sl@0: // Copyright (c) 2008-2009 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: /**
sl@0:  @file
sl@0:  @internalComponent
sl@0: */
sl@0: 
sl@0: #include <e32def.h>
sl@0: #include <e32cmn.h>
sl@0: #include <hal.h>
sl@0: #include "EComDebug.h"
sl@0: #include "ImplementationInformation.h"  // CompareTUidValues
sl@0: #include "callback.h"
sl@0: #include "resolvercache.h"
sl@0: #include "EComPatchDataConstantv2.h"
sl@0: 
sl@0: const TInt KCacheQueueGranularity = 4;
sl@0: 
sl@0: //
sl@0: // TCounterTicks class
sl@0: //
sl@0: inline TCounterTicks::TCounterTicks(TUint aTicks)
sl@0: 	: iTicks(aTicks)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: /** This substraction calculate elapsed ticks: aEndTick - this */
sl@0: inline
sl@0: TUint TCounterTicks::ElapsedSinceThis(TUint aEndTick) const
sl@0: 	{
sl@0: 	TUint diff;
sl@0: 	if (aEndTick < iTicks) // wrap around occurred
sl@0: 		{
sl@0: 		diff = KMaxTUint - iTicks + aEndTick + 1;
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		diff = aEndTick - iTicks;
sl@0: 		}
sl@0: 	return diff;
sl@0: 	}
sl@0: 
sl@0: /** default constructor which initializes all member data to 0. */
sl@0: RResolverCacheEntry::RResolverCacheEntry()
sl@0: 	: iLastUse( TCounterTicks(0) ), iLruRank(0), iResolverUid(KNullUid),
sl@0: 	iNewLFuncPtr(NULL), iFlags(EEntryFlagsNone)
sl@0: 	{
sl@0: 	iLibrary.SetHandle(KNullHandle);
sl@0: 	}
sl@0: 
sl@0: /** construct RResolverCacheEntry with specific data
sl@0: @param aResolverUid TUid of the resolver.
sl@0: @param aLib RLibrary with handle open on the resolver DLL.
sl@0: @param aNewL Function ptr to instantiate the resolver.
sl@0: @param aFlags Special conditions about the cache entry.
sl@0: */
sl@0: RResolverCacheEntry::RResolverCacheEntry(const TUid aResolverUid,
sl@0: 										RLibrary aLib,
sl@0: 										TProxyNewLPtr aNewL,
sl@0: 										TUint32 aFlags)
sl@0: 	: iLastUse( TCounterTicks(0) ), iLruRank(0), iResolverUid(aResolverUid),
sl@0: 	iNewLFuncPtr(aNewL), iFlags(aFlags)
sl@0: 	{
sl@0: 	iLibrary.SetHandle(aLib.Handle());
sl@0: 	}
sl@0: 
sl@0: /** unallocate resources owned by the RResolverCacheEntry object */
sl@0: void RResolverCacheEntry::Close()
sl@0: 	{
sl@0: 	iLibrary.Close();
sl@0: 	}
sl@0: 
sl@0: /** This method compares two RResolverCacheEntry objects.
sl@0: @param aEntry1 first RResolverCacheEntry object.
sl@0: @param aEntry2 second RResolverCacheEntry object.
sl@0: @return 0 means the two objects are equal.
sl@0:         positive value means first object is greater than the second.
sl@0: 		negative vlaue means second object is greater than the first.
sl@0: */
sl@0: TInt RResolverCacheEntry::CompareUid(const RResolverCacheEntry& aEntry1,
sl@0: 								     const RResolverCacheEntry& aEntry2)
sl@0: 	{
sl@0: 	return CompareTUidValues(aEntry1.iResolverUid.iUid,
sl@0: 							 aEntry2.iResolverUid.iUid);
sl@0: 	}
sl@0: 
sl@0: /** Compare the age of two cache entries.
sl@0: @param aOther The RResolverCacheEntry to compare with.
sl@0: @param aCurrTick The current system tick. It simplifies handling
sl@0: 	of system tick wrap around to zero.
sl@0: @return ETrue means "this" object is older than aOther.
sl@0: 	EFalse means aOther is older than "this".
