photosgallery/viewframework/medialists/src/glxgarbagecollector.cpp
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     1 /*
       
     2 * Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies). 
       
     3 * All rights reserved.
       
     4 * This component and the accompanying materials are made available
       
     5 * under the terms of "Eclipse Public License v1.0"
       
     6 * which accompanies this distribution, and is available
       
     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".
       
     8 *
       
     9 * Initial Contributors:
       
    10 * Nokia Corporation - initial contribution.
       
    11 *
       
    12 * Contributors:
       
    13 *
       
    14 * Description:    Garbage collector
       
    15 *
       
    16 */
       
    17 
       
    18 
       
    19 
       
    20 
       
    21 #include "glxgarbagecollector.h"
       
    22 
       
    23 #include <glxassert.h>
       
    24 #include <glxtracer.h>
       
    25 #include <glxlog.h>
       
    26 
       
    27 #include "glxcache.h"
       
    28 #include "glxerrormanager.h"
       
    29 #include "glxmedia.h"
       
    30 #include "glxmedialist.h"
       
    31 #include "mglxmediauser.h"
       
    32 #include "glxthumbnailutility.h"
       
    33 
       
    34 /**
       
    35  * Interval for the periodic timer, in microseconds
       
    36  */
       
    37 const TInt KPeriodicInterval = 500000;
       
    38 /**
       
    39  * Start Delay for the periodic timer, in microseconds
       
    40  */
       
    41 const TInt KPeriodicStartDelay = 300000;   // It is Changed to 300Micro Second ; To be able to give Others a Chance to Run before it starts
       
    42 /** 
       
    43  * Max number of items to scan per periodic callback
       
    44  * @todo Find optimal value for this
       
    45  */
       
    46 const TInt KMaxScannedMediaCountPerPeriodicCallback = 15;  // Changed from 30; Still there is Scope for Nominal Value Or Dynamic Value
       
    47 
       
    48 /**
       
    49  * Max number of attributes that an item may have in use
       
    50  */
       
    51 const TInt KMaxAttributesInUse = 50;
       
    52 
       
    53 // -----------------------------------------------------------------------------
       
    54 // NewL
       
    55 // -----------------------------------------------------------------------------
       
    56 //
       
    57 CGlxGarbageCollector* CGlxGarbageCollector::NewL( 
       
    58         const RPointerArray<CGlxCache>& aCaches )
       
    59     {
       
    60     TRACER( "CGlxGarbageCollector::NewL" );
       
    61 
       
    62     CGlxGarbageCollector* self = new( ELeave ) CGlxGarbageCollector( aCaches );
       
    63     CleanupStack::PushL( self );
       
    64     self->ConstructL();
       
    65     CleanupStack::Pop(self);
       
    66     return self;
       
    67     }
       
    68 
       
    69 // -----------------------------------------------------------------------------
       
    70 // Constructor
       
    71 // -----------------------------------------------------------------------------
       
    72 //
       
    73 CGlxGarbageCollector::CGlxGarbageCollector( 
       
    74     const RPointerArray<CGlxCache>& aCaches )
       
    75         : iCaches( aCaches )
       
    76     {
       
    77     TRACER("CGlxGarbageCollector::Default Constructor");
       
    78     }
       
    79     
       
    80 // -----------------------------------------------------------------------------
       
    81 // ConstructL
       
    82 // -----------------------------------------------------------------------------
       
    83 //
       
    84 void CGlxGarbageCollector::ConstructL()
       
    85     {
       
    86     TRACER("CGlxGarbageCollector::ConstructL");
       
    87     
       
    88     // Create callback loop in the lowest priority, so that the garbage
       
    89     // collection does not slow down the application
       
    90     iPeriodic = CPeriodic::NewL( CActive::EPriorityIdle );
       
    91     iAttributesInUse.ReserveL(KMaxAttributesInUse);
       
