sorcery: Add ast_sorcery_retrieve_by_prefix()

Some consumers of the sorcery API use ast_sorcery_retrieve_by_regex
only so that they can anchor the potential match as a prefix and not
because they truly need regular expressions.

Rather than using regular expressions for simple prefix lookups, add
a new operation - ast_sorcery_retrieve_by_prefix - that does them.

Patches against 13 and 15 have a compatibility layer needed to
maintain ABI that is not needed in master.

Change-Id: I56f4e20ba1154bd52281f995c27a429a854f6a79

include/asterisk/sorcery.h

@@ -315,6 +315,14 @@ struct ast_sorcery_wizard {
 
 	/* \brief Callback for whether or not the wizard believes the object is stale */
 	int (*is_stale)(const struct ast_sorcery *sorcery, void *data, void *object);
+
+	/*! \brief Optional callback for retrieving multiple objects by matching their id with a prefix */
+	void (*retrieve_prefix)(const struct ast_sorcery *sorcery,
+			void *data,
+			const char *type,
+			struct ao2_container *objects,
+			const char *prefix,
+			const size_t prefix_len);
 };
 
 /*! \brief Interface for a sorcery object type observer */
@@ -366,10 +374,21 @@ int ast_sorcery_init(void);
  */
 int __ast_sorcery_wizard_register(const struct ast_sorcery_wizard *interface, struct ast_module *module);
 
+/*!
+ * \brief Register a sorcery wizard
+ *
+ * \param interface Pointer to a wizard interface
+ * \param module Pointer to the module implementing the interface
+ *
+ * \retval 0 success
+ * \retval -1 failure
+ */
+int __ast_sorcery_wizard_register_with_prefix(const struct ast_sorcery_wizard *interface, struct ast_module *module);
+
 /*!
  * \brief See \ref __ast_sorcery_wizard_register()
  */
-#define ast_sorcery_wizard_register(interface) __ast_sorcery_wizard_register(interface, AST_MODULE_SELF)
+#define ast_sorcery_wizard_register(interface) __ast_sorcery_wizard_register_with_prefix(interface, ast_module_info ? ast_module_info->self : NULL)
 
 /*!
  * \brief Unregister a sorcery wizard
@@ -1240,6 +1259,22 @@ void *ast_sorcery_retrieve_by_fields(const struct ast_sorcery *sorcery, const ch
  */
 struct ao2_container *ast_sorcery_retrieve_by_regex(const struct ast_sorcery *sorcery, const char *type, const char *regex);
 
+/*!
+ * \brief Retrieve multiple objects whose id begins with the specified prefix
+ * \since 13.19.0
+ *
+ * \param sorcery Pointer to a sorcery structure
+ * \param type Type of object to retrieve
+ * \param prefix Object id prefix
+ * \param prefix_len The length of prefix in bytes
+ *
+ * \retval non-NULL if error occurs
+ * \retval NULL success
+ *
+ * \note The prefix is matched in a case sensitive manner.
+ */
+struct ao2_container *ast_sorcery_retrieve_by_prefix(const struct ast_sorcery *sorcery, const char *type, const char *prefix, const size_t prefix_len);
+
 /*!
  * \brief Update an object
  *

main/sorcery.c

@@ -551,6 +551,28 @@ static void sorcery_internal_wizard_destructor(void *obj)
 }
 
 int __ast_sorcery_wizard_register(const struct ast_sorcery_wizard *interface, struct ast_module *module)
+{
+	struct ast_sorcery_wizard compat = {
+		.name = interface->name,
+		.open = interface->open,
+		.load = interface->load,
+		.reload = interface->reload,
+		.create = interface->create,
+		.retrieve_id = interface->retrieve_id,
+		.retrieve_regex = interface->retrieve_regex,
+		.retrieve_fields = interface->retrieve_fields,
+		.retrieve_multiple = interface->retrieve_multiple,
+		.update = interface->update,
+		.delete = interface->delete,
+		.close = interface->close,
+		.is_stale = interface->is_stale,
+		.retrieve_prefix = NULL,
+	};
+
+	return __ast_sorcery_wizard_register_with_prefix(&compat, module);
+}
+
+int __ast_sorcery_wizard_register_with_prefix(const struct ast_sorcery_wizard *interface, struct ast_module *module)
 {
 	struct ast_sorcery_internal_wizard *wizard;
 	int res = -1;
@@ -2036,6 +2058,36 @@ struct ao2_container *ast_sorcery_retrieve_by_regex(const struct ast_sorcery *so
 	return objects;
 }
 
