// Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "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:

// HEADER FILES

// 

//

#include "msvcachevisiblefolder.h"

#include "msvcacheindextableentry.h"

#include "msvindexadapter.h"

#include "msventryfreepool.h"

#include "msvinifile.h"

#include "MSVPANIC.H"

/**

 * MACRO DEFINITION

 */

#define BLOCK_SIZE 64

#define PERCENTAGE_VALUE 100

#define DEFAULT_MAXIMUM_CACHE_SIZE 1024

#define DEFAULT_INITIAL_CACHE_SIZE_IN_PERCENTAGE 40

#define DEFAULT_CACHE_INCREMENT_SIZE_IN_PERCENTAGE 20

#define DEFAULT_CACHE_THRESHOLD_IN_PERCENTAGE 70

#define CACHE_THRESHOLD_AFTER_FULL_CACHE 80

#define PERCENTAGE_TO_SWAP_OUT 20

/**

 * LITERAL DEFINITION

 */

//Ini file which contains the cache setting

#ifdef SYMBIAN_MESSAGESTORE_UNIT_TESTCODE

	_LIT(KMSGINI, "C:\\private\\1000484b\\msgcache.ini");

#else

	_LIT(KMSGINI, "Z:\\private\\1000484b\\msgcache.ini");

#endif

//Ini keywords used for cache setting

_LIT(KIniMsvInitialCacheCreation, "MsvInitialCacheCreation");

_LIT(KIniMsvMaximumCacheSize, "MsvMaximumCacheSize");

_LIT(KIniMsvCacheIncrement, "MsvCacheIncrement");

_LIT(KIniMsvCacheThreshold, "MsvCacheThreshold");

_LIT(KIniMsvSearchSortCache, "MsvSearchSortCachePercentage");

/**

 * STATIC MEMBER FUNCTION DEFINITION

 */

CMsvEntryFreePool* CMsvEntryFreePool::iMsvEntryFreePool = NULL;

/**

 * FUNCTION DEFINITION

 */

/**

 * CMsvEntryFreePool()

 *

 * Constructor is kept private, since the class

 * is singleton.

 */

CMsvEntryFreePool::CMsvEntryFreePool(TDblQue<CMsvCacheVisibleFolder>* aEntryCache):iEntryCache(aEntryCache)

	{

	}

/**

 * ~CMsvEntryFreePool()

 *

 * Default Destructor. 

 * The function should delete CMsvCacheEntry

 * created so far. The destructor is made 

 * private so that only friend class can call it.

 */

CMsvEntryFreePool::~CMsvEntryFreePool()

	{

	if(iMsvTmpEntries.Count())

		{

		CommitTransaction();

		}

	if(iUsedCacheEntries.Count())

		{

		iUsedCacheEntries.ResetAndDestroy();

		}

	iUsedCacheEntries.Close();

	if(iMsvEntries)

		{

		iMsvEntries->ResetAndDestroy();	

		iMsvEntries->Close();	

		}

	delete iMsvEntries;

	iMsvEntries = NULL;

	iMsvTmpEntries.Close();

	iMsvEntryFreePool = NULL;

	}

/**

 * Instance()

 *

 * The function returns already created instance of

 * this class to the caller. To create a new instance

 * the caller should call CreateL(). If an instance of

 * this object does not already exists, the function 

 * throws a panic EMsvFreePoolNotCreated in DEBUG mode.

 */ 

CMsvEntryFreePool* CMsvEntryFreePool::Instance()

	{

	__ASSERT_DEBUG(iMsvEntryFreePool!=NULL, PanicServer(EMsvFreePoolNotCreated));

	return iMsvEntryFreePool;

	}

/**

 * CreateL()

 *

 * The only way to create an object of this class.

 * The function ensures that only one instance of

 * the object is created. This is a static interface.

 * The function is made private to ensure that only

 * friend function can create instance of this class.

 */ 

CMsvEntryFreePool* CMsvEntryFreePool::CreateL(TDblQue<CMsvCacheVisibleFolder>* aEntryCache /*DEFAULT=NULL*/)

	{

	CMsvEntryFreePool* self = new (ELeave) CMsvEntryFreePool(aEntryCache);

	//Push object in to cleanup stack so that it 

	// will be handles properly incase of a leave.

