X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=http-fetch.c;h=a1b03cd9c842e9daa8f743939d4382faac0c534f;hb=0f8fdc3958ad0cb7c740b76189f98307eebcd64b;hp=7fc363f8ea7ca622330eb17260bf76f977875d03;hpb=5acb6de13d7af33abcfcbdc885ec365e6a51c486;p=git.git

diff --git a/http-fetch.c b/http-fetch.c
index 7fc363f8..a1b03cd9 100644
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -1,11 +1,16 @@
 #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
@@ -13,12 +18,29 @@
 #define curl_global_init(a) do { /* nothing */ } while(0)
 #endif
 
-static CURL *curl;
+#if LIBCURL_VERSION_NUM < 0x070c04
+#define NO_CURL_EASY_DUPHANDLE
+#endif
+
+#define PREV_BUF_SIZE 4096
+#define RANGE_HEADER_SIZE 30
+
+static int got_alternates = 0;
+static int active_requests = 0;
+static int data_received;
+
+#ifdef USE_CURL_MULTI
+static int max_requests = -1;
+static CURLM *curlm;
+#endif
+#ifndef NO_CURL_EASY_DUPHANDLE
+static CURL *curl_default;
+#endif
+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];
 
-static char *initial_base;
-
 struct alt_base
 {
 	char *base;
@@ -27,19 +49,61 @@ struct alt_base
 	struct alt_base *next;
 };
 
-struct alt_base *alt = NULL;
+static struct alt_base *alt = NULL;
 
-static SHA_CTX c;
-static z_stream stream;
+enum transfer_state {
+	WAITING,
+	ABORTED,
+	ACTIVE,
+	COMPLETE,
+};
 
-static int local;
-static int zret;
+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;
+};
 
-static int curl_ssl_verify;
-static char *ssl_cert;
-static char *ssl_key;
-static char *ssl_capath;
-static char *ssl_cainfo;
+struct active_request_slot
+{
+	CURL *curl;
+	FILE *local;
+	int in_use;
+	int done;
+	CURLcode curl_result;
+	long http_code;
+	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 = -1;
+static char *ssl_cert = NULL;
+#if LIBCURL_VERSION_NUM >= 0x070902
+static char *ssl_key = NULL;
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+static char *ssl_capath = NULL;
+#endif
+static char *ssl_cainfo = NULL;
+static long curl_low_speed_limit = -1;
+static long curl_low_speed_time = -1;
 
 struct buffer
 {
@@ -48,6 +112,71 @@ struct buffer
         void *buffer;
 };
 
+static int http_options(const char *var, const char *value)
+{
+	if (!strcmp("http.sslverify", var)) {
+		if (curl_ssl_verify == -1) {
+			curl_ssl_verify = git_config_bool(var, value);
+		}
+		return 0;
+	}
+
+	if (!strcmp("http.sslcert", var)) {
+		if (ssl_cert == NULL) {
+			ssl_cert = xmalloc(strlen(value)+1);
+			strcpy(ssl_cert, value);
+		}
+		return 0;
+	}
+#if LIBCURL_VERSION_NUM >= 0x070902
+	if (!strcmp("http.sslkey", var)) {
+		if (ssl_key == NULL) {
+			ssl_key = xmalloc(strlen(value)+1);
+			strcpy(ssl_key, value);
+		}
+		return 0;
+	}
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	if (!strcmp("http.sslcapath", var)) {
+		if (ssl_capath == NULL) {
+			ssl_capath = xmalloc(strlen(value)+1);
+			strcpy(ssl_capath, value);
+		}
+		return 0;
+	}
+#endif
+	if (!strcmp("http.sslcainfo", var)) {
+		if (ssl_cainfo == NULL) {
+			ssl_cainfo = xmalloc(strlen(value)+1);
+			strcpy(ssl_cainfo, value);
+		}
+		return 0;
+	}
+
+#ifdef USE_CURL_MULTI	
+	if (!strcmp("http.maxrequests", var)) {
+		if (max_requests == -1)
+			max_requests = git_config_int(var, value);
+		return 0;
+	}
+#endif
+
+	if (!strcmp("http.lowspeedlimit", var)) {
+		if (curl_low_speed_limit == -1)
+			curl_low_speed_limit = (long)git_config_int(var, value);
+		return 0;
+	}
+	if (!strcmp("http.lowspeedtime", var)) {
+		if (curl_low_speed_time == -1)
+			curl_low_speed_time = (long)git_config_int(var, value);
+		return 0;
+	}
+
+	/* Fall back on the default ones */
+	return git_default_config(var, value);
+}
+
 static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
                             struct buffer *buffer)
 {
@@ -56,77 +185,563 @@ static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
                 size = buffer->size - buffer->posn;
         memcpy(buffer->buffer + buffer->posn, ptr, size);
         buffer->posn += size;
+	data_received++;
         return size;
 }
 
