diff options
Diffstat (limited to 'http-walker.c')
| -rw-r--r-- | http-walker.c | 591 |
1 files changed, 591 insertions, 0 deletions
diff --git a/http-walker.c b/http-walker.c new file mode 100644 index 0000000000..51a906e9e3 --- /dev/null +++ b/http-walker.c @@ -0,0 +1,591 @@ +#include "cache.h" +#include "commit.h" +#include "walker.h" +#include "http.h" + +struct alt_base { + char *base; + int got_indices; + struct packed_git *packs; + struct alt_base *next; +}; + +enum object_request_state { + WAITING, + ABORTED, + ACTIVE, + COMPLETE +}; + +struct object_request { + struct walker *walker; + unsigned char sha1[20]; + struct alt_base *repo; + enum object_request_state state; + struct http_object_request *req; + struct object_request *next; +}; + +struct alternates_request { + struct walker *walker; + const char *base; + char *url; + struct strbuf *buffer; + struct active_request_slot *slot; + int http_specific; +}; + +struct walker_data { + const char *url; + int got_alternates; + struct alt_base *alt; +}; + +static struct object_request *object_queue_head; + +static void fetch_alternates(struct walker *walker, const char *base); + +static void process_object_response(void *callback_data); + +static void start_object_request(struct walker *walker, + struct object_request *obj_req) +{ + struct active_request_slot *slot; + struct http_object_request *req; + + req = new_http_object_request(obj_req->repo->base, obj_req->sha1); + if (req == NULL) { + obj_req->state = ABORTED; + return; + } + obj_req->req = req; + + slot = req->slot; + slot->callback_func = process_object_response; + slot->callback_data = obj_req; + + /* Try to get the request started, abort the request on error */ + obj_req->state = ACTIVE; + if (!start_active_slot(slot)) { + obj_req->state = ABORTED; + release_http_object_request(req); + return; + } +} + +static void finish_object_request(struct object_request *obj_req) +{ + if (finish_http_object_request(obj_req->req)) + return; + + if (obj_req->req->rename == 0) + walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1)); +} + +static void process_object_response(void *callback_data) +{ + struct object_request *obj_req = + (struct object_request *)callback_data; + struct walker *walker = obj_req->walker; + struct walker_data *data = walker->data; + struct alt_base *alt = data->alt; + + process_http_object_request(obj_req->req); + obj_req->state = COMPLETE; + + /* Use alternates if necessary */ + if (missing_target(obj_req->req)) { + fetch_alternates(walker, alt->base); + if (obj_req->repo->next != NULL) { + obj_req->repo = + obj_req->repo->next; + release_http_object_request(obj_req->req); + start_object_request(walker, obj_req); + return; + } + } + + finish_object_request(obj_req); +} + +static void release_object_request(struct object_request *obj_req) +{ + struct object_request *entry = object_queue_head; + + if (obj_req->req !=NULL && obj_req->req->localfile != -1) + error("fd leakage in release: %d", obj_req->req->localfile); + if (obj_req == object_queue_head) { + object_queue_head = obj_req->next; + } else { + while (entry->next != NULL && entry->next != obj_req) + entry = entry->next; + if (entry->next == obj_req) + entry->next = entry->next->next; + } + + free(obj_req); +} + +#ifdef USE_CURL_MULTI +static int fill_active_slot(struct walker *walker) +{ + struct object_request *obj_req; + + for (obj_req = object_queue_head; obj_req; obj_req = obj_req->next) { + if (obj_req->state == WAITING) { + if (has_sha1_file(obj_req->sha1)) + obj_req->state = COMPLETE; + else { + start_object_request(walker, obj_req); + return 1; + } + } + } + return 0; +} +#endif + +static void prefetch(struct walker *walker, unsigned char *sha1) +{ + struct object_request *newreq; + struct object_request *tail; + struct walker_data *data = walker->data; + + newreq = xmalloc(sizeof(*newreq)); + newreq->walker = walker; + hashcpy(newreq->sha1, sha1); + newreq->repo = data->alt; + newreq->state = WAITING; + newreq->req = NULL; + newreq->next = NULL; + + http_is_verbose = walker->get_verbosely; + + if (object_queue_head == NULL) { + object_queue_head = newreq; + } else { + tail = object_queue_head; + while (tail->next != NULL) + tail = tail->next; + tail->next = newreq; + } + +#ifdef USE_CURL_MULTI + fill_active_slots(); + step_active_slots(); +#endif +} + +static void process_alternates_response(void *callback_data) +{ + struct alternates_request *alt_req = + (struct alternates_request *)callback_data; + struct walker *walker = alt_req->walker; + struct walker_data *cdata = walker->data; + struct active_request_slot *slot = alt_req->slot; + struct alt_base *tail = cdata->alt; + const char *base = alt_req->base; + const char null_byte = '\0'; + char *data; + int i = 0; + + if (alt_req->http_specific) { + if (slot->curl_result != CURLE_OK || + !alt_req->buffer->len) { + + /* Try reusing the slot to get non-http alternates */ + alt_req->http_specific = 0; + sprintf(alt_req->url, "%s/objects/info/alternates", + base); + curl_easy_setopt(slot->curl, CURLOPT_URL, + alt_req->url); + active_requests++; + slot->in_use = 1; + if (slot->finished != NULL) + (*slot->finished) = 0; + if (!start_active_slot(slot)) { + cdata->got_alternates = -1; + slot->in_use = 0; + if (slot->finished != NULL) + (*slot->finished) = 1; + } + return; + } + } else if (slot->curl_result != CURLE_OK) { + if (!missing_target(slot)) { + cdata->got_alternates = -1; + return; + } + } + + fwrite_buffer((char *)&null_byte, 1, 1, alt_req->buffer); + alt_req->buffer->len--; + data = alt_req->buffer->buf; + + while (i < alt_req->buffer->len) { + int posn = i; + while (posn < alt_req->buffer->len && data[posn] != '\n') + posn++; + if (data[posn] == '\n') { + int okay = 0; + int serverlen = 0; + struct alt_base *newalt; + char *target = NULL; + if (data[i] == '/') { + /* + * This counts + * http://git.host/pub/scm/linux.git/ + * -----------here^ + * so memcpy(dst, base, serverlen) will + * copy up to "...git.host". + */ + const char *colon_ss = strstr(base,"://"); + if (colon_ss) { + serverlen = (strchr(colon_ss + 3, '/') + - base); + okay = 1; + } + } else if (!memcmp(data + i, "../", 3)) { + /* + * Relative URL; chop the corresponding + * number of subpath from base (and ../ + * from data), and concatenate the result. + * + * The code first drops ../ from data, and + * then drops one ../ from data and one path + * from base. IOW, one extra ../ is dropped + * from data than path is dropped from base. + * + * This is not wrong. The alternate in + * http://git.host/pub/scm/linux.git/ + * to borrow from + * http://git.host/pub/scm/linus.git/ + * is ../../linus.git/objects/. You need + * two ../../ to borrow from your direct + * neighbour. + */ + 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 (alt_req->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\n" at end */ + if (okay) { + target = xmalloc(serverlen + posn - i - 6); + memcpy(target, base, serverlen); + memcpy(target + serverlen, data + i, + posn - i - 7); + target[serverlen + posn - i - 7] = 0; + if (walker->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; + } + } + i = posn + 1; + } + + cdata->got_alternates = 1; +} + +static void fetch_alternates(struct walker *walker, const char *base) +{ + struct strbuf buffer = STRBUF_INIT; + char *url; + struct active_request_slot *slot; + struct alternates_request alt_req; + struct walker_data *cdata = walker->data; + + /* + * If another request has already started fetching alternates, + * wait for them to arrive and return to processing this request's + * curl message + */ +#ifdef USE_CURL_MULTI + while (cdata->got_alternates == 0) { + step_active_slots(); + } +#endif + + /* Nothing to do if they've already been fetched */ + if (cdata->got_alternates == 1) + return; + + /* Start the fetch */ + cdata->got_alternates = 0; + + if (walker->get_verbosely) + fprintf(stderr, "Getting alternates list for %s\n", base); + + url = xmalloc(strlen(base) + 31); + sprintf(url, "%s/objects/info/http-alternates", base); + + /* + * Use a callback to process the result, since another request + * may fail and need to have alternates loaded before continuing + */ + slot = get_active_slot(); + slot->callback_func = process_alternates_response; + alt_req.walker = walker; + slot->callback_data = &alt_req; + + 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); + + alt_req.base = base; + alt_req.url = url; + alt_req.buffer = &buffer; + alt_req.http_specific = 1; + alt_req.slot = slot; + + if (start_active_slot(slot)) + run_active_slot(slot); + else + cdata->got_alternates = -1; + + strbuf_release(&buffer); + free(url); +} + +static int fetch_indices(struct walker *walker, struct alt_base *repo) +{ + int ret; + + if (repo->got_indices) + return 0; + + if (walker->get_verbosely) + fprintf(stderr, "Getting pack list for %s\n", repo->base); + + switch (http_get_info_packs(repo->base, &repo->packs)) { + case HTTP_OK: + case HTTP_MISSING_TARGET: + repo->got_indices = 1; + ret = 0; + break; + default: + repo->got_indices = 0; + ret = -1; + } + + return ret; +} + +static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1) +{ + struct packed_git *target; + int ret; + struct slot_results