res_pjsip: Cache global config options.

We may check a global config option hundreds of times a second or more.
Asking sorcery for the global configuration from the config files backend
involves several allocations and container traversals.  Using realtime
without a memory cache is a lot worse because you have to lookup in the
realtime database each time to reconstitute the sorcery object.  With a
memory cache for realtime, there is about the same amount of overhead as
for config files.  Either way, it is still fairly expensive to access the
sorcery object that much.

* Cache the global config options so we can access them faster.  You must
now always perform a res_pjsip reload to change the global options.

Change-Id: Ice16c7a4cbca4614da344aaea21a072b86263ef7

1 files changed, 6 insertions, 0 deletions

diff --git a/CHANGES b/CHANGES
index 39f9dfebc..2462d382b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -43,6 +43,12 @@ res_pjsip
    when set will override the default user set on Contact headers in outgoing
    requests.
 
+ * If you are using a sorcery realtime backend to store global res_pjsip
+   options (ps_globals table) then you now have to do a res_pjsip reload for
+   changes to these options to take effect.  If you are using pjsip.conf to
+   configure these options then you already had to do a reload after making
+   changes.
+
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 --- Functionality changes from Asterisk 13 to Asterisk 14 --------------------
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