--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/commands/chkdeps/byte_pair.cpp	Wed Jun 23 15:52:26 2010 +0100
@@ -0,0 +1,170 @@
+// Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of the License "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:
+// e32\kernel\byte_pair.cpp
+// 
+//
+
+#include <e32cia.h>
+#include "u32std.h"
+
+TInt BytePairDecompress(TUint8* dst, TInt dstSize, TUint8* src, TInt srcSize, TUint8*& srcNext)
+	{
+	TUint8* dstStart = dst;
+	TUint8* dstEnd = dst+dstSize;
+	TUint8* srcEnd = src+srcSize;
+
+	TUint32 LUT[0x100/2];
+	TUint8* LUT0 = (TUint8*)LUT;
+	TUint8* LUT1 = LUT0+0x100;
+
+	TUint8 stack[0x100];
+	TUint8* stackStart = stack+sizeof(stack);
+	TUint8* sp = stackStart;
+
+	TUint32 marker = ~0u;
+	TInt numTokens;
+	TUint32 p1;
+	TUint32 p2;
+
+	TUint32* l = (TUint32*)LUT;
+	TUint32 b = 0x03020100;
+	TUint32 step = 0x04040404;
+	do
+		{
+		*l++ = b;
+		b += step;
+		}
+	while(b>step);
+
+	if(src>=srcEnd)
+		goto error;
+	numTokens = *src++;
+	if(numTokens)
+		{
+		if(src>=srcEnd)
+			goto error;
+		marker = *src++;
+		LUT0[marker] = (TUint8)~marker;
+
+		if(numTokens<32)
+			{
+			TUint8* tokenEnd = src+3*numTokens;
+			if(tokenEnd>srcEnd)
+				goto error;
+			do
+				{
+				TInt b = *src++;
+				TInt p1 = *src++;
+				TInt p2 = *src++;
+				LUT0[b] = (TUint8)p1;
+				LUT1[b] = (TUint8)p2;
+				}
+			while(src<tokenEnd);
+			}
+		else
+			{
+			TUint8* bitMask = src;
+			src += 32;
+			if(src>srcEnd)
+				goto error;
+			TInt b=0;
+			do
+				{
+				TUint8 mask = bitMask[b>>3];
+				if(mask&(1<<(b&7)))
+					{
+					if(src>=srcEnd)
+						goto error;
+					TInt p1 = *src++;
+					if(src>=srcEnd)
+						goto error;
+					TInt p2 = *src++;
+					LUT0[b] = (TUint8)p1;
+					LUT1[b] = (TUint8)p2;		
+					--numTokens;
+					}
+				++b;
+				}
+			while(b<0x100);
+			if(numTokens)
+				goto error;
+			}
+		}
+
+	if(src>=srcEnd)
+		goto error;
+	b = *src++;
+	if(dst>=dstEnd)
+		goto error;
+	p1 = LUT0[b];
+	if(p1!=b)
+		goto not_single;
+next:
+	if(src>=srcEnd)
+		goto done_s;
+	b = *src++;
+	*dst++ = (TUint8)p1;
+	if(dst>=dstEnd)
+		goto done_d;
+	p1 = LUT0[b];
+	if(p1==b)
+		goto next;
+
+not_single:
+	if(b==marker)
+		goto do_marker;
+
+do_pair:
+	p2 = LUT1[b];
+	b = p1;
+	p1 = LUT0[b];
+	if(sp<=stack)
+		goto error;
+	*--sp = (TUint8)p2;
+
+recurse:
+	if(b!=p1)
+		goto do_pair;
+
+	if(sp==stackStart)
+		goto next;
+	b = *sp++;
+	*dst++ = (TUint8)p1;
+	if(dst>=dstEnd)
+		goto error;
+	p1 = LUT0[b];
+	goto recurse;
+
+do_marker:
+	if(src>=srcEnd)
+		goto error;
+	p1 = *src++;
+	goto next;
+
+error:
+	srcNext = 0;
+	return KErrCorrupt;
+
+done_s:
+	*dst++ = (TUint8)p1;
+	srcNext = src;
+	return dst-dstStart;
+
+done_d:
+	--src;
+	srcNext = src;
+	return dst-dstStart;
+	}
+
+