sl@0: // Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: //
sl@0: 
sl@0: #include <ezcompressor.h>
sl@0: #include "libzcore.h"
sl@0: 
sl@0: CEZCompressor::CEZCompressor(MEZBufferManager* aInit) : 
sl@0: 		iBufferInit(aInit)
sl@0: 	{
sl@0: 	
sl@0: 	}
sl@0: 
sl@0: CEZCompressor::~CEZCompressor()
sl@0: 	{
sl@0: 		// Note that deflateEnd may have already been called by zlib if for example and alloc failure
sl@0: 		// occurred in deflateInit2.  However there is no harm in calling deflateEnd twice.
sl@0: 
sl@0: 		deflateEnd_r(&iStream);		
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Creates a new CEZCompressor object and leaves it on the CleanupStack
sl@0: 
sl@0: @param aInit buffer manager to handle both input and output buffers
sl@0: @param aLevel compression levels
sl@0: @param aWindowBits the base two logarithm of the window size (the size of the history buffer).  It should 
sl@0: be in the range 8..15 for this version of the library. Larger values of this parameter result in better 
sl@0: compression at the expense of memory usage.
sl@0: @param aMemLevel specifies how much memory should be allocated for the internal compression state.  
sl@0: memLevel=1 uses minimum memory but is slow and reduces compression ratio; memLevel=9 uses maximum memory
sl@0: for optimal speed.
sl@0: @param aStrategy compression strategy - used to tune the compression algorithm.  The strategy parameter only affects 
sl@0: the compression ratio but not the correctness of the compressed output even if it is not set appropriately
sl@0: @see TStrategy
sl@0: @return the new CEZCompressor object (on the CleanupStack)
sl@0: */
sl@0: EXPORT_C CEZCompressor *CEZCompressor::NewLC(MEZBufferManager& aInit, TInt aLevel, TInt aWindowBits, 
sl@0: 									 TInt aMemLevel, TStrategy aStrategy)
sl@0: 	{
sl@0: 	CEZCompressor* deflater = new (ELeave) CEZCompressor(&aInit);
sl@0: 	CleanupStack::PushL(deflater);
sl@0: 	deflater->ConstructL(aLevel,aWindowBits,aMemLevel,aStrategy);
sl@0: 	return deflater;
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Creates a new CEZCompressor object
sl@0: 
sl@0: @param aInit buffer manager to handle both input and output buffers
sl@0: @param aLevel compression levels
sl@0: @param aWindowBits the base two logarithm of the window size (the size of the history buffer).  It should 
sl@0: be in the range 8..15 for this version of the library. Larger values of this parameter result in better 
sl@0: compression at the expense of memory usage.
sl@0: @param aMemLevel specifies how much memory should be allocated for the internal compression state.  
sl@0: memLevel=1 uses minimum memory but is slow and reduces compression ratio; memLevel=9 uses maximum memory
sl@0: for optimal speed.
sl@0: @param aStrategy compression strategy - used to tune the compression algorithm.  The strategy parameter only affects 
sl@0: the compression ratio but not the correctness of the compressed output even if it is not set appropriately
sl@0: @see TStrategy
sl@0: @return the new CEZCompressor object
sl@0: */
sl@0: EXPORT_C CEZCompressor* CEZCompressor::NewL(MEZBufferManager& aInit, TInt aLevel, TInt aWindowBits, 
sl@0: 									TInt aMemLevel, TStrategy aStrategy)
sl@0: 	{
sl@0: 	CEZCompressor* deflater = new (ELeave) CEZCompressor(&aInit);
sl@0: 	CleanupStack::PushL(deflater);
sl@0: 	deflater->ConstructL(aLevel,aWindowBits,aMemLevel,aStrategy);
sl@0: 	CleanupStack::Pop();
sl@0: 	return deflater;
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Overload of CEZCompressor constructor takes aDictionary argument
sl@0: 
sl@0: @param aInit buffer manager to handle both input and output buffers
sl@0: @param aDictionary used to initialize the compression dictionary from the given byte sequence
sl@0: without producing any compressed output.  The compressor and decompressor must use exactly the same dictionary.  
