williamr@2: // Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
williamr@2: // All rights reserved.
williamr@2: // This component and the accompanying materials are made available
williamr@4: // under the terms of "Eclipse Public License v1.0"
williamr@2: // which accompanies this distribution, and is available
williamr@4: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
williamr@2: //
williamr@2: // Initial Contributors:
williamr@2: // Nokia Corporation - initial contribution.
williamr@2: //
williamr@2: // Contributors:
williamr@2: //
williamr@2: // Description:
williamr@2: // Header for the Standard Compression Scheme for Unicode.
williamr@2: // This code is compiled only in the Unicode build.
williamr@2: // 
williamr@2: //
williamr@2: 
williamr@2: #ifndef __S32UCMP_H__
williamr@2: #define __S32UCMP_H__ 1
williamr@2: 
williamr@2: #ifdef _UNICODE
williamr@2: 
williamr@2: #include <e32std.h>
williamr@2: #include <s32mem.h>
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  */
williamr@2: class TUnicodeCompressionState
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	TUnicodeCompressionState();
williamr@2: 	void Reset();
williamr@2: 	static TInt StaticWindowIndex(TUint16 aCode);
williamr@2: 	static TInt DynamicWindowOffsetIndex(TUint16 aCode);
williamr@2: 	static TUint32 DynamicWindowBase(TInt aOffsetIndex);
williamr@2: 	static TBool EncodeAsIs(TUint16 aCode);
williamr@2: 
williamr@2: 	enum TPanic
williamr@2: 		{
williamr@2: 		EUnhandledByte,			// expander code fails to handle all possible byte codes
williamr@2: 		ENotUnicode,			// expander can't handle Unicode values outside range 0x0..0x10FFFF;
williamr@2: 								// that is, 16-bit codes plus 32-bit codes that can be expressed using
williamr@2: 								// 16-bit surrogates
williamr@2: 		EOutputBufferOverflow	// output buffer is not big enough
williamr@2: 		};
williamr@2: 
williamr@2: 	static void Panic(TPanic aPanic);
williamr@2: 
williamr@2: 	protected:
williamr@2: 
williamr@2: 	enum
williamr@2: 		{
williamr@2: 		EStaticWindows = 8,
williamr@2: 		EDynamicWindows = 8,
williamr@2: 		ESpecialBases = 7
williamr@2: 		};
williamr@2: 
williamr@2: 	TBool iUnicodeMode;									// TRUE if in Unicode mode as opposed to single-byte mode
williamr@2: 	TUint32 iActiveWindowBase;							// base of the active window - bases are 32-bit because they
williamr@2: 														// can be set to the surrogate area, which represents codes
williamr@2: 														// from 0x00010000 to 0x0010FFFF - planes 1-16 of ISO-10646.
williamr@2: 	static const TUint32 iStaticWindow[EStaticWindows];	// bases of the static windows
williamr@2: 	static const TUint32 iDynamicWindowDefault[EDynamicWindows];	// default bases of the dynamic windows
williamr@2: 	static const TUint16 iSpecialBase[ESpecialBases];	// bases for window offsets F9..FF
williamr@2: 
williamr@2: 	TUint32 iDynamicWindow[EDynamicWindows];			// bases of the dynamic windows
williamr@2: 	TInt iUnicodeWords;									// Unicode words processed; read by compressor, written by expander
williamr@2: 	TInt iMaxUnicodeWords;								// maximum number of Unicode words to read or write
williamr@2: 	TInt iCompressedBytes;								// compressed bytes processed: read by expander, written by compressor
williamr@2: 	TInt iMaxCompressedBytes;							// maximum number of compressed bytes to read or write
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  */
williamr@2: class MUnicodeSource
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	virtual TUint16 ReadUnicodeValueL() = 0;
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  A class to read Unicode values directly from memory.
williamr@2:  */
williamr@2: class TMemoryUnicodeSource: public MUnicodeSource
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	inline TMemoryUnicodeSource(const TUint16* aPtr);
williamr@2: 	inline TUint16 ReadUnicodeValueL();
williamr@2: 
williamr@2: 	private:
williamr@2: 	const TUint16* iPtr;
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  A class to read Unicode values from a stream built on a memory object.
williamr@2:  */
williamr@2: class TMemoryStreamUnicodeSource: public MUnicodeSource
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	inline TMemoryStreamUnicodeSource(RReadStream& aStream);
williamr@2: 	inline TUint16 ReadUnicodeValueL();
williamr@2: 
williamr@2: 	private:
williamr@2: 	RReadStream& iStream;
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  */
williamr@2: class MUnicodeSink
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	virtual void WriteUnicodeValueL(TUint16 aValue) = 0;
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  A class to write Unicode values directly to memory.
