userlibandfileserver/fileserver/sfile/sf_pgcompr.h
changeset 0 a41df078684a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/userlibandfileserver/fileserver/sfile/sf_pgcompr.h	Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,88 @@
+// Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).
+// 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:
+// f32\sfile\sf_pgcompr.h
+// 
+//
+
+#ifndef __SF_PGCOMPR_H__
+#define __SF_PGCOMPR_H__
+
+#include <e32base.h>
+#include<f32file.h>
+//#include "sf_std.h"
+#include <f32image.h>
+#include "sf_image.h"
+#include <e32uid.h>
+#include <e32rom.h>
+#include "sf_cache.h"
+
+
+const TUint KBytePairPageSize = 4096;
+
+// Buffer sized for at least 8 compressed pages - a noncompressible page is one byte larger
+const TUint KReadNumberOfPages = 8;
+const TUint KPagesBufferSize = (KBytePairPageSize + 1) * KReadNumberOfPages;
+
+typedef TUint8* (*TMemoryMoveFunction)(TAny* aTrg,const TAny* aSrc,TInt aLength); 
+
+struct IndexTableHeader
+	{
+	TInt	iSizeOfData;					// Includes the index and compressed pages
+	TInt	iDecompressedSize;
+	TUint16	iNumberOfPages;
+	};
+
+// sizeof(IndexTableHeader) returns the wrong value due to rounding/padding, so calculate it
+const TUint KIndexTableHeaderSize = sizeof(TInt) + sizeof(TInt) + sizeof(TUint16);
+
+NONSHARABLE_CLASS(CBytePairReader) : public CBase
+	{
+public:
+	static CBytePairReader* NewLC(TUint8* aBuffer, TUint32 aLength);
+	CBytePairReader(TUint8* aBuffer, TUint32 aLength);
+
+	virtual TUint DecompressPagesL(TUint8* aTarget, TInt aLength, TMemoryMoveFunction aMemMoveFn);
+	void GetPageOffsetsL(TInt32 aInitialOffset, TInt& aPageCount, TInt32*& aPageStarts);
+	TUint GetPageL(TUint aPageNum, TUint8* aTarget, TInt aLength, TMemoryMoveFunction aMemMoveFn);		
+	virtual void SeekForwardL(TUint aBytes);
+
+protected:
+	virtual void ReadInTableL();
+	void ReleaseTable();
+
+	IndexTableHeader iHeader;
+	TUint16* iIndexTable;
+	TUint8* iNextPage;
+	TUint iBytesLeft;
+	TUint8 iPageBuf[KBytePairPageSize];
+	};
+
+NONSHARABLE_CLASS(CBytePairFileReader) : public CBytePairReader
+	{
+public:
+	static CBytePairFileReader* NewLC(RFile& aFile);
+	CBytePairFileReader(RFile& aFile);
+	~CBytePairFileReader();
+
+	virtual TUint DecompressPagesL(TUint8* aTarget, TInt aLength, TMemoryMoveFunction aMemMovefn);
+	virtual void SeekForwardL(TUint aBytes);
+
+protected:
+	virtual void ReadInTableL();
+
+	RFile& iFile;
+	TUint8 iBuffer[KPagesBufferSize];
+	};
+
+#endif // __SF_PGCOMPR_H__