/*

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

* Definition of the Swi::Sis::CCompressed

*

*/

#include "siscompressed.h"

#include "sisfiledata.h"

#include "compresseddataprovider.h"

using namespace Swi;

using namespace Swi::Sis;

const TInt KMaxTemporaryBufferSize = 0x8000;

/*static*/ CCompressed* CCompressed::NewLC(MSisDataProvider& aDataProvider, TInt64& aBytesRead, TReadTypeBehaviour aTypeReadBehaviour)

	{

	CCompressed* self = new (ELeave) CCompressed(aDataProvider);

	CleanupStack::PushL(self);

	self->ConstructL(aBytesRead, aTypeReadBehaviour);

	return self;

	}

/*static*/ CCompressed* CCompressed::NewL(MSisDataProvider& aDataProvider, TInt64& aBytesRead, TReadTypeBehaviour aTypeReadBehaviour)

	{

	CCompressed* self = NewLC(aDataProvider, aBytesRead, aTypeReadBehaviour);

	CleanupStack::Pop(self);

	return self;

	}

CCompressed::CCompressed(MSisDataProvider& aDataProvider) : iDataProvider(aDataProvider)

	{

	}

CCompressed::~CCompressed()

	{

	delete iCompressedReader;

	}

void CCompressed::ConstructL(TInt64& aBytesRead, TReadTypeBehaviour aTypeReadBehaviour)

	{	

	CField::ConstructL(iDataProvider, EFieldTypeCompressed, aBytesRead, aTypeReadBehaviour);	

	User::LeaveIfError(iDataProvider.Seek(ESeekCurrent, iOffset));

	// Calculate CRC of header and field data

	User::LeaveIfError(iDataProvider.Seek(ESeekStart, fieldOffset));

	CField::CalculateCrcL(iDataProvider, HeaderSize() + Length() + PaddingSize(), iCrc );

	aBytesRead += Length() + PaddingSize();

	}

MSisDataProvider& CCompressed::DataProviderL()

	{

	TInt64 bytesRead=0;

	User::LeaveIfError(iDataProvider.Seek (ESeekStart, iOffset));

	TCompressionAlgorithm alg;

	CField::ReadEnumL<TCompressionAlgorithm,TUint32>(iDataProvider, alg, bytesRead);

	CField::ReadTTypeL(iDataProvider, iUncompressedLength, bytesRead);

	// SISX defines the maximum to be 2^31 - 1 bytes. However, RHeap::Alloc will panic if you 

	// ask for KMaxTInt / 2 or more bytes and at the same time length shouldn't be negative.

	if ((iUncompressedLength >= KMaxTInt / 2) || (iUncompressedLength < 0))  

		{

		User::Leave(KErrSISFieldLengthInvalid);

		}

	TFieldLength compressedLength = Length() - sizeof(TUint32) - sizeof(TFieldLength); // 12 = length(TCompressionAlgorithm) + length (TFieldLength)

	switch (alg)

		{

		case ECompressDeflate:

			{

			if (iCompressedReader)

				{

				delete iCompressedReader;

				iCompressedReader = NULL;

				}

			iCompressedReader = CCompressedDataProvider::NewL(iDataProvider, I64INT(compressedLength));

			return *iCompressedReader;

			}

		case ECompressNone:

			{

			if (iUncompressedLength != compressedLength)

				{

				User::Leave(KErrSISFieldLengthInvalid);

				}

			return iDataProvider;

			}

		default:

			{

			User::Leave(KErrSISCompressionNotSupported);

			}			

		}

	return iDataProvider;   // Will not get here

	}

void CCompressed::ExtractDataFieldL(RFile& aFile)

	{

	MSisDataProvider& provider = DataProviderL();

	ExtractDataFieldL(provider, aFile, iUncompressedLength);

	}

void CCompressed::ExtractDataFieldL(RFile& aFile, TInt64 aLength)

	{

	if (iCurrentDataProvider==NULL)

		{

		iBytesExtracted=0;

		iCurrentDataProvider=&DataProviderL();

		}

	ExtractDataFieldL(*iCurrentDataProvider, aFile, aLength);

	}

void CCompressed::ExtractDataFieldL(MSisDataProvider& aDataProvider, RFile& aFile, TInt64 aLength)

	{

	HBufC8* buffer = HBufC8::NewMaxLC(KMaxTemporaryBufferSize);

	TInt32 endPosition = iBytesExtracted + I64INT(aLength);

	TPtr8 bufferPtr(buffer->Des());

	while (buffer->Length() > 0 && iBytesExtracted != endPosition)

		{

		TInt requestSize = ((endPosition - iBytesExtracted) < KMaxTemporaryBufferSize) ? (endPosition - iBytesExtracted) : KMaxTemporaryBufferSize;

		User::LeaveIfError(aDataProvider.Read(bufferPtr, requestSize));

		User::LeaveIfError(aFile.Write(*buffer));

		iBytesExtracted += buffer->Length();

		}

	if (iBytesExtracted != endPosition)

		{

		User::Leave(KErrSISFieldBufferTooShort);

		}

	if(iBytesExtracted == iUncompressedLength)

		{

		// reached end of field, nothing left to extract so free memory

		delete iCompressedReader;

		iCompressedReader = NULL;

		iCurrentDataProvider = NULL;

		}

	CleanupStack::PopAndDestroy(buffer);

	}

HBufC8* CCompressed::ReadControllerDataL()

	{

	MSisDataProvider& provider = DataProviderL();

	HBufC8* controller = HBufC8::NewMaxLC(iUncompressedLength);

	TPtr8 controllerBuf(controller->Des());

	TInt err = provider.Read(controllerBuf, iUncompressedLength);

	User::LeaveIfError(err);

 	if (controllerBuf.Length() != iUncompressedLength)

		{

		User::Leave(KErrSISFieldBufferTooShort);

		}	

	CleanupStack::Pop(controller); // pass on ownership

	return controller;

	}