sl@0: // Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: //
sl@0: 
sl@0: #include "US_STD.H"
sl@0: 
sl@0: EXPORT_C TStreamFilter::TStreamFilter()
sl@0: 	: iHost(NULL),iMode(0)
sl@0: /** Constructs an empty stream filter object. */
sl@0: 	{}
sl@0: 
sl@0: EXPORT_C void TStreamFilter::EmitL(const TAny* aPtr,TInt aLength)
sl@0: /** Writes data from the specified memory location directly to the host without 
sl@0: filtering.
sl@0: 
sl@0: This is useful for sending any final data, when flushing the filter as part 
sl@0: of DoSynchL().
sl@0: 
sl@0: In debug mode: the filter must be in write mode, otherwise the function raises 
sl@0: a STORE-Stream 11 panic. 
sl@0: 
sl@0: In debug mode, a host stream must have been set before calling this function, 
sl@0: otherwise it raises a STORE-Stream 0 panic.
sl@0: 
sl@0: @param aPtr A pointer to the memory location from which data is to be written 
sl@0: to the host stream.
sl@0: @param aLength The number of bytes to be written.
sl@0: @see DoSynchL() */
sl@0: 	{
sl@0: 	__ASSERT_DEBUG(iMode&EWrite,Panic(EStreamCannotWrite));
sl@0: 	__ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen));
sl@0: 	iHost->WriteL(aPtr,aLength);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TStreamFilter::DoRelease()
sl@0: /** Frees the host stream's resources.
sl@0: 
sl@0: @see MStreamBuf::DoRelease() */
sl@0: 	{
sl@0: 	if (iHost!=NULL&&(iMode&EAttached))
sl@0: 		iHost->Release();
sl@0: 	iHost=NULL;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TStreamFilter::DoSynchL()
sl@0: /** Synchronizes the host's intermediate buffer with its stream, leaving if any 
sl@0: error occurs.
sl@0: 
sl@0: @see MStreamBuf::DoSynchL() */
sl@0: 	{
sl@0: 	if (iHost!=NULL&&(iMode&EAttached))
sl@0: 		iHost->SynchL();
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TStreamFilter::DoReadL(TAny* aPtr,TInt aMaxLength)
sl@0: /** Reads data from the host stream through the filter into the specified memory 
sl@0: location.
sl@0: 
sl@0: In debug mode: the filter must be in read mode, otherwise the function raises 
sl@0: a STORE-Stream 10 panic.
sl@0: 
sl@0: In debug mode, a host stream must have been set before calling this function, 
sl@0: otherwise it raises a STORE-Stream 0 panic.
sl@0: 
sl@0: @param aPtr A pointer to the target memory location for the filtered data.
sl@0: @param aMaxLength The maximum number of bytes to be read. In debug mode: if 
sl@0: this value is negative then the function raises a STORE-Stream 1 panic; if 
sl@0: this value is zero, then the function raises a STORE-Stream 3 panic.
sl@0: @return The number of bytes read. */
sl@0: 	{
sl@0: 	__ASSERT_DEBUG(aMaxLength>=0,Panic(EStreamReadLengthNegative));
sl@0: 	__ASSERT_DEBUG(aMaxLength>0,Panic(EStreamReadNoTransfer));
sl@0: 	__ASSERT_DEBUG(iMode&ERead,Panic(EStreamCannotRead));
sl@0: 	__ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen));
sl@0: 	TFilterInput input(*this,aPtr,aMaxLength);
sl@0: 	do
sl@0: 		{
sl@0: 		iHost->ReadL(input);
sl@0: 		} while (!(input.Done()||input.Eof()));
sl@0: 	return aMaxLength-input.Left();
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TStreamFilter::DoWriteL(const TAny* aPtr,TInt aLength)
sl@0: /** Writes data to the host stream through the filter from the specified memory 
sl@0: location.
sl@0: 
sl@0: In debug mode: the filter must be in write mode, otherwise the function raises 
sl@0: a STORE-Stream 11 panic.
sl@0: 
sl@0: In debug mode, a host stream must have been set before calling this function, 
sl@0: otherwise it raises a STORE-Stream 0 panic.
sl@0: 
sl@0: @param aPtr A pointer to the source memory location.
sl@0: @param aLength The number of bytes to be written. In debug mode: if this value 
sl@0: is negative then the function raises a STORE-Stream 1 panic; if this value 
sl@0: is zero, then the function raises a STORE-Stream 7 panic. */
sl@0: 	{
sl@0: 	__ASSERT_DEBUG(aLength>=0,Panic(EStreamWriteLengthNegative));
sl@0: 	__ASSERT_DEBUG(aLength>0,Panic(EStreamWriteNoTransfer));
sl@0: 	__ASSERT_DEBUG(iMode&EWrite,Panic(EStreamCannotWrite));
sl@0: 	__ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen));
sl@0: 	TFilterOutput output(*this,aPtr,aLength);
sl@0: 	do
sl@0: 		{
sl@0: 		iHost->WriteL(output);
sl@0: 		} while (!output.Done());
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TStreamFilter::__DbgChkMode(TInt aMode)
sl@0: //
sl@0: // Check mode allows either reading or writing, but not both.
sl@0: //
sl@0: 	{
sl@0: 	__ASSERT_ALWAYS((aMode&(ERead|EWrite))&&(aMode&(ERead|EWrite))!=(ERead|EWrite),Panic(EStreamModeInvalid));
sl@0: 	}
sl@0: