1);
-       int ret;
-       struct transfer_request *request = request_queue_head;
-
-       while (request != NULL && memcmp(request->sha1, sha1, 20))
-               request = request->next;
-       if (request == NULL)
-               return error("Couldn't find request for %s in the queue", hex);
-
-       if (has_sha1_file(request->sha1)) {
-               release_request(request);
-               return 0;
-       }
-
-#ifdef USE_CURL_MULTI
-       int num_transfers;
-       while (request->state == WAITING) {
-               curl_multi_perform(curlm, &num_transfers);
-               if (num_transfers < active_requests) {
-                       process_curl_messages();
-                       process_request_queue();
-               }
-       }
-#else
-       start_request(request);
-#endif
-
-       while (request->state == ACTIVE) {
-               run_active_slot(request->slot);
-#ifndef USE_CURL_MULTI
-               request->curl_result = request->slot->curl_result;
-               curl_easy_getinfo(request->slot->curl,
-                                 CURLINFO_HTTP_CODE,
-                                 &request->http_code);
-               request->slot = NULL;
-
-               /* Use alternates if necessary */
-               if (request->http_code == 404 &&
-                   request->repo->next != NULL) {
-                       request->repo = request->repo->next;
-                       start_request(request);
-               } else {
-                       finish_request(request);
-                       request->state = COMPLETE;
-               }
-#endif
-       }
-
-       if (request->state == ABORTED) {
-               release_request(request);
-               return error("Request for %s aborted", hex);
-       }
-
-       if (request->curl_result != CURLE_OK && request->http_code != 416) {
-               ret = error("%s", request->errorstr);
-               release_request(request);
-               return ret;
-       }
-
-       if (request->zret != Z_STREAM_END) {
-               ret = error("File %s (%s) corrupt\n", hex, request->url);
-               release_request(request);
-               return ret;
-       }
-
-       if (memcmp(request->sha1, request->real_sha1, 20)) {
-               release_request(request);
-               return error("File %s has bad hash\n", hex);
-       }
-
-       if (request->rename < 0) {
-               ret = error("unable to write sha1 filename %s: %s",
-                           request->filename,
-                           strerror(request->rename));
-               release_request(request);
-               return ret;
-       }
-
-       release_request(request);
-       return 0;
-}
-
-int fetch(unsigned char *sha1)
-{
-       struct alt_base *altbase = alt;
-
-       if (!fetch_object(altbase, sha1))
-               return 0;
-       while (altbase) {
-               if (!fetch_pack(altbase, sha1))
-                       return 0;
-               altbase = altbase->next;
-       }
-       return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
-                    alt->base);
-}
-
-int fetch_ref(char *ref, unsigned char *sha1)
-{
-        char *url, *posn;
-        char hex[42];
-        struct buffer buffer;
-       char *base = alt->base;
-       struct active_request_slot *slot;
-        buffer.size = 41;
-        buffer.posn = 0;
-        buffer.buffer = hex;
-        hex[41] = '\0';
-        
-        url = xmalloc(strlen(base) + 6 + strlen(ref));
-        strcpy(url, base);
-        posn = url + strlen(base);
-        strcpy(posn, "refs/");
-        posn += 5;
-        strcpy(posn, ref);
-
-       slot = get_active_slot();
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (slot->curl_result != CURLE_OK)
-                       return error("Couldn't get %s for %s\n%s",
-                                    url, ref, curl_errorstr);
-       } else {
-               return error("Unable to start request");
-       }
-
-        hex[40] = '\0';
-        get_sha1_hex(hex, sha1);
-        return 0;
-}
-
-int main(int argc, char **argv)
-{
-       char *commit_id;
-       char *url;
+#include "exec_cmd.h"
+#include "walker.h"
+
+static const char http_fetch_usage[] = "git http-fetch "
+"[-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin] commit-id url";
+
+int main(int argc, const char **argv)
+{
+       const char *prefix;
+       struct walker *walker;
+       int commits_on_stdin = 0;
+       int commits;
+       const char **write_ref = NULL;
+       char **commit_id;
+       const char *url;
+       char *rewritten_url = NULL;
        int arg = 1;
-       struct active_request_slot *slot;
+       int rc = 0;
+       int get_tree = 0;
+       int get_history = 0;
+       int get_all = 0;
+       int get_verbosely = 0;
+       int get_recover = 0;
+
+       git_extract_argv0_path(argv[0]);
 
