From acc075a8ad5ee798c170fc2276e1c840a03b5fa4 Mon Sep 17 00:00:00 2001 From: Nick Hengeveld Date: Sat, 12 Nov 2005 09:11:32 -0800 Subject: [PATCH] Fix for multiple alternates requests in http-fetch Stop additional alternates requests from starting if one is already in progress. This adds an optional callback which is processed after a slot has finished running. Signed-off-by: Nick Hengeveld Signed-off-by: Junio C Hamano --- http-fetch.c | 178 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 117 insertions(+), 61 deletions(-) diff --git a/http-fetch.c b/http-fetch.c index f39e748fc..99b6cc7e4 100644 --- a/http-fetch.c +++ b/http-fetch.c @@ -25,7 +25,7 @@ #define PREV_BUF_SIZE 4096 #define RANGE_HEADER_SIZE 30 -static int got_alternates = 0; +static int got_alternates = -1; static int active_requests = 0; static int data_received; @@ -87,9 +87,19 @@ struct active_request_slot int done; CURLcode curl_result; long http_code; + void *callback_data; + void (*callback_func)(void *data); struct active_request_slot *next; }; +struct alt_request { + char *base; + char *url; + struct buffer *buffer; + struct active_request_slot *slot; + int http_specific; +}; + static struct transfer_request *request_queue_head = NULL; static struct active_request_slot *active_queue_head = NULL; @@ -237,7 +247,7 @@ static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb, static void process_curl_messages(void); static void process_request_queue(void); #endif -static int fetch_alternates(char *base); +static void fetch_alternates(char *base); static CURL* get_curl_handle(void) { @@ -324,6 +334,8 @@ static struct active_request_slot *get_active_slot(void) slot->in_use = 1; slot->done = 0; slot->local = NULL; + slot->callback_data = NULL; + slot->callback_func = 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); @@ -601,6 +613,12 @@ static void process_curl_messages(void) } else { fprintf(stderr, "Received DONE message for unknown request!\n"); } + + /* Process slot callback if appropriate */ + if (slot->callback_func != NULL) { + slot->callback_func(slot->callback_data); + } + if (request != NULL) { request->curl_result = curl_result; request->http_code = slot->http_code; @@ -766,72 +784,51 @@ static int setup_index(struct alt_base *repo, unsigned char *sha1) return 0; } -static int fetch_alternates(char *base) +static void process_alternates(void *callback_data) { - int ret = 0; - struct buffer buffer; - char *url; - char *data; - int i = 0; - int http_specific = 1; + struct alt_request *alt_req = (struct alt_request *)callback_data; + struct active_request_slot *slot = alt_req->slot; struct alt_base *tail = alt; + char *base = alt_req->base; static const char null_byte = '\0'; + char *data; + int i = 0; - struct active_request_slot *slot; - - if (got_alternates) - return 0; - - data = xmalloc(4096); - buffer.size = 4096; - buffer.posn = 0; - buffer.buffer = data; - - if (get_verbosely) - fprintf(stderr, "Getting alternates list for %s\n", base); - - 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_dynamic); - 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_dynamic); - curl_easy_setopt(slot->curl, CURLOPT_URL, url); + if (alt_req->http_specific) { + if (slot->curl_result != CURLE_OK || + !alt_req->buffer->posn) { + + /* 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; + slot->done = 0; if (start_active_slot(slot)) { - run_active_slot(slot); - if (slot->curl_result != CURLE_OK) { - free(buffer.buffer); - if (slot->http_code == 404) - got_alternates = 1; - return 0; - } + return; + } else { + got_alternates = -1; + slot->done = 1; + return; } } - } else { - free(buffer.buffer); - return 0; + } else if (slot->curl_result != CURLE_OK) { + if (slot->http_code != 404) { + got_alternates = -1; + return; + } } - fwrite_buffer_dynamic(&null_byte, 1, 1, &buffer); - buffer.posn--; - data = buffer.buffer; + fwrite_buffer_dynamic(&null_byte, 1, 1, alt_req->buffer); + alt_req->buffer->posn--; + data = alt_req->buffer->buffer; - while (i < buffer.posn) { + while (i < alt_req->buffer->posn) { int posn = i; - while (posn < buffer.posn && data[posn] != '\n') + while (posn < alt_req->buffer->posn && data[posn] != '\n') posn++; if (data[posn] == '\n') { int okay = 0; @@ -855,7 +852,7 @@ static int fetch_alternates(char *base) // If the server got removed, give up. okay = strchr(base, ':') - base + 3 < serverlen; - } else if (http_specific) { + } else if (alt_req->http_specific) { char *colon = strchr(data + i, ':'); char *slash = strchr(data + i, '/'); if (colon && slash && colon < data + posn && @@ -881,15 +878,74 @@ static int fetch_alternates(char *base) while (tail->next != NULL) tail = tail->next; tail->next = newalt; - ret++; } } i = posn + 1; } got_alternates = 1; - free(buffer.buffer); - return ret; +} + +static void fetch_alternates(char *base) +{ + struct buffer buffer; + char *url; + char *data; + struct active_request_slot *slot; + static struct alt_request alt_req; + int num_transfers; + + /* If another request has already started fetching alternates, + wait for them to arrive and return to processing this request's + curl message */ + while (got_alternates == 0) { + curl_multi_perform(curlm, &num_transfers); + process_curl_messages(); + process_request_queue(); + } + + /* Nothing to do if they've already been fetched */ + if (got_alternates == 1) + return; + + /* Start the fetch */ + got_alternates = 0; + + data = xmalloc(4096); + buffer.size = 4096; + buffer.posn = 0; + buffer.buffer = data; + + if (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; + slot->callback_data = &alt_req; + + curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer); + curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, + fwrite_buffer_dynamic); + 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 + got_alternates = -1; + + free(data); + free(url); } static int fetch_indices(struct alt_base *repo) -- 2.30.2