results; + struct http_pack_request *preq; + + if (fetch_indices(walker, repo)) + return -1; + target = find_sha1_pack(sha1, repo->packs); + if (!target) + return -1; + + if (walker->get_verbosely) { + fprintf(stderr, "Getting pack %s\n", + sha1_to_hex(target->sha1)); + fprintf(stderr, " which contains %s\n", + sha1_to_hex(sha1)); + } + + preq = new_http_pack_request(target, repo->base); + if (preq == NULL) + goto abort; + preq->lst = &repo->packs; + preq->slot->results = &results; + + if (start_active_slot(preq->slot)) { + run_active_slot(preq->slot); + if (results.curl_result != CURLE_OK) { + error("Unable to get pack file %s\n%s", preq->url, + curl_errorstr); + goto abort; + } + } else { + error("Unable to start request"); + goto abort; + } + + ret = finish_http_pack_request(preq); + release_http_pack_request(preq); + if (ret) + return ret; + + return 0; + +abort: + return -1; +} + +static void abort_object_request(struct object_request *obj_req) +{ + release_object_request(obj_req); +} + +static int fetch_object(struct walker *walker, struct alt_base *repo, unsigned char *sha1) +{ + char *hex = sha1_to_hex(sha1); + int ret = 0; + struct object_request *obj_req = object_queue_head; + struct http_object_request *req; + + while (obj_req != NULL && hashcmp(obj_req->sha1, sha1)) + obj_req = obj_req->next; + if (obj_req == NULL) + return error("Couldn't find request for %s in the queue", hex); + + if (has_sha1_file(obj_req->sha1)) { + if (obj_req->req != NULL) + abort_http_object_request(obj_req->req); + abort_object_request(obj_req); + return 0; + } + +#ifdef USE_CURL_MULTI + while (obj_req->state == WAITING) + step_active_slots(); +#else + start_object_request(walker, obj_req); +#endif + + /* + * obj_req->req might change when fetching alternates in the callback + * process_object_response; therefore, the "shortcut" variable, req, + * is used only after we're done with slots. + */ + while (obj_req->state == ACTIVE) + run_active_slot(obj_req->req->slot); + + req = obj_req->req; + + if (req->localfile != -1) { + close(req->localfile); + req->localfile = -1; + } + + if (obj_req->state == ABORTED) { + ret = error("Request for %s aborted", hex); + } else if (req->curl_result != CURLE_OK && + req->http_code != 416) { + if (missing_target(req)) + ret = -1; /* Be silent, it is probably in a pack. */ + else + ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)", + req->errorstr, req->curl_result, + req->http_code, hex); + } else if (req->zret != Z_STREAM_END) { + walker->corrupt_object_found++; + ret = error("File %s (%s) corrupt", hex, req->url); + } else if (hashcmp(obj_req->sha1, req->real_sha1)) { + ret = error("File %s has bad hash", hex); + } else if (req->rename < 0) { + ret = error("unable to write sha1 filename %s", + sha1_file_name(req->sha1)); + } + + release_http_object_request(req); + release_object_request(obj_req); + return ret; +} + +static int fetch(struct walker *walker, unsigned char *sha1) +{ + struct walker_data *data = walker->data; + struct alt_base *altbase = data->alt; + + if (!fetch_object(walker, altbase, sha1)) + return 0; + while (altbase) { + if (!fetch_pack(walker, altbase, sha1)) + return 0; + fetch_alternates(walker, data->alt->base); + altbase = altbase->next; + } + return error("Unable to find %s under %s", sha1_to_hex(sha1), + data->alt->base); +} + +static int fetch_ref(struct walker *walker, struct ref *ref) +{ + struct walker_data *data = walker->data; + return http_fetch_ref(data->alt->base, ref); +} + +static void cleanup(struct walker *walker) +{ + struct walker_data *data = walker->data; + struct alt_base *alt, *alt_next; + + if (data) { + alt = data->alt; + while (alt) { + alt_next = alt->next; + + free(alt->base); + free(alt); + + alt = alt_next; + } + free(data); + walker->data = NULL; + } +} + +struct walker *get_http_walker(const char *url) +{ + char *s; + struct walker_data *data = xmalloc(sizeof(struct walker_data)); + struct walker *walker = xmalloc(sizeof(struct walker)); + + data->alt = xmalloc(sizeof(*data->alt)); + data->alt->base = xmalloc(strlen(url) + 1); + strcpy(data->alt->base, url); + for (s = data->alt->base + strlen(data->alt->base) - 1; *s == '/'; --s) + *s = 0; + + data->alt->got_indices = 0; + data->alt->packs = NULL; + data->alt->next = NULL; + data->got_alternates = -1; + + walker->corrupt_object_found = 0; + walker->fetch = fetch; + walker->fetch_ref = fetch_ref; + walker->prefetch = prefetch; + walker->cleanup = cleanup; + walker->data = data; + +#ifdef USE_CURL_MULTI + add_fill_function(walker, (int (*)(void *)) fill_active_slot); +#endif + + return walker; +} |