Tweak caching topics to fix CEL tests

The Stasis changes in r395954 had an unanticipated side effect: messages
published directly to an _all topic does not get forwarded to the
corresponding caching topic.

This patch fixes that by changing how caching topics forward messages,
and how the caching pattern forwards are setup.

For the caching pattern, the all_topic is forwarded to the
all_topic_cached. This forwards messages published directly to the
all_topic to all_topic_cached.

In order to avoid duplicate messages on all_topic_cached, caching topics
were changed to no longer forward uncached messages. Subscribers to an
individual caching topic should only expect to receive cache updates,
and subscription change messages. Since individual caching topics are
new, this shouldn't be a problem.

There are a few minor changes to the pre-cache split behavior.

 * For topics changed to use the caching pattern, the all_topic_cached
   will forward snapshots in addition to cache updates. Since
   subscribers by design ignore unexpected messages, this should be
   fine.

 * Caching topics that don't use the caching pattern no longer forward
   non-cache updates. This makes no difference for the current caching
   topics.

   * mwi_topic_cached, channel_by_name_topic and
     presence_state_topic_cached have no subscribers

   * device_state_topic_cached's only subscriber only processes cache
     udpates

(issue ASTERISK-22243)
Review: https://reviewboard.asterisk.org/r/2738


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@396329 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 6 insertions, 6 deletions

diff --git a/include/asterisk/stasis.h b/include/asterisk/stasis.h
index 3b9cec34f..1a3dae00f 100644
--- a/include/asterisk/stasis.h
+++ b/include/asterisk/stasis.h
@@ -110,12 +110,12 @@
  * It's a thread safe container, so freely use the stasis_cache_get() and
  * stasis_cache_dump() to query the cache.
  *
- * The \ref stasis_caching_topic provides a topic that forwards non-cacheable
- * messages unchanged. A cacheable message is wrapped in a \ref
- * stasis_cache_update message which provides the old snapshot (or \c NULL if
- * this is a new cache entry), and the new snapshot (or \c NULL if the entry was
- * removed from the cache). A stasis_cache_clear_create() message must be sent
- * to the topic in order to remove entries from the cache.
+ * The \ref stasis_caching_topic discards non-cacheable messages. A cacheable
+ * message is wrapped in a \ref stasis_cache_update message which provides the
+ * old snapshot (or \c NULL if this is a new cache entry), and the new snapshot
+ * (or \c NULL if the entry was removed from the cache). A
+ * stasis_cache_clear_create() message must be sent to the topic in order to
+ * remove entries from the cache.
  *
  * In order to unsubscribe a \ref stasis_caching_topic from the upstream topic,
  * call stasis_caching_unsubscribe(). Due to cyclic references, the \ref