+static size_t fwrite_buffer_dynamic(const void *ptr, size_t eltsize,
+				    size_t nmemb, struct buffer *buffer)
+{
+	size_t size = eltsize * nmemb;
+	if (size > buffer->size - buffer->posn) {
+		buffer->size = buffer->size * 3 / 2;
+		if (buffer->size < buffer->posn + size)
+			buffer->size = buffer->posn + size;
+		buffer->buffer = xrealloc(buffer->buffer, buffer->size);
+	}
+	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(local, ptr + posn, size - posn);
+		ssize_t retval = write(request->local,
+				       ptr + posn, size - posn);
 		if (retval < 0)
 			return posn;
 		posn += retval;
 	} while (posn < size);
 
-	stream.avail_in = size;
-	stream.next_in = ptr;
+	request->stream.avail_in = size;
+	request->stream.next_in = ptr;
 	do {
-		stream.next_out = expn;
-		stream.avail_out = sizeof(expn);
-		zret = inflate(&stream, Z_SYNC_FLUSH);
-		SHA1_Update(&c, expn, sizeof(expn) - stream.avail_out);
-	} while (stream.avail_in && zret == Z_OK);
+		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;
 }
 
-void prefetch(unsigned char *sha1)
+#ifdef USE_CURL_MULTI
+static void process_curl_messages(void);
+static void process_request_queue(void);
+#endif
+static int fetch_alternates(char *base);
+
+static CURL* get_curl_handle(void)
 {
+	CURL* result = curl_easy_init();
+
+	curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
+#if LIBCURL_VERSION_NUM >= 0x070907
+	curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
+#endif
+
+	if (ssl_cert != NULL)
+		curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
+#if LIBCURL_VERSION_NUM >= 0x070902
+	if (ssl_key != NULL)
+		curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	if (ssl_capath != NULL)
+		curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
+#endif
+	if (ssl_cainfo != NULL)
+		curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
+	curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
+
+	if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
+		curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
+				 curl_low_speed_limit);
+		curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
+				 curl_low_speed_time);
+	}
+
+	return result;
 }
 
-static int got_alternates = 0;
+static struct active_request_slot *get_active_slot(void)
+{
+	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 = NULL;
+		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;
+	}
+
+	if (slot->curl == NULL) {
+#ifdef NO_CURL_EASY_DUPHANDLE
+		slot->curl = get_curl_handle();
+#else
+		slot->curl = curl_easy_duphandle(curl_default);
+#endif
+	}
+
+	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;
+}
+
+static 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;
+}
+
+static 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
+}
+
+static 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;
+}
+
+static 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));
+}
+
+static 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(void)
+{
+	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;
+				curl_easy_getinfo(slot->curl,
+						  CURLINFO_HTTP_CODE,
+						  &slot->http_code);
+				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;
+				request->http_code = slot->http_code;
+				request->slot = NULL;
+				request->state = COMPLETE;
+
+				/* Use alternates if necessary */
+				if (request->http_code == 404) {
+					fetch_alternates(alt->base);
+					if (request->repo->next != NULL) {
+						request->repo =
+							request->repo->next;
+						start_request(request);
+					}
+				} else {
+					finish_request(request);
+				}
+			}
+		} 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(void)
+{
+	struct transfer_request *request = request_queue_head;
+	struct active_request_slot *slot = active_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;
+	}
+
+	while (slot != NULL) {
+		if (!slot->in_use && slot->curl != NULL) {
+			curl_easy_cleanup(slot->curl);
+			slot->curl = NULL;
+		}
+		slot = slot->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 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",
-			sha1_to_hex(sha1));
+		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, sha1_to_hex(sha1));
+	sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 	
 	filename = sha1_pack_index_name(sha1);
-	indexfile = fopen(filename, "w");
+	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);
 