    92     }
       
    93                 
       
    94 // -----------------------------------------------------------------------------
       
    95 // Destructor
       
    96 // -----------------------------------------------------------------------------
       
    97 //
       
    98 CGlxGarbageCollector::~CGlxGarbageCollector()
       
    99     {
       
   100     TRACER("CGlxGarbageCollector::Destructor");
       
   101     delete iPeriodic;
       
   102     iAttributesInUse.Close();
       
   103     }
       
   104 
       
   105 // -----------------------------------------------------------------------------
       
   106 // CleanupL
       
   107 // -----------------------------------------------------------------------------
       
   108 //
       
   109 void CGlxGarbageCollector::CleanupL()
       
   110     {
       
   111     TRACER("CGlxGarbageCollector::CleanupL");
       
   112     
       
   113     if ( !iPeriodic->IsActive() )
       
   114         {
       
   115         iPeriodic->Start( KPeriodicStartDelay, KPeriodicInterval, TCallBack( &PeriodicCallbackL, static_cast<TAny*>( this ) ) );
       
   116         }
       
   117     else
       
   118         {
       
   119         // a full cleanup round is required to make the cache fully clean,
       
   120         // if cleanup is currently ongoing. we don't know whether the cache
       
   121         // was modified before or after the current (cache or media) index being
       
   122         // cleaned up.
       
   123         iRequiresFullCleanupRound = ETrue;
       
   124         }
       
   125     }
       
   126 
       
   127 // -----------------------------------------------------------------------------
       
   128 // CancelCleanup
       
   129 // -----------------------------------------------------------------------------
       
   130 //
       
   131 void CGlxGarbageCollector::CancelCleanup()
       
   132     {
       
   133     TRACER("CGlxGarbageCollector::CancelCleanup");
       
   134     
       
   135     if (iPeriodic->IsActive())
       
   136         {
       
   137         iPeriodic->Cancel();
       
   138         // Consideration of Restarting the timer is there; 
       
   139         }
       
   140     }
       
   141 
       
   142 // -----------------------------------------------------------------------------
       
   143 // Callback from periodic timer
       
   144 // -----------------------------------------------------------------------------
       
   145 //
       
   146 TInt CGlxGarbageCollector::PeriodicCallbackL( TAny* aPtr )
       
   147     {
       
   148     TRACER("CGlxGarbageCollector::PeriodicCallback");
       
   149     
       
   150     GLX_ASSERT_DEBUG( aPtr != NULL, Panic( EGlxPanicLogicError ), 
       
   151         "Received null pointer for garbage collector" );
       
   152         
       
   153     // get "this" pointer
       
   154     static_cast< CGlxGarbageCollector* >( aPtr )->PeriodicCallbackL();
       
   155 
       
   156     // return value ignored for periodic timers
       
   157     return 0;
       
   158     }
       
   159 
       
   160 // -----------------------------------------------------------------------------
       
   161 // Flush Count Pages
       
   162 // -----------------------------------------------------------------------------
       
   163 //
       
   164 void CGlxGarbageCollector::FlushPagesL(TInt aCount)
       
   165     {
       
   166     TBool reachedEnd = CleanupCaches(aCount);
       
   167     
       
   168     if ( reachedEnd )
       
   169         {
       
   170         // reset to the start of the caches
       
   171         iScanningPosition.iCurrentCacheIndex = 0;
       
   172         iScanningPosition.iNextMediaIndexToCleanup = 0;
       
   173         
       
   174         // next time the full round reaches end, the caches will be fully clean
       
   175         // (unless client calls Cleanup() )
       
   176         iRequiresFullCleanupRound = EFalse;
       
   177         }
       
   178     }
       
   179 // -----------------------------------------------------------------------------
       
   180 // Callback from periodic timer
       
   181 // inlined in cpp only => inlines for arm
       
   182 // -----------------------------------------------------------------------------
       
