// 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:

 //

 #include <assert.h>

 #include <pcstore/storeexception.h>

 #include "filestreambuf.h"

 namespace PCStore

 {

 /**

 Constructs a file stream buffer object with the specified file name and open mode.

 Opens the file in specified read/write mode.

 @param aFileName The name of the file which the file stream buffer will open and access.

 @param aMode The mode in which the file would be opened.

 @exception TStoreException::EFileOpenError Error occurs in file opening.

 */

 CFileStreamBuf::CFileStreamBuf(const char* aFileName, TFileMode aMode)

 	:iFile(NULL), iStreamOpened(false)

 	{

 	if(aMode == EWriteFile) 

 		{

 		iFile=fopen(aFileName,"wb");

 		}

 	else

 		{

 		iFile=fopen(aFileName,"rb");

 		}

 	if(iFile == NULL) 

 		{

 		throw TStoreException(TStoreException::EFileOpenError);

 		}

 	}

 /**

 Destructor.

 Closes the file.

 */

 CFileStreamBuf::~CFileStreamBuf()

 	{

 	fclose(iFile);

 	}

 /**

 Flags that a stream with the specified stream id is opened.

 Checks whether a stream has been opened. If not, moves the file pointer to the position 

 which is represented by the given stream id, and sets the stream open flag to TRUE. If a 

 stream has been opened, throws an exception.

 This function is called by the constructor of CStoreReadStream and CStoreWriteStream

 to flag the new stream is opened. 

 @param aStreamId The stream id of the open stream.

 @exception TStoreException::EStreamExclusionError Another stream is still opened.

 @exception TStoreException::EFileSeekError Error occurs when seeking within the file 

 due to an incorrect stream id or other reason.

 */

 void CFileStreamBuf::StreamOpen(TStreamId aStreamId)

 	{

 	//check the opened stream

 	if(iStreamOpened)

 		{

 		throw TStoreException(TStoreException::EStreamExclusionError);

 		}

 	// set pointer to the correct position

 	TInt ret = fseek(iFile,aStreamId.Value(),SEEK_SET);  

 	if(ret)

 		{

 		throw TStoreException(TStoreException::EFileSeekError);

 		}

 	iStreamOpened = true;

 	}

 /** 

 Flags that the opened stream is closed.

 This function is called by the destructor of the CStoreReadStream and CStoreWriteStream 

 to indicate the stream is being closed.

 */

 void CFileStreamBuf::StreamClose()

 	{

 	iStreamOpened = false;

 	}

 /**

 Gets a new stream id which will be used to create a write stream.

 The new stream id is the end position of the store file.

 Moves the read/write pointer to the end to the file to get the stream id.

 @return The new stream id.

 @exception TStoreException::EStreamExclusionError Another stream is still opened.

 @exception TStoreException::EFileSeekError Error occurs when the file pointer is moved to 

 the end of file.

 */	

 TStreamId CFileStreamBuf::GetNewStreamId()

 	{

 	//check the opened stream

 	if(iStreamOpened)

 		{

 		throw TStoreException(TStoreException::EStreamExclusionError);

 		}

 	// move pointer to the end of the file

 	TInt ret = fseek(iFile,0,SEEK_END);  

 	if(ret) 

 		{

 		throw TStoreException(TStoreException::EFileSeekError);

 		}

 	TUint size = ftell(iFile);

 	TStreamId id = size;

 	return id;

 	}

 /**

 Reads the specified length of 8-bit data to the supplied buffer from the file.

 Assert aLength must not be negative and aPtr must not be NULL.

 @param aPtr The pointer to the buffer to receive the read data.

 @param aLength The length of the data to read.

 @exception TStoreException::EFileReadError Error occurs in data reading.

 */

 void CFileStreamBuf::Read(const TUint8* aPtr, TInt32 aLength)

 	{

 	assert(aLength >= 0 && aPtr != NULL);

 	if (aLength > 0) 

 		{

 		size_t numRead;

 		numRead = fread(reinterpret_cast<void*>(const_cast<TUint8*>(aPtr)),\

 			sizeof(TUint8), aLength, iFile);

 		if(numRead < static_cast<TUint32>(aLength))

 			{

 			throw TStoreException(TStoreException::EFileReadError);

 			}

 		}

 	}

 /**

 Writes the specified length of 8-bit data from the supplied buffer to the file.

 Assert aLength must not be negative and aPtr must not be NULL.

 @param aPtr The pointer to the buffer holding the written data.

 @param aLength The length of the data to write.

 @exception TStoreException::EFileWriteError Error occurs in data writing.

 */

 void CFileStreamBuf::Write(const TUint8* aPtr, TInt32 aLength)

 	{

 	assert(aLength >= 0 && aPtr != NULL);	

 	if (aLength > 0)

 		{

 		size_t numWritten ;

 		numWritten  = fwrite(reinterpret_cast<void*>(const_cast<TUint8*>(aPtr)),\

 			sizeof(TUint8), aLength, iFile);

 		if(numWritten < static_cast<TUint32>(aLength))

 			{

 			throw TStoreException(TStoreException::EFileWriteError);

 			}

 		}

 	}

 }