RiverSoftAVG Products Help

Zoom Window Out
Larger Text | Smaller Text
Hide Page Header
Show Expanding Text
Printable Version
Send Mail Feedback
Save Permalink URL

Navigation: Code Documentation > RSCommon > GStreams > Classes

TGBufferStream Class

The TGBufferStream class is a metastream class which provides buffering capabilities for another stream. This class manages buffering input and output for the stream passed to it in the constructor. For lots of small reads and writes especially with file i/o (such as the TFileStream class), the TGBufferStream class can improve performance.

The TGBufferStream class is based largely on the TS_BufferStream class from "Secrets of Delphi 2" by Ray Lischner. Modified and used here by his kind permission.

Namespace: GStreams

	Name	Description
	Create(TStream)	The constructor creates the buffer metastream and prepares the stream for reading or writing.
	Destroy	Represents the destructor of the TGBufferStream class.

Top

	Name	Description
	Buffer	Represents property Buffer.
	BufferEnd	Represents property BufferEnd.
	BufferPosition	Represents property BufferPosition.
	BufferPtr	Represents property BufferPtr.
	BufferSize	The BufferSize property specifies the size of the buffer created by the stream, i.e., the smallest number of bytes that are read or written at once (except for when the buffer is flushed). The size of the buffer can make a big difference in the efficiency of the object. The default buffer size is 8192 bytes.
	OnFillBuffer	Occurs whenever the buffer is refilled from the stream. Write an OnFillBuffer event when you want to take action every time the buffer is filled.
	OnFlushBuffer	Occurs when the buffer is flushed of all of its contents and written to the stream. Write an OnFlushBuffer event handler when you want to take some action when the buffer is flushed.
	State	Specifies whether the buffer is being used for reading or writing. The unknown state occurs when the buffer is created, flushed, or the stream has been completely read.
	Stream	Represents property Stream.

Top

	Name	Description
	Close	Closes and flushes the buffer.
	FillBuffer	Represents method FillBuffer.
	FlushBuffer	Represents method FlushBuffer.
	IsEof	Returns true if the stream is at the end of file.
	PrepareBuffer	Represents method PrepareBuffer.
	PutBack(Byte)	Overloaded. Represents method PutBack(Byte).
	PutBack(Char)	Overloaded. Represents method PutBack(Char).
	Read(Void,Longint)	Represents method Read(Void,Longint).
	Seek(Longint,Word)	Represents method Seek(Longint,Word).
	Write(Void,Longint)	Represents method Write(Void,Longint).

Top

The following code shows how to use the TGBufferStream class to buffer the file i/o:

Delphi
var FileStream: TFileStream; Stream: TGBufferStream; begin FileStream := TFileStream.Create( FileName, fmOpenRead ); try Stream := TGBufferStream.Create( FileStream ); try // Lots of buffer reads here finally Stream.Free; end; finally FileStream.Free; end; end;

RiverSoftAVG Products Help

Reference