Squashed 'third_party/git/' content from commit cb71568594

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

1 files changed, 567 insertions, 0 deletions

diff --git a/object.c b/object.c
new file mode 100644
index 000000000000..07bdd5b26e2b
--- /dev/null
+++ b/object.c
@@ -0,0 +1,567 @@
+#include "cache.h"
+#include "object.h"
+#include "replace-object.h"
+#include "object-store.h"
+#include "blob.h"
+#include "tree.h"
+#include "commit.h"
+#include "tag.h"
+#include "alloc.h"
+#include "object-store.h"
+#include "packfile.h"
+#include "commit-graph.h"
+
+unsigned int get_max_object_index(void)
+{
+	return the_repository->parsed_objects->obj_hash_size;
+}
+
+struct object *get_indexed_object(unsigned int idx)
+{
+	return the_repository->parsed_objects->obj_hash[idx];
+}
+
+static const char *object_type_strings[] = {
+	NULL,		/* OBJ_NONE = 0 */
+	"commit",	/* OBJ_COMMIT = 1 */
+	"tree",		/* OBJ_TREE = 2 */
+	"blob",		/* OBJ_BLOB = 3 */
+	"tag",		/* OBJ_TAG = 4 */
+};
+
+const char *type_name(unsigned int type)
+{
+	if (type >= ARRAY_SIZE(object_type_strings))
+		return NULL;
+	return object_type_strings[type];
+}
+
+int type_from_string_gently(const char *str, ssize_t len, int gentle)
+{
+	int i;
+
+	if (len < 0)
+		len = strlen(str);
+
+	for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
+		if (!strncmp(str, object_type_strings[i], len) &&
+		    object_type_strings[i][len] == '\0')
+			return i;
+
+	if (gentle)
+		return -1;
+
+	die(_("invalid object type \"%s\""), str);
+}
+
+/*
+ * Return a numerical hash value between 0 and n-1 for the object with
+ * the specified sha1.  n must be a power of 2.  Please note that the
+ * return value is *not* consistent across computer architectures.
+ */
+static unsigned int hash_obj(const struct object_id *oid, unsigned int n)
+{
+	return oidhash(oid) & (n - 1);
+}
+
+/*
+ * Insert obj into the hash table hash, which has length size (which
+ * must be a power of 2).  On collisions, simply overflow to the next
+ * empty bucket.
+ */
+static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
+{
+	unsigned int j = hash_obj(&obj->oid, size);
+
+	while (hash[j]) {
+		j++;
+		if (j >= size)
+			j = 0;
+	}
+	hash[j] = obj;
+}
+
+/*
+ * Look up the record for the given sha1 in the hash map stored in
+ * obj_hash.  Return NULL if it was not found.
+ */
+struct object *lookup_object(struct repository *r, const struct object_id *oid)
+{
+	unsigned int i, first;
+	struct object *obj;
+
+	if (!r->parsed_objects->obj_hash)
+		return NULL;
+
+	first = i = hash_obj(oid, r->parsed_objects->obj_hash_size);
+	while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
+		if (oideq(oid, &obj->oid))
+			break;
+		i++;
+		if (i == r->parsed_objects->obj_hash_size)
+			i = 0;
+	}
+	if (obj && i != first) {
+		/*
+		 * Move object to where we started to look for it so
+		 * that we do not need to walk the hash table the next
+		 * time we look for it.
+		 */
+		SWAP(r->parsed_objects->obj_hash[i],
+		     r->parsed_objects->obj_hash[first]);
+	}
+	return obj;
+}
+
+/*
+ * Increase the size of the hash map stored in obj_hash to the next
+ * power of 2 (but at least 32).  Copy the existing values to the new
+ * hash map.
+ */
+static void grow_object_hash(struct repository *r)
+{
+	int i;
+	/*
+	 * Note that this size must always be power-of-2 to match hash_obj
+	 * above.
