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