Implementation of BufferedTransformation's attachment interface. More...

#include <filters.h>

Inheritance diagram for Filter:

Public Member Functions
ATTACHMENT
	Filter (BufferedTransformation *attachment=NULL)
	Construct a Filter.

bool	Attachable ()
	Determine if attachable.

BufferedTransformation *	AttachedTransformation ()
	Retrieve attached transformation.

const BufferedTransformation *	AttachedTransformation () const
	Retrieve attached transformation.

void	Detach (BufferedTransformation *newAttachment=NULL)
	Replace an attached transformation.

RETRIEVAL OF ONE MESSAGE
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.

Public Member Functions inherited from BufferedTransformation
	BufferedTransformation ()
	Construct a BufferedTransformation.

BufferedTransformation &	Ref ()
	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)
	Input a 16-bit word for processing.

size_t	PutWord32 (word32 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
	Input a 32-bit word for processing.

size_t	PutWord64 (word64 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
	Input a 64-bit word for processing.

virtual byte *	CreatePutSpace (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	Put2 (const byte *inString, size_t length, int messageEnd, bool blocking)=0
	Input multiple bytes for processing.

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 void	IsolatedInitialize (const NameValuePairs &parameters)
	Initialize or reinitialize this object, without signal propagation.

virtual bool	IsolatedFlush (bool hardFlush, bool blocking)=0
	Flushes data buffered by this object, without signal propagation.

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 byte *	ChannelCreatePutSpace (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 Clonable *	Clone () const
	Copies this object.

Public Member Functions inherited from Waitable
bool	Wait (unsigned long milliseconds, CallStack const &callStack)
	Wait on this object.

SIGNALS
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.

Detailed Description

Implementation of BufferedTransformation's attachment interface.

Filter is a cornerstone of the Pipeline trinity. Data flows from Sources, through Filters, and then terminates in Sinks. The difference between a Source and Filter is a Source pumps data, while a Filter does not. The difference between a Filter and a Sink is a Filter allows an attached transformation, while a Sink does not.

See the discussion of BufferedTransformation in cryptlib.h for more details.

Definition at line 35 of file filters.h.

Constructor & Destructor Documentation

◆ ~Filter()

virtual Filter::~Filter ( )

inlinevirtual

Definition at line 38 of file filters.h.

◆ Filter()

Filter::Filter ( BufferedTransformation * attachment = NULL )

Construct a Filter.

Parameters

attachment an optional attached transformation

attachment can be NULL.

Member Function Documentation

◆ Attachable()

bool Filter::Attachable ( )

inlinevirtual

Determine if attachable.

Returns: true if the object allows attached transformations, false otherwise.

Note: Source and Filter offer attached transformations; while Sink does not.

Reimplemented from BufferedTransformation.

Definition at line 51 of file filters.h.

◆ AttachedTransformation() [1/2]

BufferedTransformation * Filter::AttachedTransformation ( )

virtual

Retrieve attached transformation.

Returns: pointer to a BufferedTransformation if there is an attached transformation, NULL otherwise.

Reimplemented from BufferedTransformation.

◆ AttachedTransformation() [2/2]

const BufferedTransformation * Filter::AttachedTransformation ( ) const

virtual

Retrieve attached transformation.

Returns: pointer to a BufferedTransformation if there is an attached transformation, NULL otherwise.

Reimplemented from BufferedTransformation.

◆ Detach()

void Filter::Detach ( BufferedTransformation * newAttachment = NULL )

virtual

Replace an attached transformation.

Parameters

newAttachment an optional attached transformation

newAttachment can be a single filter, a chain of filters or NULL. Pass NULL to remove an existing BufferedTransformation or chain of filters

Reimplemented from BufferedTransformation.

◆ TransferTo2()

size_t Filter::TransferTo2	(	BufferedTransformation &	target,
		lword &	byteCount,
		const std::string &	channel = DEFAULT_CHANNEL,
		bool	blocking = true )

virtual

Transfer bytes from this object to another BufferedTransformation.

