usbmgmt/usbmgr/device/classdrivers/acm/classimplementation/ecacm/src/AcmWriter.cpp
changeset 0 c9bc50fca66e
child 29 59aa7d6e3e0f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/usbmgmt/usbmgr/device/classdrivers/acm/classimplementation/ecacm/src/AcmWriter.cpp	Tue Feb 02 02:02:59 2010 +0200
@@ -0,0 +1,307 @@
+/*
+* 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