builtin "git prune"

This actually removes the objects to be pruned, unless you specify "-n"
(at which point it will just tell you which files it would prune).

This doesn't do the pack-file pruning that the shell-script used to do,
but if somebody really wants to, they could add it easily enough. I wonder
how useful it is, though, considering that "git repack -a -d" is just a
lot more efficient and generates a better end result.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 259 insertions, 0 deletions

diff --git a/builtin-prune.c b/builtin-prune.c
new file mode 100644
index 000000000..ebdecee92
--- /dev/null
+++ b/builtin-prune.c
@@ -0,0 +1,259 @@
+#include "cache.h"
+#include "refs.h"
+#include "tag.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "tree-walk.h"
+#include "diff.h"
+#include "revision.h"
+#include "builtin.h"
+#include "cache-tree.h"
+
+static const char prune_usage[] = "git prune [-n]";
+static int show_only = 0;
+static struct rev_info revs;
+
+static int prune_object(char *path, const char *filename, const unsigned char *sha1)
+{
+	if (show_only) {
+		printf("would prune %s/%s\n", path, filename);
+		return 0;
+	}
+	unlink(mkpath("%s/%s", path, filename));
+	rmdir(path);
+	return 0;
+}
+
+static int prune_dir(int i, char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *de;
+
+	if (!dir)
+		return 0;
+
+	while ((de = readdir(dir)) != NULL) {
+		char name[100];
+		unsigned char sha1[20];
+		int len = strlen(de->d_name);
+
+		switch (len) {
+		case 2:
+			if (de->d_name[1] != '.')
+				break;
+		case 1:
+			if (de->d_name[0] != '.')
+				break;
+			continue;
+		case 38:
+			sprintf(name, "%02x", i);
+			memcpy(name+2, de->d_name, len+1);
+			if (get_sha1_hex(name, sha1) < 0)
+				break;
+
+			/*
+			 * Do we know about this object?
+			 * It must have been reachable
+			 */
+			if (lookup_object(sha1))
+				continue;
+
+			prune_object(path, de->d_name, sha1);
+			continue;
+		}
+		fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
+	}
+	closedir(dir);
+	return 0;
+}
+
+static void prune_object_dir(const char *path)
+{
+	int i;
+	for (i = 0; i < 256; i++) {
+		static char dir[4096];
+		sprintf(dir, "%s/%02x", path, i);
+		prune_dir(i, dir);
+	}
+}
+
+static void process_blob(struct blob *blob,
+			 struct object_array *p,
+			 struct name_path *path,
+			 const char *name)
+{
+	struct object *obj = &blob->object;
+
+	if (obj->flags & SEEN)
+		return;
+	obj->flags |= SEEN;
+	/* Nothing to do, really .. The blob lookup was the important part */
+}
+
+static void process_tree(struct tree *tree,
+			 struct object_array *p,
+			 struct name_path *path,
+			 const char *name)
+{
+	struct object *obj = &tree->object;
+	struct tree_desc desc;
+	struct name_entry entry;
+	struct name_path me;
+
+	if (obj->flags & SEEN)
+		return;
+	obj->flags |= SEEN;
+	if (parse_tree(tree) < 0)
+		die("bad tree object %s", sha1_to_hex(obj->sha1));
+	name = strdup(name);
+	add_object(obj, p, path, name);
+	me.up = path;
+	me.elem = name;
+	me.elem_len = strlen(name);
+
+	desc.buf = tree->buffer;
+	desc.size = tree->size;
+
+	while (tree_entry(&desc, &entry)) {
+		if (S_ISDIR(entry.mode))
+			process_tree(lookup_tree(entry.sha1), p, &me, entry.path);
+		else
+			process_blob(lookup_blob(entry.sha1), p, &me, entry.path);
+	}
+	free(tree->buffer);
+	tree->buffer = NULL;
+}
+
+static void process_tag(struct tag *tag, struct object_array *p, const char *name)
+{
+	struct object *obj = &tag->object;
+	struct name_path me;
+
+	if (obj->flags & SEEN)
+		return;
+	obj->flags |= SEEN;
+
+	me.up = NULL;
+	me.elem = "tag:/";
+	me.elem_len = 5;
+
+	if (parse_tag(tag) < 0)
+		die("bad tag object %s", sha1_to_hex(obj->sha1));
+	add_object(tag->tagged, p, NULL, name);
+}
+
+static void walk_commit_list(struct rev_info *revs)
+{
+	int i;
+	struct commit *commit;
+	struct object_array objects = { 0, 0, NULL };
+
+	/* Walk all commits, process their trees */
+	while ((commit = get_revision(revs)) != NULL)
+		process_tree(commit->tree, &objects, NULL, "");
+
+	/* Then walk all the pending objects, recursively processing them too */
+	for (i = 0; i < revs->pending.nr; i++) {
+		struct object_array_entry *pending = revs->pending.objects + i;
+		struct object *obj = pending->item;
+		const char *name = pending->name;
+		if (obj->type == TYPE_TAG) {
+			process_tag((struct tag *) obj, &objects, name);
+			continue;
+		}
+		if (obj->type == TYPE_TREE) {
+			process_tree((struct tree *)obj, &objects, NULL, name);
+			continue;
+		}
+		if (obj->type == TYPE_BLOB) {
+			process_blob((struct blob *)obj, &objects, NULL, name);
+			continue;
+		}
+		die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
+	}
+}
+
+static int add_one_ref(const char *path, const unsigned char *sha1)
+{
+	struct object *object = parse_object(sha1);
+	if (!object)
+		die("bad object ref: %s:%s", path, sha1_to_hex(sha1));
+	add_pending_object(&revs, object, "");
+	return 0;
+}
+
+static void add_one_tree(const unsigned char *sha1)
+{
+	struct tree *tree = lookup_tree(sha1);
+	add_pending_object(&revs, &tree->object, "");
+}
+
+static void add_cache_tree(struct cache_tree *it)
+{
+	int i;
+
+	if (it->entry_count >= 0)
+		add_one_tree(it->sha1);
+	for (i = 0; i < it->subtree_nr; i++)
+		add_cache_tree(it->down[i]->cache_tree);
+}
+
+static void add_cache_refs(void)
+{
+	int i;
+
+	read_cache();
+	for (i = 0; i < active_nr; i++) {
+		lookup_blob(active_cache[i]->sha1);
+		/*
+		 * We could add the blobs to the pending list, but quite
+		 * frankly, we don't care. Once we've looked them up, and
+		 * added them as objects, we've really done everything
+		 * there is to do for a blob
+		 */
+	}
+	if (active_cache_tree)
+		add_cache_tree(active_cache_tree);
+}
+
+int cmd_prune(int argc, const char **argv, char **envp)
+{
+	int i;
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (!strcmp(arg, "-n")) {
+			show_only = 1;
+			continue;
+		}
+		usage(prune_usage);
+	}
+
+	/*
+	 * Set up revision parsing, and mark us as being interested
+	 * in all object types, not just commits.
+	 */
+	init_revisions(&revs);
+	revs.tag_objects = 1;
+	revs.blob_objects = 1;
+	revs.tree_objects = 1;
+
+	/* Add all external refs */
+	for_each_ref(add_one_ref);
+
+	/* Add all refs from the index file */
+	add_cache_refs();
+
+	/*
+	 * Set up the revision walk - this will move all commits
+	 * from the pending list to the commit walking list.
+	 */
+	prepare_revision_walk(&revs);
+
+	walk_commit_list(&revs);
+
+	prune_object_dir(get_object_directory());
+
+	return 0;
+}