Burger::Compress Class Reference

Base class for data compression. More...

Inheritance diagram for Burger::Compress:

Collaboration diagram for Burger::Compress:

Public Member Functions
const Burger::StaticRTTI *	get_StaticRTTI (void) const noexcept override
	Get the description to the class.
	Compress (void)
	Default constructor.
virtual	~Compress ()
	Default destructor.
virtual eError	Init (void)=0
	Initialize the compression algorithm.
virtual eError	Process (const void *pInput, uintptr_t uInputLength)=0
	Compress data.
virtual eError	Finalize (void)=0
	Finish the compression.
OutputMemoryStream *	GetOutput (void) noexcept
	Get the output data.
uintptr_t	GetOutputSize (void) const noexcept
	Get the output data size in bytes.
uint32_t	GetSignature (void) const noexcept
	Return the signature for this compressor.
Public Member Functions inherited from Burger::Base
const char *	get_class_name (void) const noexcept
	Get the name of the class.
virtual	~Base () noexcept=default
	Destructor.

Static Public Attributes
static const Burger::StaticRTTI	g_StaticRTTI
	The global description of the class.
Static Public Attributes inherited from Burger::Base
static const Burger::StaticRTTI	g_StaticRTTI
	The global description of the class.

Protected Attributes
OutputMemoryStream	m_Output
	Main output buffer for compressed data.
uint32_t	m_uSignature
	4 character code to identify this compressor

Detailed Description

Base class for data compression.

---

For functions that allow compression, this class will allow any compression algorithm to be used as long as they derive from this base class.

The only data present is an OutputMemoryStream that will contain the compressed data stream and will be valid once the Compress::Finalize() function is called.

See also

Burger::Decompress

Constructor & Destructor Documentation

Compress()

Burger::Compress::Compress

(

void

)

Default constructor.

---

Initializes the output buffer.

~Compress()

Burger::Compress::~Compress ( )

virtual

Default destructor.

---

Releases the output buffer if needed

Member Function Documentation

Finalize()

Burger::eError Burger::Compress::Finalize ( void )

pure virtual

Finish the compression.

---

Perform the final data compaction and clean up. After this call is performed, the output is valid and can be accessed with calls to GetOutput() and GetOutputSize()

Note

This is must be implemented by derived class.

Returns

Zero if no failure, non-zero is an error code

See also

GetOutput() and GetOutputSize()

Implemented in Burger::CompressILBMRLE, Burger::CompressLZSS, and Burger::CompressDeflate.

get_StaticRTTI()

const Burger::StaticRTTI * Burger::Compress::get_StaticRTTI ( void ) const

overridevirtualnoexcept

Get the description to the class.

---

This virtual function will pull the pointer to the StaticRTTI instance that has the name of the class. Due to it being virtual, it will be the name of the most derived class.

Returns

Pointer to a global, read only instance of StaticRTTI for the true class

Reimplemented from Burger::Base.

Reimplemented in Burger::CompressILBMRLE, Burger::CompressLZSS, and Burger::CompressDeflate.

GetOutput()

OutputMemoryStream * Burger::Compress::GetOutput ( void )

inlinenoexcept

Get the output data.

---

After Finalize() has been called, the output data can be obtained with this call

Returns

Pointer to the OutputMemoryStream structure containing the output

See also

Finalize() and GetOutputSize()

GetOutputSize()

uintptr_t Burger::Compress::GetOutputSize ( void ) const

inlinenoexcept

Get the output data size in bytes.

---

After Finalize() has been called, the output data size can be obtained with this call

Returns

Number of bytes contained in the output stream

See also

Finalize() and GetOutput()

GetSignature()

uint32_t Burger::Compress::GetSignature ( void ) const

inlinenoexcept

Return the signature for this compressor.

---

Each compressor has a unique signature to identify the algorithm used for compression. It's in the form of a 4 character code.

Popular codes are...

Algorithm	Code
LZSS	LZSS
ILBM RLE	RLE
Inflate (ZLib)	ZLIB
LZARI	LZAR
RefPack	REFP
Huffman	HUFF

Returns

A 32 bit number form of the 4 byte character code. It's an endian neutral text string

Init()

Burger::eError Burger::Compress::Init ( void )

pure virtual

Initialize the compression algorithm.

---

This function will reset the compression algorithm (Which may or may not require memory allocations) and returns an error code if there was a failure.

Note

This is must be implemented by derived class and it also acts as a "reset" function to recycle this class to perform compression on new data.

Returns

Zero if no failure, non-zero is an error code

Implemented in Burger::CompressILBMRLE, Burger::CompressLZSS, and Burger::CompressDeflate.

Process()

Burger::eError Burger::Compress::Process ( const void * pInput, uintptr_t uInputLength )

pure virtual

Compress data.

---

Pass data into the compressor and store the output into the data stream

Note

This is must be implemented by derived class.

Parameters

pInput	Pointer to data to compress
uInputLength	Number of bytes in the data

Returns

Zero if no failure, non-zero is an error code

Implemented in Burger::CompressILBMRLE, Burger::CompressLZSS, and Burger::CompressDeflate.

Member Data Documentation

g_StaticRTTI

const Burger::StaticRTTI Burger::Compress::g_StaticRTTI

static

The global description of the class.

---

This record contains the name of this class and a reference to the parent

m_Output

OutputMemoryStream Burger::Compress::m_Output

protected

Main output buffer for compressed data.

m_uSignature

uint32_t Burger::Compress::m_uSignature

protected

4 character code to identify this compressor