StreamFilter Class Reference

A stream filter. More...

#include <StreamFilter.h>

Inheritance diagram for StreamFilter:

Collaboration diagram for StreamFilter:

Public Member Functions
	StreamFilter (IEventQueue *events, deskflow::IStream *stream, bool adoptStream=true)
	StreamFilter (StreamFilter const &)=delete
	StreamFilter (StreamFilter &&)=delete
	~StreamFilter () override
StreamFilter &	operator= (StreamFilter const &)=delete
StreamFilter &	operator= (StreamFilter &&)=delete
void	close () override
	Close the stream.
uint32_t	read (void *buffer, uint32_t n) override
	Read from stream.
void	write (const void *buffer, uint32_t n) override
	Write to stream.
void	flush () override
	Flush the stream.
void	shutdownInput () override
	Shutdown input.
void	shutdownOutput () override
	Shutdown output.
void *	getEventTarget () const override
	Get event target.
bool	isReady () const override
	Test if read() will succeed.
uint32_t	getSize () const override
	Get bytes available to read.
deskflow::IStream *	getStream () const
	Get the stream.
Public Member Functions inherited from deskflow::IStream
	IStream ()=default
Public Member Functions inherited from IInterface
virtual	~IInterface ()=default
	Interface destructor does nothing.

Protected Member Functions
virtual void	filterEvent (const Event &)
	Handle events from source stream.

Detailed Description

A stream filter.

This class wraps a stream. Subclasses provide indirect access to the wrapped stream, typically performing some filtering.

Constructor & Destructor Documentation

StreamFilter() [1/3]

StreamFilter::StreamFilter	(	IEventQueue *	events,
		deskflow::IStream *	stream,
		bool	adoptStream = true )

Create a wrapper around stream. Iff adoptStream is true then this object takes ownership of the stream and will delete it in the d'tor.

StreamFilter() [2/3]

StreamFilter::StreamFilter ( StreamFilter const & )

delete

StreamFilter() [3/3]

StreamFilter::StreamFilter ( StreamFilter && )

delete

~StreamFilter()

StreamFilter::~StreamFilter ( )

override

Member Function Documentation

close()

void StreamFilter::close ( )

overridevirtual

Close the stream.

Closes the stream. Pending input data and buffered output data are discarded. Use flush() before close() to send buffered output data. Attempts to read() after a close return 0, attempts to write() generate output error events, and attempts to flush() return immediately.

Implements deskflow::IStream.

filterEvent()

void StreamFilter::filterEvent ( const Event & event )

protectedvirtual

Handle events from source stream.

Does the event filtering. The default simply dispatches an event identical except using this object as the event target.

Reimplemented in PacketStreamFilter.

flush()

void StreamFilter::flush ( )

overridevirtual

Flush the stream.

Waits until all buffered data has been written to the stream.

Implements deskflow::IStream.

getEventTarget()

void * StreamFilter::getEventTarget ( ) const

overridevirtual

Get event target.

Returns the event target for events generated by this stream. It should be the source stream in a chain of stream filters.

Implements deskflow::IStream.

getSize()

uint32_t StreamFilter::getSize ( ) const

overridevirtual

Get bytes available to read.

Returns a conservative estimate of the available bytes to read (i.e. a number not greater than the actual number of bytes). Some streams may not be able to determine this and will always return zero.

Implements deskflow::IStream.

getStream()

deskflow::IStream * StreamFilter::getStream

(

)

const

Get the stream.

Returns the stream passed to the c'tor.

isReady()

bool StreamFilter::isReady ( ) const

overridevirtual

Test if read() will succeed.

Returns true iff an immediate read() will return data. This may or may not be the same as getSize() > 0, depending on the stream type.

Implements deskflow::IStream.

operator=() [1/2]

StreamFilter & StreamFilter::operator= ( StreamFilter && )

delete

operator=() [2/2]

StreamFilter & StreamFilter::operator= ( StreamFilter const & )

delete

read()

uint32_t StreamFilter::read ( void * buffer, uint32_t n )

overridevirtual

Read from stream.

Read up to n bytes into buffer, returning the number read (zero if no data is available or input is shutdown). buffer may be nullptr in which case the data is discarded.

Implements deskflow::IStream.

shutdownInput()

void StreamFilter::shutdownInput ( )

overridevirtual

Shutdown input.

Shutdown the input side of the stream. Any pending input data is discarded and further reads immediately return 0.

Implements deskflow::IStream.

shutdownOutput()

void StreamFilter::shutdownOutput ( )

overridevirtual

Shutdown output.

Shutdown the output side of the stream. Any buffered output data is discarded and further writes generate output error events. Use flush() before shutdownOutput() to send buffered output data.

Implements deskflow::IStream.

write()

void StreamFilter::write ( const void * buffer, uint32_t n )

overridevirtual

Write to stream.

Write n bytes from buffer to the stream. If this can't complete immediately it will block. Data may be buffered in order to return more quickly. A output error event is generated when writing fails.

Implements deskflow::IStream.

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

• src/lib/io/StreamFilter.h
• src/lib/io/StreamFilter.cpp