asterisk/res/ari/resource_endpoints.c
David M. Lee e1b959ccbb Split caching out from the stasis_caching_topic.
In working with res_stasis, I discovered a significant limitation to
the current structure of stasis_caching_topics: you cannot subscribe
to cache updates for a single channel/bridge/endpoint/etc.

To address this, this patch splits the cache away from the
stasis_caching_topic, making it a first class object. The stasis_cache
object is shared amongst individual stasis_caching_topics that are
created per channel/endpoint/etc. These are still forwarded to global
whatever_all_cached topics, so their use from most of the code does
not change.

In making these changes, I noticed that we frequently used a similar
pattern for bridges, endpoints and channels:

     single_topic  ---------------->  all_topic
           ^
           |
     single_topic_cached  ----+---->  all_topic_cached
                              |
                              +---->  cache

This pattern was extracted as the 'Stasis Caching Pattern', defined in
stasis_caching_pattern.h. This avoids a lot of duplicate code between
the different domain objects.

Since the cache is now disassociated from its upstream caching topics,
this also necessitated a change to how the 'guaranteed' flag worked
for retrieving from a cache. The code for handling the caching
guarantee was extracted into a 'stasis_topic_wait' function, which
works for any stasis_topic.

(closes issue ASTERISK-22002)
Review: https://reviewboard.asterisk.org/r/2672/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@395954 65c4cc65-6c06-0410-ace0-fbb531ad65f3
2013-08-01 13:49:34 +00:00

158 lines
4.1 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2012 - 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 /api-docs/endpoints.{format} implementation- Endpoint resources
*
* \author David M. Lee, II <dlee@digium.com>
*/
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include "resource_endpoints.h"
#include "asterisk/astobj2.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_endpoints.h"
void ast_ari_get_endpoints(struct ast_variable *headers,
struct ast_get_endpoints_args *args,
struct ast_ari_response *response)
{
RAII_VAR(struct stasis_cache *, cache, NULL, ao2_cleanup);
RAII_VAR(struct ao2_container *, snapshots, NULL, ao2_cleanup);
RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
struct ao2_iterator i;
void *obj;
cache = ast_endpoint_cache();
if (!cache) {
ast_ari_response_error(
response, 500, "Internal Server Error",
"Message bus not initialized");
return;
}
ao2_ref(cache, +1);
snapshots = stasis_cache_dump(cache, ast_endpoint_snapshot_type());
if (!snapshots) {
ast_ari_response_alloc_failed(response);
return;
}
json = ast_json_array_create();
if (!json) {
ast_ari_response_alloc_failed(response);
return;
}
i = ao2_iterator_init(snapshots, 0);
while ((obj = ao2_iterator_next(&i))) {
RAII_VAR(struct stasis_message *, msg, obj, ao2_cleanup);
struct ast_endpoint_snapshot *snapshot = stasis_message_data(msg);
int r = ast_json_array_append(
json, ast_endpoint_snapshot_to_json(snapshot));
if (r != 0) {
ast_ari_response_alloc_failed(response);
return;
}
}
ao2_iterator_destroy(&i);
ast_ari_response_ok(response, ast_json_ref(json));
}
void ast_ari_get_endpoints_by_tech(struct ast_variable *headers,
struct ast_get_endpoints_by_tech_args *args,
struct ast_ari_response *response)
{
RAII_VAR(struct stasis_cache *, cache, NULL, ao2_cleanup);
RAII_VAR(struct ao2_container *, snapshots, NULL, ao2_cleanup);
RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
struct ao2_iterator i;
void *obj;
/* TODO - if tech isn't a recognized type of endpoint, it should 404 */
cache = ast_endpoint_cache();
if (!cache) {
ast_ari_response_error(
response, 500, "Internal Server Error",
"Message bus not initialized");
return;
}
ao2_ref(cache, +1);
snapshots = stasis_cache_dump(cache, ast_endpoint_snapshot_type());
if (!snapshots) {
ast_ari_response_alloc_failed(response);
return;
}
json = ast_json_array_create();
if (!json) {
ast_ari_response_alloc_failed(response);
return;
}
i = ao2_iterator_init(snapshots, 0);
while ((obj = ao2_iterator_next(&i))) {
RAII_VAR(struct stasis_message *, msg, obj, ao2_cleanup);
struct ast_endpoint_snapshot *snapshot = stasis_message_data(msg);
int r;
if (strcmp(args->tech, snapshot->tech) != 0) {
continue;
}
r = ast_json_array_append(
json, ast_endpoint_snapshot_to_json(snapshot));
if (r != 0) {
ast_ari_response_alloc_failed(response);
return;
}
}
ao2_iterator_destroy(&i);
ast_ari_response_ok(response, ast_json_ref(json));
}
void ast_ari_get_endpoint(struct ast_variable *headers,
struct ast_get_endpoint_args *args,
struct ast_ari_response *response)
{
RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
RAII_VAR(struct ast_endpoint_snapshot *, snapshot, NULL, ao2_cleanup);
snapshot = ast_endpoint_latest_snapshot(args->tech, args->resource, 0);
if (!snapshot) {
ast_ari_response_error(response, 404, "Not Found",
"Endpoint not found");
return;
}
json = ast_endpoint_snapshot_to_json(snapshot);
if (!json) {
ast_ari_response_alloc_failed(response);
return;
}
ast_ari_response_ok(response, ast_json_ref(json));
}