Add "--expire <time>" option to 'git prune'

dscho · gitster · commit f01913e4190b · 2007-11-30T15:47:01.000-08:00
Earlier, 'git prune' would prune all loose unreachable objects.
This could be quite dangerous, as the objects could be used in
an ongoing operation.

This patch adds a mode to expire only loose, unreachable objects
which are older than a certain time.  For example, by

	git prune --expire 14.days

you can prune only those objects which are loose, unreachable
and older than 14 days (and thus probably outdated).

The implementation uses st.st_mtime rather than st.st_ctime,
because it can be tested better, using 'touch -d &lt;time&gt;' (and
omitting the test when the platform does not support that
command line switch).

Signed-off-by: Johannes Schindelin &lt;johannes.schindelin@gmx.de&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Documentation/git-prune.txt b/Documentation/git-prune.txt
@@ -8,7 +8,7 @@ git-prune - Prune all unreachable objects from the object database
 
 SYNOPSIS
 --------
-'git-prune' [-n] [--] [<head>...]
+'git-prune' [-n] [--expire <expire>] [--] [<head>...]
 
 DESCRIPTION
 -----------
@@ -31,6 +31,9 @@ OPTIONS
 \--::
 	Do not interpret any more arguments as options.
 
+\--expire <time>::
+	Only expire loose objects older than <time>.
+
 <head>...::
 	In addition to objects
 	reachable from any of our references, keep objects
diff --git a/builtin-prune.c b/builtin-prune.c
@@ -7,15 +7,24 @@
 
 static const char prune_usage[] = "git-prune [-n]";
 static int show_only;
+static unsigned long expire;
 
 static int prune_object(char *path, const char *filename, const unsigned char *sha1)
 {
+	const char *fullpath = mkpath("%s/%s", path, filename);
+	if (expire) {
+		struct stat st;
+		if (lstat(fullpath, &st))
+			return error("Could not stat '%s'", fullpath);
+		if (st.st_mtime > expire)
+			return 0;
+	}
 	if (show_only) {
 		enum object_type type = sha1_object_info(sha1, NULL);
 		printf("%s %s\n", sha1_to_hex(sha1),
 		       (type > 0) ? typename(type) : "unknown");
 	} else
-		unlink(mkpath("%s/%s", path, filename));
+		unlink(fullpath);
 	return 0;
 }
 
@@ -85,6 +94,16 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 			show_only = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--expire")) {
+			if (++i < argc) {
+				expire = approxidate(argv[i]);
+				continue;
+			}
+		}
+		else if (!prefixcmp(arg, "--expire=")) {
+			expire = approxidate(arg + 9);
+			continue;
+		}
 		usage(prune_usage);
 	}
 
diff --git a/t/t1410-reflog.sh b/t/t1410-reflog.sh
@@ -175,4 +175,22 @@ test_expect_success 'recover and check' '
 
 '
 
+test_expect_success 'prune --expire' '
+
+	before=$(git count-objects | sed "s/ .*//") &&
+	BLOB=$(echo aleph | git hash-object -w --stdin) &&
+	BLOB_FILE=.git/objects/$(echo $BLOB | sed "s/^../&\//") &&
+	test $((1 + $before)) = $(git count-objects | sed "s/ .*//") &&
+	test -f $BLOB_FILE &&
+	git reset --hard &&
+	git prune --expire=1.hour.ago &&
+	test $((1 + $before)) = $(git count-objects | sed "s/ .*//") &&
+	test -f $BLOB_FILE &&
+	test-chmtime -86500 $BLOB_FILE &&
+	git prune --expire 1.day &&
+	test $before = $(git count-objects | sed "s/ .*//") &&
+	! test -f $BLOB_FILE
+
+'
+
 test_done
