Merge the sorcery data access layer API.

Sorcery is a unifying data access layer which provides a pluggable mechanism to allow
object creation, retrieval, updating, and deletion using different backends (or wizards).

This is a fancy way of saying "one interface to rule them all" where them is configuration,
realtime, and anything else that comes along.

Review: https://reviewboard.asterisk.org/r/2259/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@380069 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 346 insertions, 0 deletions

diff --git a/res/res_sorcery_config.c b/res/res_sorcery_config.c
new file mode 100644
index 000000000..9fe636d68
--- /dev/null
+++ b/res/res_sorcery_config.c
@@ -0,0 +1,346 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2012 - 2013, Digium, Inc.
+ *
+ * Joshua Colp <jcolp@digium.com>
+ *
+ * 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 Sorcery Configuration File Object Wizard
+ *
+ * \author Joshua Colp <jcolp@digium.com>
+ */
+
+/*** MODULEINFO
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/module.h"
+#include "asterisk/sorcery.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/config.h"
+
+/*! \brief Default number of buckets for sorcery objects */
+#define DEFAULT_OBJECT_BUCKETS 53
+
+/*! \brief Structure for storing configuration file sourced objects */
+struct sorcery_config {
+	/*! \brief Objects retrieved from the configuration file */
+	struct ao2_global_obj objects;
+
+	/*! \brief Any specific variable criteria for considering a defined category for this object */
+	struct ast_variable *criteria;
+
+	/*! \brief Number of buckets to use for objects */
+	unsigned int buckets;
+
+	/*! \brief Enable file level integrity instead of object level */
+	unsigned int file_integrity:1;
+
+	/*! \brief Filename of the configuration file */
+	char filename[];
+};
+
+/*! \brief Structure used for fields comparison */
+struct sorcery_config_fields_cmp_params {
+	/*! \brief Pointer to the sorcery structure */
+	const struct ast_sorcery *sorcery;
+
+	/*! \brief Pointer to the fields to check */
+	const struct ast_variable *fields;
+
+	/*! \brief Optional container to put object into */
+	struct ao2_container *container;
+};
+
+static void *sorcery_config_open(const char *data);
+static void sorcery_config_load(void *data, const struct ast_sorcery *sorcery, const char *type);
+static void sorcery_config_reload(void *data, const struct ast_sorcery *sorcery, const char *type);
+static void *sorcery_config_retrieve_id(const struct ast_sorcery *sorcery, void *data, const char *type, const char *id);
+static void *sorcery_config_retrieve_fields(const struct ast_sorcery *sorcery, void *data, const char *type, const struct ast_variable *fields);
+static void sorcery_config_retrieve_multiple(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects,
+					     const struct ast_variable *fields);
+static void sorcery_config_close(void *data);
+
+static struct ast_sorcery_wizard config_object_wizard = {
+	.name = "config",
+	.open = sorcery_config_open,
+	.load = sorcery_config_load,
+	.reload = sorcery_config_reload,
+	.retrieve_id = sorcery_config_retrieve_id,
+	.retrieve_fields = sorcery_config_retrieve_fields,
+	.retrieve_multiple = sorcery_config_retrieve_multiple,
+	.close = sorcery_config_close,
+};
+
+/*! \brief Destructor function for sorcery config */
+static void sorcery_config_destructor(void *obj)
+{
+	struct sorcery_config *config = obj;
+
+	ao2_global_obj_release(config->objects);
+	ast_rwlock_destroy(&config->objects.lock);
+	ast_variables_destroy(config->criteria);
+}
+
+/*! \brief Hashing function for sorcery objects */
+static int sorcery_config_hash(const void *obj, const int flags)
+{
+	const char *id = obj;
+
+	return ast_str_hash(flags & OBJ_KEY ? id : ast_sorcery_object_get_id(obj));
+}
+
+/*! \brief Comparator function for sorcery objects */
+static int sorcery_config_cmp(void *obj, void *arg, int flags)
+{
+	const char *id = arg;
+
+	return !strcmp(ast_sorcery_object_get_id(obj), flags & OBJ_KEY ? id : ast_sorcery_object_get_id(arg)) ? CMP_MATCH | CMP_STOP : 0;
+}
+
+static int sorcery_config_fields_cmp(void *obj, void *arg, int flags)
+{
+	const struct sorcery_config_fields_cmp_params *params = arg;
+	RAII_VAR(struct ast_variable *, objset, NULL, ast_variables_destroy);
+	RAII_VAR(struct ast_variable *, diff, NULL, ast_variables_destroy);
+
+	/* If we can't turn the object into an object set OR if differences exist between the fields
+	 * passed in and what are present on the object they are not a match.