	CleanupStack::PushL(self);

	self->ConstructL();

	//Pop from cleanupstack

	CleanupStack::Pop(self);

	iMsvEntryFreePool = self;

	return self;

	}

/**

 * ConstructL()

 *

 * The function is called from InstanceL() and used to

 * initialize the instance of this class. It firsts reads

 * cache configuration information from msgcache.ini file

 * and stores them into member variable. It then allocates

 * creates initial set of entries as described in conf file. 

 */

void CMsvEntryFreePool::ConstructL()

	{

	// 1. Reading ini file

	// If drive information is not mentioned in the 

	// filename, by default the class will check in

	// C: drive. If the file is not found in C: it 

	// will check in Z: drive as well.

	CMsvIniData* iniFile = NULL;

	TRAPD(err, iniFile = CMsvIniData::NewL(KMSGINI));

	// If we find the config file, read it. Else assign default values to cache configurations.

	if(!err && iniFile)

		{

		CleanupStack::PushL(iniFile);

		// Reading maximum cache size from ini file.

		// Initially, iMsvMaximumCacheSize will have cache size in KB which

		// will later be converted to number of cache entries possible.

		User::LeaveIfError(iniFile->FindVar(KIniMsvMaximumCacheSize, iMsvMaximumCacheSize));

		// Reading initial cache size from ini file.

		// This is represented in terms of percentage 

		// of maximum cache size.

		User::LeaveIfError(iniFile->FindVar(KIniMsvInitialCacheCreation, iMsvInitialCacheSize));

		// Reading cache increment value from ini file.

		// This is represented in terms of percentage 

		// of maximum cache size.

		User::LeaveIfError(iniFile->FindVar(KIniMsvCacheIncrement, iMsvCacheIncrement));

		// Reading threshold value from ini file

		// This is represented in terms of percentage

		// of maximum cache size. 

		User::LeaveIfError(iniFile->FindVar(KIniMsvCacheThreshold, iMsvCacheThreshold));

		// Reading Search Sort Cache value in percentage from ini file

		// This is represented in terms of percentage

		// of maximum cache size.

		User::LeaveIfError(iniFile->FindVar(KIniMsvSearchSortCache, iMsvSearchSortCache));

		CleanupStack::PopAndDestroy(iniFile);

		}

	// Performing consistency check.

	if(NULL == iMsvMaximumCacheSize)

		{

		iMsvMaximumCacheSize = DEFAULT_MAXIMUM_CACHE_SIZE;

		}

	if((iMsvInitialCacheSize > PERCENTAGE_VALUE) || (NULL == iMsvInitialCacheSize))

		{

		iMsvInitialCacheSize = DEFAULT_INITIAL_CACHE_SIZE_IN_PERCENTAGE;

		}

	if((iMsvCacheIncrement > PERCENTAGE_VALUE) || (NULL == iMsvCacheIncrement))

		{

		iMsvCacheIncrement = DEFAULT_CACHE_INCREMENT_SIZE_IN_PERCENTAGE;

		}

	if((iMsvCacheThreshold > PERCENTAGE_VALUE) || (NULL == iMsvCacheThreshold))

		{

		iMsvCacheThreshold = DEFAULT_CACHE_THRESHOLD_IN_PERCENTAGE;

		}

	//Determine maximum number of cache entries possible.

	iMsvMaxEntries = ConvertMemToEntry(iMsvMaximumCacheSize * 1024);

	// Approximate number of entries to be created when server starts.

	TInt initialNumberOfEntries = (iMsvInitialCacheSize * iMsvMaxEntries) / 100;

	// Since allocation is done in specific increment size, it is best

	// to give the granularity as the increment count (not percentage here).

	iMsvEntries = new(ELeave) RPointerArray<CMsvCacheEntry>((iMsvCacheIncrement * iMsvMaxEntries) / 100);

	// Create the initial number of cache entries.