   183 //
       
   184 inline void CGlxGarbageCollector::PeriodicCallbackL()
       
   185     {
       
   186     TRACER("CGlxGarbageCollector::PeriodicCallbackL");
       
   187     
       
   188     TBool reachedEnd = CleanupCaches();
       
   189     
       
   190     // determine whether idle callback should be cancelled (note that check 
       
   191     // needs to be done before resetting iRequiresFullCleanupRound below)
       
   192     // do not cancel if reached the end, but cache is dirty
       
   193     if ( reachedEnd && !iRequiresFullCleanupRound )
       
   194         {
       
   195         iPeriodic->Cancel();
       
   196         }
       
   197 
       
   198     // if scanned to the end of caches, set up for the next cleanup round
       
   199     if ( reachedEnd )
       
   200         {
       
   201         // reset to the start of the caches
       
   202         iScanningPosition.iCurrentCacheIndex = 0;
       
   203         iScanningPosition.iNextMediaIndexToCleanup = 0;
       
   204         
       
   205         // next time the full round reaches end, the caches will be fully clean
       
   206         // (unless client calls Cleanup() )
       
   207         iRequiresFullCleanupRound = EFalse;
       
   208         }
       
   209     }
       
   210 
       
   211 // -----------------------------------------------------------------------------
       
   212 // Clean up all caches
       
   213 // -----------------------------------------------------------------------------
       
   214 //
       
   215 TBool CGlxGarbageCollector::CleanupCaches(TInt aCount)
       
   216     {
       
   217     TRACER( "CGlxGarbageCollector::CleanupCaches" );
       
   218 
       
   219     TInt remainingScanCount = 0;
       
   220 
       
   221     // set the maximum number of items to scan during this call
       
   222     // Count is Needed for Flushing Direct
       
   223     remainingScanCount = aCount*KMaxScannedMediaCountPerPeriodicCallback;
       
   224     
       
   225     // Iterate through all cache until scanned enough items (remainingScanCount)
       
   226     // (unlikely to have many caches, so ok to call RPointerArray::Count() on 
       
   227     // each iteration)
       
   228     while ( iScanningPosition.iCurrentCacheIndex < iCaches.Count() )
       
   229         {
       
   230         // clean up current cache
       
   231         remainingScanCount = CleanupCache( 
       
   232             *iCaches[iScanningPosition.iCurrentCacheIndex], remainingScanCount );
       
   233             
       
   234         // exit the loop if reached full scan count, since the above loop might
       
   235         // have reached the end of the cache. (so don't increment the current
       
   236         // cache index)
       
   237         if ( 0 == remainingScanCount )
       
   238             {
       
   239             break;
       
   240             }
       
   241         
       
   242         // set indexes to the beginning of the next cache
       
   243         iScanningPosition.iCurrentCacheIndex++;
       
   244         iScanningPosition.iNextMediaIndexToCleanup = 0; 
       
   245         }
       
   246     
       
   247     // determine if there is anything more to clean up
       
   248     TBool reachedEndOfAllCaches = 
       
   249         ( iScanningPosition.iCurrentCacheIndex == iCaches.Count() );
       
   250     return reachedEndOfAllCaches;
       
   251     }
       
   252 
       
   253 // -----------------------------------------------------------------------------
       
   254 // Clean up cache that is currently under cleanup
       
   255 // return number of items yet to scan during this idle callback
       
   256 // -----------------------------------------------------------------------------
       
   257 //
       
   258 TInt CGlxGarbageCollector::CleanupCache( CGlxCache& aCache,     
       
   259         TInt aRemainingScanCount )
       
   260     {
       
   261     TRACER( "CGlxGarbageCollector::CleanupCache" );
       
   262 
       
   263     // set the maximum number of items to scan during this call
       
   264     TInt remainingScanCount = aRemainingScanCount;
       
   265     
       
   266     // don't store cache.Count() locally, as the count changes during the loop
       
   267     while ( iScanningPosition.iNextMediaIndexToCleanup < aCache.Count() &&
       
   268             remainingScanCount > 0 && ( aCache.IdSpaceId() != KGlxIdSpaceIdRoot ) )
       
   269         {
       
   270         CGlxMedia& media = aCache.Media( iScanningPosition.iNextMediaIndexToCleanup );
       
   271         
       
   272         if ( media.UserCount() > 0 )
       
   273             {
       
   274             // the media object still has users. Check if any attributes
       
   275             // it has can be deleted.
       
