--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kernel/eka/memmodel/epoc/mmubase/kblockmap.cpp	Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,193 @@
+// 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 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\memmodel\epoc\mmubase\kblockmap.cpp
+// 
+//
+
+#include <memmodel/epoc/mmubase/kblockmap.h>
+#include <e32cmn.h>
+#include <e32cmn_private.h>
+#include <e32atomics.h>
+
+#undef ASSERT
+
+#ifdef __KERNEL_MODE__
+
+#include <kernel/kernel.h>
+#define TRACECLASS Kern
+#undef TRACE
+#define ASSERT(x) __NK_ASSERT_DEBUG(x)
+#define FREE(x) Kern::Free(x)
+
+#define RETURN_ERROR(err, traceMsg)													 \
+	{																				 \
+	__KTRACE_OPT(KPAGING,Kern::Printf("DP: %s, returning error %d", traceMsg, err)); \
+	return err;																		 \
+	}
+
+#define TRACE_FATAL(x) __KTRACE_OPT(KPANIC, Kern::x)
+
+#else
+
+#include <e32debug.h>
+#include <e32test.h>
+#define TRACECLASS RDebug
+extern RTest test;
+#define ASSERT(x) test(x);
+#define FREE(x) User::Free(x)
+
+#define RETURN_ERROR(err, traceMsg)								  \
+	{															  \
+	RDebug::Printf("DP: %s, returning error %d", traceMsg, err); \
+	return err;													  \
+	}
+
+#define TRACE_FATAL(x) RDebug::x
+
+#endif
+
+TInt TBlockMap::Initialise(const SBlockMapInfoBase& aBlockMapInfo,
+						   TBlockMapEntryBase* aBlockMapEntries,
+						   TInt aBlockMapEntriesSize,
+						   TInt aReadUnitShift,
+						   TInt aDataLengthInFile)
+	{
+	ASSERT(iExtents == NULL);
+
+	if (aBlockMapEntriesSize % sizeof(TBlockMapEntryBase) != 0)
+		RETURN_ERROR(KErrArgument, "Size of block map is not multiple of entry size");
+	iExtentCount = aBlockMapEntriesSize / sizeof(TBlockMapEntryBase);
+
+	TInt blockShift = __e32_find_ms1_32(aBlockMapInfo.iBlockGranularity);
+	if ((1u << blockShift) != aBlockMapInfo.iBlockGranularity)
+		RETURN_ERROR(KErrArgument, "Block granularity not a power of two");
+	if (blockShift < aReadUnitShift)
+		RETURN_ERROR(KErrArgument, "Block size must be greater than or equal to read unit size");
+	TInt blockScaling = blockShift - aReadUnitShift;
+	TInt readUnitMask = (1 << aReadUnitShift) - 1;
+
+	if ((aBlockMapInfo.iStartBlockAddress & ((1 << aReadUnitShift) - 1)) != 0)
+		RETURN_ERROR(KErrArgument, "Block zero address not a multiple of read unit size");
+	TUint blockZeroNumber = (TUint)(aBlockMapInfo.iStartBlockAddress >> aReadUnitShift);  // offset of block zero from start of partition
+
+	if (aBlockMapInfo.iBlockStartOffset >= aBlockMapInfo.iBlockGranularity)
+		RETURN_ERROR(KErrArgument, "Block start offset must be less than block size");
+
+	if (aDataLengthInFile <= 0)
+		RETURN_ERROR(KErrArgument, "Length of code data in file must be greater than zero"); 
+	iDataLength = aDataLengthInFile;
+	
+	// Process block map data into kernel-side reprsentation
+	TInt dataOffset = -(TInt)(aBlockMapInfo.iBlockStartOffset & readUnitMask);
+	SExtent entry;
+	for (TInt i = 0 ; i < iExtentCount ; ++i)
+		{
+		const TBlockMapEntryBase& data = aBlockMapEntries[i];
+		entry.iDataOffset = dataOffset;
+		entry.iBlockNumber = (data.iStartBlock << blockScaling) + blockZeroNumber;
+		dataOffset += data.iNumberOfBlocks << blockShift;
+		if (i == 0)
+			{
+			TInt adjustStartBlock = aBlockMapInfo.iBlockStartOffset >> aReadUnitShift;
+			entry.iBlockNumber += adjustStartBlock;
+			dataOffset -= adjustStartBlock << aReadUnitShift;
+			}
+		(SExtent&)data = entry;
+		}
+	
+	if (dataOffset < iDataLength)
+		RETURN_ERROR(KErrArgument, "Block map too short");
+
+	// Take ownership of buffer
+	iExtents = (SExtent*) aBlockMapEntries;
+
+	return KErrNone;
+	}
+
+TBlockMap::TBlockMap()
+	: iExtents(NULL)
+	{
+	}
+
+TBlockMap::~TBlockMap()
+	{
+	FREE(iExtents);
+	}
+
+TInt TBlockMap::FindFirstExtent(TInt aPos) const
+	{
+	if (aPos < 0 || aPos >= iDataLength)
+		return KErrArgument;
+	RArray<SExtent> extents(sizeof(SExtent), iExtents, iExtentCount);
+	SExtent findEntry = { aPos, 0 };
+	TInt i = -1;
+	extents.SpecificFindInSignedKeyOrder(findEntry, i, EArrayFindMode_Last);
+	--i;
+	if (i < 0 || i >= iExtentCount)
+		return KErrArgument;
+	return i;
+	}
+
+TInt TBlockMap::Read(TLinAddr aBuffer, TInt aPos, TInt aLength, TInt aReadUnitShift, TReadFunc aReadFunc, TAny* aArg1, TAny* aArg2) const
+	{
+	TInt dataOffset = aPos;
+	TInt remain = aLength;
+	TInt readUnitMask = (1 << aReadUnitShift) - 1;
+	
+	TInt i = FindFirstExtent(dataOffset);
+	if (i < 0)
+		return i;
+	TInt bufferStart = (dataOffset - Extent(i).iDataOffset) & readUnitMask;  // start of page in buffer
+	TInt bufferOffset = 0;
+	while (remain > 0)
+		{
+ 		if (i >= Count())
+			return KErrArgument;
+		
+		const SExtent& extent = Extent(i);
+		TInt blockStartOffset = dataOffset - extent.iDataOffset;
+		TInt blockNumber = extent.iBlockNumber + (blockStartOffset >> aReadUnitShift);
+		TInt nextExtentStart = i == Count() - 1 ? iDataLength : Extent(i + 1).iDataOffset;
+		TInt dataSize = Min(remain, nextExtentStart - dataOffset);
+		TInt blockCount = (dataSize + (blockStartOffset & readUnitMask) + readUnitMask) >> aReadUnitShift;
+		
+		TInt r = aReadFunc(aArg1, aArg2, aBuffer + bufferOffset, blockNumber, blockCount);
+		if (r != KErrNone)
+			{
+			TRACE_FATAL(Printf("TBlockMap::Read: error reading media at %08x + %x: %d", blockNumber << aReadUnitShift, blockCount << aReadUnitShift, r));
+			return r;
+			}
+
+		bufferOffset += blockCount << aReadUnitShift;
+		dataOffset += dataSize;
+		remain -= dataSize;
+		++i;
+		}
+	
+	return bufferStart;
+	}
+
+#ifdef _DEBUG
+
+void TBlockMap::Dump() const
+	{
+	TRACECLASS::Printf("TBlockMap:");
+	for (TInt i = 0 ; i < Count() ; ++i)
+		{
+		TInt nextExtentStart = i == Count() - 1 ? iDataLength : Extent(i + 1).iDataOffset;
+		TRACECLASS::Printf("  %d: %08x -> %08x: %08x", i, Extent(i).iDataOffset, nextExtentStart, Extent(i).iBlockNumber);
+		}
+	}
+
+#endif