	// iMsvCacheNumberOfEntriesCreated will store

	// number of CMsvCacheEntry created so far.

	for (iMsvCacheNumberOfEntriesCreated = 0; iMsvCacheNumberOfEntriesCreated < initialNumberOfEntries ; iMsvCacheNumberOfEntriesCreated++)

		{

		iMsvEntries->AppendL(CMsvCacheEntry::NewL());

		}

	// Percentage of allocated memory utilized so far.

	iMsvPercentageAllocated = iMsvInitialCacheSize;

	}

void CMsvEntryFreePool::SetEssentialParam(TDblQue<CMsvCacheVisibleFolder>* aEntryCache, CMsvIndexAdapter* aAdapterObj)

	{

	iEntryCache = aEntryCache;

	iAdapter = aAdapterObj;

	}

/**

 * ConvertMemToEntry()

 * @param aMem: Memory size in bytes.

 * @return TInt: the number of entries that the free pool can have

 *				 given a memory size in bytes.

 *

 * The function calculates the number of cache entries possible in

 * the free pool given the memory size.

 */

TInt CMsvEntryFreePool::ConvertMemToEntry(TInt aMem)

	{

	//This calculation is based on the fact that not all cache entries will have

	//children as most are leaf nodes. Our assumption is that 20% of the entries

	//will have an RArray, i.e. have children. The following formula determines

	//maximum number of entries that the cache can have as:

	//		sizeof(CMsvCacheEntry) = 120 bytes;

	//		sizeof(RArray<TMsvId>) = 36 bytes;

	//		sizeof(RArray<TMsvId>*) = 4 bytes;

	//	=>	multiplying factor = (80*120 + 20*156)/(120*100) = 1.06

	return ( (aMem) / (1.06*sizeof(CMsvCacheEntry)) );	 

	}

/**

 * Destroy()

 * @param CMsvEntryFreePool: The object to be destroyed.

 *

 * Only way to destroy an object of this class in debug 

 * mode. The functions raises a panic when amount of

 * cache entry created so far is not same as amount of 

 * entry the object currently holds. The function is 

 * declared private so that only friend class can call this.

 *

 * In release mode destructor should be called directly.

 */

#ifdef _DEBUG

void CMsvEntryFreePool::Destroy(CMsvEntryFreePool* aFreePoolInstance)

	{

	if(NULL==aFreePoolInstance)

		return;

	if(aFreePoolInstance->iMsvTmpEntries.Count())

		{

		aFreePoolInstance->CommitTransaction();

		}

	// Check if the number of entries created so far is same

	// as amount of entry currently present with freepool (iMsvEntries).	

	__ASSERT_DEBUG(aFreePoolInstance->iMsvCacheNumberOfEntriesCreated==aFreePoolInstance->iMsvEntries->Count(), User::Invariant());

	delete aFreePoolInstance;

	}

#endif

/**

 * EntryL()

 * @param None.

 * @return CMsvCacheEntry*: An unused CMsvCacheEntry.

 *

 * Returns one unused entry from the freepool. If

 * freepool is empty, it checks if a new entry can 

 * be allocated and returned. If amount of new entry

 * created equals the maximum allowed limit (as set

 * by the licencees in .ini file), the function calls

 * SwapEntries to swap few entries from cache.

 * If no entries can be allocated or swapped, it

 * leaves with KErrNoMemory.

 */

CMsvCacheEntry* CMsvEntryFreePool::EntryL()

	{

	// Number of entries available in freepool.

	TInt count = iMsvEntries->Count();

	CMsvCacheEntry* entry = NULL;

	// Is entry available in freepool?

	if (0 < count)

		{		

		// Just return the last entry.

		entry = (*iMsvEntries)[--count];

		iMsvEntries->Remove(count);

		return entry;

		}

	else

		{

		// Can we still allocate fresh memory?

		if(iMsvMaxEntries > iMsvCacheNumberOfEntriesCreated)

			{

			++iMsvCacheNumberOfEntriesCreated;

			return CMsvCacheEntry::NewL();

			}

		//Otherwise swap out BLOCK_SIZE entries to free up space.

		//Form an entry from this memory and return it.

		else

			{

			SwapEntriesL(BLOCK_SIZE);

			count = iMsvEntries->Count();

			if(count)

				{	

				entry = (*iMsvEntries)[--count];

				iMsvEntries->Remove(count);

				return entry;

				}

			else

				{

				++iMsvCacheNumberOfEntriesCreated;

				return CMsvCacheEntry::NewL();

				}

			}

		}

	}

/**

 * ReleaseEntry()

 * @param CMsvCacheEntry* : Entry to be release to freepool.

