receive-pack: run "gc --auto --quiet" and optionally "update-server-info"

Introduce two new configuration variables, receive.autogc (defaults to
true) and receive.updateserverinfo (defaults to false).  When these are
set, receive-pack runs "gc --auto --quiet" and "update-server-info"
respectively after it finishes receiving data from "git push" and updating
refs.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>

Documentation/config.txt

@@ -1320,6 +1320,11 @@ rebase.stat::
 	Whether to show a diffstat of what changed upstream since the last
 	rebase. False by default.
 
+receive.autogc::
+	By default, git-receive-pack will run "git-gc --auto" after
+	receiving data from git-push and updating refs.  You can stop
+	it by setting this variable to false.
+
 receive.fsckObjects::
 	If it is set to true, git-receive-pack will check all received
 	objects. It will abort in the case of a malformed object or a
@@ -1355,6 +1360,10 @@ receive.denyNonFastForwards::
 	even if that push is forced. This configuration variable is
 	set when initializing a shared repository.
 
+receive.updateserverinfo::
+	If set to true, git-receive-pack will run git-update-server-info
+	after receiving data from git-push and updating refs.
+
 remote.<name>.url::
 	The URL of a remote repository.  See linkgit:git-fetch[1] or
 	linkgit:git-push[1].

builtin-receive-pack.c

@@ -28,6 +28,8 @@ static int transfer_unpack_limit = -1;
 static int unpack_limit = 100;
 static int report_status;
 static int prefer_ofs_delta = 1;
+static int auto_update_server_info;
+static int auto_gc = 1;
 static const char *head_name;
 static char *capabilities_to_send;
 
@@ -88,6 +90,16 @@ static int receive_pack_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (strcmp(var, "receive.updateserverinfo") == 0) {
+		auto_update_server_info = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (strcmp(var, "receive.autogc") == 0) {
+		auto_gc = git_config_bool(var, value);
+		return 0;
+	}
+
 	return git_default_config(var, value, cb);
 }
 
@@ -672,6 +684,14 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 			report(unpack_status);
 		run_receive_hook(post_receive_hook);
 		run_update_post_hook(commands);
+		if (auto_gc) {
+			const char *argv_gc_auto[] = {
+				"gc", "--auto", "--quiet", NULL,
+			};
+			run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
+		}
+		if (auto_update_server_info)
+			update_server_info(0);
 	}
 	return 0;
 }