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Gzip Class Reference

GZIP Compression (RFC 1952) More...

#include <gzip.h>

Inheritance diagram for Gzip:
Deflator LowFirstBitWriter Filter BufferedTransformation NotCopyable Algorithm Waitable Clonable

Public Member Functions

 Gzip (BufferedTransformation *attachment=NULLPTR, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
 Construct a Gzip compressor.
 
 Gzip (const NameValuePairs &parameters, BufferedTransformation *attachment=NULLPTR)
 Construct a Gzip compressor.
 
void SetFiletime (word32 filetime)
 
void SetFilename (const std::string &filename, bool throwOnEncodingError=false)
 
void SetComment (const std::string &comment, bool throwOnEncodingError=false)
 
void IsolatedInitialize (const NameValuePairs &parameters)
 Initialize or reinitialize this object, without signal propagation.
 
- Public Member Functions inherited from Deflator
 Deflator (BufferedTransformation *attachment=NULLPTR, int deflateLevel=DEFAULT_DEFLATE_LEVEL, int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
 Construct a Deflator compressor.
 
 Deflator (const NameValuePairs &parameters, BufferedTransformation *attachment=NULLPTR)
 Construct a Deflator compressor.
 
void SetDeflateLevel (int deflateLevel)
 Sets the deflation level.
 
int GetDeflateLevel () const
 Retrieves the deflation level.
 
int GetLog2WindowSize () const
 Retrieves the window size.
 
size_t Put2 (const byte *inString, size_t length, int messageEnd, bool blocking)
 Input multiple bytes for processing.
 
bool IsolatedFlush (bool hardFlush, bool blocking)
 Flushes data buffered by this object, without signal propagation.
 
- Public Member Functions inherited from LowFirstBitWriter
 LowFirstBitWriter (BufferedTransformation *attachment)
 Construct a LowFirstBitWriter.
 
void PutBits (unsigned long value, unsigned int length)
 
void FlushBitBuffer ()
 
void ClearBitBuffer ()
 
void StartCounting ()
 
unsigned long FinishCounting ()
 
- Public Member Functions inherited from Filter
 Filter (BufferedTransformation *attachment=NULLPTR)
 Construct a Filter.
 
bool Attachable ()
 Determine if attachable.
 
BufferedTransformationAttachedTransformation ()
 Retrieve attached transformation.
 
const BufferedTransformationAttachedTransformation () const
 Retrieve attached transformation.
 
void Detach (BufferedTransformation *newAttachment=NULLPTR)
 Replace an attached transformation.
 
size_t TransferTo2 (BufferedTransformation &target, lword &transferBytes, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true)
 Transfer bytes from this object to another BufferedTransformation.
 
size_t CopyRangeTo2 (BufferedTransformation &target, lword &begin, lword end=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true) const
 Copy bytes from this object to another BufferedTransformation.
 
void Initialize (const NameValuePairs &parameters=g_nullNameValuePairs, int propagation=-1)
 Initialize or reinitialize this object, with signal propagation.
 
bool Flush (bool hardFlush, int propagation=-1, bool blocking=true)
 Flush buffered input and/or output, with signal propagation.
 
bool MessageSeriesEnd (int propagation=-1, bool blocking=true)
 Marks the end of a series of messages, with signal propagation.
 
- Public Member Functions inherited from BufferedTransformation
 BufferedTransformation ()
 Construct a BufferedTransformation.
 
