Teach git-http-fetch the --stdin switch

Speeds up things quite a lot when fetching tags with Cogito.

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-http-fetch.txt

@@ -8,7 +8,7 @@ git-http-fetch - downloads a remote git repository via HTTP
 
 SYNOPSIS
 --------
-'git-http-fetch' [-c] [-t] [-a] [-d] [-v] [-w filename] [--recover] <commit> <url>
+'git-http-fetch' [-c] [-t] [-a] [-d] [-v] [-w filename] [--recover] [--stdin] <commit> <url>
 
 DESCRIPTION
 -----------
@@ -33,6 +33,12 @@ commit-id::
         Writes the commit-id into the filename under $GIT_DIR/refs/<filename> on
         the local end after the transfer is complete.
 
+--stdin::
+	Instead of a commit id on the commandline (which is not expected in this
+	case), 'git-http-fetch' expects lines on stdin in the format
+
+		<commit-id>['\t'<filename-as-in--w>]
+
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org>

http-fetch.c

@@ -36,6 +36,8 @@ enum XML_Status {
 #define PREV_BUF_SIZE 4096
 #define RANGE_HEADER_SIZE 30
 
+static int commits_on_stdin = 0;
+
 static int got_alternates = -1;
 static int corrupt_object_found = 0;
 
@@ -43,7 +45,7 @@ static struct curl_slist *no_pragma_header;
 
 struct alt_base
 {
-	char *base;
+	const char *base;
 	int path_len;
 	int got_indices;
 	struct packed_git *packs;
@@ -81,7 +83,7 @@ struct object_request
 };
 
 struct alternates_request {
-	char *base;
+	const char *base;
 	char *url;
 	struct buffer *buffer;
 	struct active_request_slot *slot;
@@ -142,7 +144,7 @@ static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 	return size;
 }
 
-static void fetch_alternates(char *base);
+static void fetch_alternates(const char *base);
 
 static void process_object_response(void *callback_data);
 
@@ -507,7 +509,7 @@ static void process_alternates_response(void *callback_data)
 		(struct alternates_request *)callback_data;
 	struct active_request_slot *slot = alt_req->slot;
 	struct alt_base *tail = alt;
-	char *base = alt_req->base;
+	const char *base = alt_req->base;
 	static const char null_byte = '\0';
 	char *data;
 	int i = 0;
@@ -612,7 +614,7 @@ static void process_alternates_response(void *callback_data)
 	got_alternates = 1;
 }
 
-static void fetch_alternates(char *base)
+static void fetch_alternates(const char *base)
 {
 	struct buffer buffer;
 	char *url;
@@ -1185,7 +1187,7 @@ int fetch_ref(char *ref, unsigned char *sha1)
         char *url;
         char hex[42];
         struct buffer buffer;
-	char *base = alt->base;
+	const char *base = alt->base;
 	struct active_request_slot *slot;
 	struct slot_results results;
         buffer.size = 41;
@@ -1214,11 +1216,12 @@ int fetch_ref(char *ref, unsigned char *sha1)
         return 0;
 }
 
-int main(int argc, char **argv)
+int main(int argc, const char **argv)
 {
-	const char *write_ref = NULL;
-	char *commit_id;
-	char *url;
+	int commits;
+	const char **write_ref = NULL;
+	char **commit_id;
+	const char *url;
 	char *path;
 	int arg = 1;
 	int rc = 0;
@@ -1238,19 +1241,26 @@ int main(int argc, char **argv)
 		} else if (argv[arg][1] == 'v') {
 			get_verbosely = 1;
 		} else if (argv[arg][1] == 'w') {
-			write_ref = argv[arg + 1];
+			write_ref = &argv[arg + 1];
 			arg++;
 		} else if (!strcmp(argv[arg], "--recover")) {
 			get_recover = 1;
+		} else if (!strcmp(argv[arg], "--stdin")) {
+			commits_on_stdin = 1;
 		}
 		arg++;
 	}
-	if (argc < arg + 2) {
-		usage("git-http-fetch [-c] [-t] [-a] [-v] [--recover] [-w ref] commit-id url");
+	if (argc < arg + 2 - commits_on_stdin) {
+		usage("git-http-fetch [-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin] commit-id url");
 		return 1;
 	}
-	commit_id = argv[arg];
-	url = argv[arg + 1];
+	if (commits_on_stdin) {
+		commits = pull_targets_stdin(&commit_id, &write_ref);
+	} else {
+		commit_id = (char **) &argv[arg++];
+		commits = 1;
+	}
+	url = argv[arg];
 
 	http_init();
 
@@ -1268,13 +1278,16 @@ int main(int argc, char **argv)
 			alt->path_len = strlen(path);
 	}
 
-	if (pull(1, &commit_id, &write_ref, url))
+	if (pull(commits, commit_id, write_ref, url))
 		rc = 1;
 
 	http_cleanup();
 
 	curl_slist_free_all(no_pragma_header);
 
+	if (commits_on_stdin)
+		pull_targets_free(commits, commit_id, write_ref);
+
 	if (corrupt_object_found) {
 		fprintf(stderr,
 "Some loose object were found to be corrupt, but they might be just\n"