GlsRLEDecoder Class Reference

#include <gls_rle_decoder.h>

Public Member Functions
	GlsRLEDecoder (const GlsUChar *const inlineData[], const GlsUInt32 inlineDataLength, const GlsUInt32 lineLength)
	~GlsRLEDecoder ()
GlsUChar	DecodeByte (void)
GlsBool	IsDone (void) const

Protected Attributes
GlsUtil::InlineReader	_inlineReader
GlsUChar	_markerByte
GlsUInt32	_sequenceRemaining
GlsUChar	_repeatedByte

Static Protected Attributes
static const GlsUChar	TWO_BYTE_COUNT_FLAG = 0x80

Detailed Description

RLE ( Run Length Encoded compression ) decoder.
This decoder allows for incremental decoding of RLE compressed data in inline format.

Invariant

_inlineReader invariant holds

Constructor & Destructor Documentation

GlsRLEDecoder()

GlsRLEDecoder::GlsRLEDecoder	(	const GlsUChar *const	inlineData[],
		const GlsUInt32	inlineDataLength,
		const GlsUInt32	lineLength
	)

Constructor - create an instance

Parameters

inlineData	inline RLE data to decode
inlineDataLength	length in bytes of inline RLE data to decode ( not including terminators at end of lines )
lineLength	length (in bytes) of one line of data in the inline data (not including NULL terminator)

Precondition

inlineData != GLS_NULL, inlineDataLength > 1, lineLength > 0

Postcondition

instance created

~GlsRLEDecoder()

GlsRLEDecoder::~GlsRLEDecoder

(

)

Destructor - destroy instance

Precondition

none

Postcondition

instance destroyed

Member Function Documentation

DecodeByte()

GlsUChar GlsRLEDecoder::DecodeByte

(

void

)

Decode one byte of input

Returns

decoded byte

Precondition

there must be at least one more byte of input remaining

Postcondition

one byte is read from input

IsDone()

GlsBool GlsRLEDecoder::IsDone

(

void

)

const

Determine if decoder is finished decoding input data

Returns

GLS_TRUE if done else GLS_FALSE

Precondition

none

Postcondition

none

Member Data Documentation

_inlineReader

GlsUtil::InlineReader GlsRLEDecoder::_inlineReader

protected

inline data reader

_markerByte

GlsUChar GlsRLEDecoder::_markerByte

protected

marker byte to signal run length

_repeatedByte

GlsUChar GlsRLEDecoder::_repeatedByte

protected

current repeated byte if _sequenceRemaining > 0

_sequenceRemaining

GlsUInt32 GlsRLEDecoder::_sequenceRemaining

protected

number of repeated bytes remaining in sequence else 0

TWO_BYTE_COUNT_FLAG

const GlsUChar GlsRLEDecoder::TWO_BYTE_COUNT_FLAG = 0x80

staticprotected

flag in input data that indicates a two byte repeat count