--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mmlibs/mmfw/Recogniser/src/readers.h	Thu Oct 07 22:34:12 2010 +0100
@@ -0,0 +1,176 @@
+// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "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:
+//
+
+#ifndef READERS_H
+#define READERS_H
+
+#include "constants.h"
+#include "mmruf.h"
+
+
+static const TInt KAACFrameHeaderSize = 7;
+static const TInt KMP3FrameHeaderSize = 4;
+static const TInt KBufSize = 64;
+
+
+//
+// This class provides a level of abstraction that allows
+// for parsing data. It is necessary because AppArc may
+// only provide a buffer that contains a limited snapshot
+// of the beginning of a file, or a file handle that allows
+// the whole file to be parsed.
+//
+class CReader : public CBase
+	{
+public:
+
+	//
+	// Enums used so that CParsers can determine
+	// the type of reader they've been given.
+	//
+	typedef enum
+		{
+		EUnknown = 0,
+		EBuffer = 1,
+		EFile = 2
+		}
+	TReaderType;
+	
+	//
+	// This function resets the reader such that the next
+	// read operation will be performed from the start of
+	// the source.
+	// For a CFileReader the buffer is filled from the start
+	// of the file, for a CBufferReader the position in the 
+	// buffer is set to zero.
+	//
+	virtual void Reset() { iBufPos = 0; }
+	
+	//
+	// Seeks within the source.
+	// This function tries to support 64-bit compatible file
+	// formats as much as possible, but there may be some
+	// instances when the operation cannot be performed due to
+	// limitations of the file server.
+	//
+	virtual void SeekL(TInt64 aOffset) = 0;
+	
+	//
+	// Seeks within the source.
+	//
+	virtual void SeekL(TInt aOffset) = 0;
+	
+	//
+	// Returns the current position in the buffer.
+	//
+	virtual TInt Position() { return iBufPos; }
+		
+	//
+	// Data reading routines.
+	//
+	TBool Match(const TDesC8& aPattern);
+	void Read64L(TInt64& aData, TBool aLittleEndian = EFalse);
+	void Read32L(TUint32& aData, TBool aLittleEndian = EFalse);
+	void Read16L(TUint16& aData, TBool aLittleEndian = EFalse);
+	void ReadByteL(TUint8& aData);
+	void ReadBytesL(TDes8& aData);
+
+	//
+	// Gets the type of Reader being used.
+	//
+	inline TReaderType Type() { return iType; }
+		
+protected:
+	CReader(const TDesC8& aBuffer, CReader::TReaderType aType);
+	
+	//
+	// Returns ETrue if there is aAmount of unread bytes available,
+	// EFalse otherwise.
+	//
+	virtual TBool CheckEnoughData(TInt aAmount);
+	
+	//
+	// Non-leaving Seek
+	//
+	TInt Seek(TInt aOffset);
+	TInt Seek(TInt64 aOffset);
+	
+private:
+	const TDesC8& iBuffer;		// The buffer that contains the source data.
+	TInt iBufPos;				// The current position in the data source.
+	CReader::TReaderType iType;	// The type of reader it is.
+	};
+
+
+//
+// This class allows reading and seeking operations to be
+// performed on a data buffer. This is used when no file
+// handle is available to the recogniser.
+//
+class CBufferReader : public CReader
+	{
+public:
+	static CBufferReader* NewLC(const TDesC8& aBuffer);
+	virtual ~CBufferReader();
+	void Reset();
+	void SeekL(TInt aOffset);				// CReader
+	void SeekL(TInt64 aOffset);				// CReader
+
+protected:
+	CBufferReader(const TDesC8& aBuffer);
+	CBufferReader(const TDesC8& aBuffer, TReaderType aType);
+	void ConstructL();
+	};
+
+
+//
+// This class allows reading and seeking operations to be
+// performed on a file handle. This is used when a file
+// handle is available to the recogniser.
+//
+class CFileReader : public CBufferReader
+	{
+public:
+	static CFileReader* NewLC(RFile* aFile);
+	virtual ~CFileReader();
+	void Reset();
+	
+	//
+	// CReader::Position() override.
+	//
+	TInt Position() { return CBufferReader::Position() + iFilePos; }
+		
+	void SeekL(TInt aOffset);			// CReader
+	void SeekL(TInt64 aOffset);			// CReader
+	
+protected:
+	CFileReader(RFile* aFile);
+	void ConstructL();
+	TBool CheckEnoughData(TInt aAmount);	// CReader
+	
+	//
+	// Seeks to a new file location and fills the buffer from there.
+	//
+	TInt PhysicallySeekAndRead(TInt aAmount);
+	TInt PhysicallySeekAndRead(TInt64 aOffset);
+private:
+	RFile* iFile;
+	TInt64 iFilePos;
+	TBuf8<KBufSize> iFileBuffer;
+	};
+	
+	
+#endif
+