Gzip Class Reference

#include <gzip.h>

Inheritance diagram for Gzip:

List of all members.

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Detailed Description

GZIP Compression (RFC 1952).

Definition at line 11 of file gzip.h.

SIGNALS
virtual bool	IsolatedMessageSeriesEnd (bool blocking)
virtual void	SetAutoSignalPropagation (int propagation)
	set propagation of automatically generated and transferred signals
virtual int	GetAutoSignalPropagation () const
Public Types
enum	{ MIN_DEFLATE_LEVEL = 0, DEFAULT_DEFLATE_LEVEL = 6, MAX_DEFLATE_LEVEL = 9 }
enum	{ MIN_LOG2_WINDOW_SIZE = 9, DEFAULT_LOG2_WINDOW_SIZE = 15, MAX_LOG2_WINDOW_SIZE = 15 }
Public Member Functions
	Gzip (BufferedTransformation *attachment=NULL, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
	Gzip (const NameValuePairs &parameters, BufferedTransformation *attachment=NULL)
void	SetDeflateLevel (int deflateLevel)
	this function can be used to set the deflate level in the middle of compression
int	GetDeflateLevel () const
int	GetLog2WindowSize () const
void	IsolatedInitialize (const NameValuePairs &parameters)
unsigned int	Put2 (const byte *inString, unsigned int length, int messageEnd, bool blocking)
	input multiple bytes for blocking or non-blocking processing
bool	IsolatedFlush (bool hardFlush, bool blocking)
void	PutBits (unsigned long value, unsigned int length)
void	FlushBitBuffer ()
void	ClearBitBuffer ()
void	StartCounting ()
unsigned long	FinishCounting ()
bool	Attachable ()
	returns whether this object allows attachment
BufferedTransformation *	AttachedTransformation ()
	returns the object immediately attached to this object or NULL for no attachment
const BufferedTransformation *	AttachedTransformation () const
void	Detach (BufferedTransformation *newAttachment=NULL)
	delete the current attachment chain and replace it with newAttachment
unsigned int	TransferTo2 (BufferedTransformation &target, unsigned long &transferBytes, const std::string &channel=NULL_CHANNEL, bool blocking=true)
unsigned int	CopyRangeTo2 (BufferedTransformation &target, unsigned long &begin, unsigned long end=ULONG_MAX, const std::string &channel=NULL_CHANNEL, bool blocking=true) const
void	Initialize (const NameValuePairs &parameters=g_nullNameValuePairs, int propagation=-1)
	initialize or reinitialize this object
bool	Flush (bool hardFlush, int propagation=-1, bool blocking=true)
	flush buffered input and/or output
bool	MessageSeriesEnd (int propagation=-1, bool blocking=true)
	mark end of a series of messages
BufferedTransformation &	Ref ()
	return a reference to this object
virtual std::string	AlgorithmName () const
	returns name of this algorithm, not universally implemented yet
virtual Clonable *	Clone () const
	this is not implemented by most classes yet
bool	Wait (unsigned long milliseconds)
	wait on this object
Static Public Attributes
const std::string	NULL_CHANNEL
Protected Types
enum	{   MAGIC1 = 0x1f, MAGIC2 = 0x8b, DEFLATED = 8, FAST = 4,   SLOW = 2 }
