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InformationDispersal Class Reference

#include <ida.h>

Inheritance diagram for InformationDispersal:

Filter BufferedTransformation Algorithm Waitable Clonable List of all members.

Detailed Description

a variant of Rabin's Information Dispersal Algorithm

Definition at line 91 of file ida.h.

SIGNALS

virtual bool IsolatedMessageSeriesEnd (bool blocking)
virtual void SetAutoSignalPropagation (int propagation)
 set propagation of automatically generated and transfered signals

virtual int GetAutoSignalPropagation () const

Public Member Functions

 InformationDispersal (int threshold, int nShares, BufferedTransformation *attachment=NULL, bool addPadding=true)
void Initialize (const NameValuePairs &parameters=g_nullNameValuePairs, int propagation=-1)
 initialize or reinitialize this object

unsigned int Put2 (const byte *begin, unsigned int length, int messageEnd, bool blocking)
 input multiple bytes for blocking or non-blocking processing

bool Flush (bool hardFlush, int propagation=-1, bool blocking=true)
 flush buffered input and/or output

bool Attachable ()
 returns whether this object allows attachment

BufferedTransformationAttachedTransformation ()
 returns the object immediately attached to this object or NULL for no attachment

const BufferedTransformationAttachedTransformation () 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
bool MessageSeriesEnd (int propagation=-1, bool blocking=true)
 mark end of a series of messages

BufferedTransformationRef ()
 return a reference to this object

virtual std::string AlgorithmName () const
 returns name of this algorithm, not universally implemented yet

virtual ClonableClone () 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 Member Functions

virtual void NotifyAttachmentChange ()
virtual BufferedTransformationNewDefaultAttachment () const
void Insert (Filter *nextFilter)
virtual bool ShouldPropagateMessageEnd () const
virtual bool ShouldPropagateMessageSeriesEnd () const
void PropagateInitialize (const NameValuePairs &parameters, int propagation, const std::string &channel=NULL_CHANNEL)
unsigned int Output (int outputSite, const 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

RawIDA m_ida
bool m_pad
unsigned int m_nextChannel
unsigned int m_inputPosition
int m_continueAt


Member Function Documentation

unsigned int InformationDispersal::Put2 const byte *  begin,
unsigned int  length,
int  messageEnd,
bool  blocking
[virtual]
 

input multiple bytes for blocking or non-blocking processing

Parameters:
messageEnd means how many filters to signal MessageEnd to, including this one

Implements BufferedTransformation.

bool InformationDispersal::Flush bool  hardFlush,
int  propagation = -1,
bool  blocking = true
[inline, virtual]
 

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 Filter.

Definition at line 100 of file ida.h.

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::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 84 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 702 of file cryptlib.h.

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

request space to write bytes into for processing

Parameters:
size is requested size (as a hint) for input, and size of the returned space for output

Reimplemented in HashFilter, ArraySink, ArrayXorSink, and ByteQueue.

Definition at line 720 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 FilterWithBufferedInput.

Definition at line 738 of file cryptlib.h.

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

set propagation of automatically generated and transfered signals

propagation == 0 means do not automaticly generate signals

Reimplemented in SourceTemplate< T >, SourceTemplate< FileStore >, SourceTemplate< RandomNumberStore >, and SourceTemplate< StringStore >.

Definition at line 778 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 229 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 318 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 101 of file wait.cpp.

References Waitable::GetWaitObjects(), and WaitObjectContainer::Wait().

Referenced by NetworkSource::GeneralPump2(), and NetworkSink::TimedFlush().


The documentation for this class was generated from the following file:
Generated on Tue Jul 8 23:35:05 2003 for Crypto++ by doxygen 1.3.2