--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/userlibandfileserver/fileserver/sfile/sf_memory_client.cpp	Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,276 @@
+// Copyright (c) 2008-2009 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:
+// f32\sfile\sf_memory_client.cpp
+// 
+//
+
+/**
+ @file
+ @internalTechnology
+*/
+
+#include <e32std.h>
+#include <e32std_private.h>
+#include "sf_std.h"
+#include <e32uid.h>
+#include <e32wins.h>
+#include <f32file.h>
+#include "sf_memory_man.h"
+#include "sf_memory_client.h"
+
+
+CCacheMemoryClient::~CCacheMemoryClient()
+	{
+	const TUint32 segCnt = iTouchedRegionFlag <= iReservedRegionMarkInSegs ? 
+										iReservedRegionMarkInSegs : iTouchedRegionFlag;
+	DecommitSegments(iBase, segCnt);
+	iReusablePagePool.Close();
+	delete iName;
+	}
+
+/**
+Static factory function for CCacheMemoryClient
+@param	aManager	reference of CCacheMemoryManager that this client register with
+@param	aClientName	the unique identification of CCacheMemoryClient
+@param	aOffsetInBytes	the offset to the base position of CCacheMemoryManager it registered
+@param	aMinSizeInSegs	the minimum client size in segments, equals to the number of reserved segments
+@param	aMaxSizeInSegs	the maximum client size in segments
+*/
+CCacheMemoryClient* CCacheMemoryClient::NewL(CCacheMemoryManager& aManager, const TDesC& aClientName, TUint32 aOffsetInBytes, TUint32 aMinSizeInSegs, TUint32 aMaxSizeInSegs)
+	{
+	// only create clients when sensible parameters are provided, otherwise will cause fatal error to file server 
+	if (aMinSizeInSegs > 0 && aMaxSizeInSegs >= aMinSizeInSegs && aClientName.Length() > 0)
+		{
+		CCacheMemoryClient* self = new(ELeave) CCacheMemoryClient(aManager, aMinSizeInSegs, aMaxSizeInSegs);
+		CleanupStack::PushL(self);
+		self->ConstructL(aClientName, aOffsetInBytes);
+		CleanupStack::Pop(1, self);
+		return self;
+		}
+	return NULL;
+	}
+
+/**
+Constructor of CCacheMemoryClient
+@param	aManager	reference of CCacheMemoryManager that this client register with
+@param	aMinSizeInSegs	the minimum client size in segments, equals to the number of reserved segments
+@param	aMaxSizeInSegs	the maximum client size in segments
+*/
+CCacheMemoryClient::CCacheMemoryClient(CCacheMemoryManager& aManager, TUint32 aMinSizeInSegs, TUint32 aMaxSizeInSegs)
+:iManager(aManager),
+iMinSizeInSegs(aMinSizeInSegs),
+iMaxSizeInSegs(aMaxSizeInSegs)
+	{
+	}
+
+/**
+Second phase constructor of CCacheMemoryClient
+@param	aClientName	the unique identification of CCacheMemoryClient
+@param	aOffsetInBytes	the offset to the base position of CCacheMemoryManager it registered
+*/
+void CCacheMemoryClient::ConstructL(const TDesC& aClientName, TUint32 aOffsetInBytes)
+	{
+	iName = HBufC::NewMaxL(aClientName.Length());
+	*iName = aClientName;
+	iSegSizeInBytesLog2 = iManager.SegmentSizeInBytesLog2();
+	iSegSizeInBytes = 1 << iSegSizeInBytesLog2;
+	iReusablePagePool.Close();
+	iReusablePagePool.ReserveL(iMinSizeInSegs);
+	iBase = iManager.Base() + aOffsetInBytes;
+	iReservedRegionMarkInSegs = iMinSizeInSegs;
+	TInt r = iManager.AllocateAndLockSegments(iBase, iReservedRegionMarkInSegs);
+	ASSERT(r==KErrNone);
+	User::LeaveIfError(r);
+	iTouchedRegionFlag = 0;
+	__PRINT4(_L("CCacheMemoryClient::ConstructL(%S, min=%d, max=%d, base=0x%X)"), &aClientName, iMinSizeInSegs, iMaxSizeInSegs, iBase);
+	}
+
+/**
+Reset the client state, this is normally issued from the cache it connected with.
