sl@0: // Copyright (c) 1998-2009 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: #ifndef __S32SHARE_H__ sl@0: #define __S32SHARE_H__ sl@0: sl@0: #include sl@0: #include sl@0: sl@0: class TStreamExchange; sl@0: /** sl@0: * @publishedAll sl@0: * @released sl@0: * Manages the position of a read mark or a write mark within a shared stream. sl@0: sl@0: A shared stream is one that shares its host with other streams. In practice, sl@0: the host is a stream buffer that is, itself, hosted by a file, an RFileBuf sl@0: object. sl@0: sl@0: TStreamMark objects are owned by RShareBuf, one for reading and one for writing. sl@0: They re-direct read/write operations through a TStreamExchange object to the sl@0: RFileBuf object, which handles the actual file read and write operations. sl@0: sl@0: @see RFileBuf sl@0: @see RShareBuf sl@0: @see TStreamExchange sl@0: */ sl@0: class TStreamMark sl@0: { sl@0: public: sl@0: inline TStreamMark(); sl@0: inline TStreamMark(TStreamPos aPos); sl@0: inline TStreamMark& operator=(TStreamPos aPos); sl@0: inline operator TStreamMark*(); sl@0: inline operator const TStreamMark*() const; sl@0: // sl@0: inline TBool operator==(const TStreamMark& aMark) const; sl@0: inline TBool operator==(const TStreamMark* aPtr) const; sl@0: inline TBool operator!=(const TStreamMark& aMark) const; sl@0: inline TBool operator!=(const TStreamMark* aPtr) const; sl@0: // sl@0: inline TBool IsEmpty() const; sl@0: inline void Clear(); sl@0: inline TStreamPos Position() const; sl@0: // sl@0: inline TBool IsWith(TStreamExchange& aHost) const; sl@0: inline TBool RelatesTo(TStreamExchange& aHost) const; sl@0: inline void Withdraw(TStreamExchange& aHost); sl@0: inline void ExtractL(TStreamExchange& aHost); sl@0: // sl@0: inline TInt ReadL(TStreamExchange& aHost,TAny* aPtr,TInt aMaxLength); sl@0: IMPORT_C TInt ReadL(TStreamExchange& aHost,TDes8& aDes,TRequestStatus& aStatus); sl@0: inline TInt ReadL(TStreamExchange& aHost,TDes8& aDes,TInt aMaxLength,TRequestStatus& aStatus); sl@0: inline TStreamTransfer ReadL(TStreamExchange& aHost,MStreamInput& anInput,TStreamTransfer aTransfer); sl@0: inline TInt ReadL(TStreamExchange& aHost,MStreamInput& anInput,TInt aMaxLength); sl@0: inline void ReadL(TStreamExchange& aHost,MStreamInput& anInput); sl@0: // sl@0: inline void WriteL(TStreamExchange& aHost,const TAny* aPtr,TInt aLength); sl@0: IMPORT_C TInt WriteL(TStreamExchange& aHost,const TDesC8& aDes,TRequestStatus& aStatus); sl@0: inline TInt WriteL(TStreamExchange& aHost,const TDesC8& aDes,TInt aMaxLength,TRequestStatus& aStatus); sl@0: inline TStreamTransfer WriteL(TStreamExchange& aHost,MStreamOutput& anOutput,TStreamTransfer aTransfer); sl@0: inline TInt WriteL(TStreamExchange& aHost,MStreamOutput& anOutput,TInt aMaxLength); sl@0: inline void WriteL(TStreamExchange& aHost,MStreamOutput& anOutput); sl@0: // sl@0: inline void SeekL(TStreamExchange& aHost,TStreamPos aPos); sl@0: inline TStreamPos SeekL(TStreamExchange& aHost,TStreamLocation aLocation,TInt anOffset=0); sl@0: inline TStreamPos SeekL(TStreamExchange& aHost,TInt anOffset); sl@0: // sl@0: inline TStreamPos TellL(TStreamExchange& aHost) const; sl@0: private: sl@0: /** Constructs a default shared stream mark object. sl@0: sl@0: The position for the mark is uninitialised. sl@0: sl@0: An uninitialised mark means that a call to IsEmpty() returns true. sl@0: sl@0: @see IsEmpty() */ sl@0: TStreamMark(const TStreamMark&); sl@0: TStreamMark& operator=(const TStreamMark&); sl@0: private: sl@0: TStreamPos iPos; sl@0: private: sl@0: inline TBool IsTracking(TStreamMark*const& aRef) const; sl@0: inline void Track(TStreamMark*const& aRef); sl@0: private: sl@0: friend class