source: box/trunk/lib/common/ReadLoggingStream.cpp @ 2245

// --------------------------------------------------------------------------
//
// File
//              Name:    ReadLoggingStream.cpp
//              Purpose: Buffering wrapper around IOStreams
//              Created: 2007/01/16
//
// --------------------------------------------------------------------------

#include "Box.h"

#include <string.h>

#include "ReadLoggingStream.h"
#include "CommonException.h"
#include "Logging.h"

#include "MemLeakFindOn.h"

// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::ReadLoggingStream(const char *, int, int)
//              Purpose: Constructor, set up buffer
//              Created: 2007/01/16
//
// --------------------------------------------------------------------------
ReadLoggingStream::ReadLoggingStream(IOStream& rSource, Logger& rLogger)
: mrSource(rSource),
  mOffset(0),
  mLength(mrSource.BytesLeftToRead()),
  mTotalRead(0),
  mStartTime(GetCurrentBoxTime()),
  mrLogger(rLogger)
{ }


// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::Read(void *, int)
//              Purpose: Reads bytes from the file
//              Created: 2007/01/16
//
// --------------------------------------------------------------------------
int ReadLoggingStream::Read(void *pBuffer, int NBytes, int Timeout)
{
        int numBytesRead = mrSource.Read(pBuffer, NBytes, Timeout);

        if (numBytesRead > 0)
        {
                mTotalRead += numBytesRead;
                mOffset += numBytesRead;
        }

        if (mLength == 0)
        {       
                mrLogger.Log(numBytesRead, mOffset);
        }
        else if (mTotalRead == 0)
        {
                mrLogger.Log(numBytesRead, mOffset, mLength);
        }
        else
        {       
                box_time_t timeNow = GetCurrentBoxTime();
                box_time_t elapsed = timeNow - mStartTime;
                box_time_t finish  = (elapsed * mLength) / mTotalRead;
                // box_time_t remain  = finish - elapsed;
                mrLogger.Log(numBytesRead, mOffset, mLength, elapsed, finish);
        }
        
        return numBytesRead;
}


// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::BytesLeftToRead()
//              Purpose: Returns number of bytes to read (may not be most efficient function ever)
//              Created: 2007/01/16
//
// --------------------------------------------------------------------------
IOStream::pos_type ReadLoggingStream::BytesLeftToRead()
{
        return mLength - mOffset;
}


// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::Write(void *, int)
//              Purpose: Writes bytes to the underlying stream (not supported)
//              Created: 2003/07/31
//
// --------------------------------------------------------------------------
void ReadLoggingStream::Write(const void *pBuffer, int NBytes)
{
        THROW_EXCEPTION(CommonException, NotSupported);
}


// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::GetPosition()
//              Purpose: Get position in stream
//              Created: 2003/08/21
//
// --------------------------------------------------------------------------
IOStream::pos_type ReadLoggingStream::GetPosition() const
{
        return mOffset;
}


// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::Seek(pos_type, int)
//              Purpose: Seeks within file, as lseek, invalidate buffer
//              Created: 2003/07/31
//
// --------------------------------------------------------------------------
void ReadLoggingStream::Seek(IOStream::pos_type Offset, int SeekType)
{
        mrSource.Seek(Offset, SeekType);

        switch (SeekType)
        {
                case SeekType_Absolute:
                {
                        // just go there
                        mOffset = Offset;
                }
                break;

                case SeekType_Relative:
                {
                        // Actual underlying file position is 
                        // (mBufferSize - mBufferPosition) ahead of us.
                        // Need to subtract that amount from the seek
                        // to seek forward that much less, putting the 
                        // real pointer in the right place.
                        mOffset += Offset;
                }
                break;

                case SeekType_End:
                {
                        // Actual underlying file position is 
                        // (mBufferSize - mBufferPosition) ahead of us.
                        // Need to add that amount to the seek
                        // to seek backwards that much more, putting the 
                        // real pointer in the right place.
                        mOffset = mLength - Offset;
                }
        }
}


// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::Close()
//              Purpose: Closes the underlying stream (not needed)
//              Created: 2003/07/31
//
// --------------------------------------------------------------------------
void ReadLoggingStream::Close()
{
        THROW_EXCEPTION(CommonException, NotSupported);
}


// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::StreamDataLeft()
//              Purpose: Any data left to write?
//              Created: 2003/08/02
//
// --------------------------------------------------------------------------
bool ReadLoggingStream::StreamDataLeft()
{
        return mrSource.StreamDataLeft();
}

// --------------------------------------------------------------------------
//
// Function
//              Name:    ReadLoggingStream::StreamClosed()
//              Purpose: Is the stream closed?
//              Created: 2003/08/02
//
// --------------------------------------------------------------------------
bool ReadLoggingStream::StreamClosed()
{
        return mrSource.StreamClosed();
}