BufferedTransformationRef ()
 Provides a reference to this object.
 
virtual void Attach (BufferedTransformation *newAttachment)
 Add newAttachment to the end of attachment chain.
 
size_t Put (byte inByte, bool blocking=true)
 Input a byte for processing.
 
size_t Put (const byte *inString, size_t length, bool blocking=true)
 Input a byte buffer for processing.
 
size_t PutWord16 (word16 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 
size_t PutWord32 (word32 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 
size_t PutWord64 (word64 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 
virtual byteCreatePutSpace (size_t &size)
 Request space which can be written into by the caller.
 
virtual bool CanModifyInput () const
 Determines whether input can be modified by the callee.
 
size_t PutModifiable (byte *inString, size_t length, bool blocking=true)
 Input multiple bytes that may be modified by callee.
 
bool MessageEnd (int propagation=-1, bool blocking=true)
 Signals the end of messages to the object.
 
size_t PutMessageEnd (const byte *inString, size_t length, int propagation=-1, bool blocking=true)
 Input multiple bytes for processing and signal the end of a message.
 
virtual size_t PutModifiable2 (byte *inString, size_t length, int messageEnd, bool blocking)
 Input multiple bytes that may be modified by callee.
 
unsigned int GetMaxWaitObjectCount () const
 Retrieves the maximum number of waitable objects.
 
void GetWaitObjects (WaitObjectContainer &container, CallStack const &callStack)
 Retrieves waitable objects.
 
virtual bool IsolatedMessageSeriesEnd (bool blocking)
 Marks the end of a series of messages, without signal propagation.
 
virtual void SetAutoSignalPropagation (int propagation)
 Set propagation of automatically generated and transferred signals.
 
virtual int GetAutoSignalPropagation () const
 Retrieve automatic signal propagation value.
 
virtual lword MaxRetrievable () const
 Provides the number of bytes ready for retrieval.
 
virtual bool AnyRetrievable () const
 Determines whether bytes are ready for retrieval.
 
virtual size_t Get (byte &outByte)
 Retrieve a 8-bit byte.
 
virtual size_t Get (byte *outString, size_t getMax)
 Retrieve a block of bytes.
 
virtual size_t Peek (byte &outByte) const
 Peek a 8-bit byte.
 
virtual size_t Peek (byte *outString, size_t peekMax) const
 Peek a block of bytes.
 
size_t GetWord16 (word16 &value, ByteOrder order=BIG_ENDIAN_ORDER)
 Retrieve a 16-bit word.
 
size_t GetWord32 (word32 &value, ByteOrder order=BIG_ENDIAN_ORDER)
 Retrieve a 32-bit word.
 
size_t GetWord64 (word64 &value, ByteOrder order=BIG_ENDIAN_ORDER)
 Retrieve a 64-bit word.
 
size_t PeekWord16 (word16 &value, ByteOrder order=BIG_ENDIAN_ORDER) const
 Peek a 16-bit word.
 
size_t PeekWord32 (word32 &value, ByteOrder order=BIG_ENDIAN_ORDER) const
 Peek a 32-bit word.
 
size_t PeekWord64 (word64 &value, ByteOrder order=BIG_ENDIAN_ORDER) const
 Peek a 64-bit word.
 
lword TransferTo (BufferedTransformation &target, lword transferMax=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL)
 move transferMax bytes of the buffered output to target as input
 
virtual lword Skip (lword skipMax=LWORD_MAX)
 Discard skipMax bytes from the output buffer.
 
lword CopyTo (BufferedTransformation &target, lword copyMax=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL) const
 Copy bytes from this object to another BufferedTransformation.
 
lword CopyRangeTo (BufferedTransformation &target, lword position, lword copyMax=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL) const
 Copy bytes from this object using an index to another BufferedTransformation.
 
virtual lword TotalBytesRetrievable () const
 Provides the number of bytes ready for retrieval.
 
virtual unsigned int NumberOfMessages () const
 Provides the number of meesages processed by this object.
 
virtual bool AnyMessages () const
 Determines if any messages are available for retrieval.
 
virtual bool GetNextMessage ()
 Start retrieving the next message.
 
virtual unsigned int SkipMessages (unsigned int count=UINT_MAX)
 Skip a number of meessages.
 
unsigned int TransferMessagesTo (BufferedTransformation &target, unsigned int count=UINT_MAX, const std::string &channel=DEFAULT_CHANNEL)
 Transfer messages from this object to another BufferedTransformation.
 
