metadata: Add metadata factory and implementation for integer types

Co-authored-by: Thomas Egerer <[email protected]>

src/libstrongswan/metadata/metadata_factory.c

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2021 Tobias Brunner, codelabs GmbH
+ * Copyright (C) 2021 Thomas Egerer, secunet AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "metadata_factory.h"
+#include "metadata_int.h"
+
+#include <library.h>
+#include <collections/hashtable.h>
+
+typedef struct private_metadata_factory_t private_metadata_factory_t;
+
+/**
+ * Private data
+ */
+struct private_metadata_factory_t {
+
+	/**
+	 * Public interface
+	 */
+	metadata_factory_t public;
+
+	/**
+	 * Registered metadata types (entry_t)
+	 */
+	hashtable_t *types;
+};
+
+/**
+ * Registered constructor data
+ */
+typedef struct {
+	/** Type name */
+	char *type;
+	/** Constructor */
+	metadata_create_t create;
+} entry_t;
+
+/**
+ * Destroy an entry
+ */
+static void destroy_entry(entry_t *this)
+{
+	if (this)
+	{
+		free(this->type);
+		free(this);
+	}
+}
+
+METHOD(metadata_factory_t, create, metadata_t*,
+	private_metadata_factory_t *this, const char *type, ...)
+{
+	metadata_t *metadata = NULL;
+	entry_t *entry;
+	va_list args;
+
+	entry = this->types->get(this->types, type);
+	if (entry)
+	{
+		va_start(args, type);
+		metadata = entry->create(type, args);
+		va_end(args);
+	}
+	return metadata;
+}
+
+METHOD(metadata_factory_t, register_type, void,
+	private_metadata_factory_t *this, const char *type,
+	metadata_create_t create)
+{
+	entry_t *entry;
+
+	INIT(entry,
+		.type = strdup(type),
+		.create = create,
+	);
+
+	destroy_entry(this->types->put(this->types, entry->type, entry));
+}
+
+METHOD(metadata_factory_t, destroy, void,
+	private_metadata_factory_t *this)
+{
+	this->types->destroy_function(this->types, (void*)destroy_entry);
+	free(this);
+}
+
+metadata_factory_t *metadata_factory_create()
+{
+	private_metadata_factory_t *this;
+
+	INIT(this,
+		.public = {
+			.create = _create,
+			.register_type = _register_type,
+			.destroy = _destroy,
+		},
+		.types = hashtable_create(hashtable_hash_str, hashtable_equals_str, 0),
+	);
+
+	/* register pre-defined types */
+	register_type(this, METADATA_TYPE_INT, metadata_create_int);
+	register_type(this, METADATA_TYPE_UINT64, metadata_create_int);
+
+	return &this->public;
+}