Redesigned the walking/object lookup interface

The old 'git_revpool' object has been removed and
split into two distinct objects with separate
functionality, in order to have separate methods for
object management and object walking.

*	A new object 'git_repository' does the high-level
	management of a repository's objects (commits, trees,
	tags, etc) on top of a 'git_odb'.

	Eventually, it will also manage other repository
	attributes (e.g. tag resolution, references, etc).

	See: src/git/repository.h

*	A new external method
		'git_repository_lookup(repo, oid, type)'
	has been added to the 'git_repository' API.

	All object lookups (git_XXX_lookup()) are now
	wrappers to this method, and duplicated code
	has been removed. The method does automatic type
	checking and returns a generic 'git_revpool_object'
	that can be cast to any specific object.

	See: src/git/repository.h

*	The external methods for object parsing of repository
	objects (git_XXX_parse()) have been removed.

	Loading objects from the repository is now managed
	through the 'lookup' functions. These objects are
	loaded with minimal information, and the relevant
	parsing is done automatically when the user requests
	any of the parsed attributes through accessor methods.

	An attribute has been added to 'git_repository' in
	order to force the parsing of all the repository objects
	immediately after lookup.

	See: src/git/commit.h
	See: src/git/tag.h
	See: src/git/tree.h

*	The previous walking functionality of the revpool
	is now found in 'git_revwalk', which does the actual
	revision walking on a repository; the attributes
	when walking through commits in a database have been
	decoupled from the actual commit objects.
	This increases performance when accessing commits
	during the walk and allows to have several
	'git_revwalk' instances working at the same time on
	top of the same repository, without having to load
	commits in memory several times.

	See: src/git/revwalk.h

*	The old 'git_revpool_table' has been renamed to
	'git_hashtable' and now works as a generic hashtable
	with support for any kind of object and custom hash
	functions.

	See: src/hashtable.h

*	All the relevant unit tests have been updated, renamed
	and grouped accordingly.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/src/repository.c b/src/repository.c
new file mode 100644
index 000000000..dd5b5f70f
--- /dev/null
+++ b/src/repository.c
@@ -0,0 +1,143 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "common.h"
+#include "repository.h"
+#include "commit.h"
+#include "tag.h"
+
+static const int default_table_size = 32;
+static const double max_load_factor = 0.65;
+
+uint32_t git_repository_object_hash(const void *key)
+{
+	uint32_t r;
+	git_oid *id;
+
+	id = (git_oid *)key;
+	memcpy(&r, id->id, sizeof(r));
+	return r;
+}
+
+int git_repository_object_haskey(void *object, const void *key)
+{
+	git_repository_object *obj;
+	git_oid *oid;
+
+	obj = (git_repository_object *)object;
+	oid = (git_oid *)key;
+
+	return (git_oid_cmp(oid, &obj->id) == 0);
+}
+
+git_repository *git_repository_alloc(git_odb *odb)
+{
+	git_repository *repo = git__malloc(sizeof(git_repository));
+	if (!repo)
+		return NULL;
+
+	memset(repo, 0x0, sizeof(git_repository));
+
+	repo->objects = git_hashtable_alloc(
+			default_table_size, 
+			git_repository_object_hash,
+			git_repository_object_haskey);
+
+	if (repo->objects == NULL) {
+		free(repo);
+		return NULL;
+	}
+
+	repo->db = odb; /* TODO: create ODB manually! */
+
+	return repo;
+}
+
+void git_repository_free(git_repository *repo)
+{
+	git_hashtable_iterator it;
+	git_repository_object *object;
+
+	git_hashtable_iterator_init(repo->objects, &it);
+
+	while ((object = (git_repository_object *)
+				git_hashtable_iterator_next(&it)) != NULL) {
+	
+		switch (object->type) {
+		case GIT_OBJ_COMMIT:
+			git_commit__free((git_commit *)object);
+			break;
+
+		case GIT_OBJ_TREE:
+			git_tree__free((git_tree *)object);
+			break;
+
+		case GIT_OBJ_TAG:
+			git_tag__free((git_tag *)object);
+			break;
+
+		default:
+			free(object);
+			break;
+		}
+	}
+
+	git_hashtable_free(repo->objects);
+	/* TODO: free odb */
+	free(repo);
+}
+
+git_repository_object *git_repository_lookup(git_repository *repo, const git_oid *id, git_otype type)
+{
+	git_repository_object *object = NULL;
+	git_obj obj_file;
+
+	assert(repo);
+
+	object = git_hashtable_lookup(repo->objects, id);
+	if (object != NULL)
+		return object;
+
+	if (git_odb_read(&obj_file, repo->db, id) < 0 ||
+		(type != GIT_OBJ_ANY && type != obj_file.type))
+		return NULL;
+
+	object = git__malloc(sizeof(git_commit));
+
+	if (object == NULL)
+		return NULL;
+
+	memset(object, 0x0, sizeof(git_commit));
+
+	/* Initialize parent object */
+	git_oid_cpy(&object->id, id);
+	object->repo = repo;
+	object->type = obj_file.type;
+
+	git_hashtable_insert(repo->objects, &object->id, object);
+	git_obj_close(&obj_file);
+
+	return object;
+}