Parameters

target	the destination BufferedTransformation
byteCount	the number of bytes to transfer
channel	the channel on which the transfer should occur
blocking	specifies whether the object should block when processing input

Returns: the number of bytes that remain in the transfer block (i.e., bytes not transferred)

TransferTo2() removes bytes from this object and moves them to the destination. Transfer begins at the index position in the current stream, and not from an absolute position in the stream.

byteCount is an IN and OUT parameter. When the call is made, byteCount is the requested size of the transfer. When the call returns, byteCount is the number of bytes that were transferred.

Implements BufferedTransformation.

◆ CopyRangeTo2()

size_t Filter::CopyRangeTo2	(	BufferedTransformation &	target,
		lword &	begin,
		lword	end = LWORD_MAX,
		const std::string &	channel = DEFAULT_CHANNEL,
		bool	blocking = true ) const

virtual

Copy bytes from this object to another BufferedTransformation.

Parameters

target	the destination BufferedTransformation
begin	the 0-based index of the first byte to copy in the stream
end	the 0-based index of the last byte to copy in the stream
channel	the channel on which the transfer should occur
blocking	specifies whether the object should block when processing input

Returns: the number of bytes that remain in the copy block (i.e., bytes not copied)

CopyRangeTo2 copies bytes from this object to the destination. The bytes are not removed from this object. Copying begins at the index position in the current stream, and not from an absolute position in the stream.

begin is an IN and OUT parameter. When the call is made, begin is the starting position of the copy. When the call returns, begin is the position of the first byte that was not copied (which may be different than end). begin can be used for subsequent calls to CopyRangeTo2().

Implements BufferedTransformation.

◆ Initialize()

void Filter::Initialize	(	const NameValuePairs &	parameters = g_nullNameValuePairs,
		int	propagation = -1 )

virtual

Initialize or reinitialize this object, with signal propagation.

Parameters

parameters	a set of NameValuePairs to initialize or reinitialize this object
propagation	the number of attached transformations the Initialize() signal should be passed

Initialize() 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.

propagation count includes this object. Setting propagation to 1 means this object only. Setting propagation to -1 means unlimited propagation.

Reimplemented from BufferedTransformation.

◆ Flush()

bool Filter::Flush	(	bool	hardFlush,
		int	propagation = -1,
		bool	blocking = true )

virtual

Flush buffered input and/or output, with signal propagation.

Parameters

hardFlush	is used to indicate whether all data should be flushed
propagation	the number of attached transformations the Flush() signal should be passed
blocking	specifies whether the object should block when processing input

Returns: true if the flush was successful, false otherwise

propagation count includes this object. Setting propagation to 1 means this object only. Setting propagation to -1 means unlimited propagation.

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, like 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 Unflushable< Filter >, SecretSharing, and InformationDispersal.

◆ MessageSeriesEnd()

bool Filter::MessageSeriesEnd	(	int	propagation = -1,
		bool	blocking = true )

virtual

Marks the end of a series of messages, with signal propagation.

Parameters

propagation	the number of attached transformations the MessageSeriesEnd() signal should be passed
blocking	specifies whether the object should block when processing input

Returns: true if the message was successful, false otherwise

Each object that receives the signal will perform its processing, decrement propagation, and then pass the signal on to attached transformations if the value is not 0.

propagation count includes this object. Setting propagation to 1 means this object only. Setting propagation to -1 means unlimited propagation.

Note: There should be a MessageEnd() immediately before MessageSeriesEnd().

Reimplemented from BufferedTransformation.

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

filters.h

Public Member Functions

SIGNALS

Detailed Description

Constructor & Destructor Documentation

◆ ~Filter()

◆ Filter()

Member Function Documentation

◆ Attachable()

◆ AttachedTransformation() [1/2]

◆ AttachedTransformation() [2/2]

◆ Detach()

◆ TransferTo2()

◆ CopyRangeTo2()

◆ Initialize()

◆ Flush()

◆ MessageSeriesEnd()