make datastore creation and destruction a generic API since it is not really channel related, and add the ability to add/find/remove datastores to manager sessions

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@135680 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/datastore.h

@@ -0,0 +1,78 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2007 - 2008, Digium, Inc.
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ * \brief Asterisk datastore objects
+ */
+
+#ifndef _ASTERISK_DATASTORE_H
+#define _ASTERISK_DATASTORE_H
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+#include "asterisk/linkedlists.h"
+
+#define DATASTORE_INHERIT_FOREVER	INT_MAX
+
+/*! \brief Structure for a data store type */
+struct ast_datastore_info {
+	const char *type;			/*!< Type of data store */
+	void *(*duplicate)(void *data);		/*!< Duplicate item data (used for inheritance) */
+	void (*destroy)(void *data);		/*!< Destroy function */
+
+	/*!
+	 * \brief Fix up channel references
+	 *
+	 * \arg data The datastore data
+	 * \arg old_chan The old channel owning the datastore
+	 * \arg new_chan The new channel owning the datastore
+	 *
+	 * This is exactly like the fixup callback of the channel technology interface.
+	 * It allows a datastore to fix any pointers it saved to the owning channel
+	 * in case that the owning channel has changed.  Generally, this would happen
+	 * when the datastore is set to be inherited, and a masquerade occurs.
+	 *
+	 * \return nothing.
+	 */
+	void (*chan_fixup)(void *data, struct ast_channel *old_chan, struct ast_channel *new_chan);
+};
+
+/*! \brief Structure for a data store object */
+struct ast_datastore {
+	const char *uid;			/*!< Unique data store identifier */
+	void *data;				/*!< Contained data */
+	const struct ast_datastore_info *info;	/*!< Data store type information */
+	unsigned int inheritance;		/*!< Number of levels this item will continue to be inherited */
+	AST_LIST_ENTRY(ast_datastore) entry; 	/*!< Used for easy linking */
+};
+
+/*! 
+ * \brief Create a data store object
+ */
+struct ast_datastore *ast_datastore_alloc(const struct ast_datastore_info *info, const char *uid);
+
+/*!
+ * \brief Free a data store object
+ */
+int ast_datastore_free(struct ast_datastore *datastore);
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}
+#endif
+
+#endif /* _ASTERISK_DATASTORE_H */