unsigned int CopyMessagesTo (BufferedTransformation &target, unsigned int count=UINT_MAX, const std::string &channel=DEFAULT_CHANNEL) const
 Copy messages from this object to another BufferedTransformation.
 
virtual void SkipAll ()
 Skip all messages in the series.
 
void TransferAllTo (BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL)
 Transfer all bytes from this object to another BufferedTransformation.
 
void CopyAllTo (BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL) const
 Copy messages from this object to another BufferedTransformation.
 
virtual bool GetNextMessageSeries ()
 Retrieve the next message in a series.
 
virtual unsigned int NumberOfMessagesInThisSeries () const
 Provides the number of messages in a series.
 
virtual unsigned int NumberOfMessageSeries () const
 Provides the number of messages in a series.
 
size_t TransferMessagesTo2 (BufferedTransformation &target, unsigned int &messageCount, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true)
 Transfer messages from this object to another BufferedTransformation.
 
size_t TransferAllTo2 (BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true)
 Transfer all bytes from this object to another BufferedTransformation.
 
size_t ChannelPut (const std::string &channel, byte inByte, bool blocking=true)
 Input a byte for processing on a channel.
 
size_t ChannelPut (const std::string &channel, const byte *inString, size_t length, bool blocking=true)
 Input a byte buffer for processing on a channel.
 
size_t ChannelPutModifiable (const std::string &channel, byte *inString, size_t length, bool blocking=true)
 Input multiple bytes that may be modified by callee on a channel.
 
size_t ChannelPutWord16 (const std::string &channel, word16 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 Input a 16-bit word for processing on a channel.
 
size_t ChannelPutWord32 (const std::string &channel, word32 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 Input a 32-bit word for processing on a channel.
 
size_t ChannelPutWord64 (const std::string &channel, word64 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 Input a 64-bit word for processing on a channel.
 
bool ChannelMessageEnd (const std::string &channel, int propagation=-1, bool blocking=true)
 Signal the end of a message.
 
size_t ChannelPutMessageEnd (const std::string &channel, const byte *inString, size_t length, int propagation=-1, bool blocking=true)
 Input multiple bytes for processing and signal the end of a message.
 
virtual byteChannelCreatePutSpace (const std::string &channel, size_t &size)
 Request space which can be written into by the caller.
 
virtual size_t ChannelPut2 (const std::string &channel, const byte *inString, size_t length, int messageEnd, bool blocking)
 Input multiple bytes for processing on a channel.
 
virtual size_t ChannelPutModifiable2 (const std::string &channel, byte *inString, size_t length, int messageEnd, bool blocking)
 Input multiple bytes that may be modified by callee on a channel.
 
virtual bool ChannelFlush (const std::string &channel, bool hardFlush, int propagation=-1, bool blocking=true)
 Flush buffered input and/or output on a channel.
 
virtual bool ChannelMessageSeriesEnd (const std::string &channel, int propagation=-1, bool blocking=true)
 Marks the end of a series of messages on a channel.
 
virtual void SetRetrievalChannel (const std::string &channel)
 Sets the default retrieval channel.
 
- Public Member Functions inherited from Algorithm
 Algorithm (bool checkSelfTestStatus=true)
 Interface for all crypto algorithms.
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm.
 
virtual std::string AlgorithmProvider () const
 Retrieve the provider of this algorithm.
 
- Public Member Functions inherited from Clonable
virtual ClonableClone () const
 Copies this object.
 
- Public Member Functions inherited from Waitable
bool Wait (unsigned long milliseconds, CallStack const &callStack)
 Wait on this object.
 

