strigi/src/streams

Strigi::BufferedStream

Strigi::BufferedStream< T > Class Template Reference

#include <bufferedstream.h>

Inheritance diagram for Strigi::BufferedStream< T >:

[legend]

List of all members.

Detailed Description

template<class T>
class Strigi::BufferedStream< T >

Abstract class providing a buffered input stream.

You can inherit this class to provide buffered access to a resource. You just need to implement fillBuffer, and BufferedStream will do the rest.

Definition at line 37 of file bufferedstream.h.


Public Member Functions
int32_t	read (const T *&start, int32_t min, int32_t max)
int64_t	reset (int64_t pos)
virtual int64_t	skip (int64_t ntoskip)
Protected Member Functions
	BufferedStream ()
virtual int32_t	fillBuffer (T *start, int32_t space)=0
void	resetBuffer ()
void	setMinBufSize (int32_t s)

Constructor & Destructor Documentation

template<class T>

Strigi::BufferedStream< T >::BufferedStream ( ) [inline, protected]

Definition at line 100 of file bufferedstream.h.

Member Function Documentation

template<class T>

virtual int32_t Strigi::BufferedStream< T >::fillBuffer	(	T *	start,
		int32_t	space
	)			`[protected, pure virtual]`

Fill the buffer with the provided data.

This function should be implemented by subclasses. It should write up to space characters from the stream to the buffer position pointed to by start.

If the end of the stream is encountered, -1 should be returned.

If an error occurs, the status should be set to Error, an error message should be set and -1 should be returned.

You should not call this function yourself.

Parameters:

	start	where the data should be written to
	space	the maximum amount of data to write

Returns:: Number of characters written, or -1 on error

Implemented in Strigi::GZipCompressInputStream, and Strigi::ProcessInputStream.

template<class T>

int32_t Strigi::BufferedStream< T >::read	(	const T *&	start,
		int32_t	min,
		int32_t	max
	)			`[inline, virtual]`

Reads items from the stream and sets start to point to the first item that was read.

Note: unless stated otherwise in the documentation for that method, this pointer will no longer be valid after calling another method of this class. The pointer will also no longer be valid after the class is destroyed.

The functions inherited from StreamBaseBase do not invalidate the pointer.

At least min items will be read from the stream, unless an error occurs or the end of the stream is reached. Under no circumstances will more than max items be read.

If the end of the stream is reached before min items are read, the read is still considered successful and the number of items read will be returned.

Parameters:

	start	pointer passed by reference that will be set to point to the retrieved array of items. If the end of the stream is encountered or an error occurs, the value of `start` is undefined
	min	the minimal number of items to read from the stream. This value should be larger than 0. If it is 0 or smaller, the result is undefined
	max	the maximal number of items to read from the stream. If this value is smaller than `min`, there is no limit on the number of items that can be read

Returns:: the number of items that were read. -1 is returned if end of the stream has already been reached. -2 is returned if an error has occurred

Implements Strigi::StreamBase< T >.

Definition at line 129 of file bufferedstream.h.

template<class T>

int64_t Strigi::BufferedStream< T >::reset ( int64_t pos ) [inline, virtual]

Repositions this stream to a given position.

A call to StreamBase::reset is only guaranteed to be successful when the requested position lies within the segment of a stream corresponding to a valid pointer obtained from StreamBase::read. In this case, the pointer will not be invalidated.

Calling this function invalidates the data pointer that was obtained from StreamBase::read unless the conditions outlined above apply.

To read n items, leaving the stream at the same position as before, you can do the following:

 int64_t start = stream.position();
 if ( stream.read(data, min, max) > 0 ) {
     stream.reset(start);
     // The data pointer is still valid here
 }

Parameters:

pos

the position in the stream you want to go to, relative to the start of the stream

Returns:: the new position in the stream

Implements Strigi::StreamBase< T >.

Definition at line 165 of file bufferedstream.h.

template<class T>

void Strigi::BufferedStream< T >::resetBuffer ( ) [inline, protected]

Resets the buffer, allowing it to be used again.

This function resets the buffer, allowing it to be re-used.

Definition at line 69 of file bufferedstream.h.

template<class T>

void Strigi::BufferedStream< T >::setMinBufSize ( int32_t s ) [inline, protected]

Sets the minimum size of the buffer.

Definition at line 81 of file bufferedstream.h.

template<class T>

int64_t Strigi::BufferedStream< T >::skip ( int64_t ntoskip ) [inline, virtual]

Skip ntoskip items.

If an error occurs, or the end of the stream is encountered, fewer than ntoskip items may be skipped. This can be checked by comparing the return value to ntoskip.

Calling this function invalidates the data pointer that was obtained from StreamBase::read.

Parameters:

ntoskip

the number of items that should be skipped

Returns:: the number of items skipped

Reimplemented from Strigi::StreamBase< T >.

Definition at line 180 of file bufferedstream.h.

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

bufferedstream.h

strigi/src/streams

Strigi::BufferedStream< T > Class Template Reference

Detailed Description

template<class T> class Strigi::BufferedStream< T >

Public Member Functions

Protected Member Functions

Constructor & Destructor Documentation

Member Function Documentation

strigi/src/streams

API Reference

template<class T>
class Strigi::BufferedStream< T >