diff -r 000000000000 -r bde4ae8d615e os/mm/mmlibs/mmfw/Recogniser/src/reader.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/os/mm/mmlibs/mmfw/Recogniser/src/reader.cpp Fri Jun 15 03:10:57 2012 +0200 @@ -0,0 +1,191 @@ +// Copyright (c) 2006-2009 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 "readers.h" + +// +// Creates a new CReader object. +// +CReader::CReader(const TDesC8& aBuffer, TReaderType aType) + : iBuffer(aBuffer), + iType(aType) + { + } + +// +// Returns ETrue is aPattern is in the buffer, EFalse otherwise. +// +TBool CReader::Match(const TDesC8& aPattern) + { + return (iBuffer.Match(aPattern) != KErrNotFound); + } + + +// +// Reads aBuf.Length() bytes into a descriptor. +// +void CReader::ReadBytesL(TDes8& aBuf) + { + TInt bufLen = aBuf.Length(); + + if (!CheckEnoughData(bufLen)) + { + User::Leave(KErrEof); + } + + for (TInt i = 0; i < bufLen; i++) + { + aBuf[i] = iBuffer[iBufPos++]; + } + } + + +// +// Reads a byte from the buffer. +// +void CReader::ReadByteL(TUint8& aData) + { + if (!CheckEnoughData(sizeof(TUint8))) + { + User::Leave(KErrEof); + } + + aData = iBuffer[iBufPos++]; + } + +// +// Reads 16 bits of data at the current reader position. +// Some formats (mainly those developed by Microsoft) still use little-endian +// encoding of fields. The file format specifications will specify which +// byte-ordering scheme is used. +// +void CReader::Read16L(TUint16& aData, TBool aLittleEndian) + { + if (!CheckEnoughData(sizeof(TUint16))) + { + User::Leave(KErrEof); + } + + TUint8 a = iBuffer[iBufPos++]; + TUint8 b = iBuffer[iBufPos++]; + + if (aLittleEndian) + { + aData = (b << 8) | a; + } + else + { + aData = (a << 8) | b; + } + } + + +// +// Reads 32 bits of data at the current reader position. +// Some formats (mainly those developed by Microsoft) still use little-endian +// encoding of fields. The file format specifications will specify which +// byte-ordering scheme is used. +// +void CReader::Read32L(TUint32& aData, TBool aLittleEndian) + { + if (!CheckEnoughData(sizeof(TUint32))) + { + User::Leave(KErrEof); + } + + TUint8 a = iBuffer[iBufPos++]; + TUint8 b = iBuffer[iBufPos++]; + TUint8 c = iBuffer[iBufPos++]; + TUint8 d = iBuffer[iBufPos++]; + + if (aLittleEndian) + { + aData = MAKE_INT32(d, c, b, a); + } + else + { + aData = MAKE_INT32(a, b, c, d); + } + } + + +// +// Reads 64 bits of data at the current reader position. +// Some formats (mainly those developed by Microsoft) still use little-endian +// encoding of fields. The file format specifications will specify which +// byte-ordering scheme is used. +// +void CReader::Read64L(TInt64& aData, TBool aLittleEndian) + { + TUint32 high; + TUint32 low; + + Read32L(high, aLittleEndian); + Read32L(low, aLittleEndian); + + if (aLittleEndian) + { + aData = MAKE_TINT64(low, high); + } + else + { + aData = MAKE_TINT64(high, low); + } + } + + +// +// +// +TBool CReader::CheckEnoughData(TInt aNeeded) + { + return ((iBufPos + aNeeded) <= iBuffer.Length()); + } + + +// +// Skips forwards or backwards aOffset number of bytes. +// +TInt CReader::Seek(TInt aOffset) + { + TInt newBufPos = iBufPos + aOffset; + + if ((newBufPos < 0) || (newBufPos >= iBuffer.Length())) + { + // Trying to seek past the bounds of the buffer. + return KErrUnderflow; + } + + iBufPos += aOffset; + return KErrNone; + } + +// +// Skips forwards or backwards aOffset number of bytes. +// +TInt CReader::Seek(TInt64 aOffset) + { + TInt64 newBufPos = iBufPos + aOffset; + + if ((newBufPos < 0) || (newBufPos >= iBuffer.Length())) + { + // Trying to seek past the bounds of the buffer. + return KErrUnderflow; + } + + iBufPos += aOffset; + return KErrNone; + } +