sl@0: The dictionary should consist of strings (byte sequences) that are likely to be encountered later in the data to be compressed, 
sl@0: with the most commonly used strings preferably put towards the end of the dictionary. Using a dictionary is most useful 
sl@0: when the data to be compressed is short and can be predicted with good accuracy; the data can then be compressed better than 
sl@0: with the default empty dictionary.
sl@0: @param aLevel compression level
sl@0: @param aWindowBits the base two logarithm of the window size (the size of the history buffer).  It should 
sl@0: be in the range 8..15 for this version of the library. Larger values of this parameter result in better 
sl@0: compression at the expense of memory usage.
sl@0: @param aMemLevel specifies how much memory should be allocated for the internal compression state.  
sl@0: memLevel=1 uses minimum memory but is slow and reduces compression ratio; memLevel=9 uses maximum memory
sl@0: for optimal speed.
sl@0: @param aStrategy compression strategy - used to tune the compression algorithm.  The strategy parameter only affects 
sl@0: the compression ratio but not the correctness of the compressed output even if it is not set appropriately
sl@0: @see TStrategy
sl@0: @return the new CEZCompressor object (on the CleanupStack)
sl@0: */
sl@0: EXPORT_C CEZCompressor* CEZCompressor::NewLC(MEZBufferManager& aInit, const TDesC8& aDictionary, 
sl@0: 				TInt aLevel, TInt aWindowBits, TInt aMemLevel, TStrategy aStrategy)
sl@0: 	{
sl@0: 	CEZCompressor* deflater = new (ELeave) CEZCompressor(&aInit);
sl@0: 	CleanupStack::PushL(deflater);
sl@0: 	deflater->ConstructL(aLevel,aDictionary.Ptr(),aDictionary.Size(),aWindowBits,aMemLevel,aStrategy);
sl@0: 	return deflater;	
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Overload of CEZCompressor constructor takes aDictionary argument
sl@0: 
sl@0: @param aInit buffer manager to handle both input and output buffers
sl@0: @param aDictionary used to initialize the compression dictionary from the given byte sequence
sl@0: without producing any compressed output.  The compressor and decompressor must use exactly the same dictionary.  
sl@0: The dictionary should consist of strings (byte sequences) that are likely to be encountered later in the data to be compressed, 
sl@0: with the most commonly used strings preferably put towards the end of the dictionary. Using a dictionary is most useful 
sl@0: when the data to be compressed is short and can be predicted with good accuracy; the data can then be compressed better than 
sl@0: with the default empty dictionary.   
sl@0: @param aLevel compression level
sl@0: @param aWindowBits the base two logarithm of the window size (the size of the history buffer).  It should 
sl@0: be in the range 8..15 for this version of the library. Larger values of this parameter result in better 
sl@0: compression at the expense of memory usage.
sl@0: @param aMemLevel specifies how much memory should be allocated for the internal compression state.  
sl@0: memLevel=1 uses minimum memory but is slow and reduces compression ratio; memLevel=9 uses maximum memory
sl@0: for optimal speed.
