// file_reader.cpp

// 

// Copyright (c) 2005 - 2010 Accenture. All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the "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:

// Accenture - Initial contribution

//

#include "file_reader.h"

CFileReader* CFileReader::NewL(TInt aBlockSize, RFs& aFs, TBool aDirect)

	{

	CFileReader* self = new(ELeave) CFileReader(aFs, aDirect, aBlockSize);

	CleanupStack::PushL(self);

	self->ConstructL();

	CleanupStack::Pop(self);

	return self;

	}

CFileReader::~CFileReader()

	{

	Cancel();

	iFile.Close();

	delete iBuf;

	}

void CFileReader::Read(const TDesC& aFileName, MFileReaderObserver& aObserver)

	{

	Read(aFileName, 0, aObserver);

	}

void CFileReader::Read(const TDesC& aFileName, TInt aOffset, MFileReaderObserver& aObserver)

	{

	ASSERT(!IsActive());

	iObserver = &aObserver;

	iFirstRead = ETrue;

	if (iDirect)

		{

		iDirectOffset = aOffset;

		iFileName = aFileName;

		ReadNextDirectChunk();

		}

	else

		{

		iFile.Close();

		TInt err = iFile.Open(iFs, aFileName, EFileRead);

		if (err)

			{

			iObserver->HandleFileReadError(err);

			}

		else

			{

			err = iFile.Seek(ESeekStart, aOffset);

			if (err)

				{

				iObserver->HandleFileReadError(err);

				}

			ReadNextChunk();

			}

		}

	}

CFileReader::CFileReader(RFs& aFs, TBool aDirect, TInt aBlockSize)

	: CActive(CActive::EPriorityStandard), iFs(aFs), iBlockSize(aBlockSize), iPtr(NULL, 0), iDirect(aDirect)

	{

	CActiveScheduler::Add(this);

	}

void CFileReader::ConstructL()

	{

	iBuf = HBufC8::NewL(iBlockSize);

	iPtr.Set(iBuf->Des());

	}

void CFileReader::ReadNextChunk()

	{

	ASSERT(!IsActive());

	iPtr.Zero();

	iFile.Read(iPtr, iBlockSize, iStatus);

	SetActive();

	}

void CFileReader::ReadNextDirectChunk()

	{

	ASSERT(!IsActive());

	iPtr.Zero();

	SetActive();

	TRequestStatus* status = &iStatus;

	User::RequestComplete(status, KErrNone);

	}

void CFileReader::DoCancel()

	{

	// Can't cancel reads, to do nothing.

	}

void CFileReader::RunL()

	{

	TInt err;

	if (iDirect)

		{

		err = iFs.ReadFileSection(iFileName, iDirectOffset, iPtr, iBlockSize);

		if (err == KErrNone)

			{

			iDirectOffset += iPtr.Length();

			}

		}

	else

		{

		err = iStatus.Int();

		}

	if (err)

		{

		iObserver->HandleFileReadError(err);

		return;

		}

	TBool keepGoing(EFalse);

	if (iFirstRead)

		{

		iFirstRead = EFalse;

		iObserver->HandleFileData(iPtr, MFileReaderObserver::EFirst, keepGoing);

		}

	else if (iPtr.Length() < iBlockSize)

		{

		iFile.Close();

		TBool dummy;

		iObserver->HandleFileData(iPtr, MFileReaderObserver::ELast, dummy);

		}

	else

		{

		iObserver->HandleFileData(iPtr, MFileReaderObserver::EMiddle, keepGoing);

		}

	if (keepGoing)

		{

		iDirect ? ReadNextDirectChunk() : ReadNextChunk();

		}

	}