Protected Types

enum  {
  MAGIC1 =0x1f , MAGIC2 =0x8b , DEFLATED =8 , FAST =4 ,
  SLOW =2
}
 
enum  FLAG_MASKS { FILENAME =8 , COMMENTS =16 }
 
- Protected Types inherited from Deflator
enum  { STORED = 0 , STATIC = 1 , DYNAMIC = 2 }
 
enum  { MIN_MATCH = 3 , MAX_MATCH = 258 }
 

Protected Member Functions

void WritePrestreamHeader ()
 
void ProcessUncompressedData (const byte *string, size_t length)
 
void WritePoststreamTail ()
 
- Protected Member Functions inherited from Deflator
void InitializeStaticEncoders ()
 
void Reset (bool forceReset=false)
 
unsigned int FillWindow (const byte *str, size_t 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)
 
- Protected Member Functions inherited from Filter
virtual BufferedTransformationNewDefaultAttachment () const
 
void Insert (Filter *nextFilter)
 
virtual bool ShouldPropagateMessageEnd () const
 
virtual bool ShouldPropagateMessageSeriesEnd () const
 
void PropagateInitialize (const NameValuePairs &parameters, int propagation)
 
size_t Output (int outputSite, const byte *inString, size_t length, int messageEnd, bool blocking, const std::string &channel=DEFAULT_CHANNEL)
 Forward processed data on to attached transformation.
 
size_t OutputModifiable (int outputSite, byte *inString, size_t length, int messageEnd, bool blocking, const std::string &channel=DEFAULT_CHANNEL)
 Output multiple bytes that may be modified by callee.
 
bool OutputMessageEnd (int outputSite, int propagation, bool blocking, const std::string &channel=DEFAULT_CHANNEL)
 Signals the end of messages to the object.
 
bool OutputFlush (int outputSite, bool hardFlush, int propagation, bool blocking, const std::string &channel=DEFAULT_CHANNEL)
 Flush buffered input and/or output, with signal propagation.
 
bool OutputMessageSeriesEnd (int outputSite, int propagation, bool blocking, const std::string &channel=DEFAULT_CHANNEL)
 Marks the end of a series of messages, with signal propagation.
 

Protected Attributes

word32 m_totalLen
 
CRC32 m_crc
 
word32 m_filetime
 
std::string m_filename
 
std::string m_comment
 
- Protected Attributes inherited from Deflator
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< word16m_head
 
SecBlock< word16m_prev
 
FixedSizeSecBlock< unsigned int, 286 > m_literalCounts
 
FixedSizeSecBlock< unsigned int, 30 > m_distanceCounts
 
SecBlock< EncodedMatchm_matchBuffer
 
unsigned int m_matchBufferEnd
 
unsigned int m_blockStart
 
unsigned int m_blockLength
 
- Protected Attributes inherited from LowFirstBitWriter
bool m_counting
 
unsigned long m_bitCount
 
unsigned long m_buffer
 
unsigned int m_bitsBuffered
 
unsigned int m_bytesBuffered
 
FixedSizeSecBlock< byte, 256 > m_outputBuffer
 
- Protected Attributes inherited from Filter
size_t m_inputPosition
 
int m_continueAt
 

Additional Inherited Members

- Public Types inherited from Deflator
enum  { MIN_DEFLATE_LEVEL = 0 , DEFAULT_DEFLATE_LEVEL = 6 , MAX_DEFLATE_LEVEL = 9 }
 Deflate level as enumerated values. More...
 
enum  { MIN_LOG2_WINDOW_SIZE = 9 , DEFAULT_LOG2_WINDOW_SIZE = 15 , MAX_LOG2_WINDOW_SIZE = 15 }
 Windows size as enumerated values. More...
 
- Static Protected Member Functions inherited from BufferedTransformation
static int DecrementPropagation (int propagation)
 Decrements the propagation count while clamping at 0.
 

Detailed Description

GZIP Compression (RFC 1952)

Definition at line 17 of file gzip.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum
protected

Definition at line 61 of file gzip.h.

◆ FLAG_MASKS

enum Gzip::FLAG_MASKS
protected

Definition at line 64 of file gzip.h.

Constructor & Destructor Documentation

◆ Gzip() [1/2]

Gzip::Gzip ( BufferedTransformation attachment = NULLPTR,
unsigned int  deflateLevel = DEFAULT_DEFLATE_LEVEL,
unsigned int  log2WindowSize = DEFAULT_LOG2_WINDOW_SIZE,
bool  detectUncompressible = true 
)
inline

Construct a Gzip compressor.