+	 */
+	int new_hash_size = r->parsed_objects->obj_hash_size < 32 ? 32 : 2 * r->parsed_objects->obj_hash_size;
+	struct object **new_hash;
+
+	new_hash = xcalloc(new_hash_size, sizeof(struct object *));
+	for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
+		struct object *obj = r->parsed_objects->obj_hash[i];
+
+		if (!obj)
+			continue;
+		insert_obj_hash(obj, new_hash, new_hash_size);
+	}
+	free(r->parsed_objects->obj_hash);
+	r->parsed_objects->obj_hash = new_hash;
+	r->parsed_objects->obj_hash_size = new_hash_size;
+}
+
+void *create_object(struct repository *r, const struct object_id *oid, void *o)
+{
+	struct object *obj = o;
+
+	obj->parsed = 0;
+	obj->flags = 0;
+	oidcpy(&obj->oid, oid);
+
+	if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
+		grow_object_hash(r);
+
+	insert_obj_hash(obj, r->parsed_objects->obj_hash,
+			r->parsed_objects->obj_hash_size);
+	r->parsed_objects->nr_objs++;
+	return obj;
+}
+
+void *object_as_type(struct repository *r, struct object *obj, enum object_type type, int quiet)
+{
+	if (obj->type == type)
+		return obj;
+	else if (obj->type == OBJ_NONE) {
+		if (type == OBJ_COMMIT)
+			init_commit_node(r, (struct commit *) obj);
+		else
+			obj->type = type;
+		return obj;
+	}
+	else {
+		if (!quiet)
+			error(_("object %s is a %s, not a %s"),
+			      oid_to_hex(&obj->oid),
+			      type_name(obj->type), type_name(type));
+		return NULL;
+	}
+}
+
+struct object *lookup_unknown_object(const struct object_id *oid)
+{
+	struct object *obj = lookup_object(the_repository, oid);
+	if (!obj)
+		obj = create_object(the_repository, oid,
+				    alloc_object_node(the_repository));
+	return obj;
+}
+
+struct object *parse_object_buffer(struct repository *r, const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
+{
+	struct object *obj;
+	*eaten_p = 0;
+
+	obj = NULL;
+	if (type == OBJ_BLOB) {
+		struct blob *blob = lookup_blob(r, oid);
+		if (blob) {
+			if (parse_blob_buffer(blob, buffer, size))
+				return NULL;
+			obj = &blob->object;
+		}
+	} else if (type == OBJ_TREE) {
+		struct tree *tree = lookup_tree(r, oid);
+		if (tree) {
+			obj = &tree->object;
+			if (!tree->buffer)
+				tree->object.parsed = 0;
+			if (!tree->object.parsed) {
+				if (parse_tree_buffer(tree, buffer, size))
+					return NULL;
+				*eaten_p = 1;
+			}
+		}
+	} else if (type == OBJ_COMMIT) {
+		struct commit *commit = lookup_commit(r, oid);
+		if (commit) {
+			if (parse_commit_buffer(r, commit, buffer, size, 1))
+				return NULL;
+			if (!get_cached_commit_buffer(r, commit, NULL)) {
+				set_commit_buffer(r, commit, buffer, size);
+				*eaten_p = 1;
+			}
+			obj = &commit->object;
+		}
+	} else if (type == OBJ_TAG) {
+		struct tag *tag = lookup_tag(r, oid);
+		if (tag) {
+			if (parse_tag_buffer(r, tag, buffer, size))
+			       return NULL;
+			obj = &tag->object;
+		}
+	} else {
+		warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
+		obj = NULL;
+	}
+	return obj;
+}
+
+struct object *parse_object_or_die(const struct object_id *oid,
+				   const char *name)
+{
+	struct object *o = parse_object(the_repository, oid);
+	if (o)
+		return o;
+
+	die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
+}
+
+struct object *parse_object(struct repository *r, const struct object_id *oid)
+{
+	unsigned long size;
+	enum object_type type;
+	int eaten;
+	const struct object_id *repl = lookup_replace_object(r, oid);
+	void *buffer;
+	struct object *obj;
+
+	obj = lookup_object(r, oid);
+	if (obj && obj->parsed)
+		return obj;
+
+	if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
+	    (!obj && repo_has_object_file(r, oid) &&
+	     oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
+		if (check_object_signature(repl, NULL, 0, NULL) < 0) {
+			error(_("hash mismatch %s"), oid_to_hex(oid));
+			return NULL;
+		}
+		parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
+		return lookup_object(r, oid);
+	}
+
+	buffer = repo_read_object_file(r, oid, &type, &size);
+	if (buffer) {
+		if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
+			free(buffer);
+			error(_("hash mismatch %s"), oid_to_hex(repl));
+			return NULL;
+		}
+
+		obj = parse_object_buffer(r, oid, type, size,
+					  buffer, &eaten);
+		if (!eaten)
+			free(buffer);
+		return obj;
+	}
+	return NULL;
+}
+
+struct object_list *object_list_insert(struct object *item,
+				       struct object_list **list_p)
+{
+	struct object_list *new_list = xmalloc(sizeof(struct object_list));
+	new_list->item = item;
+	new_list->next = *list_p;
+	*list_p = new_list;
+	return new_list;
+}
+
+int object_list_contains(struct object_list *list, struct object *obj)
+{
+	while (list) {
+		if (list->item == obj)
+			return 1;
+		list = list->next;
+	}
+	return 0;
+}
+
+/*
+ * A zero-length string to which object_array_entry::name can be
+ * initialized without requiring a malloc/free.
