http-fetch: support fetching packfiles by URL

Teach http-fetch the ability to download packfiles directly, given a
URL, and to verify them.

The http_pack_request suite has been augmented with a function that
takes a URL directly. With this function, the hash is only used to
determine the name of the temporary file.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 53 insertions, 10 deletions

diff --git a/http-fetch.c b/http-fetch.c
index e538174..1df376e 100644
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -5,7 +5,7 @@
 #include "walker.h"
 
 static const char http_fetch_usage[] = "git http-fetch "
-"[-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin] commit-id url";
+"[-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin | --packfile=hash | commit-id] url";
 
 static int fetch_using_walker(const char *raw_url, int get_verbosely,
 			      int get_recover, int commits, char **commit_id,
@@ -43,6 +43,37 @@ static int fetch_using_walker(const char *raw_url, int get_verbosely,
 	return rc;
 }
 
+static void fetch_single_packfile(struct object_id *packfile_hash,
+				  const char *url) {
+	struct http_pack_request *preq;
+	struct slot_results results;
+	int ret;
+
+	http_init(NULL, url, 0);
+
+	preq = new_direct_http_pack_request(packfile_hash->hash, xstrdup(url));
+	if (preq == NULL)
+		die("couldn't create http pack request");
+	preq->slot->results = &results;
+	preq->generate_keep = 1;
+
+	if (start_active_slot(preq->slot)) {
+		run_active_slot(preq->slot);
+		if (results.curl_result != CURLE_OK) {
+			die("Unable to get pack file %s\n%s", preq->url,
+			    curl_errorstr);
+		}
+	} else {
+		die("Unable to start request");
+	}
+
+	if ((ret = finish_http_pack_request(preq)))
+		die("finish_http_pack_request gave result %d", ret);
+
+	release_http_pack_request(preq);
+	http_cleanup();
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	int commits_on_stdin = 0;
@@ -52,8 +83,12 @@ int cmd_main(int argc, const char **argv)
 	int arg = 1;
 	int get_verbosely = 0;
 	int get_recover = 0;
+	int packfile = 0;
+	struct object_id packfile_hash;
 
 	while (arg < argc && argv[arg][0] == '-') {
+		const char *p;
+
 		if (argv[arg][1] == 't') {
 		} else if (argv[arg][1] == 'c') {
 		} else if (argv[arg][1] == 'a') {
@@ -68,25 +103,33 @@ int cmd_main(int argc, const char **argv)
 			get_recover = 1;
 		} else if (!strcmp(argv[arg], "--stdin")) {
 			commits_on_stdin = 1;
+		} else if (skip_prefix(argv[arg], "--packfile=", &p)) {
+			const char *end;
+
+			packfile = 1;
+			if (parse_oid_hex(p, &packfile_hash, &end) || *end)
+				die(_("argument to --packfile must be a valid hash (got '%s')"), p);
 		}
 		arg++;
 	}
-	if (argc != arg + 2 - commits_on_stdin)
+	if (argc != arg + 2 - (commits_on_stdin || packfile))
 		usage(http_fetch_usage);
-	if (commits_on_stdin) {
-		commits = walker_targets_stdin(&commit_id, &write_ref);
-	} else {
-		commit_id = (char **) &argv[arg++];
-		commits = 1;
-	}
 
 	setup_git_directory();
 
 	git_config(git_default_config, NULL);
 
-	if (!argv[arg])
-		BUG("must have one arg remaining");
+	if (packfile) {
+		fetch_single_packfile(&packfile_hash, argv[arg]);
+		return 0;
+	}
 
+	if (commits_on_stdin) {
+		commits = walker_targets_stdin(&commit_id, &write_ref);
+	} else {
+		commit_id = (char **) &argv[arg++];
+		commits = 1;
+	}
 	return fetch_using_walker(argv[arg], get_verbosely, get_recover,
 				  commits, commit_id, write_ref,
 				  commits_on_stdin);