stasis_cache_pattern.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <dlee@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 Typical cache pattern for Stasis topics.
 *
 * \author David M. Lee, II <dlee@digium.com>
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include "asterisk/astobj2.h"
#include "asterisk/stasis_cache_pattern.h"
 
struct stasis_cp_all {
    struct stasis_topic *topic;
    struct stasis_topic *topic_cached;
    struct stasis_cache *cache;
 
    struct stasis_forward *forward_all_to_cached;
};
 
struct stasis_cp_single {
    struct stasis_topic *topic;
    struct stasis_caching_topic *topic_cached;
 
    struct stasis_forward *forward_topic_to_all;
    struct stasis_forward *forward_cached_to_all;
};
 
static void all_dtor(void *obj)
{
    struct stasis_cp_all *all = obj;
 
    ao2_cleanup(all->topic);
    all->topic = NULL;
    ao2_cleanup(all->topic_cached);
    all->topic_cached = NULL;
    ao2_cleanup(all->cache);
    all->cache = NULL;
    stasis_forward_cancel(all->forward_all_to_cached);
    all->forward_all_to_cached = NULL;
}
 
struct stasis_cp_all *stasis_cp_all_create(const char *name,
    snapshot_get_id id_fn)
{
    char *cached_name = NULL;
    struct stasis_cp_all *all;
    static int cache_id;
 
    all = ao2_t_alloc(sizeof(*all), all_dtor, name);
    if (!all) {
        return NULL;
    }
 
    ast_asprintf(&cached_name, "cache_pattern:%d/%s", ast_atomic_fetchadd_int(&cache_id, +1), name);
    if (!cached_name) {
        ao2_ref(all, -1);
 
        return NULL;
    }
 
    all->topic = stasis_topic_create(name);
    all->topic_cached = stasis_topic_create(cached_name);
    ast_free(cached_name);
    all->cache = stasis_cache_create(id_fn);
    all->forward_all_to_cached =
        stasis_forward_all(all->topic, all->topic_cached);
 
    if (!all->topic || !all->topic_cached || !all->cache ||
        !all->forward_all_to_cached) {
        ao2_ref(all, -1);
 
        return NULL;
    }
 
    return all;
}
 
struct stasis_topic *stasis_cp_all_topic(struct stasis_cp_all *all)
{
    if (!all) {
        return NULL;
    }
    return all->topic;
}
 
struct stasis_topic *stasis_cp_all_topic_cached(
    struct stasis_cp_all *all)
{
    if (!all) {
        return NULL;
    }
    return all->topic_cached;
}
 
struct stasis_cache *stasis_cp_all_cache(struct stasis_cp_all *all)
{
    if (!all) {
        return NULL;
    }
    return all->cache;
}
 
static void one_dtor(void *obj)
{
    struct stasis_cp_single *one = obj;
 
    /* Should already be unsubscribed */
    ast_assert(one->topic_cached == NULL);
    ast_assert(one->forward_topic_to_all == NULL);
    ast_assert(one->forward_cached_to_all == NULL);
 
    ao2_cleanup(one->topic);
    one->topic = NULL;
}
 
struct stasis_cp_single *stasis_cp_single_create(struct stasis_cp_all *all,
    const char *name)
{
    struct stasis_cp_single *one;
 
    one = stasis_cp_sink_create(all, name);
    if (!one) {
        return NULL;
    }
 
    one->forward_topic_to_all = stasis_forward_all(one->topic, all->topic);
    one->forward_cached_to_all = stasis_forward_all(
        stasis_caching_get_topic(one->topic_cached), all->topic_cached);
 
    if (!one->forward_topic_to_all || !one->forward_cached_to_all) {
        ao2_ref(one, -1);
 
        return NULL;
    }
 
    return one;
}
 
struct stasis_cp_single *stasis_cp_sink_create(struct stasis_cp_all *all,
    const char *name)
{
    struct stasis_cp_single *one;
 
    one = ao2_t_alloc(sizeof(*one), one_dtor, name);
    if (!one) {
        return NULL;
    }
 
    one->topic = stasis_topic_create(name);
    if (!one->topic) {
        ao2_ref(one, -1);
 
        return NULL;
    }
 
    one->topic_cached = stasis_caching_topic_create(one->topic, all->cache);
    if (!one->topic_cached) {
        ao2_ref(one, -1);
 
        return NULL;
    }
 
    return one;
}
 
void stasis_cp_single_unsubscribe(struct stasis_cp_single *one)
{
    if (!one) {
        return;
    }
 
    stasis_forward_cancel(one->forward_topic_to_all);
    one->forward_topic_to_all = NULL;
    stasis_forward_cancel(one->forward_cached_to_all);
    one->forward_cached_to_all = NULL;
    stasis_caching_unsubscribe(one->topic_cached);
    one->topic_cached = NULL;
 
    ao2_cleanup(one);
}
 
struct stasis_topic *stasis_cp_single_topic(struct stasis_cp_single *one)
{
    if (!one) {
        return NULL;
    }
    return one->topic;
}
 
struct stasis_topic *stasis_cp_single_topic_cached(
    struct stasis_cp_single *one)
{
    if (!one) {
        return NULL;
    }
    return stasis_caching_get_topic(one->topic_cached);
}
 
int stasis_cp_single_accept_message_type(struct stasis_cp_single *one,
    struct stasis_message_type *type)
{
    if (!one) {
        return -1;
    }
    return stasis_caching_accept_message_type(one->topic_cached, type);
}
 
int stasis_cp_single_set_filter(struct stasis_cp_single *one,
    enum stasis_subscription_message_filter filter)
{
    if (!one) {
        return -1;
    }
    return stasis_caching_set_filter(one->topic_cached, filter);
}