+	 */
+	if (params->fields &&
+	    (!(objset = ast_sorcery_objectset_create(params->sorcery, obj)) ||
+	     (ast_sorcery_changeset_create(objset, params->fields, &diff)) ||
+	     diff)) {
+		return 0;
+	}
+
+	if (params->container) {
+		ao2_link(params->container, obj);
+
+		/* As multiple objects are being returned keep going */
+		return 0;
+	} else {
+		/* Immediately stop and return, we only want a single object */
+		return CMP_MATCH | CMP_STOP;
+	}
+}
+
+static void *sorcery_config_retrieve_fields(const struct ast_sorcery *sorcery, void *data, const char *type, const struct ast_variable *fields)
+{
+	struct sorcery_config *config = data;
+	RAII_VAR(struct ao2_container *, objects, ao2_global_obj_ref(config->objects), ao2_cleanup);
+	struct sorcery_config_fields_cmp_params params = {
+		.sorcery = sorcery,
+		.fields = fields,
+		.container = NULL,
+	};
+
+	/* If no fields are present return nothing, we require *something*, same goes if no objects exist yet */
+	if (!objects || !fields) {
+		return NULL;
+	}
+
+	return ao2_callback(objects, 0, sorcery_config_fields_cmp, &params);
+}
+
+static void *sorcery_config_retrieve_id(const struct ast_sorcery *sorcery, void *data, const char *type, const char *id)
+{
+	struct sorcery_config *config = data;
+	RAII_VAR(struct ao2_container *, objects, ao2_global_obj_ref(config->objects), ao2_cleanup);
+
+	return objects ? ao2_find(objects, id, OBJ_KEY | OBJ_NOLOCK) : NULL;
+}
+
+static void sorcery_config_retrieve_multiple(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const struct ast_variable *fields)
+{
+	struct sorcery_config *config = data;
+	RAII_VAR(struct ao2_container *, config_objects, ao2_global_obj_ref(config->objects), ao2_cleanup);
+	struct sorcery_config_fields_cmp_params params = {
+		.sorcery = sorcery,
+		.fields = fields,
+		.container = objects,
+	};
+
+	if (!config_objects) {
+		return;
+	}
+
+	ao2_callback(config_objects, 0, sorcery_config_fields_cmp, &params);
+}
+
+/*! \brief Internal function which determines if criteria has been met for considering an object set applicable */
+static int sorcery_is_criteria_met(struct ast_variable *objset, struct ast_variable *criteria)
+{
+	RAII_VAR(struct ast_variable *, diff, NULL, ast_variables_destroy);
+
+	return (!criteria || (!ast_sorcery_changeset_create(objset, criteria, &diff) && !diff)) ? 1 : 0;
+}
+
+static void sorcery_config_internal_load(void *data, const struct ast_sorcery *sorcery, const char *type, unsigned int reload)
+{
+	struct sorcery_config *config = data;
+	struct ast_flags flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
+	struct ast_config *cfg = ast_config_load2(config->filename, "res_sorcery_config", flags);
+	RAII_VAR(struct ao2_container *, objects, NULL, ao2_cleanup);
+	const char *id = NULL;
+
+	if (!cfg) {
+		ast_log(LOG_ERROR, "Unable to load config file '%s'n", config->filename);
+		return;
+	} else if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
+		ast_debug(1, "Config file '%s' was unchanged\n", config->filename);
+		return;
+	} else if (cfg == CONFIG_STATUS_FILEINVALID) {
+		ast_log(LOG_ERROR, "Contents of config file '%s' are invalid and cannot be parsed\n", config->filename);
+		return;
+	}
+
+	if (!(objects = ao2_container_alloc(config->buckets, sorcery_config_hash, sorcery_config_cmp))) {
+		ast_log(LOG_ERROR, "Could not create bucket for new objects from '%s', keeping existing objects\n",
+			config->filename);
+		ast_config_destroy(cfg);
+		return;
+	}
+
+	while ((id = ast_category_browse(cfg, id))) {
+		RAII_VAR(void *, obj, NULL, ao2_cleanup);
+
+		/* If given criteria has not been met skip the category, it is not applicable */
+		if (!sorcery_is_criteria_met(ast_variable_browse(cfg, id), config->criteria)) {