sl@0: @param aStrategy compression strategy - used to tune the compression algorithm.  The strategy parameter only affects 
sl@0: the compression ratio but not the correctness of the compressed output even if it is not set appropriately
sl@0: @see TStrategy
sl@0: @return the new CEZCompressor object
sl@0: */
sl@0: EXPORT_C CEZCompressor* CEZCompressor::NewL(MEZBufferManager& aInit, const TDesC8& aDictionary,  
sl@0: 			TInt aLevel, TInt aWindowBits, TInt aMemLevel, TStrategy aStrategy)
sl@0: 	{
sl@0: 	CEZCompressor* deflater = new (ELeave) CEZCompressor(&aInit);
sl@0: 	CleanupStack::PushL(deflater);
sl@0: 	deflater->ConstructL(aLevel,aDictionary.Ptr(),aDictionary.Size(),aWindowBits,aMemLevel,aStrategy);
sl@0: 	CleanupStack::Pop();
sl@0: 	return deflater;	
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Resets the current compression operation, with the new buffer manager
sl@0: 
sl@0: @param aInit new buffer manager to handle the new input and output buffers
sl@0: @leave ... Any of the system wide error codes
sl@0: */
sl@0: EXPORT_C void CEZCompressor::ResetL(MEZBufferManager& aInit)
sl@0: 	{
sl@0: 	iBufferInit = &aInit;
sl@0: 	iBufferInit->InitializeL(*this);
sl@0: 	if (deflateReset_r(&iStream) == Z_STREAM_ERROR)		
sl@0: 		User::Leave(KEZlibErrStream);
sl@0: 	iDeflationState = ENoFlush;
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Compress the data to the buffer in stages, return value indicates if the compression has finalised 
sl@0: or if further calls are necessary
sl@0: 
sl@0: @leave KEZlibErrStream There is a problem with the stream
sl@0: @leave KEZlibErrBuf There is a problem with the buffer
sl@0: @leave KEZlibErrUnexpected Unexpected programming error
sl@0: @leave ... Any of the System wide error codes
sl@0: @return ETrue if the function must be called again, EFalse if compression is finalised
sl@0: */
sl@0: EXPORT_C TBool CEZCompressor::DeflateL()
sl@0: 	{
sl@0: 	TInt err;
sl@0: 	TBool callAgain = ETrue;
sl@0: 	
sl@0: 	switch (iDeflationState)
sl@0: 		{
sl@0: 	case ENoFlush:
sl@0: 			err = deflate_r(&iStream,Z_NO_FLUSH);
sl@0: 		
sl@0: 			switch (err)
sl@0: 				{
sl@0: 			case Z_STREAM_ERROR:
sl@0: 				User::Leave(KEZlibErrStream);
sl@0: 				break;
sl@0: 
sl@0: 			case Z_OK:
sl@0: 				if (iStream.avail_in == 0)
sl@0: 					iBufferInit->NeedInputL(*this);
sl@0: 				
sl@0: 				if (iStream.avail_out == 0)
sl@0: 					iBufferInit->NeedOutputL(*this);
sl@0: 				break;
sl@0: 
sl@0: 			case Z_BUF_ERROR:  
sl@0: 				// this is probably ok we have just run out of input.
sl@0: 
sl@0: 				iDeflationState = EFinish;
sl@0: 				break;
sl@0: 
sl@0: 			default:
sl@0: 
sl@0: 				// there's something wrong with this code if we get here !
sl@0: 				
sl@0: 				User::Leave(KEZlibErrUnexpected);
sl@0: 				break;
sl@0: 				}
sl@0: 
sl@0: 			break;
sl@0: 
sl@0: 	case EFinish:
sl@0: 		err = deflate_r(&iStream,Z_FINISH);
sl@0: 		
sl@0: 		switch (err)
sl@0: 			{
sl@0: 		case Z_STREAM_ERROR:				
sl@0: 				User::Leave(KEZlibErrStream);
sl@0: 				break;
sl@0: 
sl@0: 		case Z_BUF_ERROR:
sl@0: 				User::Leave(KEZlibErrBuf);
sl@0: 				break;
sl@0: 
sl@0: 		case Z_OK:
sl@0: 				if (iStream.avail_in == 0)
sl@0: 					iBufferInit->NeedInputL(*this);
sl@0: 				
sl@0: 				if (iStream.avail_out == 0)
sl@0: 					iBufferInit->NeedOutputL(*this);
sl@0: 				break;
sl@0: 
sl@0: 		case Z_STREAM_END:
sl@0: 				iDeflationState = EFinalize;
sl@0: 				break;
sl@0: 			
sl@0: 		default:
sl@0: 				// there's something wrong with this code if we get here !
