Decouple subscription handling from NOTIFY/PUBLISH body generation.
authorMark Michelson <mmichelson@digium.com>
Fri, 31 Jan 2014 22:27:07 +0000 (22:27 +0000)
committerMark Michelson <mmichelson@digium.com>
Fri, 31 Jan 2014 22:27:07 +0000 (22:27 +0000)
commitf55abe9cf19911ae365bc16c63e3524b0b17e71f
tree2ce5c30e3f1cf65c54fb2e91fb7a230752125c16
parente29c5e0c5c952427047860ec44038a85d479c202
Decouple subscription handling from NOTIFY/PUBLISH body generation.

When the PJSIP pubsub framework was created, subscription handlers were required
to state what event they handled along with what body types they knew how to
generate. While this serves well when implementing a base RFC, it has problems
when trying to extend the body to support non-standard or proprietary body
elements. The code also was NOTIFY-specific, meaning that when the time comes
that we start writing code to send out PUBLISH requests with MWI or presence
bodies, we would likely find ourselves duplicating code that had previously been
written.

This changeset introduces the concept of body generators and body supplements. A
body generator is responsible for allocating a native structure for a given body
type, providing the primary body content, converting the native structure to a
string, and deallocating resources. A body supplement takes the primary body
content (the native structure, not a string) generated by the body generator and
adds nonstandard elements to the body. With these elements living in their own
module, it becomes easy to extend our support for body types and to re-use
resources when sending a PUBLISH request.

Body generators and body supplements register themselves with the pubsub core,
similar to how subscription and publish handlers had done. Now, subscription
handlers do not need to know what type of body content they generate, but they
still need to inform the pubsub core about what the default body type for a
given event package is. The pubsub core keeps track of what body generators and
body supplements have been registered. When a SUBSCRIBE arrives, the pubsub core
will check that there is a subscription handler for the event in the SUBSCRIBE,
then it will check that there is a body generator that can provide the content
specified in the Accept header(s).

Because of the nature of body generators and supplements, it means
res_pjsip_exten_state and res_pjsip_mwi have been completely gutted. They no
longer worry about body types, instead calling
ast_sip_pubsub_generate_body_content() when they need to generate a NOTIFY body.

Review: https://reviewboard.asterisk.org/r/3150
........

Merged revisions 407016 from http://svn.asterisk.org/svn/asterisk/branches/12

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@407030 65c4cc65-6c06-0410-ace0-fbb531ad65f3
13 files changed:
include/asterisk/res_pjsip_body_generator_types.h [new file with mode: 0644]
include/asterisk/res_pjsip_exten_state.h [deleted file]
include/asterisk/res_pjsip_pubsub.h
res/res_pjsip/presence_xml.c [new file with mode: 0644]
res/res_pjsip_exten_state.c
res/res_pjsip_mwi.c
res/res_pjsip_mwi_body_generator.c [new file with mode: 0644]
res/res_pjsip_pidf.c [deleted file]
res/res_pjsip_pidf_body_generator.c [new file with mode: 0644]
res/res_pjsip_pidf_eyebeam_body_supplement.c [new file with mode: 0644]
res/res_pjsip_pubsub.c
res/res_pjsip_pubsub.exports.in
res/res_pjsip_xpidf_body_generator.c [new file with mode: 0644]