Add callback to git_objects_table

This adds create and free callback to the git_objects_table so
that more of the creation and destruction of objects can be table
driven instead of using switch statements.  This also makes the
semantics of certain object creation functions consistent so that
we can make better use of function pointers.  This also fixes a
theoretical error case where an object allocation fails and we
end up storing NULL into the cache.

1 files changed, 20 insertions, 11 deletions

diff --git a/src/odb.c b/src/odb.c
index 16a842aa8..53630dddc 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -82,23 +82,24 @@ int git_odb__hashobj(git_oid *id, git_rawobj *obj)
 }
 
 
-static git_odb_object *new_odb_object(const git_oid *oid, git_rawobj *source)
+static git_odb_object *odb_object__alloc(const git_oid *oid, git_rawobj *source)
 {
-	git_odb_object *object = git__malloc(sizeof(git_odb_object));
-	memset(object, 0x0, sizeof(git_odb_object));
+	git_odb_object *object = git__calloc(1, sizeof(git_odb_object));
 
-	git_oid_cpy(&object->cached.oid, oid);
-	object->cached.size = source->len;
-	object->cached.type = source->type;
-	object->buffer = source->data;
+	if (object != NULL) {
+		git_oid_cpy(&object->cached.oid, oid);
+		object->cached.type = source->type;
+		object->cached.size = source->len;
+		object->buffer      = source->data;
+	}
 
 	return object;
 }
 
-void git_odb_object__free(git_odb_object *object)
+void git_odb_object__free(void *object)
 {
 	if (object != NULL) {
-		git__free(object->buffer);
+		git__free(((git_odb_object *)object)->buffer);
 		git__free(object);
 	}
 }
@@ -679,6 +680,7 @@ int git_odb_read(git_odb_object **out, git_odb *db, const git_oid *id)
 	int error;
 	bool refreshed = false;
 	git_rawobj raw;
+	git_odb_object *object;
 
 	assert(out && db && id);
 
@@ -713,7 +715,10 @@ attempt_lookup:
 	if (error && error != GIT_PASSTHROUGH)
 		return error;
 
-	*out = git_cache_store_raw(odb_cache(db), new_odb_object(id, &raw));
+	if ((object = odb_object__alloc(id, &raw)) == NULL)
+		return -1;
+
+	*out = git_cache_store_raw(odb_cache(db), object);
 	return 0;
 }
 
@@ -726,6 +731,7 @@ int git_odb_read_prefix(
 	git_rawobj raw;
 	void *data = NULL;
 	bool found = false, refreshed = false;
+	git_odb_object *object;
 
 	assert(out && db);
 
@@ -777,7 +783,10 @@ attempt_lookup:
 	if (!found)
 		return git_odb__error_notfound("no match for prefix", short_id);
 
-	*out = git_cache_store_raw(odb_cache(db), new_odb_object(&found_full_oid, &raw));
+	if ((object = odb_object__alloc(&found_full_oid, &raw)) == NULL)
+		return -1;
+
+	*out = git_cache_store_raw(odb_cache(db), object);
 	return 0;
 }