sl@0: */
sl@0: TBool RResolverCacheEntry::ThisIsOlder(const RResolverCacheEntry& aOther,
sl@0: 										TUint aCurrTick) const
sl@0: 	{
sl@0: 	if (iLastUse.iTicks == aOther.iLastUse.iTicks)
sl@0: 		{
sl@0: 		return iLruRank < aOther.iLruRank;
sl@0: 		}
sl@0: 
sl@0: 	// Because of counter wrap around, it is not safe to directly
sl@0: 	// compare the two ticks. Drag in the current system tick.
sl@0: 	return iLastUse.ElapsedSinceThis(aCurrTick) >
sl@0: 			aOther.iLastUse.ElapsedSinceThis(aCurrTick);
sl@0: 	}
sl@0: 
sl@0: //=================================
sl@0: // CCustomResolverCache class
sl@0: //=================================
sl@0: 
sl@0: /** CCustomResolverCache constructor
sl@0: @param aCacheSize Maximum number of entries allowed to cache.
sl@0: */
sl@0: CCustomResolverCache::CCustomResolverCache(TUint32 aCacheSize)
sl@0: 	: CTimer(CActive::EPriorityStandard),
sl@0: 	iResolvers(KCacheQueueGranularity), 
sl@0: 	iMaxCacheSize(aCacheSize)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: /** static factory method to instantiate CCustomResolverCache
sl@0: @param aCacheSize Maximum number of entries allowed to cache.
sl@0: @param aCacheTimeout Cache timeout in microseconds.
sl@0: @leave Any of the system wide error codes.
sl@0: */
sl@0: CCustomResolverCache* CCustomResolverCache::NewL(TUint32 aCacheSize, TUint32 aCacheTimeout)
sl@0: 	{
sl@0: 	CCustomResolverCache* self = new (ELeave) CCustomResolverCache(aCacheSize);
sl@0: 	CleanupStack::PushL(self);
sl@0: 	self->ConstructL(aCacheTimeout);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: /** Standard two phase construction to complete construction of
sl@0: the CCustomResolverCache object.
sl@0: @param aCacheTimeout Cache timeout in microseconds.
sl@0: @leave Any of the system wide error codes.
sl@0: */
sl@0: void CCustomResolverCache::ConstructL(TUint32 aCacheTimeout)
sl@0: 	{
sl@0: 	User::LeaveIfError(HAL::Get(HALData::ESystemTickPeriod,
sl@0: 								iSystemTickPeriod));
sl@0: 	iEntryTimeToLive = (aCacheTimeout + iSystemTickPeriod - 1) / iSystemTickPeriod;
sl@0: 
sl@0: 	CTimer::ConstructL();
sl@0: 	CActiveScheduler::Add(this);
sl@0: 	}
sl@0: 
sl@0: /** CCustomResolverCache destructor */
sl@0: CCustomResolverCache::~CCustomResolverCache()
sl@0: 	{
sl@0: 	Cancel();
sl@0: 	for (TInt i = iResolvers.Count() - 1; i >= 0; i--)
sl@0: 		{
sl@0: 		iResolvers[i].Close();
sl@0: 		}
sl@0: 	iResolvers.Reset();
sl@0: 	}
sl@0: 
sl@0: /** Implement the CActive RunL pure virtual */
sl@0: void CCustomResolverCache::RunL()
sl@0: 	{
sl@0: 	TUint currTickCount = User::TickCount();
sl@0: 	TUint lruAge = 0;
sl@0: 
sl@0: 	for (TInt i = iResolvers.Count() - 1; i >= 0; i--)
sl@0: 		{
sl@0: 		RResolverCacheEntry& resolverEntry = iResolvers[i];
sl@0: 		TUint age = resolverEntry.iLastUse.ElapsedSinceThis(currTickCount);
sl@0: 		if (age >= iEntryTimeToLive)
sl@0: 			{
sl@0: 			resolverEntry.Close();
sl@0: 			iResolvers.Remove(i);
sl@0: 			}
sl@0: 		else if (age > lruAge)
sl@0: 			{
sl@0: 			lruAge = age;
sl@0: 			}
sl@0: 		}
sl@0: 
sl@0: 	if (iResolvers.Count() > 0)
sl@0: 		{
sl@0: 		After( iSystemTickPeriod * (iEntryTimeToLive - lruAge + 1) );
sl@0: 		}
sl@0: 
sl@0: #ifdef __ECOMSERVER_TESTING__
sl@0: 	// In unit testing notify test bed that cache timer has fired.