TStreamExchange; sl@0: private: sl@0: IMPORT_C static void __DbgChkPos(TStreamPos aPos); sl@0: }; sl@0: sl@0: /** sl@0: * @publishedAll sl@0: * @released sl@0: * Manages access to a shared host buffer for shared stream buffers. sl@0: sl@0: The class maintains independent markers for the shared stream buffer that sl@0: has most recently read or written to the shared host buffer. sl@0: sl@0: This is the way in which multiple requests from the same shared stream buffer sl@0: are handled without the need for repeated seeking. The shared host buffer sl@0: only needs to seek when a new shared buffer needs to use it sl@0: sl@0: @see RShareBuf sl@0: */ sl@0: class TStreamExchange sl@0: { sl@0: public: sl@0: inline TStreamExchange(); sl@0: inline TStreamExchange(MStreamBuf* aHost); sl@0: inline void Share(MStreamBuf* aHost); sl@0: inline TBool IsActive() const; sl@0: IMPORT_C MStreamBuf* Host(); sl@0: IMPORT_C MStreamBuf* HostL(); sl@0: IMPORT_C void Release(); sl@0: // sl@0: IMPORT_C TInt SizeL() const; sl@0: private: sl@0: /** Used to identify the type of mark in a stream. sl@0: sl@0: The type is used by functions of this class and derived classes that perform sl@0: seek operations to marks within a stream. sl@0: sl@0: The type uses the ERead and EWrite enumeration values, as bit flags, to identify sl@0: the read and write marks respectively. sl@0: sl@0: ERead is an MStreamBuf::TRead enumerator. EWrite is an MStreamBuf::EWrite sl@0: enumerator. sl@0: sl@0: @see MStreamBuf::TRead sl@0: @see MStreamBuf::TWrite */ sl@0: typedef MStreamBuf::TMark TMark; sl@0: private: sl@0: /** Constructs an empty object. sl@0: sl@0: Call Share() to prepare for access to a shared stream buffer. */ sl@0: TStreamExchange(const TStreamExchange&); sl@0: TStreamExchange& operator=(const TStreamExchange&); sl@0: // sl@0: IMPORT_C TBool RefersTo(const TStreamMark& aMark); sl@0: IMPORT_C void Drop(const TStreamMark& aMark); sl@0: IMPORT_C void GetL(TStreamMark& aMark); sl@0: IMPORT_C TInt DoReadL(TAny* aPtr,TInt aMaxLength,TStreamMark& aMark); sl@0: IMPORT_C TInt DoReadL(TDes8& aDes,TInt aMaxLength,TRequestStatus& aStatus,TStreamMark& aMark); sl@0: IMPORT_C TStreamTransfer DoReadL(MStreamInput& anInput,TStreamTransfer aTransfer,TStreamMark& aMark); sl@0: IMPORT_C void DoWriteL(const TAny* aPtr,TInt aLength,TStreamMark& aMark); sl@0: IMPORT_C TInt DoWriteL(const TDesC8& aDes,TInt aMaxLength,TRequestStatus& aStatus,TStreamMark& aMark); sl@0: IMPORT_C TStreamTransfer DoWriteL(MStreamOutput& anOutput,TStreamTransfer aTransfer,TStreamMark& aMark); sl@0: IMPORT_C TStreamPos DoSeekL(TStreamMark& aMark,TStreamLocation aLocation,TInt anOffset); sl@0: // sl@0: void PrepareForReadingL(TStreamMark& aMark); sl@0: void PrepareForWritingL(TStreamMark& aMark); sl@0: // sl@0: TInt PrepareAndReadL(TAny* aPtr,TInt aMaxLength,TStreamMark& aMark); sl@0: TInt PrepareAndReadL(TDes8& aDes,TInt aMaxLength,TRequestStatus& aStatus,TStreamMark& aMark); sl@0: TStreamTransfer PrepareAndReadL(MStreamInput& anInput,TStreamTransfer aTransfer,TStreamMark& aMark); sl@0: void PrepareAndWriteL(const TAny* aPtr,TInt aLength,TStreamMark& aMark); sl@0: TInt PrepareAndWriteL(const TDesC8& aDes,TInt aMaxLength,TRequestStatus& aStatus,TStreamMark& aMark); sl@0: TStreamTransfer PrepareAndWriteL(MStreamOutput& anOutput,TStreamTransfer aTransfer,TStreamMark& aMark); sl@0: TStreamPos MarkSeekL(TStreamMark& aMark,TStreamLocation aLocation,TInt anOffset); sl@0: // sl@0: inline MStreamBuf& BufL() const; sl@0: inline MStreamBuf& Buf() const; sl@0: private: sl@0: MStreamBuf* iHost; sl@0: TStreamMark* iRMrk; sl@0: TStreamMark* iWMrk; sl@0: private: sl@0: friend class TStreamMark; sl@0: }; sl@0: sl@0: /** sl@0: * @publishedAll sl@0: * @released sl@0: * A shared stream buffer. sl@0: sl@0: This class is part of the framework used by CFileStore that allows multiple sl@0: stream buffers to concurrently access the single hosting file buffer, an RFileBuf sl@0: object. sl@0: sl@0: Each shared stream buffer maintains its own read and write positions. sl@0: sl@0: Read and write operations to RShareBuf are directed through separate TStreamMark sl@0: objects, one for read and one for write. The TStreamMark objects re-direct sl@0: read/write operations through a TStreamExchange object to the RFileBuf object, sl@0: which handles the actual file read and write operations. sl@0: sl@0: This stream buffer can also be accessed through RShareReadStream and RShareWriteStream sl@0: objects. sl@0: sl@0: @see TStreamMark sl@0: @see TStreamExchange sl@0: @see RFileBuf sl@0: @see RShareReadStream sl@0: @see RShareWriteStream sl@0: */ sl@0: class RShareBuf : public MStreamBuf sl@0: { sl@0: public: sl@0: IMPORT_C RShareBuf(); sl@0: IMPORT_C void Open(TStreamExchange& aHost,TStreamPos aPos,TInt aMode=ERead|EWrite); sl@0: inline void Open(TStreamExchange& aHost,TInt aMode=ERead|EWrite); sl@0: protected: sl@0: IMPORT_C void DoRelease(); sl@0: IMPORT_C TInt DoReadL(TAny* aPtr,TInt aMaxLength); sl@0: IMPORT_C TInt DoReadL(TDes8& aDes,TInt aMaxLength,TRequestStatus& aStatus); sl@0: IMPORT_C TStreamTransfer DoReadL(MStreamInput& anInput,TStreamTransfer aTransfer); sl@0: IMPORT_C void DoWriteL(const TAny* aPtr,TInt aLength); sl@0: IMPORT_C TInt DoWriteL(const TDesC8& aDes,TInt aMaxLength,TRequestStatus& aStatus); sl@0: IMPORT_C TStreamTransfer DoWriteL(MStreamOutput& anOutput,TStreamTransfer aTransfer); sl@0: IMPORT_C TStreamPos DoSeekL(TMark aMark,TStreamLocation aLocation,TInt anOffset); sl@0: private: sl@0: inline TStreamExchange& Host() const; sl@0: private: sl@0: TStreamExchange* iHost; sl@0: TStreamMark iRMark; sl@0: TStreamMark iWMark; sl@0: }; sl@0: sl@0: /** sl@0: * @publishedAll sl@0: * @released sl@0: * Supports the opening, for reading, of a stream which shares its host with other sl@0: streams. sl@0: sl@0: This is also called a shared read stream. sl@0: sl@0: The class uses a RShareBuf stream buffer. sl@0: sl@0: @see RShareBuf sl@0: @see RFileBuf sl@0: */ sl@0: class RShareReadStream : public RReadStream sl@0: { sl@0: public: sl@0: /** Constructs an empty shared read stream object. sl@0: sl@0: Call Open() to prepare the shared stream for reading. sl@0: sl@0: @see RShareReadStream::Open() */ sl@0: RShareReadStream() {} sl@0: IMPORT_C RShareReadStream(TStreamExchange& aHost,TStreamPos aPos=KStreamBeginning); sl@0: IMPORT_C void Open(TStreamExchange& aHost,TStreamPos aPos=KStreamBeginning); sl@0: private: sl@0: RShareBuf iSource; sl@0: }; sl@0: sl@0: /** sl@0: * @publishedAll sl@0: * @released sl@0: * Supports the opening, for writing, of a stream which shares its host with other sl@0: streams. sl@0: sl@0: This is also called a shared write stream. sl@0: sl@0: The class uses a RShareBuf stream buffer. sl@0: sl@0: @see RShareBuf sl@0: @see RFileBuf sl@0: */ sl@0: class RShareWriteStream : public RWriteStream sl@0: { sl@0: public: sl@0: /** Constructs an empty shared write stream object. sl@0: sl@0: Call Open() to prepare the shared stream for writing. sl@0: sl@0: @see RShareWriteStream::Open() */ sl@0: RShareWriteStream() {} sl@0: inline RShareWriteStream(const MExternalizer& anExter); sl@0: IMPORT_C RShareWriteStream(TStreamExchange& aHost,TStreamPos aPos=KStreamBeginning); sl@0: IMPORT_C void Open(TStreamExchange& aHost,TStreamPos aPos=KStreamBeginning); sl@0: private: sl@0: RShareBuf iSink; sl@0: }; sl@0: sl@0: #include sl@0: #endif