X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=http-fetch.c;h=435317342be0d31088f5aae5b337e090b40199b5;hb=4ddba79db76bd6425f00e99ceb1d82d179319aec;hp=e6181b0ee603a3b9601a0ffebcfa0bd95632ef9f;hpb=820eca68c2577d7499d203d7f4f7ae479b577683;p=git.git

diff --git a/http-fetch.c b/http-fetch.c
index e6181b0e..43531734 100644
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -1,23 +1,16 @@
 #include "cache.h"
 #include "commit.h"
-
+#include "pack.h"
 #include "fetch.h"
+#include "http.h"
 
-#include <curl/curl.h>
-#include <curl/easy.h>
+#define PREV_BUF_SIZE 4096
+#define RANGE_HEADER_SIZE 30
 
-#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
+static int got_alternates = -1;
 
-static CURL *curl;
 static struct curl_slist *no_pragma_header;
 
-static char *initial_base;
-
 struct alt_base
 {
 	char *base;
@@ -26,33 +19,45 @@ 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;
-
-static int local;
-static int zret;
-
-static int curl_ssl_verify;
+enum object_request_state {
+	WAITING,
+	ABORTED,
+	ACTIVE,
+	COMPLETE,
+};
 
-struct buffer
+struct object_request
 {
-        size_t posn;
-        size_t size;
-        void *buffer;
+	unsigned char sha1[20];
+	struct alt_base *repo;
+	char *url;
+	char filename[PATH_MAX];
+	char tmpfile[PATH_MAX];
+	int local;
+	enum object_request_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 object_request *next;
 };
 
-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;
-        return size;
-}
+struct alternates_request {
+	char *base;
+	char *url;
+	struct buffer *buffer;
+	struct active_request_slot *slot;
+	int http_specific;
+};
+
+static struct object_request *object_queue_head = NULL;
 
 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 			       void *data)
@@ -60,66 +65,367 @@ static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 	unsigned char expn[4096];
 	size_t size = eltsize * nmemb;
 	int posn = 0;
+	struct object_request *obj_req = (struct object_request *)data;
 	do {
-		ssize_t retval = write(local, ptr + posn, size - posn);
+		ssize_t retval = write(obj_req->local,
+				       ptr + posn, size - posn);
 		if (retval < 0)
 			return posn;
 		posn += retval;
 	} while (posn < size);
 
-	stream.avail_in = size;
-	stream.next_in = ptr;
+	obj_req->stream.avail_in = size;
+	obj_req->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);
+		obj_req->stream.next_out = expn;
+		obj_req->stream.avail_out = sizeof(expn);
+		obj_req->zret = inflate(&obj_req->stream, Z_SYNC_FLUSH);
+		SHA1_Update(&obj_req->c, expn,
+			    sizeof(expn) - obj_req->stream.avail_out);
+	} while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
+	data_received++;
 	return size;
 }
 