+struct ao2_container *ast_sorcery_retrieve_by_prefix(const struct ast_sorcery *sorcery, const char *type, const char *prefix, const size_t prefix_len)
+{
+	RAII_VAR(struct ast_sorcery_object_type *, object_type, ao2_find(sorcery->types, type, OBJ_KEY), ao2_cleanup);
+	struct ao2_container *objects;
+	int i;
+
+	if (!object_type || !(objects = ao2_container_alloc_options(AO2_ALLOC_OPT_LOCK_NOLOCK, 1, NULL, NULL))) {
+		return NULL;
+	}
+
+	AST_VECTOR_RW_RDLOCK(&object_type->wizards);
+	for (i = 0; i < AST_VECTOR_SIZE(&object_type->wizards); i++) {
+		struct ast_sorcery_object_wizard *wizard =
+			AST_VECTOR_GET(&object_type->wizards, i);
+
+		if (!wizard->wizard->callbacks.retrieve_prefix) {
+			continue;
+		}
+
+		wizard->wizard->callbacks.retrieve_prefix(sorcery, wizard->data, object_type->name, objects, prefix, prefix_len);
+
+		if (wizard->caching && ao2_container_count(objects)) {
+			break;
+		}
+	}
+	AST_VECTOR_RW_UNLOCK(&object_type->wizards);
+
+	return objects;
+}
+
 /*! \brief Internal function which returns if the wizard has created the object */
 static int sorcery_wizard_create(const struct ast_sorcery_object_wizard *object_wizard, const struct sorcery_details *details)
 {

res/res_sorcery_astdb.c

@@ -44,6 +44,7 @@ static void *sorcery_astdb_retrieve_fields(const struct ast_sorcery *sorcery, vo
 static void sorcery_astdb_retrieve_multiple(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects,
 					     const struct ast_variable *fields);
 static void sorcery_astdb_retrieve_regex(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *regex);
+static void sorcery_astdb_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *prefix, const size_t prefix_len);
 static int sorcery_astdb_update(const struct ast_sorcery *sorcery, void *data, void *object);
 static int sorcery_astdb_delete(const struct ast_sorcery *sorcery, void *data, void *object);
 static void sorcery_astdb_close(void *data);
@@ -56,6 +57,7 @@ static struct ast_sorcery_wizard astdb_object_wizard = {
 	.retrieve_fields = sorcery_astdb_retrieve_fields,
 	.retrieve_multiple = sorcery_astdb_retrieve_multiple,
 	.retrieve_regex = sorcery_astdb_retrieve_regex,
+	.retrieve_prefix = sorcery_astdb_retrieve_prefix,
 	.update = sorcery_astdb_update,
 	.delete = sorcery_astdb_delete,
 	.close = sorcery_astdb_close,
@@ -327,6 +329,42 @@ static void sorcery_astdb_retrieve_regex(const struct ast_sorcery *sorcery, void
 	regfree(&expression);
 }
 