+For exmaple, a FAT volume is dismounted so the directory cache needs to be reset.
+Although the cache is reset, the CCacheMemoryClient object should not be destroyed and the reserved region should still 
+be hold to make sure when the cache re-connect with the CCacheMemoryClient, it will not fail due to OOM conditions.
+
+@internalTechnology
+@released
+*/
+EXPORT_C void CCacheMemoryClient::Reset()
+	{
+	__PRINT3(_L("CCacheMemoryClient::Reset(%S, reserved=%d, touched=%d)"), iName, iReservedRegionMarkInSegs, iTouchedRegionFlag);
+	
+	// in case that client user has incorrectly decommited reserved region (normally on destruction), 
+	//	we should re-commit reserved region here to prepare the next connection.
+	TInt r = DecommitSegments(iBase, iReservedRegionMarkInSegs);
+	if (r != KErrNone)	// this 'if() {}' is to remove build warnings in debug mode, same is below
+		{
+		ASSERT(0);
+		}
+
+	r = iManager.AllocateAndLockSegments(iBase, iReservedRegionMarkInSegs);
+	if (r != KErrNone)
+		{
+		ASSERT(0);
+		}
+
+	// if we have touched more than reserved, we also need to make sure it's decommitted.
+	if (iTouchedRegionFlag > iReservedRegionMarkInSegs)
+		{
+		TInt r = iManager.DecommitSegments(iBase + (iReservedRegionMarkInSegs << iSegSizeInBytesLog2), iTouchedRegionFlag - iReservedRegionMarkInSegs);
+		if (r != KErrNone)
+			{
+			ASSERT(0);
+			}
+		}
+	
+	iTouchedRegionFlag = 0;
+	iReusablePagePool.Close();
+	iReusablePagePool.Reserve(iReservedRegionMarkInSegs);
+	}
+
+/**
+Commit an unused set of contiguous segments. 
+@param	aSegmentCount	the segment number to be commited.
+@return	TUint8*	the starting ram address of the commited segments.
+
+@internalTechnology
+@released
+*/
+EXPORT_C TUint8* CCacheMemoryClient::AllocateAndLockSegments(TUint32 aSegmentCount)
+	{
+	__PRINT3(_L("CCacheMemoryClient::AllocateAndLockSegments(%S, reserved=%d, touched=%d)"), iName, iReservedRegionMarkInSegs, iTouchedRegionFlag);
+//	__PRINT2(_L("iBase = 0x%x, segcnt = %d"), iBase, aSegmentCount);
+    TUint8* addr = NULL;
+    // if we are walking through the reserved region first time, we should
+    // make assumption that this area is locked already
+    if (iTouchedRegionFlag + aSegmentCount <= iReservedRegionMarkInSegs)
+       	{
+       	addr = iBase + (iTouchedRegionFlag << iSegSizeInBytesLog2);
+       	iTouchedRegionFlag += aSegmentCount;
+//       	__PRINT3(_L("!! USED RESERVED SEGS: addr=0x%x, touched=%d, reserved=%d"), addr, iTouchedRegionFlag, iReservedRegionMarkInSegs);
+       	return addr;
+       	}
+    
+	// if we have used up reserved region, get new pages from reusable pool first
+    if (iReusablePagePool.Count())
+    	{
+		addr = iReusablePagePool[0];
+		iReusablePagePool.Remove(0);
+//       	__PRINT2(_L("!! USED REUSABLE POOL SEGS: addr=0x%x, reusable.Count()=%d"), addr, iReusablePagePool.Count());
+    	}
+    // or we grow the touched region flag
+    else
+    	{
+    	addr = iBase + (iTouchedRegionFlag << iSegSizeInBytesLog2);
+    	iTouchedRegionFlag += aSegmentCount;
+//       	__PRINT2(_L("!! GROW TOUCHED SEGS: addr=0x%x, touched=%d"), addr, iTouchedRegionFlag);
+    	}
+	
+    // parameter validation
+    ASSERT(((addr - iBase) >> iSegSizeInBytesLog2) + aSegmentCount <= iMaxSizeInSegs);
+    if(((addr - iBase) >> iSegSizeInBytesLog2) + aSegmentCount > iMaxSizeInSegs)
+    	{
+    	ASSERT(0);
+    	return NULL;
+    	}
+
+    TInt r = iManager.AllocateAndLockSegments(addr, aSegmentCount);
+	if (r != KErrNone)
+		return NULL;
+
+	return addr;
+	}
+
+/**
+Decommit a set of contiguous segments. 
