zlibinstream.cpp

vncviewer_source_1.0

/* Copyright (C) 2006 Lucas Gomez  All Rights Reserved.
 * 
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this software; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
 * USA.
 */

// INCLUDE FILES
#include "ZLibInStream.h"
#include "VncViewer.pan"

//LITERALS

// ============================ MEMBER FUNCTIONS ===============================

// -----------------------------------------------------------------------------
// ZLibInStream::ZLibInStream()
// C++ default constructor can NOT contain any code, that might leave.
// -----------------------------------------------------------------------------
//
ZLibInStream::ZLibInStream(TInt aBufSize)
{
    iBufSize=aBufSize;
    iBuf.CreateMaxL(iBufSize);
    iPtr=iEnd=iPtrOffset=0;
    iInflater=CEZDecompressor::NewL(*this);
}

// ---------------------------------------------------------------------------
// ZLibInStream::~ZLibInStream()
// Destructor.
// ---------------------------------------------------------------------------
//
ZLibInStream::~ZLibInStream()
{
	if(iInflater!=NULL)
	{
		delete iInflater;
		iInflater=NULL;
	}
}

void ZLibInStream::SetUnderlying(InStream* aIS,TInt aBytesIn)
{
	iUnderlying=aIS;
	iBytesIn=aBytesIn;
	iPtr=iEnd=0;
}
	
void ZLibInStream::Reset()
{
	iPtr=iEnd=0;
	if(iUnderlying==NULL) return;
	
	while(iBytesIn>0)
	{
		Decompress();
		iEnd=0;
		
	}
	delete iUnderlying;
	iUnderlying=NULL;
}

TInt ZLibInStream::Pos()
{
	return iPtrOffset+iPtr;
}

TInt ZLibInStream::Overrun(TInt aItemSize,TInt aNItems)
{
	if(aItemSize>iBufSize)
		User::Leave(EVncViewerZLibInStreamOverrun);
	if(iUnderlying==NULL)
		User::Leave(EVncViewerZLibInStreamOverrun);
	
	if(iEnd-iPtr!=0)
	{
		iBuf.Copy(iBuf.Mid(iPtr,iEnd-iPtr));
    	iBuf.SetMax();
	}
	
	iPtrOffset+=iPtr;
	iEnd-=iPtr;
	iPtr=0;
	
	while(iEnd<aItemSize)
		Decompress();
	
	if(aItemSize*aNItems>iEnd)
		aNItems=iEnd/aItemSize;
	
	return aNItems;
}

void ZLibInStream::Decompress()
{
	iUnderlying->Check(1);
	TInt avail_in=iUnderlying->GetEnd()-iUnderlying->GetPtr();
	if(avail_in>iBytesIn)
		avail_in=iBytesIn;
	
	TPtrC8 input(iUnderlying->GetBuf().Mid(iUnderlying->GetPtr(),avail_in));
	TInt asco=input.Length();	
	TPtr8 output(iBuf.MidTPtr(iEnd,iBufSize-iEnd));
	output.Zero();
	iInflater->SetInput(input);
	iInflater->SetOutput(output);
	
	TBool moreData=iInflater->InflateL();
	
	iEnd+=iInflater->AvailOut();
	
	if(moreData)
	{
		iBytesIn-=avail_in;
		iUnderlying->SetPtr(iUnderlying->GetPtr()+avail_in);
	}
}

void ZLibInStream::InitializeL(CEZZStream& /*aZStream*/)
{
	
}
	
void ZLibInStream::NeedInputL(CEZZStream& aZStream)
{
	TInt avail_in=iUnderlying->GetEnd()-iUnderlying->GetPtr();
	if(avail_in>iBytesIn)
		avail_in=iBytesIn;
	
	TPtrC8 input(iUnderlying->GetBuf().Mid(iUnderlying->GetPtr(),avail_in));
	aZStream.SetInput(input);
}

void ZLibInStream::NeedOutputL(CEZZStream& aZStream)
{
	TPtr8 output(iBuf.MidTPtr(iEnd,iBufSize-iEnd));
	output.Zero();
	aZStream.SetOutput(output);
}

void ZLibInStream::FinalizeL(CEZZStream& /*aZStream*/)
{
	
}