http*: add helper methods for fetching packs

The code handling the fetching of packs in http-push.c and
http-walker.c have been refactored into new methods and a new struct
(http_pack_request) in http.c. They are not meant to be invoked
elsewhere.

The new methods in http.c are
 - new_http_pack_request
 - finish_http_pack_request
 - release_http_pack_request

and the new struct is http_pack_request.

Add a function, new_http_pack_request(), that deals with the details of
coming up with the filename to store the retrieved packfile, resuming a
previously aborted request, and making a new curl request. Update
http-push.c::start_fetch_packed() and http-walker.c::fetch_pack() to
use this.

Add a function, finish_http_pack_request(), that deals with renaming
the pack, advancing the pack list, and installing the pack. Update
http-push.c::finish_request() and http-walker.c::fetch_pack to use
this.

Update release_request() in http-push.c and http-walker.c to invoke
release_http_pack_request() to clean up pack request helper data.

The local_stream member of the transfer_request struct in http-push.c
has been removed, as the packfile pointer will be managed in the struct
http_pack_request.

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 18 insertions, 67 deletions

diff --git a/http-walker.c b/http-walker.c
index ac343fd..8f7a975 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -1,6 +1,5 @@
 #include "cache.h"
 #include "commit.h"
-#include "pack.h"
 #include "walker.h"
 #include "http.h"
 
@@ -590,19 +589,10 @@ static int fetch_indices(struct walker *walker, struct alt_base *repo)
 
 static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
 {
-	char *url;
 	struct packed_git *target;
-	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;
 	struct slot_results results;
+	struct http_pack_request *preq;
 
 	if (fetch_indices(walker, repo))
 		return -1;
@@ -617,72 +607,33 @@ static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned cha
 			sha1_to_hex(sha1));
 	}
 
-	url = xmalloc(strlen(repo->base) + 65);
-	sprintf(url, "%s/objects/pack/pack-%s.pack",
-		repo->base, sha1_to_hex(target->sha1));
+	preq = new_http_pack_request(target, repo->base);
+	if (preq == NULL)
+		goto abort;
+	preq->lst = &repo->packs;
+	preq->slot->results = &results;
 
-	filename = sha1_pack_name(target->sha1);
-	snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-	packfile = fopen(tmpfile, "a");
-	if (!packfile)
-		return error("Unable to open local file %s for pack",
-			     tmpfile);
-
-	slot = get_active_slot();
-	slot->results = &results;
-	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 (walker->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 (start_active_slot(preq->slot)) {
+		run_active_slot(preq->slot);
 		if (results.curl_result != CURLE_OK) {
-			fclose(packfile);
-			slot->local = NULL;
-			return error("Unable to get pack file %s\n%s", url,
-				     curl_errorstr);
+			error("Unable to get pack file %s\n%s", preq->url,
+			      curl_errorstr);
+			goto abort;
 		}
 	} else {
-		fclose(packfile);
-		slot->local = NULL;
-		return error("Unable to start request");
+		error("Unable to start request");
+		goto abort;
 	}
 
-	target->pack_size = ftell(packfile);
-	fclose(packfile);
-	slot->local = NULL;
-
-	ret = move_temp_to_file(tmpfile, filename);
+	ret = finish_http_pack_request(preq);
+	release_http_pack_request(preq);
 	if (ret)
 		return ret;
 
-	lst = &repo->packs;
-	while (*lst != target)
-		lst = &((*lst)->next);
-	*lst = (*lst)->next;
-
-	if (verify_pack(target))
-		return -1;
-	install_packed_git(target);
-
 	return 0;
+
+abort:
+	return -1;
 }
 
 static void abort_object_request(struct object_request *obj_req)