sl@0: 	iTimerExpireCB.CallBack(0, NULL);
sl@0: #endif
sl@0: 	}
sl@0: 
sl@0: /** Search of a resolver UID in cache
sl@0: @param aResolverUid the resolver to search for.
sl@0: @return If find is successful, index of the resolver in RArray of cached resolvers.
sl@0: 		Return KErrNotFound if resolver is not in cache.
sl@0: */
sl@0: TInt CCustomResolverCache::FindResolver(const TUid aResolverUid) const
sl@0: 	{
sl@0: 	RResolverCacheEntry trgt;
sl@0: 	trgt.iResolverUid = aResolverUid;
sl@0: 	TLinearOrder<RResolverCacheEntry> comparator(RResolverCacheEntry::CompareUid);
sl@0: 	return iResolvers.FindInOrder(trgt, comparator);
sl@0: 	}
sl@0: 
sl@0: /** Add a resolver library to cache 
sl@0: @param aResolverUid Implementation UID of the resolver.
sl@0: @param aLib	The RLibrary object which has the resolver loaded. The handle
sl@0: 	of the RLibrary is owned by the cache if call is successful.
sl@0: @param aNewL value for the iNewLFuncPtr member data of RResolverCacheEntry.
sl@0: @param aFlags value for the iFlags member data of RResolverCacheEntry.
sl@0: @return KErrNone if the data is added to cache.
sl@0: 	KErrNoMemory if fail to insert the data in RArray.
sl@0: */
sl@0: TInt CCustomResolverCache::CacheResolver(const TUid aResolverUid,
sl@0: 										  RLibrary aLib,
sl@0: 										  TProxyNewLPtr aNewL,
sl@0: 										  TUint32 aFlags)
sl@0: 	{
sl@0: 	if (iResolvers.Count() == iMaxCacheSize)
sl@0: 		{
sl@0: 		EvictLeastRecentlyUsed();
sl@0: 		}
sl@0: 
sl@0: 	RResolverCacheEntry entry(aResolverUid, aLib, aNewL, aFlags);
sl@0: 	SetLastUseTime(entry);
sl@0: 
sl@0: #ifdef ECOM_TRACE
sl@0: 	__ECOM_TRACE2("ECOM: adding custom resolver 0x%X to cache. New queue size will be %d.\n", aResolverUid.iUid, 1 + iResolvers.Count());
sl@0: #endif
sl@0: 
sl@0: 	TLinearOrder<RResolverCacheEntry> comparator(RResolverCacheEntry::CompareUid);
sl@0: 	TInt err = iResolvers.InsertInOrder(entry, comparator);
sl@0: 
sl@0: 	// if cache was empty before need to start timer
sl@0: 	if (err == KErrNone && ! IsActive())
sl@0: 		{
sl@0: 		After( iSystemTickPeriod * (iEntryTimeToLive + 1) );
sl@0: 		}
sl@0: 	return err;
sl@0: 	}
sl@0: 
sl@0: /** Check if both queue size and cache timeout are non zero  */
sl@0: TBool CCustomResolverCache::CachingEnabled() const
sl@0: 	{
sl@0: 	return (iMaxCacheSize && iEntryTimeToLive);
sl@0: 	}
sl@0: 
sl@0: /** Remove a cached entry
sl@0: @param aIndex position of entry in the array.
sl@0: */
sl@0: void CCustomResolverCache::Remove(TInt aIndex)
sl@0: 	{
sl@0: 	iResolvers[aIndex].Close();
sl@0: 	iResolvers.Remove(aIndex);
sl@0: 	}
sl@0: 
sl@0: /** Search for a resolverUID. If found, return the NewL pointer and
sl@0: update time to live of the entry.
sl@0: @param aResolverUid the resolver to lookup
sl@0: @param aNewLFuncPtr output parameter. If lookup successful it has
sl@0: 	the function pointer to instantiate the resolver.
