/*

* Copyright (c) 1997-2009 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 <usb/usblogger.h>

#include "AcmWriter.h"

#include "AcmPort.h"

#include "AcmPanic.h"

#include "AcmUtils.h"

#ifdef __FLOG_ACTIVE

_LIT8(KLogComponent, "ECACM");

#endif

CAcmWriter* CAcmWriter::NewL(CAcmPort& aPort, 

							 TUint aBufSize)

/**

 * Factory function.

 *

 * @param aPort Owning CAcmPort object.

 * @param aBufSize Required buffer size.

 * @return Ownership of a newly created CAcmWriter object

 */

	{

	LOG_STATIC_FUNC_ENTRY

	CAcmWriter* self = new(ELeave) CAcmWriter(aPort, aBufSize);

	CleanupStack::PushL(self);

	self->ConstructL();

	CLEANUPSTACK_POP(self);

	return self;

	}

CAcmWriter::~CAcmWriter()

/**

 * Destructor.

 */

	{

	LOG_FUNC

	WriteCancel();

	delete iBuffer;

	}

void CAcmWriter::Write(const TAny* aClientBuffer, TUint aLength)

/**

 * Queue a write.

 *

 * @param aClientBuffer pointer to the Client's buffer

 * @param aLength Number of bytes to write

 */

	{

	LOGTEXT3(_L8("CAcmWriter::Write aClientBuffer=0x%08x, aLength=%d"), 

		aClientBuffer, aLength);

	// Check we're open to requests and make a note of interesting data.

	CheckNewRequest(aClientBuffer, aLength);

	// If the write size greater than the current buffer size then the

	// request will now complete over multiple operations. (This used to 

	// simply reject the write request with KErrNoMemory)

	// Get as much data as we can from the client into our buffer

	ReadDataFromClient();

	// ...and write as much as we've got to the LDD

	IssueWrite();

	}

void CAcmWriter::WriteCancel()

/**

 * Cancel a write.

 */

	{

	LOG_FUNC

	// Cancel any outstanding request on the LDD.

	if ( iPort.Acm() )

		{

		LOGTEXT(_L8("\tiPort.Acm() exists- calling WriteCancel on it"));

		iPort.Acm()->WriteCancel();

		}

	// Reset our flag to say there's no current outstanding request. What's 

	// already in our buffer can stay there.

	iCurrentRequest.iClientPtr = NULL;

	}

void CAcmWriter::ResetBuffer()

/**

 * Called by the port to clear the buffer.

 */

	{

	LOG_FUNC

	// A request is outstanding- C32 should protect against this.

	__ASSERT_DEBUG(!iCurrentRequest.iClientPtr, 

		_USB_PANIC(KAcmPanicCat, EPanicInternalError));

	// Don't have anything to do. There are no pointers to reset. This 

	// function may in the future (if we support KConfigWriteBufferedComplete) 

	// do work, so leave the above assertion in.

	}

TInt CAcmWriter::SetBufSize(TUint aSize)

/**

 * Called by the port to set the buffer size. Also used as a utility by us to 

 * create the buffer at instantiation. 

 *

 * @param aSize The required size of the buffer.

 */

	{

	LOG_FUNC

	LOGTEXT2(_L8("\taSize=%d"), aSize);

	if ( iCurrentRequest.iClientPtr )

		{

		// A request is outstanding. C32 does not protect us against this.

		LOGTEXT(_L8("\t***a request is outstanding- returning KErrInUse"));

		return KErrInUse;

		}

	// Create the new buffer.

	HBufC8* newBuf = HBufC8::New(static_cast<TInt>(aSize));

	if ( !newBuf )

		{

		LOGTEXT(_L8("\tfailed to create new buffer- returning KErrNoMemory"));

		return KErrNoMemory;

		}

	delete iBuffer;

	iBuffer = newBuf;

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

	iBufSize = aSize;

	return KErrNone;

	}

CAcmWriter::CAcmWriter(CAcmPort& aPort, 

					   TUint aBufSize)

/**

 * Constructor.

 *

 * @param aPort The CPort parent.

 * @param aBufSize The size of the buffer.

 */

 :	iBufSize(aBufSize),

	iBuf(NULL,0,0),

	iPort(aPort)

	{

	}

void CAcmWriter::ConstructL()

/**

 * 2nd-phase constructor. 

 */

	{

	// Create the required buffer.

	LOGTEXT(_L8("\tabout to create iBuffer"));

	LEAVEIFERRORL(SetBufSize(iBufSize));

	}

void CAcmWriter::WriteCompleted(TInt aError)

/**

 * This function is called when a write on the LDD has completed. 

