Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

1 files changed, 251 insertions, 0 deletions

diff --git a/reachable.c b/reachable.c
new file mode 100644
index 000000000000..8f50235b28ed
--- /dev/null
+++ b/reachable.c
@@ -0,0 +1,251 @@
+#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"
+#include "list-objects.h"
+#include "packfile.h"
+#include "worktree.h"
+#include "object-store.h"
+#include "pack-bitmap.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 int add_one_ref(const char *path, const struct object_id *oid,
+		       int flag, void *cb_data)
+{
+	struct rev_info *revs = (struct rev_info *)cb_data;
+	struct object *object;
+
+	if ((flag & REF_ISSYMREF) && (flag & REF_ISBROKEN)) {
+		warning("symbolic ref is dangling: %s", path);
+		return 0;
+	}
+
+	object = parse_object_or_die(oid, path);
+	add_pending_object(revs, object, "");
+
+	return 0;
+}
+
+/*
+ * The traversal will have already marked us as SEEN, so we
+ * only need to handle any progress reporting here.
+ */
+static void mark_object(struct object *obj, const char *name, void *data)
+{
+	update_progress(data);
+}
+
+static void mark_commit(struct commit *c, void *data)
+{
+	mark_object(&c->object, NULL, data);
+}
+
+struct recent_data {
+	struct rev_info *revs;
+	timestamp_t timestamp;
+};
+
+static void add_recent_object(const struct object_id *oid,
+			      timestamp_t mtime,
+			      struct recent_data *data)
+{
+	struct object *obj;
+	enum object_type type;
+
+	if (mtime <= data->timestamp)
+		return;
+
+	/*
+	 * We do not want to call parse_object here, because
+	 * inflating blobs and trees could be very expensive.
+	 * However, we do need to know the correct type for
+	 * later processing, and the revision machinery expects
+	 * commits and tags to have been parsed.
+	 */
+	type = oid_object_info(the_repository, oid, NULL);
+	if (type < 0)
+		die("unable to get object info for %s", oid_to_hex(oid));
+
+	switch (type) {
+	case OBJ_TAG:
+	case OBJ_COMMIT:
+		obj = parse_object_or_die(oid, NULL);
+		break;
+	case OBJ_TREE:
+		obj = (struct object *)lookup_tree(the_repository, oid);
+		break;
+	case OBJ_BLOB:
+		obj = (struct object *)lookup_blob(the_repository, oid);
+		break;
+	default:
+		die("unknown object type for %s: %s",
+		    oid_to_hex(oid), type_name(type));
+	}
+
+	if (!obj)
+		die("unable to lookup %s", oid_to_hex(oid));
+
+	add_pending_object(data->revs, obj, "");
+}
+
+static int add_recent_loose(const struct object_id *oid,
+			    const char *path, void *data)
+{
+	struct stat st;
+	struct object *obj = lookup_object(the_repository, oid);
+
+	if (obj && obj->flags & SEEN)
+		return 0;
+
+	if (stat(path, &st) < 0) {
+		/*
+		 * It's OK if an object went away during our iteration; this
+		 * could be due to a simultaneous repack. But anything else
+		 * we should abort, since we might then fail to mark objects
+		 * which should not be pruned.
+		 */
+		if (errno == ENOENT)
+			return 0;
+		return error_errno("unable to stat %s", oid_to_hex(oid));
+	}
+
+	add_recent_object(oid, st.st_mtime, data);
+	return 0;
+}
+
+static int add_recent_packed(const struct object_id *oid,
+			     struct packed_git *p, uint32_t pos,
+			     void *data)
+{
+	struct object *obj = lookup_object(the_repository, oid);
+
+	if (obj && obj->flags & SEEN)
+		return 0;
+	add_recent_object(oid, p->mtime, data);
+	return 0;
+}
+
+int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
+					   timestamp_t timestamp)
+{
+	struct recent_data data;
+	int r;
+
+	data.revs = revs;
+	data.timestamp = timestamp;
+
+	r = for_each_loose_object(add_recent_loose, &data,
+				  FOR_EACH_OBJECT_LOCAL_ONLY);
+	if (r)
+		return r;
+	return for_each_packed_object(add_recent_packed, &data,
+				      FOR_EACH_OBJECT_LOCAL_ONLY);
+}
+
+static void *lookup_object_by_type(struct repository *r,
+				   const struct object_id *oid,
+				   enum object_type type)
+{
+	switch (type) {
+	case OBJ_COMMIT:
+		return lookup_commit(r, oid);
+	case OBJ_TREE:
+		return lookup_tree(r, oid);
+	case OBJ_TAG:
+		return lookup_tag(r, oid);
+	case OBJ_BLOB:
+		return lookup_blob(r, oid);
+	default:
+		die("BUG: unknown object type %d", type);
+	}
+}
+
+static int mark_object_seen(const struct object_id *oid,
+			     enum object_type type,
+			     int exclude,
+			     uint32_t name_hash,
+			     struct packed_git *found_pack,
+			     off_t found_offset)
+{
+	struct object *obj = lookup_object_by_type(the_repository, oid, type);
+	if (!obj)
+		die("unable to create object '%s'", oid_to_hex(oid));
+
+	obj->flags |= SEEN;
+	return 0;
+}
+
+void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
+			    timestamp_t mark_recent, struct progress *progress)
+{
+	struct connectivity_progress cp;
+	struct bitmap_index *bitmap_git;
+
+	/*
+	 * 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_index_objects_to_pending(revs, 0);
+
+	/* Add all external refs */
+	for_each_ref(add_one_ref, revs);
+
+	/* detached HEAD is not included in the list above */
+	head_ref(add_one_ref, revs);
+	other_head_refs(add_one_ref, revs);
+
+	/* Add all reflog info */
+	if (mark_reflog)
+		add_reflogs_to_pending(revs, 0);
+
+	cp.progress = progress;
+	cp.count = 0;
+
+	bitmap_git = prepare_bitmap_walk(revs);
+	if (bitmap_git) {
+		traverse_bitmap_commit_list(bitmap_git, mark_object_seen);
+		free_bitmap_index(bitmap_git);
+		return;
+	}
+
+	/*
+	 * 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");
+	traverse_commit_list(revs, mark_commit, mark_object, &cp);
+
+	if (mark_recent) {
+		revs->ignore_missing_links = 1;
+		if (add_unseen_recent_objects_to_traversal(revs, mark_recent))
+			die("unable to mark recent objects");
+		if (prepare_revision_walk(revs))
+			die("revision walk setup failed");
+		traverse_commit_list(revs, mark_commit, mark_object, &cp);
+	}
+
+	display_progress(cp.progress, cp.count);
+}