-	curl_easy_setopt(curl, CURLOPT_FILE, indexfile);
-	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
-	curl_easy_setopt(curl, CURLOPT_URL, url);
-	curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
-	curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-	
-	if (curl_easy_perform(curl)) {
-		fclose(indexfile);
-		return error("Unable to get pack index %s\n%s", url,
-			     curl_errorstr);
+	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 0;
+
+	return move_temp_to_file(tmpfile, filename);
 }
 
 static int setup_index(struct alt_base *repo, unsigned char *sha1)
@@ -152,10 +767,16 @@ static int fetch_alternates(char *base)
 	char *data;
 	int i = 0;
 	int http_specific = 1;
+	struct alt_base *tail = alt;
+	static const char null_byte = '\0';
+
+	struct active_request_slot *slot;
+
 	if (got_alternates)
 		return 0;
+
 	data = xmalloc(4096);
-	buffer.size = 4095;
+	buffer.size = 4096;
 	buffer.posn = 0;
 	buffer.buffer = data;
 
@@ -165,25 +786,41 @@ static int fetch_alternates(char *base)
 	url = xmalloc(strlen(base) + 31);
 	sprintf(url, "%s/objects/info/http-alternates", base);
 
-	curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	curl_easy_setopt(curl, CURLOPT_URL, url);
-
-	if (curl_easy_perform(curl) || !buffer.posn) {
-		http_specific = 0;
-
-		sprintf(url, "%s/objects/info/alternates", base);
-		
-		curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-		curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-		curl_easy_setopt(curl, CURLOPT_URL, url);
-		
-		if (curl_easy_perform(curl)) {
-			return 0;
+	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 (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;
+				}
+			}
 		}
+	} else {
+		free(buffer.buffer);
+		return 0;
 	}
 
-	data[buffer.posn] = '\0';
+	fwrite_buffer_dynamic(&null_byte, 1, 1, &buffer);
+	buffer.posn--;
+	data = buffer.buffer;
 
 	while (i < buffer.posn) {
 		int posn = i;
@@ -230,18 +867,21 @@ static int fetch_alternates(char *base)
 					fprintf(stderr, 
 						"Also look at %s\n", target);
 				newalt = xmalloc(sizeof(*newalt));
-				newalt->next = alt;
+				newalt->next = NULL;
 				newalt->base = target;
 				newalt->got_indices = 0;
 				newalt->packs = NULL;
-				alt = newalt;
+				while (tail->next != NULL)
+					tail = tail->next;
+				tail->next = newalt;
 				ret++;
 			}
 		}
 		i = posn + 1;
 	}
+
 	got_alternates = 1;
-	
+	free(buffer.buffer);
 	return ret;
 }
 
@@ -253,6 +893,8 @@ static int fetch_indices(struct alt_base *repo)
 	char *data;
 	int i = 0;
 
+	struct active_request_slot *slot;
+
 	if (repo->got_indices)
 		return 0;
 
@@ -267,15 +909,24 @@ static int fetch_indices(struct alt_base *repo)
 	url = xmalloc(strlen(repo->base) + 21);
 	sprintf(url, "%s/objects/info/packs", repo->base);
 