 * @return None.

 * 

 * The function resets and appends the passed 

 * entry to freepool so that it can be reused.

 */

void CMsvEntryFreePool::ReleaseEntryL(CMsvCacheEntry* aMsvCacheEntry, TBool aBypassTransaction /* DEFAULT=EFalse*/)

	{

	if( NULL == aMsvCacheEntry )

		{

		return;

		}

	if(isTransactionOpen && (EFalse == aBypassTransaction))

		{

		iMsvTmpEntries.AppendL(aMsvCacheEntry);

		}

	else

		{

		// 1. Reset the entry data.

		aMsvCacheEntry->ResetEntry();

		// 2. Append entry to the freepool.

		iMsvEntries->AppendL(aMsvCacheEntry);

		}

	}

void CMsvEntryFreePool::ReleaseEntryWithoutTransaction(CMsvCacheEntry* aMsvCacheEntry)

    {

    if(NULL == aMsvCacheEntry)

        {

        return;

        }

    aMsvCacheEntry->ResetEntry();

    TRAPD(Err, iMsvEntries->AppendL(aMsvCacheEntry));

    if(Err)

        {

        delete aMsvCacheEntry;

        iMsvCacheNumberOfEntriesCreated--;

        }

    }

/**

 * ReleaseEntrySet()

 * @param RPointerArray<CMsvCacheEntry>* : Entry set to be released.

 * @return None.

 *

 * The function resets and appends the passed set

 * of entries to freepool so that it can be reused.

 */

void CMsvEntryFreePool::ReleaseEntrySet(RPointerArray<CMsvCacheEntry>& aMsvCacheEntryArray)

	{

	TRAPD(error, DoReleaseEntrySetL(aMsvCacheEntryArray));

	if(error)

		{

		// 1. delete the remaining cache entries from aMsvCacheEntryArray

		// 2. reduce appropriate variables in CMsvEntryFreePool

		TInt count = aMsvCacheEntryArray.Count();

		iMsvCacheNumberOfEntriesCreated -= count;

		while(count)

			{

			// 1. Reset the entry data.

			aMsvCacheEntryArray[--count]->ResetEntry();

			// 2. Delete the memory allocated to the cache entry.

			delete aMsvCacheEntryArray[count];

			aMsvCacheEntryArray.Remove(count);

			}		

		}

	}

/**

 * DoReleaseEntrySetL()

 * @param RPointerArray<CMsvCacheEntry>* : Entry set to be released.

 * @return None.

 *

 * The function resets and appends the passed set

 * of entries to freepool so that it can be reused.

 */

void CMsvEntryFreePool::DoReleaseEntrySetL(RPointerArray<CMsvCacheEntry>& aMsvCacheEntryArray)

	{

	TInt count = aMsvCacheEntryArray.Count();

	while ( 0 < count)

		{

		if(isTransactionOpen)

			{

			iMsvTmpEntries.AppendL(aMsvCacheEntryArray[--count]);

			}

		else

			{

			// 1. Reset the entry data.

			aMsvCacheEntryArray[--count]->ResetEntry();

#ifdef SYMBIAN_MESSAGESTORE_UNIT_TESTCODE

			if(iReleaseError)

				{

				if(iReleaseErrorOffset == count)

					{

					iReleaseError = EFalse;

					User::Leave(KErrNoMemory); // an arbitrary error purely for testing purpose

					}

				}

#endif

			// 2. Add entry to the freepool.

			iMsvEntries->AppendL(aMsvCacheEntryArray[count]);

			}

		// 3. Remove entry from the input array.

		aMsvCacheEntryArray.Remove(count);

		}

	}

/**

 * 

 */

void CMsvEntryFreePool::RollbackTransaction()

	{

	TInt count = iMsvTmpEntries.Count();

	while(0 < count)

		{

		if(NULL != iAdapter)

			{

			TRAP_IGNORE(iAdapter->AddEntryNoVisibleL(iMsvTmpEntries[--count]));

			}

		}

	iMsvTmpEntries.Reset();

	isTransactionOpen = EFalse;

	}

/**

 * 

 */

void CMsvEntryFreePool::CommitTransaction()