enum	{ STORED = 0, STATIC = 1, DYNAMIC = 2 }
enum	{ MIN_MATCH = 3, MAX_MATCH = 258 }
Protected Member Functions
void	WritePrestreamHeader ()
void	ProcessUncompressedData (const byte *string, unsigned int length)
void	WritePoststreamTail ()
void	InitializeStaticEncoders ()
void	Reset (bool forceReset=false)
unsigned int	FillWindow (const byte *str, unsigned int length)
unsigned int	ComputeHash (const byte *str) const
unsigned int	LongestMatch (unsigned int &bestMatch) const
void	InsertString (unsigned int start)
void	ProcessBuffer ()
void	LiteralByte (byte b)
void	MatchFound (unsigned int distance, unsigned int length)
void	EncodeBlock (bool eof, unsigned int blockType)
void	EndBlock (bool eof)
virtual BufferedTransformation *	NewDefaultAttachment () const
void	Insert (Filter *nextFilter)
virtual bool	ShouldPropagateMessageEnd () const
virtual bool	ShouldPropagateMessageSeriesEnd () const
void	PropagateInitialize (const NameValuePairs &parameters, int propagation)
unsigned int	Output (int outputSite, const byte *inString, unsigned int length, int messageEnd, bool blocking, const std::string &channel=NULL_CHANNEL)
unsigned int	OutputModifiable (int outputSite, byte *inString, unsigned int length, int messageEnd, bool blocking, const std::string &channel=NULL_CHANNEL)
bool	OutputMessageEnd (int outputSite, int propagation, bool blocking, const std::string &channel=NULL_CHANNEL)
bool	OutputFlush (int outputSite, bool hardFlush, int propagation, bool blocking, const std::string &channel=NULL_CHANNEL)
bool	OutputMessageSeriesEnd (int outputSite, int propagation, bool blocking, const std::string &channel=NULL_CHANNEL)
Static Protected Member Functions
int	DecrementPropagation (int propagation)
Protected Attributes
unsigned long	m_totalLen
CRC32	m_crc
int	m_deflateLevel
int	m_log2WindowSize
int	m_compressibleDeflateLevel
unsigned int	m_detectSkip
unsigned int	m_detectCount
unsigned int	DSIZE
unsigned int	DMASK
unsigned int	HSIZE
unsigned int	HMASK
unsigned int	GOOD_MATCH
unsigned int	MAX_LAZYLENGTH
unsigned int	MAX_CHAIN_LENGTH
bool	m_headerWritten
bool	m_matchAvailable
unsigned int	m_dictionaryEnd
unsigned int	m_stringStart
unsigned int	m_lookahead
unsigned int	m_minLookahead
unsigned int	m_previousMatch
unsigned int	m_previousLength
HuffmanEncoder	m_staticLiteralEncoder
HuffmanEncoder	m_staticDistanceEncoder
HuffmanEncoder	m_dynamicLiteralEncoder
HuffmanEncoder	m_dynamicDistanceEncoder
SecByteBlock	m_byteBuffer
SecBlock< word16 >	m_head
SecBlock< word16 >	m_prev
FixedSizeSecBlock< unsigned int, 286 >	m_literalCounts
FixedSizeSecBlock< unsigned int, 30 >	m_distanceCounts
SecBlock< EncodedMatch >	m_matchBuffer
unsigned int	m_matchBufferEnd
unsigned int	m_blockStart
unsigned int	m_blockLength
bool	m_counting
unsigned long	m_bitCount
unsigned long	m_buffer
unsigned int	m_bitsBuffered
unsigned int	m_bytesBuffered
FixedSizeSecBlock< byte, 256 >	m_outputBuffer
unsigned int	m_inputPosition
int	m_continueAt

