ccbuffil.cpp

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// $Id: ccbuffil.cpp 751 2006-03-31 15:43:49Z alex $
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 */
// 


#include "camtypes.h"
#include "bmpsrc.h"     // for OFFSET - put it in camtypes!
#include "ccbuffil.h"


// Place any IMPLEMENT type statements here
CC_IMPLEMENT_DYNAMIC(CCBufferFile, CCStreamFile)


// Declare smart memory handling in Debug builds
// We want better memory tracking
#define new CAM_DEBUG_NEW


// Functions follow

/********************************************************************************************

>   CCBufferFile::CCBufferFile(CCLexFile* pFile, BOOL bReportErrors, BOOL bThrowExceptions)

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Inputs:     pFile:              A pointer to the stream to use
                bReportErrors:      See CCStreamFile for details
                bThrowExceptions:   See CCStreamFile for details
    
    Purpose:    Provides objects representing in-memory files.

    Notes:      This class is only partially implemented to provide support for BitmapSource

********************************************************************************************/
CCBufferFile::CCBufferFile(CCLexFile* pFile, BOOL bReportErrors, BOOL bThrowExceptions)
    : CCStreamFile(pFile->GetIOFile(), 0, bReportErrors, bThrowExceptions)
{
    m_pTrueFile             = pFile;

    m_pBuffer               = NULL;

    m_pBufferFillPosition   = NULL;
    m_BytesToFillBuffer     = 0;

    m_pBufferWritePosition  = NULL;
    m_BytesToWrite          = 0;
}



/********************************************************************************************

>   virtual CCBufferFile::~CCBufferFile()

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Purpose:    Destructor - stops the base class destructor from deleting the stream we
                borrowed

********************************************************************************************/
CCBufferFile::~CCBufferFile()
{
    IOFile = NULL;
}

/********************************************************************************************

>   virtual void CCBufferFile::init(BYTE* pBuffer, FilePos size)

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Purpose:    Initializes the buffer associated with this CCBufferFile
                Having constructed a CCBufferFile object a user can initialize the buffer
                associated with it. Useful for BitmapSources

********************************************************************************************/
void CCBufferFile::init(BYTE* pBuffer, FilePos size)
{
    m_pBuffer               = pBuffer;

    m_pBufferFillPosition   = pBuffer;
    m_BytesToFillBuffer     = size;

    m_pBufferWritePosition  = pBuffer;
    m_BytesToWrite          = size;
}


/********************************************************************************************

>   virtual BOOL CCBufferFile::setMode(INT32 fileMode)

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Returns:    TRUE
    Purpose:    Provides dummy implementation for pure function

********************************************************************************************/
BOOL CCBufferFile::setMode(INT32 fileMode)
{
    return TRUE;
}


/********************************************************************************************

>   virtual CCFile& CCBufferFile::read(void* pBuffer, UINT32 length)

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Returns:    A reference to this CCFile
    Purpose:    Attempts to read the given number of bytes into the given buffer while at
                the same time builds up the whole stream in the buffer given in the
                constructor or via init()
    Errors:     ERROR3 if internal buffer not initialized

********************************************************************************************/
CCFile& CCBufferFile::read(void* pBuffer, UINT32 length)
{
    // Read in as many bytes as the internal buffer can take up to a maximum of the
    // number given in length
    INT32 BytesToRead = m_BytesToFillBuffer > length ? length : m_BytesToFillBuffer;

    ERROR3IF(m_pBufferFillPosition == NULL, "m_pBufferFillPosition == NULL");

    m_pTrueFile->read((BYTE*)m_pBufferFillPosition, BytesToRead);

    // Find the number of bytes actually read
    INT32 BytesRead = IOFile->gcount();

    // Copy the read data to the given buffer if any
    if (pBuffer != NULL)
    {
        memcpy(pBuffer, m_pBufferFillPosition, BytesRead);
    }

    // Update the internal buffer details
    m_pBufferFillPosition += BytesRead;
    m_BytesToFillBuffer -= BytesRead;

    return *this;
}



/********************************************************************************************

>   virtual BOOL CCBufferFile::bad() const

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Returns:    TRUE if the CCBufferFile is bad
                FALSE otherwise
    Purpose:    Mimics the functionality of the stream class bad() function

********************************************************************************************/
/*BOOL CCBufferFile::bad() const
{
    return IOFile->bad();
}
*/

/********************************************************************************************

>   virtual BOOL CCBufferFile::fail() const

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Returns:    TRUE if the CCBufferFile has failed
                FALSE otherwise
    Purpose:    Mimics the functionality of the stream class fail() function

********************************************************************************************/
/*BOOL CCBufferFile::fail() const
{
    return IOFile->fail();
}
*/

/********************************************************************************************

>   CCFile& CCBufferFile::write(const void* pBuffer, UINT32 length = 1)

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Inputs:     pBuffer : Buffer to write from. If NULL internal buffer will be used
                length : the number of bytes to write
    Returns:    A reference to this CCFile
    Purpose:    Attempts to write out the given number of bytes to the CCFile given in the
                constructor.
                Supplying a pBuffer will cause the data in the given buffer to be copied to
                the internal buffer before it is written out. If the write to file is
                unsuccessful therefore, the internal buffer can be considered corrupt (much
                as the file would be).
    Errors:     ERROR3 if internal buffer not initialized

********************************************************************************************/
CCFile& CCBufferFile::write(const void* pBuffer, UINT32 length)
{
    // Write as many bytes as the internal buffer will allow up to a maximum of the
    // number given in length
    INT32 BytesToWrite = m_BytesToWrite > length ? length : m_BytesToWrite;

    ERROR3IF(m_pBufferWritePosition == NULL, "m_pBufferWritePosition == NULL");

    if (pBuffer != NULL)
    {
        // Overwrite the data in the internal buffer with that in the given buffer
        memcpy(m_pBufferWritePosition, pBuffer, BytesToWrite);
    }
    // Write out whatever's in that position
    m_pTrueFile->write((BYTE*)m_pBufferWritePosition, BytesToWrite);
        

    // Update the internal buffer details
    m_pBufferWritePosition += BytesToWrite;
    m_BytesToWrite -= BytesToWrite;

    return *this;
}


/********************************************************************************************

>   BOOL CCBufferFile::IsAllWritten() const

    Author:     Colin_Barfoot (Xara Group Ltd) <camelotdev@xara.com>
    Created:    22/08/96
    Returns:    TRUE : if all bytes in the buffer have been written
                FALSE : otherwise
    Purpose:    Determines whether write() has been called sufficiently often to have
                written out the whole buffer.

********************************************************************************************/
BOOL CCBufferFile::IsAllWritten() const
{
    return (m_BytesToWrite == 0);
}

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