Receiver session router. More...

#include <receiver_session_router.h>

Inheritance diagram for roc::pipeline::ReceiverSessionRouter:

Collaboration diagram for roc::pipeline::ReceiverSessionRouter:

Public Member Functions
	ReceiverSessionRouter (core::IArena &arena)
	Initialize. More...

	~ReceiverSessionRouter ()
	Deinitialize. More...

size_t	num_routes ()
	Get number of know routes. More...

core::SharedPtr< ReceiverSession >	find_by_source (packet::stream_source_t source_id)
	Find registered session by source id of sender's stream. More...

core::SharedPtr< ReceiverSession >	find_by_address (const address::SocketAddr &source_addr)
	Find registered session by source address of sender's stream. More...

bool	has_session (const core::SharedPtr< ReceiverSession > &session)
	Check if there is a route for given session. More...

ROC_ATTR_NODISCARD status::StatusCode	add_session (const core::SharedPtr< ReceiverSession > &session, packet::stream_source_t source_id, const address::SocketAddr &source_addr)
	Register session in router. More...

void	remove_session (const core::SharedPtr< ReceiverSession > &session)
	Unregister session from router. More...

ROC_ATTR_NODISCARD status::StatusCode	link_source (packet::stream_source_t source_id, const char *cname)
	Link source id with unique CNAME. More...

void	unlink_source (packet::stream_source_t source_id)
	Unlink source id from session. More...

Detailed Description

Receiver session router.

Helps routing packets to sessions within session group.

Session group corresponds to all sessions handled by one receiver slot - a set of related complementary endpoints, e.g. one endpoint for audio, one for repair, and one for control packets.

For each remote sender, receiver creates a session inside session group. All audio, repair, and control packets from same sender are then routed to same session.

Session management is implemented in ReceiverSessionGroup, and algorithm for selecting session for a packet is implemented in ReceiverSessionRouter (this class).

Session router provides two methods to select session:

By source id.

Sender can assign unique source id (SSRC) to each stream (audio, repair), and then transmit RTCP SDES packet that associate all sender's SSRCs with the same unique (randomly generated) CNAME string.

Session router will remember that these SSRCs are related and will route packets from those streams to same session.
By source address.

As a fallback for the case when RTCP is not used, session router will assume that packets with same source address belong to the same session.

To make it work, sender should ensure that it sends all streams (audio, repair) from the same socket, and that there are no proxies or retranslators that combine multiple senders on the same socket.

Definition at line 67 of file receiver_session_router.h.

Constructor & Destructor Documentation

◆ ReceiverSessionRouter()

roc::pipeline::ReceiverSessionRouter::ReceiverSessionRouter ( core::IArena & arena )

Initialize.

◆ ~ReceiverSessionRouter()

roc::pipeline::ReceiverSessionRouter::~ReceiverSessionRouter ( )

Deinitialize.

Member Function Documentation

◆ add_session()

ROC_ATTR_NODISCARD status::StatusCode roc::pipeline::ReceiverSessionRouter::add_session	(	const core::SharedPtr< ReceiverSession > &	session,
		packet::stream_source_t	source_id,
		const address::SocketAddr &	source_addr
	)

Register session in router.

Remarks

session defines session where to route packets.
source_id defines SSRC of stream which will be routed to the session. Additional streams may be associated with same session via link_source() call.
source_addr defines source address which will be routed to the session. If other streams share the same source address, they will be routed to it.

◆ find_by_address()

core::SharedPtr<ReceiverSession> roc::pipeline::ReceiverSessionRouter::find_by_address ( const address::SocketAddr & source_addr )

Find registered session by source address of sender's stream.

Remarks: Sender can use one source address for all its streams. Session router will remember this address and map it to sender's session.

Note: To make it work, sender's source address should be provided to add_session(), and all sender's streams should have the same source address.

◆ find_by_source()

core::SharedPtr<ReceiverSession> roc::pipeline::ReceiverSessionRouter::find_by_source ( packet::stream_source_t source_id )

Find registered session by source id of sender's stream.

Remarks: Sender can have multiple streams, each with its own SSRC. Session router will remember all those SSRCs and map them to sender's session.

Note: To make it work, one of the SSRCs should be explicitly mapped to a session using add_session(), and the rest of SSRCs should be linked together using link_source() with same CNAME. The order of these calls does not matter.

◆ has_session()

bool roc::pipeline::ReceiverSessionRouter::has_session ( const core::SharedPtr< ReceiverSession > & session )

Check if there is a route for given session.

Remarks: Will return false after session was removed via remove_session() or unlink_source().

◆ link_source()

ROC_ATTR_NODISCARD status::StatusCode roc::pipeline::ReceiverSessionRouter::link_source	(	packet::stream_source_t	source_id,
		const char *	cname
	)

Link source id with unique CNAME.

Remarks: Remembers what SSRCs are linked together by sharing the same CNAME. If/when one of the linked SSRCs is associated with a session using add_session(), all linked SSRCs become being routed to that session.

◆ num_routes()

size_t roc::pipeline::ReceiverSessionRouter::num_routes ( )

Get number of know routes.

◆ remove_session()

void roc::pipeline::ReceiverSessionRouter::remove_session ( const core::SharedPtr< ReceiverSession > & session )

Unregister session from router.

Remarks: All associated SSRCs, CNAMEs, and addresses are removed.

◆ unlink_source()

void roc::pipeline::ReceiverSessionRouter::unlink_source ( packet::stream_source_t source_id )

Unlink source id from session.

Remarks: Removes association of SSRC with session and CNAME. If this was the last SSRC, the whole route is removed.

The documentation for this class was generated from the following file:

roc_pipeline/receiver_session_router.h

Public Member Functions