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Member Function Documentation

unsigned int Deflator::Put2 (  const byte *  inString, unsigned int  length, int  messageEnd, bool  blocking )  [virtual, inherited]

input multiple bytes for blocking or non-blocking processing Parameters: messageEnd  means how many filters to signal MessageEnd to, including this one Implements BufferedTransformation. Definition at line 477 of file zdeflate.cpp.

bool Filter::Attachable (   )  [inline, virtual, inherited]

returns whether this object allows attachment Some BufferedTransformation objects (e.g. Filter objects) allow other BufferedTransformation objects to be attached. When this is done, the first object instead of buffering its output, sents that output to the attached object as input. The entire attachment chain is deleted when the anchor object is destructed. Reimplemented from BufferedTransformation. Definition at line 19 of file filters.h.

bool Filter::Flush (  bool  hardFlush, int  propagation = -1, bool  blocking = true )  [virtual, inherited]

flush buffered input and/or output Parameters: hardFlush  is used to indicate whether all data should be flushed Note: Hard flushes must be used with care. It means try to process and output everything, even if there may not be enough data to complete the action. For example, hard flushing a HexDecoder would cause an error if you do it after inputing an odd number of hex encoded characters. For some types of filters, for example ZlibDecompressor, hard flushes can only be done at "synchronization points". These synchronization points are positions in the data stream that are created by hard flushes on the corresponding reverse filters, in this example ZlibCompressor. This is useful when zlib compressed data is moved across a network in packets and compression state is preserved across packets, as in the ssh2 protocol. Reimplemented from BufferedTransformation. Reimplemented in SecretSharing, and InformationDispersal. Definition at line 68 of file filters.cpp.

bool Filter::MessageSeriesEnd (  int  propagation = -1, bool  blocking = true )  [virtual, inherited]

mark end of a series of messages There should be a MessageEnd immediately before MessageSeriesEnd. Reimplemented from BufferedTransformation. Definition at line 82 of file filters.cpp.

BufferedTransformation& BufferedTransformation::Ref (   )  [inline, inherited]

return a reference to this object This function is useful for passing a temporary BufferedTransformation object to a function that takes a non-const reference. Definition at line 711 of file cryptlib.h.

virtual byte* BufferedTransformation::CreatePutSpace (  unsigned int &  size  )  [inline, virtual, inherited]

request space which can be written into by the caller, and then used as input to Put() Note: The purpose of this method is to help avoid doing extra memory allocations. Reimplemented in MeterFilter, HashFilter, Redirector, ArraySink, ArrayXorSink, and ByteQueue. Definition at line 730 of file cryptlib.h. Referenced by ArrayXorSink::CreatePutSpace().

virtual unsigned int BufferedTransformation::PutModifiable2 (  byte *  inString, unsigned int  length, int  messageEnd, bool  blocking )  [inline, virtual, inherited]

input multiple bytes that may be modified by callee for blocking or non-blocking processing Parameters: messageEnd  means how many filters to signal MessageEnd to, including this one Reimplemented in MeterFilter, and FilterWithBufferedInput. Definition at line 748 of file cryptlib.h.

virtual void BufferedTransformation::SetAutoSignalPropagation (  int  propagation  )  [inline, virtual, inherited]

set propagation of automatically generated and transferred signals propagation == 0 means do not automaticly generate signals Reimplemented in SourceTemplate< T >, SourceTemplate< FileStore >, SourceTemplate< RandomNumberStore >, and SourceTemplate< StringStore >. Definition at line 788 of file cryptlib.h.

unsigned long BufferedTransformation::MaxRetrievable (   )  const [virtual, inherited]

returns number of bytes that is currently ready for retrieval All retrieval functions return the actual number of bytes retrieved, which is the lesser of the request number and MaxRetrievable(). Reimplemented in FileStore, RandomNumberStore, NullStore, MessageQueue, ByteQueue, and RandomPool. Definition at line 247 of file cryptlib.cpp. References BufferedTransformation::AttachedTransformation(), and BufferedTransformation::CopyTo(). Referenced by RandomNumberStore::AnyRetrievable(), and Integer::BERDecode().

bool BufferedTransformation::GetNextMessage (   )  [virtual, inherited]

start retrieving the next message Returns false if no more messages exist or this message is not completely retrieved. Reimplemented in MessageQueue, and Store. Definition at line 336 of file cryptlib.cpp. References BufferedTransformation::AnyMessages(), and BufferedTransformation::AttachedTransformation().

bool Waitable::Wait (  unsigned long  milliseconds  )  [inherited]

wait on this object same as creating an empty container, calling GetWaitObjects(), and calling Wait() on the container Definition at line 321 of file wait.cpp. References Waitable::GetWaitObjects(), and WaitObjectContainer::Wait(). Referenced by NetworkSource::GeneralPump2(), and NetworkSink::TimedFlush().

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

• gzip.h
• gzip.cpp

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