+ */
+static char object_array_slopbuf[1];
+
+void add_object_array_with_path(struct object *obj, const char *name,
+				struct object_array *array,
+				unsigned mode, const char *path)
+{
+	unsigned nr = array->nr;
+	unsigned alloc = array->alloc;
+	struct object_array_entry *objects = array->objects;
+	struct object_array_entry *entry;
+
+	if (nr >= alloc) {
+		alloc = (alloc + 32) * 2;
+		REALLOC_ARRAY(objects, alloc);
+		array->alloc = alloc;
+		array->objects = objects;
+	}
+	entry = &objects[nr];
+	entry->item = obj;
+	if (!name)
+		entry->name = NULL;
+	else if (!*name)
+		/* Use our own empty string instead of allocating one: */
+		entry->name = object_array_slopbuf;
+	else
+		entry->name = xstrdup(name);
+	entry->mode = mode;
+	if (path)
+		entry->path = xstrdup(path);
+	else
+		entry->path = NULL;
+	array->nr = ++nr;
+}
+
+void add_object_array(struct object *obj, const char *name, struct object_array *array)
+{
+	add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
+}
+
+/*
+ * Free all memory associated with an entry; the result is
+ * in an unspecified state and should not be examined.
+ */
+static void object_array_release_entry(struct object_array_entry *ent)
+{
+	if (ent->name != object_array_slopbuf)
+		free(ent->name);
+	free(ent->path);
+}
+
+struct object *object_array_pop(struct object_array *array)
+{
+	struct object *ret;
+
+	if (!array->nr)
+		return NULL;
+
+	ret = array->objects[array->nr - 1].item;
+	object_array_release_entry(&array->objects[array->nr - 1]);
+	array->nr--;
+	return ret;
+}
+
+void object_array_filter(struct object_array *array,
+			 object_array_each_func_t want, void *cb_data)
+{
+	unsigned nr = array->nr, src, dst;
+	struct object_array_entry *objects = array->objects;
+
+	for (src = dst = 0; src < nr; src++) {
+		if (want(&objects[src], cb_data)) {
+			if (src != dst)
+				objects[dst] = objects[src];
+			dst++;
+		} else {
+			object_array_release_entry(&objects[src]);
+		}
+	}
+	array->nr = dst;
+}
+
+void object_array_clear(struct object_array *array)
+{
+	int i;
+	for (i = 0; i < array->nr; i++)
+		object_array_release_entry(&array->objects[i]);
+	FREE_AND_NULL(array->objects);
+	array->nr = array->alloc = 0;
+}
+
+/*
+ * Return true iff array already contains an entry with name.
