Add --aggressive option to 'git gc'

This option causes 'git gc' to more aggressively optimize the
repository at the cost of taking much more wall clock and CPU time.

Today this option causes git-pack-objects to use --no-use-delta
option, and it allows the --window parameter to be set via the
gc.aggressiveWindow configuration parameter.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 30 insertions, 2 deletions

diff --git a/builtin-gc.c b/builtin-gc.c
index 3b1f8c2f3..8ea165aef 100644
--- a/builtin-gc.c
+++ b/builtin-gc.c
@@ -15,13 +15,15 @@
 
 #define FAILED_RUN "failed to run %s"
 
-static const char builtin_gc_usage[] = "git-gc [--prune]";
+static const char builtin_gc_usage[] = "git-gc [--prune] [--aggressive]";
 
 static int pack_refs = -1;
+static int aggressive_window = -1;
 
+#define MAX_ADD 10
 static const char *argv_pack_refs[] = {"pack-refs", "--prune", NULL};
 static const char *argv_reflog[] = {"reflog", "expire", "--all", NULL};
-static const char *argv_repack[] = {"repack", "-a", "-d", "-l", NULL};
+static const char *argv_repack[MAX_ADD] = {"repack", "-a", "-d", "-l", NULL};
 static const char *argv_prune[] = {"prune", NULL};
 static const char *argv_rerere[] = {"rerere", "gc", NULL};
 
@@ -34,13 +36,31 @@ static int gc_config(const char *var, const char *value)
 			pack_refs = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "gc.aggressivewindow")) {
+		aggressive_window = git_config_int(var, value);
+		return 0;
+	}
 	return git_default_config(var, value);
 }
 
+static void append_option(const char **cmd, const char *opt, int max_length)
+{
+	int i;
+
+	for (i = 0; cmd[i]; i++)
+		;
+
+	if (i + 2 >= max_length)
+		die("Too many options specified");
+	cmd[i++] = opt;
+	cmd[i] = NULL;
+}
+
 int cmd_gc(int argc, const char **argv, const char *prefix)
 {
 	int i;
 	int prune = 0;
+	char buf[80];
 
 	git_config(gc_config);
 
@@ -53,6 +73,14 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 			prune = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--aggressive")) {
+			append_option(argv_repack, "-f", MAX_ADD);
+			if (aggressive_window > 0) {
+				sprintf(buf, "--window=%d", aggressive_window);
+				append_option(argv_repack, buf, MAX_ADD);
+			}
+			continue;
+		}
 		/* perhaps other parameters later... */
 		break;
 	}