+static void sorcery_astdb_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *prefix, const size_t prefix_len)
+{
+	const char *family_prefix = data;
+	size_t family_len = strlen(family_prefix) + strlen(type) + 1; /* +1 for slash delimiter */
+	char family[family_len + 1];
+	char tree[prefix_len + sizeof("%")];
+	RAII_VAR(struct ast_db_entry *, entries, NULL, ast_db_freetree);
+	struct ast_db_entry *entry;
+
+	snprintf(tree, sizeof(tree), "%.*s%%", (int) prefix_len, prefix);
+	snprintf(family, sizeof(family), "%s/%s", family_prefix, type);
+
+	if (!(entries = ast_db_gettree(family, tree))) {
+		return;
+	}
+
+	for (entry = entries; entry; entry = entry->next) {
+		/* The key in the entry includes the family, so we need to strip it out */
+		const char *key = entry->key + family_len + 2;
+		RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+		struct ast_json_error error;
+		RAII_VAR(void *, object, NULL, ao2_cleanup);
+		RAII_VAR(struct ast_variable *, objset, NULL, ast_variables_destroy);
+
+		if (!(json = ast_json_load_string(entry->data, &error))
+		   || (ast_json_to_ast_variables(json, &objset) != AST_JSON_TO_AST_VARS_CODE_SUCCESS)
+		   || !(objset = sorcery_astdb_filter_objectset(objset, sorcery, type))
+		   || !(object = ast_sorcery_alloc(sorcery, type, key))
+		   || ast_sorcery_objectset_apply(sorcery, object, objset)) {
+			return;
+		}
+
+		ao2_link(objects, object);
+	}
+}
+
 static int sorcery_astdb_update(const struct ast_sorcery *sorcery, void *data, void *object)
 {
 	const char *prefix = data;

res/res_sorcery_config.c

@@ -71,6 +71,12 @@ struct sorcery_config_fields_cmp_params {
 	/*! \brief Regular expression for checking object id */
 	regex_t *regex;
 
+	/*! \brief Prefix for matching object id */
+	const char *prefix;
+
+	/*! \brief Prefix length in bytes for matching object id */
+	const size_t prefix_len;
+
 	/*! \brief Optional container to put object into */
 	struct ao2_container *container;
 };
@@ -83,6 +89,7 @@ static void *sorcery_config_retrieve_fields(const struct ast_sorcery *sorcery, v
 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_retrieve_regex(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *regex);
+static void sorcery_config_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *prefix, const size_t prefix_len);
 static void sorcery_config_close(void *data);
 
 static struct ast_sorcery_wizard config_object_wizard = {
@@ -94,6 +101,7 @@ static struct ast_sorcery_wizard config_object_wizard = {
 	.retrieve_fields = sorcery_config_retrieve_fields,
 	.retrieve_multiple = sorcery_config_retrieve_multiple,
 	.retrieve_regex = sorcery_config_retrieve_regex,
+	.retrieve_prefix = sorcery_config_retrieve_prefix,
 	.close = sorcery_config_close,
 };
 
@@ -118,6 +126,11 @@ static int sorcery_config_fields_cmp(void *obj, void *arg, int flags)
 			ao2_link(params->container, obj);
 		}
 		return 0;
+	} else if (params->prefix) {
+		if (!strncmp(params->prefix, ast_sorcery_object_get_id(obj), params->prefix_len)) {
+			ao2_link(params->container, obj);
+		}
+		return 0;
 	} else if (params->fields &&
 	    (!(objset = ast_sorcery_objectset_create(params->sorcery, obj)) ||
 	     (!ast_variable_lists_match(objset, params->fields, 0)))) {
@@ -206,6 +219,24 @@ static void sorcery_config_retrieve_regex(const struct ast_sorcery *sorcery, voi
 	regfree(&expression);
 }
 
+static void sorcery_config_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *prefix, const size_t prefix_len)
+{
+	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,
+		.container = objects,
+		.prefix = prefix,
+		.prefix_len = prefix_len,
+	};
+
+	if (!config_objects) {
+		return;
+	}
+
+	ao2_callback(config_objects, OBJ_NODATA | OBJ_MULTIPLE, 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)
 {

res/res_sorcery_memory.c

@@ -46,6 +46,7 @@ static void *sorcery_memory_retrieve_fields(const struct ast_sorcery *sorcery, v
 static void sorcery_memory_retrieve_multiple(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects,
 					     const struct ast_variable *fields);
 static void sorcery_memory_retrieve_regex(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *regex);
+static void sorcery_memory_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *prefix, const size_t prefix_len);
 static int sorcery_memory_update(const struct ast_sorcery *sorcery, void *data, void *object);
 static int sorcery_memory_delete(const struct ast_sorcery *sorcery, void *data, void *object);
 static void sorcery_memory_close(void *data);
@@ -58,6 +59,7 @@ static struct ast_sorcery_wizard memory_object_wizard = {
 	.retrieve_fields = sorcery_memory_retrieve_fields,
 	.retrieve_multiple = sorcery_memory_retrieve_multiple,
 	.retrieve_regex = sorcery_memory_retrieve_regex,
+	.retrieve_prefix = sorcery_memory_retrieve_prefix,
 	.update = sorcery_memory_update,
 	.delete = sorcery_memory_delete,
 	.close = sorcery_memory_close,
@@ -74,6 +76,12 @@ struct sorcery_memory_fields_cmp_params {
 	/*! \brief Regular expression for checking object id */
 	regex_t *regex;
 
