summaryrefslogtreecommitdiff
path: root/http-walker.c
diff options
context:
space:
mode:
Diffstat (limited to 'http-walker.c')
-rw-r--r--http-walker.c591
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;
+}