 * This checks whether any data remains to be written, if so the 

 * read and write requests are re-issued until there in no data 

 * left or an error occurs.

 *

 * @param aError Error with which the write completed.

 */

	{

	LOG_FUNC

	LOGTEXT2(_L8("\taError=%d"), aError);						   	

	if(iLengthToGo == 0 || aError != KErrNone)

		{

		LOGTEXT2(_L8("\tcompleting request with %d"), aError);

		CompleteRequest(aError);	

		}

	else

		{

		//there is some data remaining to be read so reissue the Read & Write 

		//requests until there is no data left.

		ReadDataFromClient();

		IssueWrite();

		}

	}

void CAcmWriter::ReadDataFromClient()

/**

 * Read data from the client space into the internal buffer, prior to writing.

 */

	{

	LOG_FUNC

	TPtr8 ptr((TUint8*)iBuf.Ptr(),

			  0,

			  Min(iBuf.MaxLength(), iLengthToGo));

	TInt err = iPort.IPCRead(iCurrentRequest.iClientPtr,

			ptr,

			static_cast<TInt>(iOffsetIntoClientsMemory));	

	LOGTEXT2(_L8("\tIPCRead = %d"), err);

	iBuf.SetLength(ptr.Length());

	__ASSERT_DEBUG(!err, _USB_PANIC(KAcmPanicCat, EPanicInternalError));

	static_cast<void>(err);

	// Increase our pointer (into the client's space) of already-read data.

	iOffsetIntoClientsMemory += iBuf.Length();

	}

void CAcmWriter::CheckNewRequest(const TAny* aClientBuffer, TUint aLength)

/**

 * Utility function to check a new request from the port. 

 * Also checks that there isn't a request already outstanding. Makes a note of 

 * the relevant parameters and sets up internal counters.

 *

 * @param aClientBuffer Pointer to the client's memory space.

 * @param aLength Length to write.

 */

	{

	LOG_FUNC

	__ASSERT_DEBUG(aLength <= static_cast<TUint>(KMaxTInt), 

		_USB_PANIC(KAcmPanicCat, EPanicInternalError));

	// Check we have no outstanding request already.

	if ( iCurrentRequest.iClientPtr )

		{

		_USB_PANIC(KAcmPanicCat, EPanicInternalError);

		}

	// Sanity check on what C32 gave us.

	__ASSERT_DEBUG(aClientBuffer, 

		_USB_PANIC(KAcmPanicCat, EPanicInternalError));

	// Make a note of interesting data.

	iCurrentRequest.iLength = aLength;

	iCurrentRequest.iClientPtr = aClientBuffer;

	iLengthToGo = aLength;

	iOffsetIntoClientsMemory = 0;

	}

void CAcmWriter::CompleteRequest(TInt aError)

/**

 * Utility to reset our 'outstanding request' flag and complete the client's 

 * request back to them. 

 * 

 * @param aError The error code to complete with.

 */

	{

	LOGTEXT2(_L8("CAcmWriter::CompleteRequest aError=%d"), aError);

	// Set our flag to say that we no longer have an outstanding request.

	iCurrentRequest.iClientPtr = NULL;

	LOGTEXT2(_L8("\tcalling WriteCompleted with %d"), aError);

	iPort.WriteCompleted(aError);

	}

void CAcmWriter::IssueWrite()

/**

 * Writes a batch of data from our buffer to the LDD. Currently writes the 

 * entire load of buffered data in one go.

 */

	{

	LOG_FUNC

	LOGTEXT2(_L8("\tissuing Write of %d bytes"), iBuf.Length());

	__ASSERT_DEBUG(iPort.Acm(), 

		_USB_PANIC(KAcmPanicCat, EPanicInternalError));

	iPort.Acm()->Write(*this, 

		iBuf, 

		iBuf.Length());

#ifdef DEBUG

	// A Zero Length Packet is an acceptable packet so iBuf.Length == 0 is acceptable, 

	// if we receive this and the request length > 0 then we may have a problem so check 

	// that the LengthToGo is also 0, if it is not then we may end up looping through this

	// code until a driver write error occurs which may never happen. 

	// This is not expected to occur but the test is in here just to be safe.

	if(iBuf.Length() == 0 && iCurrentRequest.Length() != 0 && iLengthToGo != 0)

		{

		_USB_PANIC(KAcmPanicCat, EPanicInternalError);

		}

#endif

	// Update our counter of remaining data to write. 

	iLengthToGo -= iBuf.Length();

	}

//

// End of file