sl@0: @return True if resolver is in cache. False otherwise.
sl@0: @post If cache hit, the timestamp of the entry is updated.
sl@0: */
sl@0: TBool CCustomResolverCache::CacheLookup(const TUid aResolverUid,
sl@0: 										TProxyNewLPtr& aNewLFuncPtr)
sl@0: 	{
sl@0: 	TInt i = FindResolver(aResolverUid);
sl@0: 	if (i >= 0)
sl@0: 		{
sl@0: 		aNewLFuncPtr = iResolvers[i].iNewLFuncPtr;
sl@0: 		SetLastUseTime(iResolvers[i]);
sl@0: 		}
sl@0: 	return (i >= 0);
sl@0: 	}
sl@0: 
sl@0: /** Remove a resolver from cache.
sl@0: @param aResolverUid Identify the resolver to remove.
sl@0: @return ETrue if aResolverUid is found in cache. EFalse means the
sl@0: 	resolver is not in cache.
sl@0: */
sl@0: TBool CCustomResolverCache::Remove(const TUid aResolverUid)
sl@0: 	{
sl@0: 	TInt i = FindResolver(aResolverUid);
sl@0: 	if (i >= 0)
sl@0: 		{
sl@0: 		Remove(i);
sl@0: 		}
sl@0: 	return (i >= 0);
sl@0: 	}
sl@0: 
sl@0: /** Remove cached entries with flags set.
sl@0: @param aMask If an entry has any of the bits in aMask set, it is removed.
sl@0: */
sl@0: void CCustomResolverCache::RemoveItemsWithFlags(TUint32 aMask)
sl@0: 	{
sl@0: 	for (TInt i = iResolvers.Count() - 1; i >= 0; i--)
sl@0: 		{
sl@0: 		if (iResolvers[i].iFlags & aMask)
sl@0: 			{
sl@0: 			Remove(i);
sl@0: 			}
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: /** evict the least recently used entry in cache
sl@0: */
sl@0: void CCustomResolverCache::EvictLeastRecentlyUsed()
sl@0: 	{
sl@0: 	TUint curr = User::TickCount();
sl@0: 	TInt index = 0; // set to first entry in cache.
sl@0: 
sl@0: 	for (TInt i = 1; i < iResolvers.Count(); i++)
sl@0: 		{
sl@0: 		RResolverCacheEntry& resolverEntry = iResolvers[i];
sl@0: 		if (resolverEntry.ThisIsOlder(iResolvers[index], curr))
sl@0: 			{
sl@0: 			index = i;
sl@0: 			}
sl@0: 		}
sl@0: 
sl@0: 	Remove(index);
sl@0: 	}
sl@0: 
sl@0: /** Set the iLastUse field and iLruRank field of the entry.
sl@0: The iLruRank field serves as tie breaker when two entries are
sl@0: added within the same tick period.
sl@0: @param aEntry The entry to update.
sl@0: */
sl@0: void CCustomResolverCache::SetLastUseTime(RResolverCacheEntry& aEntry)
sl@0: 	{
sl@0: 	TUint curr = User::TickCount();
sl@0: 	aEntry.iLastUse.iTicks = curr;
sl@0: 	aEntry.iLruRank = 0;
sl@0: 
sl@0: 	if (curr == iMostRecentTimestamp)
sl@0: 		{
sl@0: 		// There are entries with same timestamp. So have to step
sl@0: 		// through each cache entry to resolve senority.
sl@0: 		for (TInt i = 0; i < iResolvers.Count(); i++)
sl@0: 			{
sl@0: 			RResolverCacheEntry& another = iResolvers[i];
sl@0: 			if (another.iLastUse.iTicks == curr &&
sl@0: 				another.iResolverUid != aEntry.iResolverUid &&
sl@0: 				another.iLruRank >= aEntry.iLruRank)
sl@0: 				{
sl@0: 				aEntry.iLruRank = another.iLruRank + 1;
sl@0: 				}
sl@0: 			}
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		iMostRecentTimestamp = curr;
sl@0: 		}
sl@0: 	}
sl@0: