Celartem::ChecksumStream Class Reference

#include <cel_checksum.h>

Inheritance diagram for Celartem::ChecksumStream:

Public Member Functions
virtual void	writeSum (Stream *inStream=NULL)=0
virtual bool	verifySum (Stream *inStream=NULL)=0
virtual void	resetSum ()=0
virtual const u8 *	getCurrentSum ()=0
virtual size_t	getSumSize () const =0
Public Member Functions inherited from Celartem::Stream
virtual size_t	readBytes (void *buffer, size_t inSize, bool wouldBlock=false)=0
virtual void	writeBytes (const void *buffer, size_t inSize)=0
virtual void	flushBuffer ()=0
virtual bool	isEof () const =0
virtual size_t	duplicateStream (Stream *inStream, size_t inBufferSize=1024, DuplicateStreamCallback inCallback=NULL, void *inCallbackContext=NULL)
virtual size_t	duplicateStreamBytes (Stream *inStream, size_t inMaximumByteSize, size_t inBufferSize=1024, DuplicateStreamCallback inCallback=NULL, void *inCallbackContext=NULL)
Public Member Functions inherited from Celartem::Referable
	Referable ()
void	addRef () const
void	releaseRef () const
size_t	getReferenceCount () const
Public Member Functions inherited from Celartem::Lockable
virtual void	lock () const =0
virtual void	unlock () const =0

Additional Inherited Members
Static Public Member Functions inherited from Celartem::Referable
static void	dumpDbgAllRefCount ()

Detailed Description

This class calculates the sum of the data that is "read from" or "write to" this stream.

// Writer sample
void writeData(Stream *inStream)
{
    AutoPtr<MD5Stream> md5 = MD5Stream::create(inStream);

    // write data as if it were the original stream.
    md5->writeBytes(...);
    md5->writeBytes(...);
    md5->writeBytes(...);

    // save the current MD5 sum
    md5->writeSum();
}

// Reader sample
void readData(Stream *inStream)
{
    AutoPtr<MD5Stream> md5 = MD5Stream::create(inStream);

    // read the data as if it were the original stream.
    // This should read the bytes exactly identical to the ones
    // written by writeData function, otherwise the verifySum
    // fails.
    md5->readBytes(...);
    md5->readBytes(...);
    md5->readBytes(...);

    // verify the current MD5 sum
    if(md5->verifySum())
    {
        // The sum is identical
    }
    else
    {
        // The sum is not identical
    }
}

ChecksumStream defines an interface for the Stream with Checksum feature.

See Also

MD5Stream, SHA1Stream, SHA256Stream, Checksum

Member Function Documentation

virtual const u8* Celartem::ChecksumStream::getCurrentSum ( )

pure virtual

This method gets the current sum as the binary block.

Returns

Pointer that points the binary block. This pointer is valid until the next call to the method of the instance. The size of that block is obtained by getSumSize method.

virtual size_t Celartem::ChecksumStream::getSumSize ( ) const

pure virtual

This method gets the size of sums in bytes that is generated by the instance. The size of sum is usually a constant; MD5 uses 16, SHA-1 uses 20.

Returns

The size of sums.

virtual void Celartem::ChecksumStream::resetSum ( )

pure virtual

This method resets the current sum and revert to the initial state.

virtual bool Celartem::ChecksumStream::verifySum ( Stream *  inStream = NULL )

pure virtual

This method verifies the sum which is read from the specified stream.

Parameters

inStream

A stream to read from. NULL to read from this stream.

Returns

true if the sum read from the specified stream is match to the one of current sum, otherwise false.

virtual void Celartem::ChecksumStream::writeSum ( Stream *  inStream = NULL )

pure virtual

This method writes the sum to the specified stream.

Parameters

inStream

A stream to write. NULL to write on this stream.

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

• cel_checksum.h