An abstraction definition of a stream data source. More...

#include <StreamDataSource.h>

Inheritance diagram for StreamDataSource:

Collaboration diagram for StreamDataSource:

Public Member Functions
Creators
	StreamDataSource (int iFlags=0)
	Constructors a StreamDataSource given optional flags. More...

virtual	~StreamDataSource ()
	Destructor. More...

Manipulators
virtual OsStatus	open ()=0
	Opens the data source. More...

virtual OsStatus	close ()=0
	Closes the data source. More...

virtual OsStatus	destroyAndDelete ()=0
	Destroys and deletes the data source object. More...

virtual OsStatus	read (char *szBuffer, int iLength, int &iLengthRead)=0

virtual OsStatus	peek (char *szBuffer, int iLength, int &iLengthRead)=0
	Identical to read, except the stream pointer is not advanced. More...

virtual OsStatus	interrupt ()
	Interrupts any time consuming operation. More...

virtual OsStatus	seek (unsigned int iLocation)=0
	Moves the stream pointer to the an absolute location. More...

void	setListener (StreamDataSourceListener *pListener)

Accessors
virtual OsStatus	getLength (int &iLength)=0
	Gets the length of the stream (if available) More...

virtual OsStatus	getPosition (int &iPosition)=0
	Gets the current position within the stream. More...

virtual OsStatus	toString (UtlString &string)=0
	Renders a string describing this data source. More...

int	getFlags ()
	Gets the flags specified at time of construction. More...

Protected Member Functions
	StreamDataSource (const StreamDataSource &rStreamDataSource)
	Copy constructor (not supported) More...

StreamDataSource &	operator= (const StreamDataSource &rhs)
	Assignment operator (not supported) More...

void	fireEvent (StreamDataSourceEvent event)
	Fires a data source event to the interested consumer. More...

Private Attributes
StreamDataSourceListener *	mpListener
	data source listener More...

int	miFlags
	flags specified during construction More...

Detailed Description

An abstraction definition of a stream data source.

Constructor & Destructor Documentation

StreamDataSource ( int iFlags = 0 )

Constructors a StreamDataSource given optional flags.

See also: StreamDefs.h for a description of available flags.

~StreamDataSource ( )

virtual

Destructor.

StreamDataSource ( const StreamDataSource & rStreamDataSource )

protected

Copy constructor (not supported)

Member Function Documentation

virtual OsStatus open ( )

pure virtual

Opens the data source.

Implemented in StreamHttpDataSource, StreamBufferDataSource, and StreamFileDataSource.

virtual OsStatus close ( )

pure virtual

Closes the data source.

Implemented in StreamHttpDataSource, StreamBufferDataSource, and StreamFileDataSource.

virtual OsStatus destroyAndDelete ( )

pure virtual

Destroys and deletes the data source object.

Implemented in StreamHttpDataSource, StreamBufferDataSource, and StreamFileDataSource.

virtual OsStatus read	(	char *	szBuffer,
		int	iLength,
		int &	iLengthRead
	)

pure virtual

Reads iLength bytes of data from the data source and places the data into the passed szBuffer buffer.

Parameters

szBuffer	- Buffer to place data
iLength	- Max length to read
iLengthRead	- The actual amount of data read.

Implemented in StreamHttpDataSource, StreamBufferDataSource, and StreamFileDataSource.

virtual OsStatus peek	(	char *	szBuffer,
		int	iLength,
		int &	iLengthRead
	)

pure virtual

Identical to read, except the stream pointer is not advanced.

Parameters

szBuffer	- Buffer to place data
iLength	- Max length to read
iLengthRead	- The actual amount of data read.

Implemented in StreamHttpDataSource, StreamBufferDataSource, and StreamFileDataSource.

OsStatus interrupt ( )

virtual

Interrupts any time consuming operation.

For example, some data sources may require network access (e.g. http) to read or fetch data. Invoking an interrupt() will cause any time consuming or blocking calls to exit with more quickly with an OS_INTERRUPTED return code.

Reimplemented in StreamHttpDataSource.

virtual OsStatus seek ( unsigned int iLocation )

pure virtual

Moves the stream pointer to the an absolute location.

Parameters

iLocation - The desired seek location

Implemented in StreamHttpDataSource, StreamBufferDataSource, and StreamFileDataSource.

void setListener ( StreamDataSourceListener * pListener )

Sets a listener to receive StreamDataSourceEvent events for this data source.

virtual OsStatus getLength ( int & iLength )

pure virtual

Gets the length of the stream (if available)