+	/*! \brief Prefix for matching object id */
+	const char *prefix;
+
+	/*! \brief Prefix length in bytes for matching object id */
+	const size_t prefix_len;
+
 	/*! \brief Optional container to put object into */
 	struct ao2_container *container;
 };
@@ -125,6 +133,11 @@ static int sorcery_memory_fields_cmp(void *obj, void *arg, int flags)
 			ao2_link(params->container, obj);
 		}
 		return 0;
+	} else if (params->prefix) {
+		if (!strncmp(params->prefix, ast_sorcery_object_get_id(obj), params->prefix_len)) {
+			ao2_link(params->container, obj);
+		}
+		return 0;
 	} else if (params->fields &&
 	    (!(objset = ast_sorcery_objectset_create(params->sorcery, obj)) ||
 	     (!ast_variable_lists_match(objset, params->fields, 0)))) {
@@ -198,6 +211,18 @@ static void sorcery_memory_retrieve_regex(const struct ast_sorcery *sorcery, voi
 	regfree(&expression);
 }
 
+static void sorcery_memory_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *prefix, const size_t prefix_len)
+{
+	struct sorcery_memory_fields_cmp_params params = {
+		.sorcery = sorcery,
+		.container = objects,
+		.prefix = prefix,
+		.prefix_len = prefix_len,
+	};
+
+	ao2_callback(data, 0, sorcery_memory_fields_cmp, &params);
+}
+
 static int sorcery_memory_update(const struct ast_sorcery *sorcery, void *data, void *object)
 {
 	RAII_VAR(void *, existing, NULL, ao2_cleanup);

res/res_sorcery_memory_cache.c

@@ -185,6 +185,10 @@ struct sorcery_memory_cache_fields_cmp_params {
 	const struct ast_variable *fields;
 	/*! \brief Regular expression for checking object id */
 	regex_t *regex;
+	/*! \brief Prefix for matching object id */
+	const char *prefix;
+	/*! \brief Prefix length in bytes for matching object id */
+	const size_t prefix_len;
 	/*! \brief Optional container to put object into */
 	struct ao2_container *container;
 };
@@ -201,6 +205,8 @@ static void sorcery_memory_cache_retrieve_multiple(const struct ast_sorcery *sor
 	struct ao2_container *objects, const struct ast_variable *fields);
 static void sorcery_memory_cache_retrieve_regex(const struct ast_sorcery *sorcery, void *data, const char *type,
 	struct ao2_container *objects, const char *regex);
+static void sorcery_memory_cache_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type,
+	struct ao2_container *objects, const char *prefix, const size_t prefix_len);
 static int sorcery_memory_cache_delete(const struct ast_sorcery *sorcery, void *data, void *object);
 static void sorcery_memory_cache_close(void *data);
 
@@ -216,6 +222,7 @@ static struct ast_sorcery_wizard memory_cache_object_wizard = {
 	.retrieve_fields = sorcery_memory_cache_retrieve_fields,
 	.retrieve_multiple = sorcery_memory_cache_retrieve_multiple,
 	.retrieve_regex = sorcery_memory_cache_retrieve_regex,
+	.retrieve_prefix = sorcery_memory_cache_retrieve_prefix,
 	.close = sorcery_memory_cache_close,
 };
 