-void prefetch(unsigned char *sha1)
+static void fetch_alternates(char *base);
+
+static void process_object_response(void *callback_data);
+
+static void start_object_request(struct object_request *obj_req)
+{
+	char *hex = sha1_to_hex(obj_req->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", obj_req->filename);
+	unlink(prevfile);
+	rename(obj_req->tmpfile, prevfile);
+	unlink(obj_req->tmpfile);
+
+	if (obj_req->local != -1)
+		error("fd leakage in start: %d", obj_req->local);
+	obj_req->local = open(obj_req->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 (obj_req->local < 0 && errno == ENOENT) {
+		char *dir = strrchr(obj_req->tmpfile, '/');
+		if (dir) {
+			*dir = 0;
+			mkdir(obj_req->tmpfile, 0777);
+			*dir = '/';
+		}
+		obj_req->local = open(obj_req->tmpfile,
+				      O_WRONLY | O_CREAT | O_EXCL, 0666);
+	}
+
+	if (obj_req->local < 0) {
+		obj_req->state = ABORTED;
+		error("Couldn't create temporary file %s for %s: %s\n",
+		      obj_req->tmpfile, obj_req->filename, strerror(errno));
+		return;
+	}
+
+	memset(&obj_req->stream, 0, sizeof(obj_req->stream));
+
+	inflateInit(&obj_req->stream);
+
+	SHA1_Init(&obj_req->c);
+
+	url = xmalloc(strlen(obj_req->repo->base) + 50);
+	obj_req->url = xmalloc(strlen(obj_req->repo->base) + 50);
+	strcpy(url, obj_req->repo->base);
+	posn = url + strlen(obj_req->repo->base);
+	strcpy(posn, "objects/");
+	posn += 8;
+	memcpy(posn, hex, 2);
+	posn += 2;
+	*(posn++) = '/';
+	strcpy(posn, hex + 2);
+	strcpy(obj_req->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,
+						     obj_req) == 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(&obj_req->stream, 0, sizeof(obj_req->stream));
+		inflateInit(&obj_req->stream);
+		SHA1_Init(&obj_req->c);
+		if (prev_posn>0) {
+			prev_posn = 0;
+			lseek(obj_req->local, SEEK_SET, 0);
+			ftruncate(obj_req->local, 0);
+		}
+	}
+
+	slot = get_active_slot();
+	slot->callback_func = process_object_response;
+	slot->callback_data = obj_req;
+	obj_req->slot = slot;
+
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
+	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->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 */
+	obj_req->state = ACTIVE;
+	if (!start_active_slot(slot)) {
+		obj_req->state = ABORTED;
+		obj_req->slot = NULL;
+		close(obj_req->local); obj_req->local = -1;
+		free(obj_req->url);
+		return;
+	}
+	
+}
+
+static void finish_object_request(struct object_request *obj_req)
+{
+	struct stat st;
+
+	fchmod(obj_req->local, 0444);
+	close(obj_req->local); obj_req->local = -1;
+
+	if (obj_req->http_code == 416) {
+		fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
+	} else if (obj_req->curl_result != CURLE_OK) {
+		if (stat(obj_req->tmpfile, &st) == 0)
+			if (st.st_size == 0)
+				unlink(obj_req->tmpfile);
+		return;
+	}
+
+	inflateEnd(&obj_req->stream);
+	SHA1_Final(obj_req->real_sha1, &obj_req->c);
+	if (obj_req->zret != Z_STREAM_END) {
+		unlink(obj_req->tmpfile);
+		return;
+	}
+	if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
+		unlink(obj_req->tmpfile);
+		return;
+	}
+	obj_req->rename =
+		move_temp_to_file(obj_req->tmpfile, obj_req->filename);
+
+	if (obj_req->rename == 0)
+		pull_say("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;
+
+	obj_req->curl_result = obj_req->slot->curl_result;
+	obj_req->http_code = obj_req->slot->http_code;
+	obj_req->slot = NULL;
+	obj_req->state = COMPLETE;
+
+	/* Use alternates if necessary */
+	if (obj_req->http_code == 404) {
+		fetch_alternates(alt->base);
+		if (obj_req->repo->next != NULL) {
+			obj_req->repo =
+				obj_req->repo->next;
+			close(obj_req->local);
+			obj_req->local = -1;
+			start_object_request(obj_req);
+			return;
+		}
+	}
+
+	finish_object_request(obj_req);
 }
 
-static int got_alternates = 0;
+static void release_object_request(struct object_request *obj_req)
+{
+	struct object_request *entry = object_queue_head;
+
+	if (obj_req->local != -1)
+		error("fd leakage in release: %d", obj_req->local);
+	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->url);
+	free(obj_req);
+}
+
+#ifdef USE_CURL_MULTI
+void fill_active_slots(void)
+{
+	struct object_request *obj_req = object_queue_head;
+	struct active_request_slot *slot = active_queue_head;
+	int num_transfers;
+
+	while (active_requests < max_requests && obj_req != NULL) {
+		if (obj_req->state == WAITING) {
+			if (has_sha1_file(obj_req->sha1))
+				release_object_request(obj_req);
+			else
+				start_object_request(obj_req);
+			curl_multi_perform(curlm, &num_transfers);
+		}
+		obj_req = obj_req->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 object_request *newreq;
+	struct object_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 (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 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);
-	
-	if (curl_easy_perform(curl)) {
+	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 {
 		fclose(indexfile);
-		return error("Unable to get pack index %s", url);
+		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)
@@ -137,50 +443,51 @@ static int setup_index(struct alt_base *repo, unsigned char *sha1)
 	return 0;
 }
 
-static int fetch_alternates(char *base)
+static void process_alternates_response(void *callback_data)
 {
-	int ret = 0;
-	struct buffer buffer;
-	char *url;
+	struct alternates_request *alt_req =
+		(struct alternates_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;
-	int http_specific = 1;
-	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);
-
-	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;
+	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;
+			if (start_active_slot(slot)) {
+				return;
+			} else {
+				got_alternates = -1;
+				slot->in_use = 0;
+				return;
+			}
+		}
+	} else if (slot->curl_result != CURLE_OK) {
+		if (slot->http_code != 404) {
+			got_alternates = -1;
+			return;
 		}
 	}
 
-	data[buffer.posn] = '\0';
+	fwrite_buffer(&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;
@@ -204,7 +511,7 @@ 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 &&
@@ -223,19 +530,79 @@ 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;
-				ret++;
+				while (tail->next != NULL)
+					tail = tail->next;
+				tail->next = newalt;
 			}
 		}
 		i = posn + 1;
 	}
+
 	got_alternates = 1;
+}
+
+static void fetch_alternates(char *base)
+{
+	struct buffer buffer;
+	char *url;
+	char *data;
+	struct active_request_slot *slot;
+	static struct alternates_request alt_req;
+
+	/* 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 (got_alternates == 0) {
+		step_active_slots();
+	}
+#endif
+
+	/* 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);
 	
