Crypto++  5.6.3
Free C++ class library of cryptographic schemes
Public Member Functions | List of all members
Filter Class Reference

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

+ Inheritance diagram for Filter:

Public Member Functions

size_t TransferTo2 (BufferedTransformation &target, lword &transferBytes, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true)
 Transfer bytes from this object to another BufferedTransformation. More...
 
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. More...
 
void Initialize (const NameValuePairs &parameters=g_nullNameValuePairs, int propagation=-1)
 Initialize or reinitialize this object, with signal propagation. More...
 
bool Flush (bool hardFlush, int propagation=-1, bool blocking=true)
 Flush buffered input and/or output, with signal propagation. More...
 
bool MessageSeriesEnd (int propagation=-1, bool blocking=true)
 Marks the end of a series of messages, with signal propagation. More...
 
ATTACHMENT
 Filter (BufferedTransformation *attachment=NULL)
 Construct a Filter. More...
 
bool Attachable ()
 Determine if attachable. More...
 
BufferedTransformationAttachedTransformation ()
 Retrieve attached transformation. More...
 
const BufferedTransformationAttachedTransformation () const
 Retrieve attached transformation. More...
 
void Detach (BufferedTransformation *newAttachment=NULL)
 Replace an attached transformation. More...
 
- Public Member Functions inherited from BufferedTransformation
 BufferedTransformation ()
 Construct a BufferedTransformation.
 
BufferedTransformationRef ()
 Provides a reference to this object. More...
 
size_t Put (byte inByte, bool blocking=true)
 Input a byte for processing. More...
 
size_t Put (const byte *inString, size_t length, bool blocking=true)
 Input a byte buffer for processing. More...
 
size_t PutWord16 (word16 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 Input a 16-bit word for processing. More...
 
size_t PutWord32 (word32 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true)
 Input a 32-bit word for processing. More...
 
virtual byte * CreatePutSpace (size_t &size)
 Request space which can be written into by the caller. More...
 
virtual bool CanModifyInput () const
 Determines whether input can be modifed by the callee. More...
 
size_t PutModifiable (byte *inString, size_t length, bool blocking=true)
 Input multiple bytes that may be modified by callee. More...
 
bool MessageEnd (int propagation=-1, bool blocking=true)
 Signals the end of messages to the object. More...
 
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. More...
 
virtual size_t Put2 (const byte *inString, size_t length, int messageEnd, bool blocking)=0
 Input multiple bytes for processing. More...
 
virtual size_t PutModifiable2 (byte *inString, size_t length, int messageEnd, bool blocking)
 Input multiple bytes that may be modified by callee. More...
 
unsigned int GetMaxWaitObjectCount () const
 Retrieves the maximum number of waitable objects.
 
void GetWaitObjects (WaitObjectContainer &container, CallStack const &callStack)
 Retrieves waitable objects. More...
 
virtual void IsolatedInitialize (const NameValuePairs &parameters)
 Initialize or reinitialize this object, without signal propagation. More...
 
virtual bool IsolatedFlush (bool hardFlush, bool blocking)=0
 Flushes data buffered by this object, without signal propagation. More...
 
virtual bool IsolatedMessageSeriesEnd (bool blocking)
 Marks the end of a series of messages, without signal propagation. More...
 
virtual void SetAutoSignalPropagation (int propagation)
 Set propagation of automatically generated and transferred signals. More...
 
virtual int GetAutoSignalPropagation () const
 Retrieve automatic signal propagation value. More...
 
virtual lword MaxRetrievable () const
 Provides the number of bytes ready for retrieval. More...
 
virtual bool AnyRetrievable () const
 Determines whether bytes are ready for retrieval. More...
 
virtual size_t Get (byte &outByte)
 Retrieve a 8-bit byte. More...
 
virtual size_t Get (byte *outString, size_t getMax)
 Retrieve a block of bytes. More...
 
virtual size_t Peek (byte &outByte) const
 Peek a 8-bit byte. More...
 
virtual size_t Peek (byte *outString, size_t peekMax) const
 Peek a block of bytes. More...
 
size_t GetWord16 (word16 &value, ByteOrder order=BIG_ENDIAN_ORDER)
 Retrieve a 16-bit word. More...
 
size_t GetWord32 (word32 &value, ByteOrder order=BIG_ENDIAN_ORDER)
 Retrieve a 32-bit word. More...
 
size_t PeekWord16 (word16 &value, ByteOrder order=BIG_ENDIAN_ORDER) const
 Peek a 16-bit word. More...
 
size_t PeekWord32 (word32 &value, ByteOrder order=BIG_ENDIAN_ORDER) const
 Peek a 32-bit word. More...
 
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 More...
 
virtual lword Skip (lword skipMax=LWORD_MAX)
 Discard skipMax bytes from the output buffer. More...
 
lword CopyTo (BufferedTransformation &target, lword copyMax=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL) const
 copy copyMax bytes of the buffered output to target as input More...
 
