Overview

A router that multiplexes multiple datagram-oriented Channel s over a single byte-oriented Channel using HDLC framing.

Deprecated:: pw_channel is deprecated; use pw::transport::Socket or pw::transport::ReliableSocket.

Public Member Functions
	Router (pw::channel::ByteReaderWriter &io_channel, ByteSpan decode_buffer)

	Router (const Router &)=delete

Router &	operator= (const Router &)=delete

	Router (Router &&)=delete

Router &	operator= (Router &&)=delete

Status	AddChannel (pw::channel::DatagramReaderWriter &channel, uint64_t receive_address, uint64_t send_address)

Status	RemoveChannel (pw::channel::DatagramReaderWriter &channel, uint64_t receive_address, uint64_t send_address)

pw::async2::Poll	Pend (pw::async2::Context &cx)

pw::async2::Poll	PendClose (pw::async2::Context &cx)
	Closes all underlying channels, attempting to flush any data.

Constructor & Destructor Documentation

◆ Router()

pw::hdlc::Router::Router	(	pw::channel::ByteReaderWriter &	io_channel,
		ByteSpan	decode_buffer
	)

inline

Constructs a Router

Parameters

[in]	io_channel	The channel on which to send and receive encoded HDLC packets.
[in]	decode_buffer	The memory to use for storing partially-decoded HDLC frames. This buffer should be at least `Decoder::RequiredBufferSizeForFrameSize(frame_size)` bytes in order to ensure that HDLC frames of size `frame_size` can be successfully decoded.

Member Function Documentation

◆ AddChannel()

Status pw::hdlc::Router::AddChannel	(	pw::channel::DatagramReaderWriter &	channel,
		uint64_t	receive_address,
		uint64_t	send_address
	)

Registers a Channel tied to the provided addresses.

All incoming HDLC messages received on io_channel with HDLC address receive_address will be decoded and routed to the provided channel.

Data read from channel will be HDLC-encoded and sent to io_channel.

Note that a non-writeable channel will exert backpressure on the entire router, so channels should strive to consume or discard incoming data as quickly as possible in order to prevent starvation of other channels.

Parameters

[in]	receive_address	Incoming HDLC messages received on the external `io_channel` with an address matching `receive_address` will be decoded and written to `channel`.
[in]	send_address	Data read from `channel` will be written to `io_channel` with the HDLC address `send_address`.

Returns

OK: Channel was successfully registered.
ALREADY_EXISTS: A registration already exists for either channel, receive_address, or send_address. Channels may not be registered with multiple addresses, nor may addresses be used with multiple channels.

◆ Pend()

pw::async2::Poll pw::hdlc::Router::Pend ( pw::async2::Context & cx )

Progress the router as far as possible, waking the provided cx when more progress can be made.

This will only return Ready if io_channel has been observed as closed, after which all messages have been flushed to the remaining channels and the channels have been closed.

◆ RemoveChannel()

Status pw::hdlc::Router::RemoveChannel	(	pw::channel::DatagramReaderWriter &	channel,
		uint64_t	receive_address,
		uint64_t	send_address
	)

Removes a previously registered Channel tied to the provided addresses.