williamr@2:  */
williamr@2: class TMemoryUnicodeSink: public MUnicodeSink
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	inline TMemoryUnicodeSink(TUint16* aPtr);
williamr@2: 	inline void WriteUnicodeValueL(TUint16 aValue);
williamr@2: 
williamr@2: 	private:
williamr@2: 	TUint16* iPtr;
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  A class to write Unicode values to a stream built on a memory object.
williamr@2:  */
williamr@2: class TMemoryStreamUnicodeSink: public MUnicodeSink
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	inline TMemoryStreamUnicodeSink(RWriteStream& aStream);
williamr@2: 	inline void WriteUnicodeValueL(TUint16 aValue);
williamr@2: 
williamr@2: 	private:
williamr@2: 	RWriteStream& iStream;
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2:  
williamr@2: A class to hold functions to compress text using the Standard Compression Scheme for Unicode.
williamr@2: 
williamr@2: A note on error handling and leaving.
williamr@2: 
williamr@2: Although all the public functions except the constructor can leave, it is possible to guarantee success: that is,
williamr@2: guarantee that a call will not leave, and that compression will be completed. To do this, (i) supply a MUnicodeSource
williamr@2: object with a non-leaving ReadUnicodeValueL function, such as a TMemoryUnicodeSource; (ii) write output to a
williamr@2: RWriteStream with a non-leaving WriteL function, or to a buffer that you already know to be big enough, which can be
williamr@2: found out using CompressedSizeL.
williamr@2: 
williamr@2: This guarantee of success is particularly useful when compressing from one memory buffer to another.
williamr@2: */
williamr@2: class TUnicodeCompressor: public TUnicodeCompressionState
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	IMPORT_C TUnicodeCompressor();
williamr@2: 	IMPORT_C void CompressL(RWriteStream& aOutput,MUnicodeSource& aInput,
williamr@2: 							TInt aMaxOutputBytes = KMaxTInt,TInt aMaxInputWords = KMaxTInt,
williamr@2: 							TInt* aOutputBytes = NULL,TInt* aInputWords = NULL);
williamr@2: 	IMPORT_C void CompressL(TUint8* aOutput,MUnicodeSource& aInput,
williamr@2: 							TInt aMaxOutputBytes = KMaxTInt,TInt aMaxInputWords = KMaxTInt,
williamr@2: 							TInt* aOutputBytes = NULL,TInt* aInputWords = NULL);
williamr@2: 	IMPORT_C TInt FlushL(RWriteStream& aOutput,TInt aMaxOutputBytes,TInt& aOutputBytes);
williamr@2: 	IMPORT_C TInt FlushL(TUint8* aOutput,TInt aMaxOutputBytes,TInt& aOutputBytes);
williamr@2: 	IMPORT_C static TInt CompressedSizeL(MUnicodeSource& aInput,TInt aInputWords);
williamr@2: 
williamr@2: 	private:
williamr@2: 
williamr@2: 	 // A structure to store a character and its treatment code
williamr@2: 	struct TAction
williamr@2: 		{
williamr@2: 		// Treatment codes: static and dynamic window numbers, plain ASCII or plain Unicode
williamr@2: 		enum
williamr@2: 			{
williamr@2: 			EPlainUnicode = -2,	// character cannot be expressed as ASCII or using static or dynamic windows
williamr@2: 			EPlainASCII = -1,	// character can be emitted as an ASCII code
williamr@2: 			EFirstDynamic = 0,	// values 0..255 are for dynamic windows with offsets at these places in the offset table
williamr@2: 			ELastDynamic = 255,
williamr@2: 			EFirstStatic = 256,	// values 256..263 are for static windows 0..7
williamr@2: 			ELastStatic = 263
williamr@2: 			};
williamr@2: 
williamr@2: 		inline TAction();
williamr@2: 		TAction(TUint16 aCode);
williamr@2: 
williamr@2: 		TUint16 iCode;		// Unicode value of the character
williamr@2: 		TInt iTreatment;	// treatment code: see above
williamr@2: 		};
williamr@2: 
