// 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