1 files changed, 247 insertions, 0 deletions
diff --git a/reachable.c b/reachable.c
new file mode 100644
index 0000000000..654a8c58d6
--- /dev/null
+++ b/reachable.c
@@ -0,0 +1,247 @@
+#include "cache.h"
+#include "refs.h"
+#include "tag.h"
+#include "commit.h"
+#include "blob.h"
+#include "diff.h"
+#include "revision.h"
+#include "reachable.h"
+#include "cache-tree.h"
+#include "progress.h"
+
+struct connectivity_progress {
+	struct progress *progress;
+	unsigned long count;
+};
+
+static void update_progress(struct connectivity_progress *cp)
+{
+	cp->count++;
+	if ((cp->count & 1023) == 0)
+		display_progress(cp->progress, cp->count);
+}
+
+static void process_blob(struct blob *blob,
+			 struct object_array *p,
+			 struct name_path *path,
+			 const char *name,
+			 struct connectivity_progress *cp)
+{
+	struct object *obj = &blob->object;
+
+	if (!blob)
+		die("bad blob object");
+	if (obj->flags & SEEN)
+		return;
+	obj->flags |= SEEN;
+	update_progress(cp);
+	/* Nothing to do, really .. The blob lookup was the important part */
+}
+
+static void process_gitlink(const unsigned char *sha1,
+			    struct object_array *p,
+			    struct name_path *path,
+			    const char *name)
+{
+	/* I don't think we want to recurse into this, really. */
+}
+
+static void process_tree(struct tree *tree,
+			 struct object_array *p,
+			 struct name_path *path,
+			 const char *name,
+			 struct connectivity_progress *cp)
+{
+	struct object *obj = &tree->object;
+	struct tree_desc desc;
+	struct name_entry entry;
+	struct name_path me;
+
+	if (!tree)
+		die("bad tree object");
+	if (obj->flags & SEEN)
+		return;
+	obj->flags |= SEEN;
+	update_progress(cp);
+	if (parse_tree(tree) < 0)
+		die("bad tree object %s", sha1_to_hex(obj->sha1));
+	add_object(obj, p, path, name);
+	me.up = path;
+	me.elem = name;
+	me.elem_len = strlen(name);
+
+	init_tree_desc(&desc, tree->buffer, tree->size);
+
+	while (tree_entry(&desc, &entry)) {
+		if (S_ISDIR(entry.mode))
+			process_tree(lookup_tree(entry.sha1), p, &me, entry.path, cp);
+		else if (S_ISGITLINK(entry.mode))
+			process_gitlink(entry.sha1, p, &me, entry.path);
+		else
+			process_blob(lookup_blob(entry.sha1), p, &me, entry.path, cp);
+	}
+	free_tree_buffer(tree);
+}
+
+static void process_tag(struct tag *tag, struct object_array *p,
+			const char *name, struct connectivity_progress *cp)
+{
+	struct object *obj = &tag->object;
+
+	if (obj->flags & SEEN)
+		return;
+	obj->flags |= SEEN;
+	update_progress(cp);
+
+	if (parse_tag(tag) < 0)
+		die("bad tag object %s", sha1_to_hex(obj->sha1));
+	if (tag->tagged)
+		add_object(tag->tagged, p, NULL, name);
+}
+
+static void walk_commit_list(struct rev_info *revs,
+			     struct connectivity_progress *cp)
+{
+	int i;
+	struct commit *commit;
+	struct object_array objects = OBJECT_ARRAY_INIT;
+
+	/* Walk all commits, process their trees */
+	while ((commit = get_revision(revs)) != NULL) {
+		process_tree(commit->tree, &objects, NULL, "", cp);
+		update_progress(cp);
+	}
+
+	/* 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 == OBJ_TAG) {
+			process_tag((struct tag *) obj, &objects, name, cp);
+			continue;
+		}
+		if (obj->type == OBJ_TREE) {
+			process_tree((struct tree *)obj, &objects, NULL, name, cp);
+			continue;
+		}
+		if (obj->type == OBJ_BLOB) {
+			process_blob((struct blob *)obj, &objects, NULL, name, cp);
+			continue;
+		}
+		die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
+	}
+}
+
+static int add_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+		const char *email, unsigned long timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct object *object;
+	struct rev_info *revs = (struct rev_info *)cb_data;
+
+	object = parse_object(osha1);
+	if (object)
+		add_pending_object(revs, object, "");
+	object = parse_object(nsha1);
+	if (object)
+		add_pending_object(revs, object, "");
+	return 0;
+}
+
+static int add_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *object = parse_object_or_die(sha1, path);
+	struct rev_info *revs = (struct rev_info *)cb_data;
+
+	add_pending_object(revs, object, "");
+
+	return 0;
+}
+
+static int add_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	for_each_reflog_ent(path, add_one_reflog_ent, cb_data);
+	return 0;
+}
+
+static void add_one_tree(const unsigned char *sha1, struct rev_info *revs)
+{
+	struct tree *tree = lookup_tree(sha1);
+	if (tree)
+		add_pending_object(revs, &tree->object, "");
+}
+
+static void add_cache_tree(struct cache_tree *it, struct rev_info *revs)
+{
+	int i;
+
+	if (it->entry_count >= 0)
+		add_one_tree(it->sha1, revs);
+	for (i = 0; i < it->subtree_nr; i++)
+		add_cache_tree(it->down[i]->cache_tree, revs);
+}
+
+static void add_cache_refs(struct rev_info *revs)
+{
+	int i;
+
+	read_cache();
+	for (i = 0; i < active_nr; i++) {
+		/*
+		 * The index can contain blobs and GITLINKs, GITLINKs are hashes
+		 * that don't actually point to objects in the repository, it's
+		 * almost guaranteed that they are NOT blobs, so we don't call
+		 * lookup_blob() on them, to avoid populating the hash table
+		 * with invalid information
+		 */
+		if (S_ISGITLINK(active_cache[i]->ce_mode))
+			continue;
+
+		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, revs);
+}
+
+void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
+			    struct progress *progress)
+{
+	struct connectivity_progress cp;
+
+	/*
+	 * Set up revision parsing, and mark us as being interested
+	 * in all object types, not just commits.
+	 */
+	revs->tag_objects = 1;
+	revs->blob_objects = 1;
+	revs->tree_objects = 1;
+
+	/* Add all refs from the index file */
+	add_cache_refs(revs);
+
+	/* Add all external refs */
+	for_each_ref(add_one_ref, revs);
+
+	/* Add all reflog info */
+	if (mark_reflog)
+		for_each_reflog(add_one_reflog, revs);
+
+	cp.progress = progress;
+	cp.count = 0;
+
+	/*
+	 * Set up the revision walk - this will move all commits
+	 * from the pending list to the commit walking list.
+	 */
+	if (prepare_revision_walk(revs))
+		die("revision walk setup failed");
+	walk_commit_list(revs, &cp);
+	display_progress(cp.progress, cp.count);
+}