1 // Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
2 // All rights reserved.
3 // This component and the accompanying materials are made available
4 // under the terms of "Eclipse Public License v1.0"
5 // which accompanies this distribution, and is available
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
8 // Initial Contributors:
9 // Nokia Corporation - initial contribution.
18 EXPORT_C TStreamFilter::TStreamFilter()
19 : iHost(NULL),iMode(0)
20 /** Constructs an empty stream filter object. */
23 EXPORT_C void TStreamFilter::EmitL(const TAny* aPtr,TInt aLength)
24 /** Writes data from the specified memory location directly to the host without
27 This is useful for sending any final data, when flushing the filter as part
30 In debug mode: the filter must be in write mode, otherwise the function raises
31 a STORE-Stream 11 panic.
33 In debug mode, a host stream must have been set before calling this function,
34 otherwise it raises a STORE-Stream 0 panic.
36 @param aPtr A pointer to the memory location from which data is to be written
38 @param aLength The number of bytes to be written.
41 __ASSERT_DEBUG(iMode&EWrite,Panic(EStreamCannotWrite));
42 __ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen));
43 iHost->WriteL(aPtr,aLength);
46 EXPORT_C void TStreamFilter::DoRelease()
47 /** Frees the host stream's resources.
49 @see MStreamBuf::DoRelease() */
51 if (iHost!=NULL&&(iMode&EAttached))
56 EXPORT_C void TStreamFilter::DoSynchL()
57 /** Synchronizes the host's intermediate buffer with its stream, leaving if any
60 @see MStreamBuf::DoSynchL() */
62 if (iHost!=NULL&&(iMode&EAttached))
66 EXPORT_C TInt TStreamFilter::DoReadL(TAny* aPtr,TInt aMaxLength)
67 /** Reads data from the host stream through the filter into the specified memory
70 In debug mode: the filter must be in read mode, otherwise the function raises
71 a STORE-Stream 10 panic.
73 In debug mode, a host stream must have been set before calling this function,
74 otherwise it raises a STORE-Stream 0 panic.
76 @param aPtr A pointer to the target memory location for the filtered data.
77 @param aMaxLength The maximum number of bytes to be read. In debug mode: if
78 this value is negative then the function raises a STORE-Stream 1 panic; if
79 this value is zero, then the function raises a STORE-Stream 3 panic.
80 @return The number of bytes read. */
82 __ASSERT_DEBUG(aMaxLength>=0,Panic(EStreamReadLengthNegative));
83 __ASSERT_DEBUG(aMaxLength>0,Panic(EStreamReadNoTransfer));
84 __ASSERT_DEBUG(iMode&ERead,Panic(EStreamCannotRead));
85 __ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen));
86 TFilterInput input(*this,aPtr,aMaxLength);
90 } while (!(input.Done()||input.Eof()));
91 return aMaxLength-input.Left();
94 EXPORT_C void TStreamFilter::DoWriteL(const TAny* aPtr,TInt aLength)
95 /** Writes data to the host stream through the filter from the specified memory
98 In debug mode: the filter must be in write mode, otherwise the function raises
99 a STORE-Stream 11 panic.
101 In debug mode, a host stream must have been set before calling this function,
102 otherwise it raises a STORE-Stream 0 panic.
104 @param aPtr A pointer to the source memory location.
105 @param aLength The number of bytes to be written. In debug mode: if this value
106 is negative then the function raises a STORE-Stream 1 panic; if this value
107 is zero, then the function raises a STORE-Stream 7 panic. */
109 __ASSERT_DEBUG(aLength>=0,Panic(EStreamWriteLengthNegative));
110 __ASSERT_DEBUG(aLength>0,Panic(EStreamWriteNoTransfer));
111 __ASSERT_DEBUG(iMode&EWrite,Panic(EStreamCannotWrite));
112 __ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen));
113 TFilterOutput output(*this,aPtr,aLength);
116 iHost->WriteL(output);
117 } while (!output.Done());
120 EXPORT_C void TStreamFilter::__DbgChkMode(TInt aMode)
122 // Check mode allows either reading or writing, but not both.
125 __ASSERT_ALWAYS((aMode&(ERead|EWrite))&&(aMode&(ERead|EWrite))!=(ERead|EWrite),Panic(EStreamModeInvalid));