+			continue;
+		}
+
+		if (!(obj = ast_sorcery_alloc(sorcery, type, id)) ||
+		    ast_sorcery_objectset_apply(sorcery, obj, ast_variable_browse(cfg, id))) {
+			ast_debug(1, "Could not create an object of type '%s' with id '%s' from configuration file '%s'\n",
+				  type, id, config->filename);
+
+			if (config->file_integrity) {
+				ast_log(LOG_ERROR, "Config file '%s' could not be loaded due to error with object '%s' of type '%s'\n",
+					config->filename, id, type);
+				ast_config_destroy(cfg);
+				return;
+			}
+
+			ao2_cleanup(obj);
+
+			/* To ensure we don't lose the object that already exists we retrieve it from the old objects container and add it to the new one */
+			if (!(obj = sorcery_config_retrieve_id(sorcery, data, type, id))) {
+				continue;
+			}
+		}
+
+		ao2_link_flags(objects, obj, OBJ_NOLOCK);
+	}
+
+	ao2_global_obj_replace_unref(config->objects, objects);
+	ast_config_destroy(cfg);
+}
+
+static void sorcery_config_load(void *data, const struct ast_sorcery *sorcery, const char *type)
+{
+	sorcery_config_internal_load(data, sorcery, type, 0);
+}
+
+static void sorcery_config_reload(void *data, const struct ast_sorcery *sorcery, const char *type)
+{
+	sorcery_config_internal_load(data, sorcery, type, 1);
+}
+
+static void *sorcery_config_open(const char *data)
+{
+	char *tmp = ast_strdupa(data), *filename = strsep(&tmp, ","), *option;
+	struct sorcery_config *config;
+
+	if (ast_strlen_zero(filename) || !(config = ao2_alloc_options(sizeof(*config) + strlen(filename) + 1, sorcery_config_destructor, AO2_ALLOC_OPT_LOCK_NOLOCK))) {
+		return NULL;
+	}
+
+	ast_rwlock_init(&config->objects.lock);
+	config->buckets = DEFAULT_OBJECT_BUCKETS;
+	strcpy(config->filename, filename);
+
+	while ((option = strsep(&tmp, ","))) {
+		char *name = strsep(&option, "="), *value = option;
+
+		if (!strcasecmp(name, "buckets")) {
+			if (sscanf(value, "%30d", &config->buckets) != 1) {
+				ast_log(LOG_ERROR, "Unsupported bucket size of '%s' used for configuration file '%s', defaulting to '%d'\n",
+					value, filename, DEFAULT_OBJECT_BUCKETS);
+			}
+		} else if (!strcasecmp(name, "integrity")) {
+			if (!strcasecmp(value, "file")) {
+				config->file_integrity = 1;
+			} else if (!strcasecmp(value, "object")) {
+				config->file_integrity = 0;
+			} else {
+				ast_log(LOG_ERROR, "Unsupported integrity value of '%s' used for configuration file '%s', defaulting to 'object'\n",
+					value, filename);
+			}
+		} else if (!strcasecmp(name, "criteria")) {
+			char *field = strsep(&value, "=");
+			struct ast_variable *criteria = ast_variable_new(field, value, "");
+
+			if (criteria) {
+				criteria->next = config->criteria;
+				config->criteria = criteria;
+			} else {
+				/* This is fatal since not following criteria would potentially yield invalid objects */
+				ast_log(LOG_ERROR, "Could not create criteria entry of field '%s' with value '%s' for configuration file '%s'\n",
+					field, value, filename);
+				ao2_ref(config, -1);
+				return NULL;
+			}
+		} else {
+			ast_log(LOG_ERROR, "Unsupported option '%s' used for configuration file '%s'\n", name, filename);
+		}
+	}
+
+	return config;
+}
+
+static void sorcery_config_close(void *data)
+{
+	struct sorcery_config *config = data;
+
+	ao2_ref(config, -1);
+}
+
+static int load_module(void)
+{
+	if (ast_sorcery_wizard_register(&config_object_wizard)) {
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+static int unload_module(void)
+{
+	ast_sorcery_wizard_unregister(&config_object_wizard);
+	return 0;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Sorcery Configuration File Object Wizard",
+	.load = load_module,
+	.unload = unload_module,
+	.load_pri = AST_MODPRI_CHANNEL_DEPEND,
+);