   276             TRAPD( err, CleanupMediaL( aCache, media ) );
       
   277             
       
   278             // skip the media object if cleanup failed. This allows cleanup to 
       
   279             // continue also when has no free memory. Skip also if there
       
   280             // are still attributes in use.
       
   281             if ( ( media.Count() == 0 && !err ) || ( err > 0 ) )
       
   282                 {
       
   283                 // the media object has no more attributes. It can be deleted.
       
   284                 // don't increment iNextMediaIndexToCleanup since the index
       
   285                 // of the next item will be decreased by one due to removal
       
   286                 aCache.Delete( iScanningPosition.iNextMediaIndexToCleanup );
       
   287                 GLX_LOG_INFO1( "CGlxGarbageCollector - Deleted Media Id=%d since no attributes left", media.Id().Value());
       
   288                 }
       
   289             else if( err < 0 )
       
   290                 {
       
   291                 // scan next item
       
   292                 iScanningPosition.iNextMediaIndexToCleanup++;                
       
   293                 }
       
   294             else 
       
   295                 {
       
   296                 // scan next item
       
   297                 iScanningPosition.iNextMediaIndexToCleanup++;                
       
   298                 }
       
   299             }
       
   300         else
       
   301             {
       
   302             // the media object has no more users in present cache. It may be deleted
       
   303             if( !MediaInUse( media ) )
       
   304 	            {
       
   305 	            // Bug Fix @ EDDG-7V3CJA:: Recheck other caches for UserCount 
       
   306 	            aCache.Delete( iScanningPosition.iNextMediaIndexToCleanup );
       
   307 	            GLX_LOG_INFO1( "CGlxGarbageCollector - Deleted Media Id=%d since no users left", media.Id().Value());
       
   308 	            }            
       
   309             }            
       
   310         remainingScanCount--;
       
   311         }
       
   312 
       
   313     return remainingScanCount;
       
   314     }
       
   315     
       
   316 // -----------------------------------------------------------------------------
       
   317 // Perform cleanup on provided media object
       
   318 // -----------------------------------------------------------------------------
       
   319 //
       
   320 void CGlxGarbageCollector::CleanupMediaL( CGlxCache& aCache, CGlxMedia& aMedia )
       
   321     {
       
   322     TRACER("CGlxGarbageCollector::CleanupMediaL");
       
   323     
       
   324     // check which attributes can be deleted.
       
   325     iAttributesInUse.Reset();
       
   326 
       
   327     GetAttributesInUseL( aMedia, iAttributesInUse );
       
   328     if ( iAttributesInUse.Count() == 0 )
       
   329         {
       
   330         User::Leave(1);
       
   331         }
       
   332     GlxErrorManager::ClearExpiredAndUnusedErrorsL( aMedia, iAttributesInUse );
       
   333     
       
   334     // add the error attribute to the list of attributes that are in use, so
       
   335     // that it won't be deleted by the loop below.
       