williamr@2: 	void DoCompressL(RWriteStream* aOutputStream,TUint8* aOutputPointer,MUnicodeSource* aInput,
williamr@2: 					 TInt aMaxCompressedBytes,TInt aMaxUnicodeWords,
williamr@2: 					 TInt* aCompressedBytes,TInt* aUnicodeWords);
williamr@2: 	void FlushInputBufferL();
williamr@2: 	void FlushOutputBufferL();
williamr@2: 	void WriteRunL();
williamr@2: 	void WriteCharacter(const TAction& aAction);
williamr@2: 	void WriteSCharacter(const TAction& aAction);
williamr@2: 	void WriteUCharacter(TUint16 aCode);
williamr@2: 	void WriteByte(TUint aByte);
williamr@2: 	void WriteCharacterFromBuffer();
williamr@2: 	void SelectTreatment(TInt aTreatment);
williamr@2: 
williamr@2: 	enum
williamr@2: 		{
williamr@2: 		EMaxInputBufferSize = 4,
williamr@2: 		EMaxOutputBufferSize = EMaxInputBufferSize * 3	// no Unicode character can be encoded as more than three bytes
williamr@2: 		};
williamr@2: 	TAction iInputBuffer[EMaxInputBufferSize];			// circular buffer; queue of Unicode characters to be processed
williamr@2: 	TInt iInputBufferStart;								// position of first Unicode character to be processed
williamr@2: 	TInt iInputBufferSize;								// characters in the input buffer
williamr@2: 	TUint8 iOutputBuffer[EMaxOutputBufferSize];			// circular buffer; queue of compressed bytes to be output
williamr@2: 	TInt iOutputBufferStart;							// position of first compressed byte to be output
williamr@2: 	TInt iOutputBufferSize;								// characters in the output buffer
williamr@2: 	TInt iDynamicWindowIndex;							// index of the current dynamic window
williamr@2: 	RWriteStream* iOutputStream;						// if non-null, output is to this stream
williamr@2: 	TUint8* iOutputPointer;								// if non-null, output is to memory
williamr@2: 	MUnicodeSource* iInput;								// input object
williamr@2: 	};
williamr@2: 
williamr@2: /**
williamr@2:  * @publishedAll 
williamr@2:  * @released
williamr@2: 
williamr@2: A class to hold functions to expand text using the Standard Compression Scheme for Unicode.
williamr@2: 
williamr@2: A note on error handling and leaving.
williamr@2: 
williamr@2: Although all the public functions except the constructor can leave, it is possible to guarantee success: that is,
williamr@2: guarantee that a call will not leave, and that expansion will be completed. To do this, (i) supply a MUnicodeSink
williamr@2: object with a non-leaving WriteUnicodeValueL function, such as a TMemoryUnicodeSink; (ii) read input from a RReadStream
williamr@2: with a non-leaving ReadL function; (iii) supply a big enough buffer to write the ouput; you can find out how big by
williamr@2: calling ExpandedSizeL, using methods (i) and (ii) to guarantee success.
williamr@2: 
williamr@2: This guarantee of success is particularly useful when expanding from one memory buffer to another.
williamr@2: */
williamr@2: class TUnicodeExpander: public TUnicodeCompressionState
williamr@2: 	{
williamr@2: 	public:
williamr@2: 	IMPORT_C TUnicodeExpander();
williamr@2: 	IMPORT_C void ExpandL(MUnicodeSink& aOutput,RReadStream& aInput,
williamr@2: 						  TInt aMaxOutputWords = KMaxTInt,TInt aMaxInputBytes = KMaxTInt,
williamr@2: 						  TInt* aOutputWords = NULL,TInt* aInputBytes = NULL);
williamr@2: 	IMPORT_C void ExpandL(MUnicodeSink& aOutput,const TUint8* aInput,
williamr@2: 						  TInt aMaxOutputWords = KMaxTInt,TInt aMaxInputBytes = KMaxTInt,
williamr@2: 						  TInt* aOutputWords = NULL,TInt* aInputBytes = NULL);
williamr@2: 	IMPORT_C TInt FlushL(MUnicodeSink& aOutput,TInt aMaxOutputWords,TInt& aOutputWords);
williamr@2: 	IMPORT_C static TInt ExpandedSizeL(RReadStream& aInput,TInt aInputBytes);
williamr@2: 	IMPORT_C static TInt ExpandedSizeL(const TUint8* aInput,TInt aInputBytes);