        while (arg < argc && argv[arg][0] == '-') {
                if (argv[arg][1] == 't') {
@@ -1030,87 +37,60 @@ int main(int argc, char **argv)
                } else if (argv[arg][1] == 'v') {
                        get_verbosely = 1;
                } else if (argv[arg][1] == 'w') {
-                       write_ref = argv[arg + 1];
+                       write_ref = &argv[arg + 1];
                        arg++;
+               } else if (argv[arg][1] == 'h') {
+                       usage(http_fetch_usage);
                } else if (!strcmp(argv[arg], "--recover")) {
                        get_recover = 1;
+               } else if (!strcmp(argv[arg], "--stdin")) {
+                       commits_on_stdin = 1;
                }
                arg++;
        }
-       if (argc < arg + 2) {
-               usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
-               return 1;
+       if (argc != arg + 2 - commits_on_stdin)
+               usage(http_fetch_usage);
+       if (commits_on_stdin) {
+               commits = walker_targets_stdin(&commit_id, &write_ref);
+       } else {
+               commit_id = (char **) &argv[arg++];
+               commits = 1;
        }
-       commit_id = argv[arg];
-       url = argv[arg + 1];
+       url = argv[arg];
 
-       curl_global_init(CURL_GLOBAL_ALL);
+       prefix = setup_git_directory();
 
-#ifdef USE_CURL_MULTI
-       char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
-       if (http_max_requests != NULL)
-               max_requests = atoi(http_max_requests);
-       if (max_requests < 1)
-               max_requests = DEFAULT_MAX_REQUESTS;
+       git_config(git_default_config, NULL);
 
-       curlm = curl_multi_init();
-       if (curlm == NULL) {
-               fprintf(stderr, "Error creating curl multi handle.\n");
-               return 1;
+       if (url && url[strlen(url)-1] != '/') {
+               rewritten_url = xmalloc(strlen(url)+2);
+               strcpy(rewritten_url, url);
+               strcat(rewritten_url, "/");
+               url = rewritten_url;
        }
-#endif
-       pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
-       no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
-       no_range_header = curl_slist_append(no_range_header, "Range:");
 
-       curl_default = curl_easy_init();
+       walker = get_http_walker(url, NULL);
+       walker->get_tree = get_tree;
+       walker->get_history = get_history;
+       walker->get_all = get_all;
+       walker->get_verbosely = get_verbosely;
+       walker->get_recover = get_recover;
 
-       curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
-       curl_easy_setopt(curl_default, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
-#if LIBCURL_VERSION_NUM >= 0x070907
-       curl_easy_setopt(curl_default, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
-#endif
+       rc = walker_fetch(walker, commits, commit_id, write_ref, url);
 
-       if ((ssl_cert = getenv("GIT_SSL_CERT")) != NULL) {
-               curl_easy_setopt(curl_default, CURLOPT_SSLCERT, ssl_cert);
-       }
-#if LIBCURL_VERSION_NUM >= 0x070902
-       if ((ssl_key = getenv("GIT_SSL_KEY")) != NULL) {
-               curl_easy_setopt(curl_default, CURLOPT_SSLKEY, ssl_key);
-       }
-#endif
-#if LIBCURL_VERSION_NUM >= 0x070908
-       if ((ssl_capath = getenv("GIT_SSL_CAPATH")) != NULL) {
-               curl_easy_setopt(curl_default, CURLOPT_CAPATH, ssl_capath);
-       }
-#endif
-       if ((ssl_cainfo = getenv("GIT_SSL_CAINFO")) != NULL) {
-               curl_easy_setopt(curl_default, CURLOPT_CAINFO, ssl_cainfo);
+       if (commits_on_stdin)
+               walker_targets_free(commits, commit_id, write_ref);
+
+       if (walker->corrupt_object_found) {
+               fprintf(stderr,
+"Some loose object were found to be corrupt, but they might be just\n"
+"a false '404 Not Found' error message sent with incorrect HTTP\n"
+"status code.  Suggest running 'git fsck'.\n");
        }
-       curl_easy_setopt(curl_default, CURLOPT_FAILONERROR, 1);
 
-       alt = xmalloc(sizeof(*alt));
-       alt->base = url;
-       alt->got_indices = 0;
-       alt->packs = NULL;
-       alt->next = NULL;
-       fetch_alternates(alt->base);
+       walker_free(walker);
 
-       if (pull(commit_id))
-               return 1;
+       free(rewritten_url);
 
-       curl_slist_free_all(pragma_header);
-       curl_slist_free_all(no_pragma_header);
-       curl_slist_free_all(no_range_header);
-       curl_easy_cleanup(curl_default);
-       slot = active_queue_head;
-       while (slot != NULL) {
-               curl_easy_cleanup(slot->curl);
-               slot = slot->next;
-       }
-#ifdef USE_CURL_MULTI
-       curl_multi_cleanup(curlm);
-#endif
-       curl_global_cleanup();
-       return 0;
+       return rc;
 }