   336     // (if there are no errors left, GlxErrorManager::ClearExpiredAndNotInUseErrorsL 
       
   337     // would have deleted the error attribute from aMedia, so checking for it
       
   338     // does no harm)
       
   339     iAttributesInUse.AppendL( GlxErrorManager::ErrorAttribute() );
       
   340     
       
   341     // delete all attributes that are not being used
       
   342     DeleteOtherAttributes( aCache, aMedia, iAttributesInUse );
       
   343     }
       
   344 
       
   345 // -----------------------------------------------------------------------------
       
   346 // GetAttributesInUseL
       
   347 // -----------------------------------------------------------------------------
       
   348 //
       
   349 void CGlxGarbageCollector::GetAttributesInUseL( const CGlxMedia& aMedia, 
       
   350         RArray<TMPXAttribute>& aAttributes ) const
       
   351     {
       
   352     TRACER("CGlxGarbageCollector::GetAttributesInUseL");
       
   353     
       
   354     // get needed attributes from each user of the media object
       
   355     // ( unlikely to have many users, so calling CGlxMedia::UserCount and 
       
   356     // CGlxMedia::Id within the loop )
       
   357     for ( TInt userIndex = 0; userIndex < aMedia.UserCount(); userIndex++ )
       
   358         {
       
   359         aMedia.User( userIndex ).GetRequiredAttributesL( aMedia.IndexInUser( userIndex ), 
       
   360             aAttributes );
       
   361         }
       
   362     }
       
   363 
       
   364 // -----------------------------------------------------------------------------
       
   365 // Delete all attributes from a media object except those specified
       
   366 // -----------------------------------------------------------------------------
       
   367 //
       
   368 void CGlxGarbageCollector::DeleteOtherAttributes( CGlxCache& aCache, CGlxMedia& aMedia, 
       
   369         const RArray<TMPXAttribute>& aAttributesToKeep ) const
       
   370     {
       
   371     TRACER("CGlxGarbageCollector::DeleteOtherAttributes");
       
   372     
       
   373     // loop backwards so can delete attributes during the loop
       
   374     for ( TInt attrIndex = aMedia.Count() - 1; attrIndex >= 0; attrIndex-- )
       
   375         {
       
   376         // delete the attribute if it is not in use
       
   377         const TMPXAttribute& attrib = aMedia.Attribute(attrIndex);
       
   378         if ( KErrNotFound == aAttributesToKeep.Find( attrib, TMPXAttribute::Match ) )
       
   379             {
       
   380             GLX_LOG_INFO( "CGlxGarbageCollector::DeleteOtherAttributes() - Deleted attribute" );
       
   381             aMedia.DeleteAttribute( attrIndex );
       
   382             if (GlxThumbnailUtility::IsFullThumbnail(attrib))
       
   383                 {
       
   384                 GLX_DEBUG2("CGlxGarbageCollector::DeleteOtherAttributes(*** TN ***) aMediaId(%d)",
       
   385                         aMedia.Id().Value());
       
   386                 aCache.CleanupMedia(aMedia.Id());
       
   387                 }
       
   388             }
       
   389         }
       
   390     }
       
   391     
       
   392 // -----------------------------------------------------------------------------
       
   393 // Check for User Count for media to be deleted in the remaining caches
       
   394 // -----------------------------------------------------------------------------
       
   395 //    
       
   396 TBool CGlxGarbageCollector::MediaInUse(const CGlxMedia&  aMedia) const
       
   397 	{
       
   398 	// Bug Fix @ EDDG-7V3CJA :: If media has non zero user count in any of the caches
       
   399 	// then deletion of texture is to be avoided.	
       
   400 	for(TInt cacheCount = 0; cacheCount < iCaches.Count(); cacheCount++ )
       
   401 		{		
       
   402 		if ( ( iCaches[cacheCount]->Media( aMedia.Id() ) ) 
       
   403 				&& ( iCaches[cacheCount]->IdSpaceId() != KGlxIdSpaceIdRoot ) )
       
   404 			{
       
   405 			if ( ( iCaches[cacheCount]->Media(aMedia.Id() ) )->UserCount() > 0 )
       
   406 				{
       
   407 				return ETrue;		
       
   408 				}
       
   409 			}
       
   410 		}
       
   411 	return EFalse;	
       
   412     }