@@ -1253,6 +1260,11 @@ static int sorcery_memory_cache_fields_cmp(void *obj, void *arg, int flags)
 			ao2_link(params->container, cached->object);
 		}
 		return 0;
+	} else if (params->prefix) {
+		if (!strncmp(params->prefix, ast_sorcery_object_get_id(cached->object), params->prefix_len)) {
+			ao2_link(params->container, cached->object);
+		}
+		return 0;
 	} else if (params->fields &&
 	     (!ast_variable_lists_match(cached->objectset, params->fields, 0))) {
 		/* If we can't turn the object into an object set OR if differences exist between the fields
@@ -1376,6 +1388,40 @@ static void sorcery_memory_cache_retrieve_regex(const struct ast_sorcery *sorcer
 	}
 }
 
+/*!
+ * \internal
+ * \brief Callback function to retrieve multiple objects whose id matches a prefix
+ *
+ * \param sorcery The sorcery instance
+ * \param data The sorcery memory cache
+ * \param type The type of the object to retrieve
+ * \param objects Container to place the objects into
+ * \param prefix Prefix to match against the object id
+ */
+static void sorcery_memory_cache_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type,
+	struct ao2_container *objects, const char *prefix, const size_t prefix_len)
+{
+	struct sorcery_memory_cache *cache = data;
+	struct sorcery_memory_cache_fields_cmp_params params = {
+		.sorcery = sorcery,
+		.cache = cache,
+		.container = objects,
+		.prefix = prefix,
+		.prefix_len = prefix_len,
+	};
+
+	if (is_passthru_update() || !cache->full_backend_cache) {
+		return;
+	}
+
+	memory_cache_full_update(sorcery, type, cache);
+	ao2_callback(cache->objects, 0, sorcery_memory_cache_fields_cmp, &params);
+
+	if (ao2_container_count(objects)) {
+		memory_cache_stale_check(sorcery, cache);
+	}
+}
+
 /*!
  * \internal
  * \brief Callback function to finish configuring the memory cache

res/res_sorcery_realtime.c

@@ -57,6 +57,8 @@ static void *sorcery_realtime_retrieve_fields(const struct ast_sorcery *sorcery,
 static void sorcery_realtime_retrieve_multiple(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects,
 					     const struct ast_variable *fields);
 static void sorcery_realtime_retrieve_regex(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *regex);
+static void sorcery_realtime_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type,
+					     struct ao2_container *objects, const char *prefix, const size_t prefix_len);
 static int sorcery_realtime_update(const struct ast_sorcery *sorcery, void *data, void *object);
 static int sorcery_realtime_delete(const struct ast_sorcery *sorcery, void *data, void *object);
 static void sorcery_realtime_close(void *data);
@@ -69,6 +71,7 @@ static struct ast_sorcery_wizard realtime_object_wizard = {
 	.retrieve_fields = sorcery_realtime_retrieve_fields,
 	.retrieve_multiple = sorcery_realtime_retrieve_multiple,
 	.retrieve_regex = sorcery_realtime_retrieve_regex,
+	.retrieve_prefix = sorcery_realtime_retrieve_prefix,
 	.update = sorcery_realtime_update,
 	.delete = sorcery_realtime_delete,
 	.close = sorcery_realtime_close,
@@ -260,6 +263,23 @@ static void sorcery_realtime_retrieve_regex(const struct ast_sorcery *sorcery, v
 	sorcery_realtime_retrieve_multiple(sorcery, data, type, objects, fields);
 }
 
+static void sorcery_realtime_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type,
+					     struct ao2_container *objects, const char *prefix, const size_t prefix_len)
+{
+	char field[strlen(UUID_FIELD) + 6], value[prefix_len + 2];
+	RAII_VAR(struct ast_variable *, fields, NULL, ast_variables_destroy);
+
+	if (prefix_len) {
+		snprintf(field, sizeof(field), "%s LIKE", UUID_FIELD);
+		snprintf(value, sizeof(value), "%.*s%%", (int) prefix_len, prefix);
+		if (!(fields = ast_variable_new(field, value, ""))) {
+			return;
+		}
+	}
+
+	sorcery_realtime_retrieve_multiple(sorcery, data, type, objects, fields);
+}
+
 static int sorcery_realtime_update(const struct ast_sorcery *sorcery, void *data, void *object)
 {
 	struct sorcery_config *config = data;