-	curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	curl_easy_setopt(curl, CURLOPT_URL, url);
-	curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
-	curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-	
-	if (curl_easy_perform(curl))
-		return error("%s", curl_errorstr);
+	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);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result != CURLE_OK) {
+			free(buffer.buffer);
+			return error("%s", curl_errorstr);
+		}
+	} else {
+		free(buffer.buffer);
+		return error("Unable to start request");
+	}
 
+	data = buffer.buffer;
 	while (i < buffer.posn) {
 		switch (data[i]) {
 		case 'P':
@@ -295,6 +946,7 @@ static int fetch_indices(struct alt_base *repo)
 		i++;
 	}
 
+	free(buffer.buffer);
 	repo->got_indices = 1;
 	return 0;
 }
@@ -306,6 +958,13 @@ static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 	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;
@@ -325,158 +984,237 @@ static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 		repo->base, sha1_to_hex(target->sha1));
 
 	filename = sha1_pack_name(target->sha1);
-	packfile = fopen(filename, "w");
+	snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
+	packfile = fopen(tmpfile, "a");
 	if (!packfile)
 		return error("Unable to open local file %s for pack",
 			     filename);
 
-	curl_easy_setopt(curl, CURLOPT_FILE, packfile);
-	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
-	curl_easy_setopt(curl, CURLOPT_URL, url);
-	curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
-	curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
+	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 (curl_easy_perform(curl)) {
-		fclose(packfile);
-		return error("Unable to get pack file %s\n%s", url,
-			     curl_errorstr);
+	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;
 }
 
-int fetch_object(struct alt_base *repo, unsigned char *sha1)
+static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 {
 	char *hex = sha1_to_hex(sha1);
-	char *filename = sha1_file_name(sha1);
-	unsigned char real_sha1[20];
-	char tmpfile[PATH_MAX];
 	int ret;
-	char *url;
-	char *posn;
-
-	snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX",
-		 get_object_directory());
+	struct transfer_request *request = request_queue_head;
 
-	local = mkstemp(tmpfile);
-	if (local < 0)
-		return error("Couldn't create temporary file %s for %s: %s\n",
-			     tmpfile, filename, strerror(errno));
+	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);
 
-	memset(&stream, 0, sizeof(stream));
-
-	inflateInit(&stream);
-
-	SHA1_Init(&c);
+	if (has_sha1_file(request->sha1)) {
+		release_request(request);
+		return 0;
+	}
 
-	curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
-	curl_easy_setopt(curl, CURLOPT_FILE, NULL);
-	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
-	curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
-	curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
+#ifdef USE_CURL_MULTI
+	while (request->state == WAITING) {
+		int num_transfers;
+		curl_multi_perform(curlm, &num_transfers);
+		if (num_transfers < active_requests) {
+			process_curl_messages();
+			process_request_queue();
+		}
+	}
+#else
+	start_request(request);
+#endif
 
-	url = xmalloc(strlen(repo->base) + 50);
-	strcpy(url, repo->base);
-	posn = url + strlen(repo->base);
-	strcpy(posn, "objects/");
-	posn += 8;
-	memcpy(posn, hex, 2);
-	posn += 2;
-	*(posn++) = '/';
-	strcpy(posn, hex + 2);
+	while (request->state == ACTIVE) {
+		run_active_slot(request->slot);
+#ifndef USE_CURL_MULTI
+		request->curl_result = request->slot->curl_result;
+		request->http_code = request->slot->http_code;
+		request->slot = NULL;
+
+		/* Use alternates if necessary */
+		if (request->http_code == 404) {
+			fetch_alternates(alt->base);
+			if (request->repo->next != NULL) {
+				request->repo = request->repo->next;
+				start_request(request);
+			}
+		} else {
+			finish_request(request);
+			request->state = COMPLETE;
+		}
+#endif
+	}
 
-	curl_easy_setopt(curl, CURLOPT_URL, url);
+	if (request->state == ABORTED) {
+		release_request(request);
+		return error("Request for %s aborted", hex);
+	}
 
-	if (curl_easy_perform(curl)) {
-		unlink(filename);
-		return error("%s", curl_errorstr);
+	if (request->curl_result != CURLE_OK && request->http_code != 416) {
+		if (request->http_code == 404)
+			ret = -1; /* Be silent, it is probably in a pack. */
+		else
+			ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
+				    request->errorstr, request->curl_result,
+				    request->http_code, hex);
+		release_request(request);
+		return ret;
 	}
 
-	fchmod(local, 0444);
-	close(local);
-	inflateEnd(&stream);
-	SHA1_Final(real_sha1, &c);
-	if (zret != Z_STREAM_END) {
-		unlink(tmpfile);
-		return error("File %s (%s) corrupt\n", hex, url);
+	if (request->zret != Z_STREAM_END) {
+		ret = error("File %s (%s) corrupt\n", hex, request->url);
+		release_request(request);
+		return ret;
 	}
-	if (memcmp(sha1, real_sha1, 20)) {
-		unlink(tmpfile);
+
+	if (memcmp(request->sha1, request->real_sha1, 20)) {
+		release_request(request);
 		return error("File %s has bad hash\n", hex);
 	}
-	ret = link(tmpfile, filename);
-	if (ret < 0) {
-		/* Same Coda hack as in write_sha1_file(sha1_file.c) */
-		ret = errno;
-		if (ret == EXDEV && !rename(tmpfile, filename))
-			goto out;
-	}
-	unlink(tmpfile);
-	if (ret) {
-		if (ret != EEXIST)
-			return error("unable to write sha1 filename %s: %s",
-				     filename, strerror(ret));
-	}
- out:
-	pull_say("got %s\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_object(altbase, sha1))
-			return 0;
 		if (!fetch_pack(altbase, sha1))
 			return 0;
-		if (fetch_alternates(altbase->base) > 0) {
-			altbase = alt;
-			continue;
-		}
+		fetch_alternates(alt->base);
 		altbase = altbase->next;
 	}
 	return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
-		     initial_base);
+		     alt->base);
+}
+
+static inline int needs_quote(int ch)
+{
+	switch (ch) {
+	case '/': case '-': case '.':
+	case 'A'...'Z':	case 'a'...'z':	case '0'...'9':
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static inline int hex(int v)
+{
+	if (v < 10) return '0' + v;
+	else return 'A' + v - 10;
+}
+
+static char *quote_ref_url(const char *base, const char *ref)
+{
+	const char *cp;
+	char *dp, *qref;
+	int len, baselen, ch;
+
+	baselen = strlen(base);
+	len = baselen + 6; /* "refs/" + NUL */
+	for (cp = ref; (ch = *cp) != 0; cp++, len++)
+		if (needs_quote(ch))
+			len += 2; /* extra two hex plus replacement % */
+	qref = xmalloc(len);
+	memcpy(qref, base, baselen);
+	memcpy(qref + baselen, "refs/", 5);
+	for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
+		if (needs_quote(ch)) {
+			*dp++ = '%';
+			*dp++ = hex((ch >> 4) & 0xF);
+			*dp++ = hex(ch & 0xF);
+		}
+		else
+			*dp++ = ch;
+	}
+	*dp = 0;
+
+	return qref;
 }
 
 int fetch_ref(char *ref, unsigned char *sha1)
 {
-        char *url, *posn;
+        char *url;
         char hex[42];
         struct buffer buffer;
-	char *base = initial_base;
+	char *base = alt->base;
+	struct active_request_slot *slot;
         buffer.size = 41;
         buffer.posn = 0;
         buffer.buffer = hex;
         hex[41] = '\0';
         
-        curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
-	curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-
-        url = xmalloc(strlen(base) + 6 + strlen(ref));
-        strcpy(url, base);
-        posn = url + strlen(base);
-        strcpy(posn, "refs/");
-        posn += 5;
-        strcpy(posn, ref);
-
-        curl_easy_setopt(curl, CURLOPT_URL, url);
-
-        if (curl_easy_perform(curl))
-                return error("Couldn't get %s for %s\n%s",
-			     url, ref, curl_errorstr);
+	url = quote_ref_url(base, 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);
@@ -488,6 +1226,11 @@ int main(int argc, char **argv)
 	char *commit_id;
 	char *url;
 	int arg = 1;
+	struct active_request_slot *slot;
+	char *low_speed_limit;
+	char *low_speed_time;
+	char *wait_url;
+	int rc = 0;
 
 	while (arg < argc && argv[arg][0] == '-') {
 		if (argv[arg][1] == 't') {
@@ -517,41 +1260,90 @@ int main(int argc, char **argv)
 
 	curl_global_init(CURL_GLOBAL_ALL);
 
-	curl = curl_easy_init();
-	no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
+#ifdef USE_CURL_MULTI
+	{
+		char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
+		if (http_max_requests != NULL)
+			max_requests = atoi(http_max_requests);
+	}
 
-	curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
-	curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
-#if LIBCURL_VERSION_NUM >= 0x070907
-	curl_easy_setopt(curl, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
+	curlm = curl_multi_init();
+	if (curlm == NULL) {
+		fprintf(stderr, "Error creating curl multi handle.\n");
+		return 1;
+	}
 #endif
 
-	if ((ssl_cert = getenv("GIT_SSL_CERT")) != NULL) {
-		curl_easy_setopt(curl, CURLOPT_SSLCERT, ssl_cert);
-	}
-	if ((ssl_key = getenv("GIT_SSL_KEY")) != NULL) {
-		curl_easy_setopt(curl, CURLOPT_SSLKEY, ssl_key);
-	}
+	if (getenv("GIT_SSL_NO_VERIFY"))
+		curl_ssl_verify = 0;
+
+	ssl_cert = getenv("GIT_SSL_CERT");
+#if LIBCURL_VERSION_NUM >= 0x070902
+	ssl_key = getenv("GIT_SSL_KEY");
+#endif
 #if LIBCURL_VERSION_NUM >= 0x070908
-	if ((ssl_capath = getenv("GIT_SSL_CAPATH")) != NULL) {
-		curl_easy_setopt(curl, CURLOPT_CAPATH, ssl_capath);
-	}
+	ssl_capath = getenv("GIT_SSL_CAPATH");
+#endif
+	ssl_cainfo = getenv("GIT_SSL_CAINFO");
+
+	low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
+	if (low_speed_limit != NULL)
+		curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
+	low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
+	if (low_speed_time != NULL)
+		curl_low_speed_time = strtol(low_speed_time, NULL, 10);
+
+	git_config(http_options);
+
+	if (curl_ssl_verify == -1)
+		curl_ssl_verify = 1;
+
+#ifdef USE_CURL_MULTI
+	if (max_requests < 1)
+		max_requests = DEFAULT_MAX_REQUESTS;
+#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:");
+
+#ifndef NO_CURL_EASY_DUPHANDLE
+	curl_default = get_curl_handle();
 #endif
-	if ((ssl_cainfo = getenv("GIT_SSL_CAINFO")) != NULL) {
-		curl_easy_setopt(curl, CURLOPT_CAINFO, ssl_cainfo);
-	}
 
 	alt = xmalloc(sizeof(*alt));
 	alt->base = url;
 	alt->got_indices = 0;
 	alt->packs = NULL;
 	alt->next = NULL;
-	initial_base = url;
 
 	if (pull(commit_id))
-		return 1;
+		rc = 1;
 
+	curl_slist_free_all(pragma_header);
 	curl_slist_free_all(no_pragma_header);
+	curl_slist_free_all(no_range_header);
+#ifndef NO_CURL_EASY_DUPHANDLE
+	curl_easy_cleanup(curl_default);
+#endif
+	slot = active_queue_head;
+	while (slot != NULL) {
+		if (slot->in_use) {
+			if (get_verbosely) {
+				curl_easy_getinfo(slot->curl,
+						  CURLINFO_EFFECTIVE_URL,
+						  &wait_url);
+				fprintf(stderr, "Waiting for %s\n", wait_url);
+			}
+			run_active_slot(slot);
+		}
+		if (slot->curl != 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;
 }