sl@0: 
sl@0: 				User::Leave(KEZlibErrUnexpected);
sl@0: 				break;
sl@0: 			}
sl@0: 
sl@0: 		break;
sl@0: 
sl@0: 	case EFinalize:
sl@0: 		iBufferInit->FinalizeL(*this);
sl@0: 		callAgain = EFalse;
sl@0: 		iDeflationState = ETerminated;
sl@0: 		break;
sl@0: 
sl@0: 	case ETerminated:
sl@0: 		User::Leave(KEZlibErrDeflateTerminated);
sl@0: 		}
sl@0: 
sl@0: 	return callAgain;
sl@0: 	}
sl@0: 
sl@0: void CEZCompressor::ConstructL(TInt aLevel, const TUint8 *aDictionary, TInt aLength, 
sl@0: 						   TInt aWindowBits, TInt aMemLevel, TStrategy aStrategy)
sl@0: 	{
sl@0: 	ConstructL(aLevel,aWindowBits,aMemLevel,aStrategy);
sl@0: 	if (deflateSetDictionary_r(&iStream,STATIC_CAST(const Bytef *,aDictionary),aLength) == 
sl@0: 			Z_STREAM_ERROR)
sl@0: 		User::Leave(KEZlibErrStream);  // This should never happen.
sl@0: 	}
sl@0: 	
sl@0: void CEZCompressor::ConstructL(TInt aLevel, TInt aWindowBits, TInt aMemLevel, TStrategy aStrategy)
sl@0: 	{
sl@0: 	// don't need to assert the validity of aWindowBits, aMemLevel & aStrategy as deflateInit2 will
sl@0: 	// do this for us.
sl@0: 
sl@0: 	iStream.zalloc = Z_NULL;
sl@0: 	iStream.zfree = Z_NULL;
sl@0: 	iStream.opaque = Z_NULL;
sl@0: 
sl@0: 	iBufferInit->InitializeL(*this);
sl@0: 
sl@0: 	TInt err = deflateInit2_r(&iStream,aLevel,Z_DEFLATED,aWindowBits,aMemLevel, STATIC_CAST(int,aStrategy));
sl@0: 	if (err == Z_STREAM_ERROR)
sl@0: 		User::Leave(KEZlibErrStream);
sl@0: 	else if (err == Z_MEM_ERROR)
sl@0: 		User::LeaveNoMemory();
sl@0: 
sl@0: 	iDeflationState = ENoFlush;
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Compresses the data in the given buffer
sl@0: 
sl@0: @param aDestination the target buffer for the compressed data
sl@0: @param aSource the buffer containing the data to be compressed
sl@0: @param aLevel the level of compression
sl@0: @leave KEZLibErrBuf There is a problem with the buffer
sl@0: @leave KEZLIbErrStream There is a problem with the stream
sl@0: @leave ... Any of the system wide error codes
sl@0: */
sl@0: EXPORT_C void CEZCompressor::CompressL(TDes8 &aDestination, const TDesC8 &aSource, 
sl@0: 										TInt aLevel)
sl@0: 	{
sl@0: 	Bytef* destinationBuffer = STATIC_CAST(Bytef* ,CONST_CAST(TUint8* ,aDestination.Ptr()));
sl@0: 	const Bytef* sourceBuffer = STATIC_CAST(const Bytef* ,aSource.Ptr());
sl@0: 	uLongf dl = aDestination.MaxSize();
sl@0: 	TInt err = compress2_r(destinationBuffer,&dl,sourceBuffer,aSource.Size(),aLevel);
sl@0: 
sl@0: 	if (err == Z_MEM_ERROR) 
sl@0: 		User::LeaveNoMemory();
sl@0: 	else if (err == Z_BUF_ERROR)
sl@0: 		User::Leave(KEZlibErrBuf);
sl@0: 	else if (err == Z_STREAM_ERROR)
sl@0: 		User::Leave(KEZlibErrStream);
sl@0: 
sl@0: 	aDestination.SetLength(dl);
sl@0: 	}