Detailed Description

Barebones class for overwriting contents of a MultiPacket.

This class performs no memory allocation; it merely replaces the in-memory contents of an existing MultiPacket.

See also: multi_buffer.h, io::MultiPacket, io::MultiWriter.

Definition at line 166 of file multi_buffer.h.

#include <multi_buffer.h>

Inheritance diagram for satcat5::io::MultiPacket::Overwriter:

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Collaboration diagram for satcat5::io::MultiPacket::Overwriter:

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Public Member Functions
	Overwriter (satcat5::io::MultiPacket *pkt)
	Create a new Writer object.

unsigned	write_count () const
	Return total bytes written by this object.

unsigned	get_write_space () const override
	How many bytes can be written without blocking? More...

void	write_bytes (unsigned nbytes, const void *src) override
	Write 0 or more bytes from a buffer. More...

void	write_u8 (u8 data)
	One of many functions for writing integer/floating point values, see details. More...

void	write_str (const char *str)
	Write the contents of a null-terminated string. More...

virtual bool	write_finalize ()
	Mark end of frame and release temporary working data. More...

virtual void	write_abort ()
	If possible, abort the current partially-written packet. More...

template<class T >
void	write_obj (const T &obj)
	Templated wrapper for any object with the following method: `void write_to(satcat5::io::Writeable* wr) const;`

Protected Member Functions
void	write_next (u8 data) override
	Write the next byte to the underlying buffer or device. More...

virtual void	write_overflow ()
	Optional error handling for write overflow. More...

Protected Attributes
friend	LimitedWrite

friend	WriteableBroadcast

friend	WriteableRedirect

Private Attributes

unsigned	m_write_pos
	Current write state.

unsigned	m_write_rem
	Current write state.

unsigned	m_write_tot
	Current write state.

satcat5::io::MultiChunk *	m_write_chunk
	Current write state.

Member Function Documentation

◆ get_write_space()

unsigned MultiPacket::Overwriter::get_write_space ( ) const

overridevirtual

How many bytes can be written without blocking?

Child objects of io::Writeable MUST override this method.

Implements satcat5::io::Writeable.

Definition at line 117 of file multi_buffer.cc.

◆ write_abort()

void Writeable::write_abort ( )

virtualinherited

If possible, abort the current partially-written packet.

Child objects of io::Writeable SHOULD override this method if it is practical to prevent in-progress data from being relayed downstream.

Reimplemented in satcat5::port::Mailmap, satcat5::io::PacketBuffer, satcat5::io::MultiWriter, satcat5::io::WriteableRedirect, satcat5::io::ArrayWrite, satcat5::io::CounterInline, satcat5::io::ChecksumRxCommon, satcat5::io::ChecksumTxCommon, satcat5::io::WriteableBroadcast, satcat5::eth::SwitchPort, satcat5::io::HdlcEncoder::ByteStuff, and satcat5::io::FileWriter.

Definition at line 186 of file io_writeable.cc.

◆ write_bytes()

void MultiPacket::Overwriter::write_bytes	(	unsigned	nbytes,
		const void *	src
	)

overridevirtual

Write 0 or more bytes from a buffer.

Child objects of io::Writeable MAY override write_bytes as needed for performance.

Reimplemented from satcat5::io::Writeable.

Definition at line 121 of file multi_buffer.cc.

◆ write_finalize()

bool Writeable::write_finalize ( )

virtualinherited

Mark end of frame and release temporary working data.

Child objects of io::Writeable SHOULD override this method to mark frame bounds.

Returns: True if successful, false on error.

Reimplemented in satcat5::port::Mailmap, satcat5::io::PacketBuffer, satcat5::io::MultiWriterBypass, satcat5::io::MultiWriter, satcat5::io::WriteableRedirect, satcat5::io::ArrayWrite, satcat5::io::WriteableThrottle, satcat5::io::CounterInline, satcat5::io::WriteableBroadcastAny, satcat5::io::WriteableBroadcast, satcat5::eth::SwitchPort, satcat5::eth::ChecksumRx, satcat5::eth::ChecksumTx, satcat5::crc16::XmodemRx, satcat5::crc16::XmodemTx, satcat5::crc16::KermitRx, satcat5::crc16::KermitTx, satcat5::io::SlipEncoder, satcat5::io::HdlcEncoder::ByteStuff, satcat5::io::CobsEncoder, satcat5::coap::Connection, satcat5::test::EthernetInterface, satcat5::io::BufferedTee, satcat5::io::WritePcapInterface, satcat5::io::WritePcap, satcat5::io::FileWriter, and satcat5::util::ChatPrinter.

Definition at line 185 of file io_writeable.cc.

◆ write_next()

void MultiPacket::Overwriter::write_next ( u8 data )

overrideprotectedvirtual

Write the next byte to the underlying buffer or device.

Child objects of io::Writeable MUST override this method.

Implements satcat5::io::Writeable.

Definition at line 141 of file multi_buffer.cc.

◆ write_overflow()

void Writeable::write_overflow ( )

protectedvirtualinherited

Optional error handling for write overflow.

Child objects of io::Writeable MAY override this method for error handling.

Reimplemented in satcat5::port::Mailmap, satcat5::io::PacketBuffer, satcat5::io::MultiWriter, satcat5::io::WriteableRedirect, satcat5::io::ArrayWrite, satcat5::io::ChecksumTxCommon, satcat5::io::WriteableBroadcast, satcat5::io::SlipDecoder, satcat5::io::SlipEncoder, satcat5::io::HdlcDecoder, satcat5::io::CobsDecoder, and satcat5::io::CobsEncoder.

Definition at line 187 of file io_writeable.cc.

◆ write_str()

void Writeable::write_str ( const char * str )

inherited

Write the contents of a null-terminated string.

Note: Null-termination is not copied to the output.

Definition at line 180 of file io_writeable.cc.

◆ write_u8()

void Writeable::write_u8 ( u8 data )

inherited

One of many functions for writing integer/floating point values, see details.

Several functions are provided for reading and writing scalar types to/from io::Readable and io::Writeable instances. Since there are many of these that are frequently inherited, they are hidden from documentation. These functions follow a shared template:

read_ or write_ prefix.
u for unsigned, s for signed, f for floating-point.
Data-type width in bits.
- Available widths for ints: 8/16/24/32/48/64.
- Available widths for floats: 32/64.
l suffix if little-endian, no suffix if big-endian.

Example: write_s48l is "Write 48 bits (6 bytes) to this io::Writeable as a signed value in little-endian order".

Definition at line 20 of file io_writeable.cc.

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