williamr@2: 
williamr@2: 	private:
williamr@2: 	void DoExpandL(MUnicodeSink* aOutput,RReadStream* aInputStream,const TUint8* aInputPointer,
williamr@2: 				   TInt aMaxOutputWords,TInt aMaxInputBytes,
williamr@2: 				   TInt* aOutputWords,TInt* aInputBytes);
williamr@2: 	void HandleByteL();
williamr@2: 	void FlushOutputBufferL();
williamr@2: 	TBool HandleSByteL(TUint8 aByte);
williamr@2: 	TBool HandleUByteL(TUint8 aByte);
williamr@2: 	TBool ReadByteL(TUint8& aByte);
williamr@2: 	TBool QuoteUnicodeL();
williamr@2: 	TBool DefineWindowL(TInt aIndex);
williamr@2: 	TBool DefineExpansionWindowL();
williamr@2: 	void WriteChar(TText aChar);
williamr@2: 	void WriteChar32(TUint aChar);
williamr@2: 
williamr@2: 	enum
williamr@2: 		{
williamr@2: 		EMaxInputBufferSize = 3,						// no Unicode character can be encoded as more than 3 bytes
williamr@2: 		EMaxOutputBufferSize = 2						// no byte can be expanded into more than 2 Unicode characters
williamr@2: 		};
williamr@2: 	TUint8 iInputBuffer[EMaxInputBufferSize];			// buffer containing a group of compressed bytes representing
williamr@2: 														// a single operation; when an input source ends in the
williamr@2: 														// middle of an operation, this buffer enables the next
williamr@2: 														// expansion to start in the correct state
williamr@2: 	TInt iInputBufferStart;								// next read position in the input buffer
williamr@2: 	TInt iInputBufferSize;								// bytes in the input buffer
williamr@2: 	TUint16 iOutputBuffer[EMaxOutputBufferSize];		// circular buffer; queue of Unicode characters to be output
williamr@2: 	TInt iOutputBufferStart;							// position of first Unicode character to be output
williamr@2: 	TInt iOutputBufferSize;								// characters in the output buffer
williamr@2: 	MUnicodeSink* iOutput;								// output object
williamr@2: 	RReadStream* iInputStream;							// if non-null, input is from this stream
williamr@2: 	const TUint8* iInputPointer;						// if non-null, input is from memory
williamr@2: 	};
williamr@2: 
williamr@2: // inline functions start here
williamr@2: 
williamr@2: inline TMemoryUnicodeSource::TMemoryUnicodeSource(const TUint16* aPtr):
williamr@2: 	iPtr(aPtr)
williamr@2: 	{
williamr@2: 	}
williamr@2: 
williamr@2: inline TUint16 TMemoryUnicodeSource::ReadUnicodeValueL()
williamr@2: 	{
williamr@2: 	return *iPtr++;
williamr@2: 	}
williamr@2: 
williamr@2: inline TMemoryStreamUnicodeSource::TMemoryStreamUnicodeSource(RReadStream& aStream):
williamr@2: 	iStream(aStream)
williamr@2: 	{
williamr@2: 	}
williamr@2: 
williamr@2: inline TUint16 TMemoryStreamUnicodeSource::ReadUnicodeValueL()
williamr@2: 	{
williamr@2: 	TUint16 x;
williamr@2: 	iStream.ReadL((TUint8*)&x,sizeof(TUint16));
williamr@2: 	return x;
williamr@2: 	}
williamr@2: 
williamr@2: inline TMemoryUnicodeSink::TMemoryUnicodeSink(TUint16* aPtr):
williamr@2: 	iPtr(aPtr)
williamr@2: 	{
williamr@2: 	}
williamr@2: 
williamr@2: inline void TMemoryUnicodeSink::WriteUnicodeValueL(TUint16 aValue)
williamr@2: 	{
williamr@2: 	*iPtr++ = aValue;
williamr@2: 	}
williamr@2: 
williamr@2: inline TMemoryStreamUnicodeSink::TMemoryStreamUnicodeSink(RWriteStream& aStream):
williamr@2: 	iStream(aStream)
williamr@2: 	{
williamr@2: 	}
williamr@2: 
williamr@2: inline void TMemoryStreamUnicodeSink::WriteUnicodeValueL(TUint16 aValue)
williamr@2: 	{
williamr@2: 	iStream.WriteL((TUint8*)&aValue,sizeof(TUint16));
williamr@2: 	}
williamr@2: 
williamr@2: inline TUnicodeCompressor::TAction::TAction():
williamr@2: 	iCode(0),
williamr@2: 	iTreatment(EPlainUnicode)
williamr@2: 	{
williamr@2: 	}
williamr@2: 
williamr@2: #endif // _UNICODE
williamr@2: 
williamr@2: #endif // __S32UCMP_H__