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. More...
 
virtual lword TotalBytesRetrievable () const
 Provides the number of bytes ready for retrieval. More...
 
virtual unsigned int NumberOfMessages () const
 Provides the number of meesages processed by this object. More...
 
virtual bool AnyMessages () const
 Determines if any messages are available for retrieval. More...
 
virtual bool GetNextMessage ()
 Start retrieving the next message. More...
 
virtual unsigned int SkipMessages (unsigned int count=UINT_MAX)
 Skip a number of meessages. More...
 
unsigned int TransferMessagesTo (BufferedTransformation &target, unsigned int count=UINT_MAX, const std::string &channel=DEFAULT_CHANNEL)
 Transfer messages from this object to another BufferedTransformation. More...
 
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. More...
 
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. More...
 
void CopyAllTo (BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL) const
 Copy messages from this object to another BufferedTransformation. More...
 
virtual bool GetNextMessageSeries ()
 Retrieve the next message in a series. More...
 
virtual unsigned int NumberOfMessagesInThisSeries () const
 Provides the number of messages in a series. More...
 
virtual unsigned int NumberOfMessageSeries () const
 Provides the number of messages in a series. More...
 
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. More...
 
size_t TransferAllTo2 (BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true)
 Transfer all bytes from this object to another BufferedTransformation. More...
 
size_t ChannelPut (const std::string &channel, byte inByte, bool blocking=true)
 Input a byte for processing on a channel. More...
 
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. More...
 
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. More...
 
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. More...
 
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. More...
 
bool ChannelMessageEnd (const std::string &channel, int propagation=-1, bool blocking=true)
 Signal the end of a message. More...
 
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. More...
 
virtual byte * ChannelCreatePutSpace (const std::string &channel, size_t &size)
 Request space which can be written into by the caller. More...
 
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. More...
 
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. More...
 
virtual bool ChannelFlush (const std::string &channel, bool hardFlush, int propagation=-1, bool blocking=true)
 Flush buffered input and/or output on a channel. More...
 
virtual bool ChannelMessageSeriesEnd (const std::string &channel, int propagation=-1, bool blocking=true)
 Marks the end of a series of messages on a channel. More...
 
virtual void SetRetrievalChannel (const std::string &channel)
 Sets the default retrieval channel. More...
 
virtual void Attach (BufferedTransformation *newAttachment)
 Add newAttachment to the end of attachment chain. More...
 
- Public Member Functions inherited from Algorithm
 Algorithm (bool checkSelfTestStatus=true)
 Interface for all crypto algorithms. More...
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm. More...
 
- Public Member Functions inherited from Clonable
virtual ClonableClone () const
 Copies this object. More...
 
- Public Member Functions inherited from Waitable
bool Wait (unsigned long milliseconds, CallStack const &callStack)
 Wait on this object. More...
 

Additional Inherited Members

- Static Public Attributes inherited from BufferedTransformation
static const std::string & NULL_CHANNEL = DEFAULT_CHANNEL
 

Detailed Description

Implementation of BufferedTransformation's attachment interface.

Filter is a cornerstone of the Pipeline trinitiy. 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 36 of file filters.h.

Constructor & Destructor Documentation

Filter::Filter ( BufferedTransformation attachment = NULL)

Construct a Filter.

Parameters
attachmentan optional attached transformation

attachment can be NULL.

Definition at line 26 of file filters.cpp.

Member Function Documentation

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 54 of file filters.h.

BufferedTransformation * Filter::AttachedTransformation ( )
virtual

Retrieve attached transformation.

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

Reimplemented from BufferedTransformation.

Definition at line 36 of file filters.cpp.

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.

Definition at line 43 of file filters.cpp.

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

Replace an attached transformation.

Parameters
newAttachmentan 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.

Definition at line 50 of file filters.cpp.

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
targetthe destination BufferedTransformation
byteCountthe number of bytes to transfer
channelthe channel on which the transfer should occur
blockingspecifies whether the object should block when processing input
Returns
the number of bytes that remain in the transfer block (i.e., bytes not transferred)

TransferTo() 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.

Definition at line 66 of file filters.cpp.

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
targetthe destination BufferedTransformation
beginthe 0-based index of the first byte to copy in the stream
endthe 0-based index of the last byte to copy in the stream
channelthe channel on which the transfer should occur
blockingspecifies 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 tahn end). begin can be used for subsequent calls to CopyRangeTo2.

Implements BufferedTransformation.

Definition at line 61 of file filters.cpp.

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

Initialize or reinitialize this object, with signal propagation.

Parameters
parametersa set of NameValuePairs to initialize or reinitialize this object
propagationthe 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 constuctors 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.

Definition at line 71 of file filters.cpp.

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

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

Parameters
hardFlushis used to indicate whether all data should be flushed
propagationthe number of attached transformations the Flush() signal should be passed
blockingspecifies whether the object should block when processing input

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 InformationDispersal, and SecretSharing.

Definition at line 78 of file filters.cpp.

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

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

Parameters
propagationthe number of attached transformations the MessageSeriesEnd() signal should be passed
blockingspecifies whether the object should block when processing input

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.

Definition at line 95 of file filters.cpp.


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