usbmgmt/usbmgr/device/classdrivers/acm/classimplementation/ecacm/src/AcmWriter.cpp
/*
* 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