Parameters
attachmentan attached transformation
deflateLevelthe deflate level
log2WindowSizethe window size
detectUncompressibleflag to detect if data is compressible

detectUncompressible makes it faster to process uncompressible files, but if a file has both compressible and uncompressible parts, it may fail to compress some of the compressible parts.

Definition at line 28 of file gzip.h.

◆ Gzip() [2/2]

Gzip::Gzip ( const NameValuePairs parameters,
BufferedTransformation attachment = NULLPTR 
)
inline

Construct a Gzip compressor.

Parameters
parametersa set of NameValuePairs to initialize this object
attachmentan attached transformation

Possible parameter names: Log2WindowSize, DeflateLevel, DetectUncompressible

Definition at line 35 of file gzip.h.

Member Function Documentation

◆ IsolatedInitialize()

void Gzip::IsolatedInitialize ( const NameValuePairs parameters)
virtual

Initialize or reinitialize this object, without signal propagation.

Parameters
parametersa set of NameValuePairs to initialize this object
Exceptions
NotImplemented

IsolatedInitialize() is used to initialize or reinitialize an object using a variable number of arbitrarily typed arguments. The function avoids the need for multiple constructors providing all possible combintations of configurable parameters.

IsolatedInitialize() does not call Initialize() on attached transformations. If initialization should be propagated, then use the Initialize() function.

If a derived class does not override IsolatedInitialize(), then the base class throws NotImplemented.

Reimplemented from Deflator.

Definition at line 15 of file gzip.cpp.

◆ ProcessUncompressedData()

void Gzip::ProcessUncompressedData ( const byte string,
size_t  length 
)
protectedvirtual

Reimplemented from Deflator.

Definition at line 57 of file gzip.cpp.

◆ SetComment()

void Gzip::SetComment ( const std::string &  comment,
bool  throwOnEncodingError = false 
)
Parameters
commentthe comment to set in the header. The application is responsible for setting it. RFC 1952 requires a ISO/IEC 8859-1 encoding.
throwOnEncodingErrorif throwOnEncodingError is true, then the comment is checked to ensure it is ISO/IEC 8859-1 encoded. If the comment does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown. If throwOnEncodingError is false then the comment is not checked.

Definition at line 75 of file gzip.cpp.

◆ SetFilename()

void Gzip::SetFilename ( const std::string &  filename,
bool  throwOnEncodingError = false 
)
Parameters
filenamethe original filename to set in the header. The application is responsible for setting it. RFC 1952 requires a ISO/IEC 8859-1 encoding.
throwOnEncodingErrorif throwOnEncodingError is true, then the filename is checked to ensure it is ISO/IEC 8859-1 encoded. If the filename does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown. If throwOnEncodingError is false then the filename is not checked.

Definition at line 89 of file gzip.cpp.

◆ SetFiletime()

void Gzip::SetFiletime ( word32  filetime)
inline
Parameters
filetimethe filetime to set in the header. The application is responsible for setting it.

Definition at line 42 of file gzip.h.

◆ WritePoststreamTail()

void Gzip::WritePoststreamTail ( )
protectedvirtual

Reimplemented from Deflator.

Definition at line 63 of file gzip.cpp.

◆ WritePrestreamHeader()

void Gzip::WritePrestreamHeader ( )
protectedvirtual

Reimplemented from Deflator.

Definition at line 27 of file gzip.cpp.

Member Data Documentation

◆ m_comment

std::string Gzip::m_comment
protected

Definition at line 76 of file gzip.h.

◆ m_crc

CRC32 Gzip::m_crc
protected

Definition at line 72 of file gzip.h.

◆ m_filename

std::string Gzip::m_filename
protected

Definition at line 75 of file gzip.h.

◆ m_filetime

word32 Gzip::m_filetime
protected

Definition at line 74 of file gzip.h.

◆ m_totalLen

word32 Gzip::m_totalLen
protected

Definition at line 71 of file gzip.h.


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