+ */
+static int contains_name(struct object_array *array, const char *name)
+{
+	unsigned nr = array->nr, i;
+	struct object_array_entry *object = array->objects;
+
+	for (i = 0; i < nr; i++, object++)
+		if (!strcmp(object->name, name))
+			return 1;
+	return 0;
+}
+
+void object_array_remove_duplicates(struct object_array *array)
+{
+	unsigned nr = array->nr, src;
+	struct object_array_entry *objects = array->objects;
+
+	array->nr = 0;
+	for (src = 0; src < nr; src++) {
+		if (!contains_name(array, objects[src].name)) {
+			if (src != array->nr)
+				objects[array->nr] = objects[src];
+			array->nr++;
+		} else {
+			object_array_release_entry(&objects[src]);
+		}
+	}
+}
+
+void clear_object_flags(unsigned flags)
+{
+	int i;
+
+	for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
+		struct object *obj = the_repository->parsed_objects->obj_hash[i];
+		if (obj)
+			obj->flags &= ~flags;
+	}
+}
+
+void clear_commit_marks_all(unsigned int flags)
+{
+	int i;
+
+	for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
+		struct object *obj = the_repository->parsed_objects->obj_hash[i];
+		if (obj && obj->type == OBJ_COMMIT)
+			obj->flags &= ~flags;
+	}
+}
+
+struct parsed_object_pool *parsed_object_pool_new(void)
+{
+	struct parsed_object_pool *o = xmalloc(sizeof(*o));
+	memset(o, 0, sizeof(*o));
+
+	o->blob_state = allocate_alloc_state();
+	o->tree_state = allocate_alloc_state();
+	o->commit_state = allocate_alloc_state();
+	o->tag_state = allocate_alloc_state();
+	o->object_state = allocate_alloc_state();
+
+	o->is_shallow = -1;
+	o->shallow_stat = xcalloc(1, sizeof(*o->shallow_stat));
+
+	o->buffer_slab = allocate_commit_buffer_slab();
+
+	return o;
+}
+
+struct raw_object_store *raw_object_store_new(void)
+{
+	struct raw_object_store *o = xmalloc(sizeof(*o));
+
+	memset(o, 0, sizeof(*o));
+	INIT_LIST_HEAD(&o->packed_git_mru);
+	return o;
+}
+
+static void free_object_directory(struct object_directory *odb)
+{
+	free(odb->path);
+	odb_clear_loose_cache(odb);
+	free(odb);
+}
+
+static void free_object_directories(struct raw_object_store *o)
+{
+	while (o->odb) {
+		struct object_directory *next;
+
+		next = o->odb->next;
+		free_object_directory(o->odb);
+		o->odb = next;
+	}
+}
+
+void raw_object_store_clear(struct raw_object_store *o)
+{
+	FREE_AND_NULL(o->alternate_db);
+
+	oidmap_free(o->replace_map, 1);
+	FREE_AND_NULL(o->replace_map);
+
+	free_commit_graph(o->commit_graph);
+	o->commit_graph = NULL;
+	o->commit_graph_attempted = 0;
+
+	free_object_directories(o);
+	o->odb_tail = NULL;
+	o->loaded_alternates = 0;
+
+	INIT_LIST_HEAD(&o->packed_git_mru);
+	close_object_store(o);
+	o->packed_git = NULL;
+}
+
+void parsed_object_pool_clear(struct parsed_object_pool *o)
+{
+	/*
+	 * As objects are allocated in slabs (see alloc.c), we do
+	 * not need to free each object, but each slab instead.
+	 *
+	 * Before doing so, we need to free any additional memory
+	 * the objects may hold.
+	 */
+	unsigned i;
+
+	for (i = 0; i < o->obj_hash_size; i++) {
+		struct object *obj = o->obj_hash[i];
+
+		if (!obj)
+			continue;
+
+		if (obj->type == OBJ_TREE)
+			free_tree_buffer((struct tree*)obj);
+		else if (obj->type == OBJ_COMMIT)
+			release_commit_memory(o, (struct commit*)obj);
+		else if (obj->type == OBJ_TAG)
+			release_tag_memory((struct tag*)obj);
+	}
+
+	FREE_AND_NULL(o->obj_hash);
+	o->obj_hash_size = 0;
+
+	free_commit_buffer_slab(o->buffer_slab);
+	o->buffer_slab = NULL;
+
+	clear_alloc_state(o->blob_state);
+	clear_alloc_state(o->tree_state);
+	clear_alloc_state(o->commit_state);
+	clear_alloc_state(o->tag_state);
+	clear_alloc_state(o->object_state);
+	stat_validity_clear(o->shallow_stat);
+	FREE_AND_NULL(o->blob_state);
+	FREE_AND_NULL(o->tree_state);
+	FREE_AND_NULL(o->commit_state);
+	FREE_AND_NULL(o->tag_state);
+	FREE_AND_NULL(o->object_state);
+	FREE_AND_NULL(o->shallow_stat);
+}