Detailed Description

Copy bytes from a Readable source to a network address.

Given a buffered source of data and a maximum chunk size, read data in chunks and stream each chunk to a net::Address. The source is a byte-stream that ignores packet boundaries. For a similiar class that retains packet boundaries,

See also: BufferedPackets.

Usage is similar to BufferedCopy, but with improved controls for packetizing the raw stream. Two thresholds control the length of outgoing packets:

Threshold "max_chunk" is the absolute maximum length. i.e., Outgoing packets MUST NOT exceed max_chunk bytes.
Threshold "min_txnow" sets the preferred minimum length. i.e., Outgoing packets SHOULD be at least min_txnow bytes, but MAY be smaller if incoming data has slowed or stopped.

To prevent trailing data from becoming stuck, a timeout allows transmission of smaller chunks as follows. With N as the number of bytes available from the Readable source:

If N >= max_chunk: Transmit max_chunk bytes immediately.
Optionally, if N >= min_txnow: Transmit N bytes immediately. (This condition is ignored if min_txnow >= max_chunk.)
Otherwise: Wait for transmit timeout, then transmit N bytes. (This condition is ignored if the trantmit timeout is zero.)

Definition at line 124 of file io_buffer.h.

#include <io_buffer.h>

Inheritance diagram for satcat5::io::BufferedStream:

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Collaboration diagram for satcat5::io::BufferedStream:

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Public Member Functions
	BufferedStream (satcat5::io::Readable src, satcat5::net::Address dst, unsigned max_chunk=512, unsigned min_txnow=UINT_MAX)
	Set source, destination, APID, and chunk-size. More...

void	set_timeout (unsigned msec)
	Set packetization timeout, in milliseconds. More...

Protected Member Functions
void	data_rcvd (satcat5::io::Readable *src) override
	The data_rcvd() callback is polled whenever data is available. More...

void	data_unlink (satcat5::io::Readable *src) override
	Unlink this EventListener from the designated source, because the designated Readable object is being destroyed. More...

Protected Attributes
satcat5::io::Readable *	m_src

satcat5::net::Address *const	m_dst

const unsigned	m_max_chunk

const unsigned	m_min_txnow

unsigned	m_timeout_msec

satcat5::util::TimeVal	m_tref

Constructor & Destructor Documentation

◆ BufferedStream()

BufferedStream::BufferedStream	(	satcat5::io::Readable *	src,
		satcat5::net::Address *	dst,
		unsigned	max_chunk = `512`,
		unsigned	min_txnow = `UINT_MAX`
	)

Set source, destination, APID, and chunk-size.

Default sets max_chunk to 512 bytes and ignores min_txnow.

Definition at line 51 of file io_buffer.cc.

Member Function Documentation

◆ data_rcvd()

void BufferedStream::data_rcvd ( satcat5::io::Readable * src )

overrideprotectedvirtual

The data_rcvd() callback is polled whenever data is available.

A pointer is provided to assist handlers with multiple sources. Child objects of io::EventListener MUST override this method.

Implements satcat5::io::EventListener.

Definition at line 72 of file io_buffer.cc.

◆ data_unlink()

void BufferedStream::data_unlink ( satcat5::io::Readable * src )

overrideprotectedvirtual

Unlink this EventListener from the designated source, because the designated Readable object is being destroyed.

Child objects of io::EventListener MAY override this method if action is required.

Reimplemented from satcat5::io::EventListener.

Definition at line 99 of file io_buffer.cc.

◆ set_timeout()

void satcat5::io::BufferedStream::set_timeout ( unsigned msec )

inline

Set packetization timeout, in milliseconds.

If the timeout is zero, copy only full-size chunks.

Definition at line 139 of file io_buffer.h.

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