WebAPI/PresentationAPI:CoreService: Difference between revisions
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# Create a session transport builder: As chrome process ready (receive control channel|NotifyOpened| for controller; receive control channel |OnOffer| and receiver page ready |NotifyResponderReady| for presenter), |PresentationSessionInfo| create a transport builder to establish a transport. | # Create a session transport builder: As chrome process ready (receive control channel|NotifyOpened| for controller; receive control channel |OnOffer| and receiver page ready |NotifyResponderReady| for presenter), |PresentationSessionInfo| create a transport builder to establish a transport. | ||
# Build a transport in content process: The transport builder is |PresentationParent| hooked by first step. It will triggered an IPC call to |PresentationIPCService| and build the underlying RTCDataChannel in the content process. It will call back to |PresentationService| the result of building. | # Build a transport in content process: The transport builder is |PresentationParent| hooked by first step. It will triggered an IPC call to |PresentationIPCService| and build the underlying RTCDataChannel in the content process. It will call back to |PresentationService| the result of building. | ||
=== Controlling UA === | |||
==== start session ==== | |||
==== close and resume connection === | |||
==== terminate connection ==== | |||
=== Receiving UA === | |||
==== handle presentation request === | |||
* establishing TCP Transport | |||
[[File:CoreService Flow handle session request.png]] |
Revision as of 03:01, 21 April 2016
Introduction
The page explains the implementation detail of core service.
Architecture
PresentationService
A mediator among WebAPI classes, IPC and |PresentationSessionInfo|.
Live in chrome process.
PresentationSessionInfo
Maintain grotty details around session transports, receiver page and connection state.
Session infos use the established control channel to negotiate the SDP of session transport and create a transport builder to do the transport establishment.
Two subclasses, |PresentationControllingInfo| and |PresentationPresentingInfo|, stands for the controller and presenter. Presenting info will establish the transport after the receiver's page ready.
Live in chrome process.
PresentationSessionTransport
Maintain the underlying transport. We have TCP transport now and work on RTCDataChannel transport.
TCP transport lives in Chrome process. RTCDataChannel lives with the DOM. That is, live in content process in e10s mode.
PresentationIPCService
A mediator between IPC and WebAPI. Also manage PresentationIPCSessionInfo if the underlying transport is RTCDataChannel.
Only lives in e10s mode and in content process.
PresentationIPCSessionInfo
Manage PresentationDataChannelSessionTransport.
Only lives in e10s mode and in content process.
Call Flow Example
Establishing OOP RTCDataChannel Transport
Since RTCDataChannel should be accompanied with DOM, we should build our transport in content process in the case. Here's the procedure:
- Hook handler: |SendRegisterTransportBuilderHandler| in |PresentationIPCService::StartSession| (controller) and |PresentationIPCService::NotifyReceiverReady| (presenter) hook a handler (|PresentationParent|) to |PresentationService| which lives in the chrome process.
- Create a session transport builder: As chrome process ready (receive control channel|NotifyOpened| for controller; receive control channel |OnOffer| and receiver page ready |NotifyResponderReady| for presenter), |PresentationSessionInfo| create a transport builder to establish a transport.
- Build a transport in content process: The transport builder is |PresentationParent| hooked by first step. It will triggered an IPC call to |PresentationIPCService| and build the underlying RTCDataChannel in the content process. It will call back to |PresentationService| the result of building.
Controlling UA
start session
= close and resume connection
terminate connection
Receiving UA
= handle presentation request
- establishing TCP Transport