-	return ret;
+	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;
+	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
+		got_alternates = -1;
+
+	free(data);
+	free(url);
 }
 
 static int fetch_indices(struct alt_base *repo)
@@ -246,6 +613,8 @@ static int fetch_indices(struct alt_base *repo)
 	char *data;
 	int i = 0;
 
+	struct active_request_slot *slot;
+
 	if (repo->got_indices)
 		return 0;
 
@@ -255,20 +624,36 @@ static int fetch_indices(struct alt_base *repo)
 	buffer.buffer = data;
 
 	if (get_verbosely)
-		fprintf(stderr, "Getting pack list\n");
+		fprintf(stderr, "Getting pack list for %s\n", repo->base);
 	
 	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);
-	
-	if (curl_easy_perform(curl)) {
-		return -1;
+	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) {
+			if (slot->http_code == 404) {
+				repo->got_indices = 1;
+				free(buffer.buffer);
+				return 0;
+			} else {
+				repo->got_indices = 0;
+				free(buffer.buffer);
+				return error("%s", curl_errorstr);
+			}
+		}
+	} else {
+		repo->got_indices = 0;
+		free(buffer.buffer);
+		return error("Unable to start request");
 	}
 
+	data = buffer.buffer;
 	while (i < buffer.posn) {
 		switch (data[i]) {
 		case 'P':
@@ -288,6 +673,7 @@ static int fetch_indices(struct alt_base *repo)
 		i++;
 	}
 
+	free(buffer.buffer);
 	repo->got_indices = 1;
 	return 0;
 }
@@ -299,6 +685,13 @@ 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;
@@ -318,153 +711,204 @@ 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);
-	
-	if (curl_easy_perform(curl)) {
+	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 {
 		fclose(packfile);
-		return error("Unable to get pack file %s", url);
+		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());
-
-	local = mkstemp(tmpfile);
-	if (local < 0)
-		return error("Couldn't create temporary file %s for %s: %s\n",
-			     tmpfile, filename, strerror(errno));
-
-	memset(&stream, 0, sizeof(stream));
-
-	inflateInit(&stream);
+	int ret = 0;
+	struct object_request *obj_req = object_queue_head;
 
-	SHA1_Init(&c);
+	while (obj_req != NULL && memcmp(obj_req->sha1, sha1, 20))
+		obj_req = obj_req->next;
+	if (obj_req == NULL)
+		return error("Couldn't find request for %s in the queue", hex);
 
-	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);
+	if (has_sha1_file(obj_req->sha1)) {
+		release_object_request(obj_req);
+		return 0;
+	}
 
-	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);
+#ifdef USE_CURL_MULTI
+	while (obj_req->state == WAITING) {
+		step_active_slots();
+	}
+#else
+	start_object_request(obj_req);
+#endif
 
-	curl_easy_setopt(curl, CURLOPT_URL, url);
+	while (obj_req->state == ACTIVE) {
+		run_active_slot(obj_req->slot);
+	}
+	if (obj_req->local != -1) {
+		close(obj_req->local); obj_req->local = -1;
+	}
 
-	if (curl_easy_perform(curl)) {
-		unlink(filename);
-		return -1;
+	if (obj_req->state == ABORTED) {
+		ret = error("Request for %s aborted", hex);
+	} else if (obj_req->curl_result != CURLE_OK &&
+		   obj_req->http_code != 416) {
+		if (obj_req->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)",
+				    obj_req->errorstr, obj_req->curl_result,
+				    obj_req->http_code, hex);
+	} else if (obj_req->zret != Z_STREAM_END) {
+		ret = error("File %s (%s) corrupt\n", hex, obj_req->url);
+	} else if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
+		ret = error("File %s has bad hash\n", hex);
+	} else if (obj_req->rename < 0) {
+		ret = error("unable to write sha1 filename %s: %s",
+			    obj_req->filename,
+			    strerror(obj_req->rename));
 	}
 
-	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 (memcmp(sha1, real_sha1, 20)) {
-		unlink(tmpfile);
-		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);
-	return 0;
+	release_object_request(obj_req);
+	return ret;
 }
 
 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);
-
-        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", url, ref);
+	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);
@@ -476,6 +920,7 @@ int main(int argc, char **argv)
 	char *commit_id;
 	char *url;
 	int arg = 1;
+	int rc = 0;
 
 	while (arg < argc && argv[arg][0] == '-') {
 		if (argv[arg][1] == 't') {
@@ -503,28 +948,22 @@ int main(int argc, char **argv)
 	commit_id = argv[arg];
 	url = argv[arg + 1];
 
-	curl_global_init(CURL_GLOBAL_ALL);
+	http_init();
 
-	curl = curl_easy_init();
 	no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 
-	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);
-#endif
-
 	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(no_pragma_header);
-	curl_global_cleanup();
-	return 0;
+
+	http_cleanup();
+
+	return rc;
 }