+@param	aStartRamAddr	the start ram address of the region to be decommitted.
+@param	aSegmentCount	the segment number to be decommited.
+@return		KErrNone if succeed, otherwise a system-wide error code.
+
+@internalTechnology
+@released
+*/
+EXPORT_C TInt CCacheMemoryClient::DecommitSegments(TUint8* aStartRamAddr, TUint32 aSegmentCount)
+	{
+	__PRINT4(_L("CCacheMemoryClient::DecommitSegments(%S, reserved=%d, touched=%d, segNo=%d)"), iName, iReservedRegionMarkInSegs, iTouchedRegionFlag, aSegmentCount);
+	// parameter validation
+	if(aStartRamAddr < iBase || 
+			(((aStartRamAddr - iBase) >> iSegSizeInBytesLog2) + aSegmentCount > iMaxSizeInSegs))
+		{
+		ASSERT(0);
+		return KErrArgument;
+		}
+	
+	TInt err = iManager.DecommitSegments(aStartRamAddr, aSegmentCount);
+	ASSERT(err == KErrNone);
+	if (err != KErrNone)
+		return err;
+	iReusablePagePool.Append(aStartRamAddr);
+	return KErrNone;
+	}
+
+/**
+Lock a set of contiguous segments. 
+@param	aStartRamAddr	the start ram address of the region to be locked.
+@param	aSegmentCount	the segment number to be locked.
+@return		KErrNone if succeed, otherwise a system-wide error code.
+
+@internalTechnology
+@released
+*/
+EXPORT_C TInt CCacheMemoryClient::LockSegments(TUint8* aStartRamAddr, TUint32 aSegmentCount)
+	{
+	__PRINT4(_L("CCacheMemoryClient::LockSegments(%S, reserved=%d, touched=%d, segNo=%d)"), iName, iReservedRegionMarkInSegs, iTouchedRegionFlag, (aStartRamAddr - iBase) >> iSegSizeInBytesLog2);
+	// parameter validation
+	if(aStartRamAddr < iBase || 
+			(((aStartRamAddr - iBase) >> iSegSizeInBytesLog2) + aSegmentCount > iMaxSizeInSegs))
+		{
+		ASSERT(0);
+		return KErrArgument;
+		}
+	return iManager.LockSegments(aStartRamAddr, aSegmentCount);
+	}
+
+/**
+Unlock a set of contiguous segments. 
+@param	aStartRamAddr	the start ram address of the region to be unlocked.
+@param	aSegmentCount	the segment number to be unlocked.
+@return		KErrNone if succeed, otherwise a system-wide error code.
+
+@internalTechnology
+@released
+*/
+EXPORT_C TInt CCacheMemoryClient::UnlockSegments(TUint8* aStartRamAddr, TUint32 aSegmentCount)
+	{
+	__PRINT4(_L("CCacheMemoryClient::UnlockSegments(%S, reserved=%d, touched=%d, segNo=%d)"), iName, iReservedRegionMarkInSegs, iTouchedRegionFlag, (aStartRamAddr - iBase) >> iSegSizeInBytesLog2);
+	// validate parameters
+	if(aStartRamAddr < iBase || 
+			(((aStartRamAddr - iBase) >> iSegSizeInBytesLog2) + aSegmentCount > iMaxSizeInSegs))
+		{
+		ASSERT(0);
+		return KErrArgument;
+		}
+	return iManager.UnlockSegments(aStartRamAddr, aSegmentCount);
+	}
+
+//////////////////////////// auxiliary functions /////////////////////////
+TUint32 CCacheMemoryClient::MaxSizeInBytes()
+	{
+	return iMaxSizeInSegs  << iSegSizeInBytesLog2;
+	}
+
+const TDesC& CCacheMemoryClient::Name() const
+	{
+	return *iName;
+	}
+