Better policies for memory management. Auto memory clean when a document is

opened. More stuff for getting async generator to work. Leakfix.

Note: memory management coolness Vol.1 : now kpdf has memory profiles that
allow using up to xx% of the total memory and clip maximum usable memory to
a half of the free one. Example: an istance of kpdf is using all the
memory (as regular cache). You open some memory hungry app or another kpdf
and you'll see the first istance dropping cached pages (freeing memory!)
to leave room for the other app! It's dynamic, fast, avoids swap and
something cool from my programmer's viewpoint.

svn path=/branches/kpdf_experiments/kdegraphics/kpdf/; revision=373123

kpdf/document.cpp

@@ -13,6 +13,7 @@
 #include <qfile.h>
 #include <qfileinfo.h>
 #include <qvaluevector.h>
+#include <qtimer.h>
 #include <qmap.h>
 #include <kdebug.h>
 #include <klocale.h>
@@ -46,6 +47,9 @@ class KPDFDocumentPrivate
         // cached stuff
         int currentPage;
 
+        // memory check/free timer
+        QTimer * memCheckTimer;
+
         // observers related (note: won't delete oservers)
         QMap< int, class ObserverData* > observers;
 };
@@ -70,6 +74,8 @@ KPDFDocument::KPDFDocument()
 {
     d->currentPage = -1;
     d->searchPage = -1;
+    d->memCheckTimer = new QTimer( this );
+    connect( d->memCheckTimer, SIGNAL( timeout() ), this, SLOT( slotCheckMemory() ) );
 }
 
 KPDFDocument::~KPDFDocument()
@@ -112,6 +118,9 @@ bool KPDFDocument::openDocument( const QString & docFile )
     if ( !openOk )
         return false;
 
+    // start memory check timer
+    d->memCheckTimer->start( 1000 );
+
     // check local directory for an overlay xml
     // TODO import overlay layers from XML
 //  QString fileName = docFile.contains('/') ? docFile.section('/', -1, -1) : docFile;
@@ -130,6 +139,9 @@ bool KPDFDocument::openDocument( const QString & docFile )
 
 void KPDFDocument::closeDocument()
 {
+    // stop memory check timer
+    d->memCheckTimer->stop();
+
     // delete pages and clear 'pages_vector' container
     for ( uint i = 0; i < pages_vector.count() ; i++ )
         delete pages_vector[i];
@@ -177,6 +189,7 @@ void KPDFDocument::removeObserver( KPDFDocumentObserver * pObserver )
         QValueVector<KPDFPage*>::iterator it = pages_vector.begin(), end = pages_vector.end();
         for ( ; it != end; ++it )
             (*it)->deletePixmap( observerId );
+
         // delete observer
         delete d->observers[ observerId ];
         d->observers.remove( observerId );
@@ -243,8 +256,8 @@ void KPDFDocument::requestPixmaps( const QValueList< PixmapRequest * > & request
             continue;
 
         // 1. Update statistics (pageMemory / totalMemory) adding this pixmap
-        int pageNumber = request->pageNumber;
         ObserverData * obs = d->observers[ request->id ];
+        int pageNumber = request->pageNumber;
         if ( obs->pageMemory.contains( pageNumber ) )
             obs->totalMemory -= obs->pageMemory[ pageNumber ];
         int pixmapMemory = 4 * request->width * request->height / 1024;
@@ -495,6 +508,7 @@ void KPDFDocument::mCleanupMemory( int observerId  )
     ObserverData * obs = d->observers[ observerId ];
 
     // choose memory parameters based on configuration profile
+    int clipValue = 0;
     int memoryToFree = 0;
     switch ( Settings::memoryLevel() )
     {
@@ -503,14 +517,21 @@ void KPDFDocument::mCleanupMemory( int observerId  )
             break;
 
         case Settings::EnumMemoryLevel::Normal:
-            memoryToFree = obs->totalMemory - mTotalMemory()/4;
+            clipValue = obs->totalMemory - mFreeMemory() / 3;
+            if ( observerId == THUMBNAILS_ID )
+                memoryToFree = obs->totalMemory - mTotalMemory() / 20;
+            else
+                memoryToFree = obs->totalMemory - mTotalMemory() / 5;
             break;
 
         case Settings::EnumMemoryLevel::Aggressive:
-            memoryToFree = 0;
+            clipValue = obs->totalMemory - mFreeMemory() / 2;
             break;
     }
 
+    if ( clipValue > memoryToFree )
+        memoryToFree = clipValue;
+
     // free memory. remove older data until we free enough memory
     int freed = 0;
     if ( memoryToFree > 0 )
@@ -532,7 +553,7 @@ void KPDFDocument::mCleanupMemory( int observerId  )
             ++it;
         }
     }
-    kdWarning() << "[" << obs->totalMemory << "kB] Removed " << freed << " pages. " << obs->pageMemory.count() << " pages kept in memory." << endl;
+    kdDebug() << "Id:" << observerId << " [" << obs->totalMemory << "kB] Removed " << freed << " pages. " << obs->pageMemory.count() << " pages kept in memory." << endl;
 }
 
 int KPDFDocument::mTotalMemory()
@@ -563,10 +584,10 @@ int KPDFDocument::mTotalMemory()
 int KPDFDocument::mFreeMemory()
 {
 #ifdef __linux__
-    // if /proc/meminfo doesn't exist, return 128MB
+    // if /proc/meminfo doesn't exist, return MEMORY FULL
     QFile memFile( "/proc/meminfo" );
     if ( !memFile.open( IO_ReadOnly ) )
-        return 131072;
+        return 0;
 
     // read /proc/meminfo and sum up the contents of 'MemFree', 'Buffers'
     // and 'Cached' fields. consider swapped memory as used memory.
@@ -587,7 +608,8 @@ int KPDFDocument::mFreeMemory()
     memFile.close();
     return memoryFree;
 #else
-    return 131072;
+    // tell the memory is full.. will act as in LOW profile
+    return 0;
 #endif
 }
 
@@ -656,8 +678,23 @@ void KPDFDocument::unHilightPages()
     }
 }
 
+
+void KPDFDocument::slotCheckMemory()
+{
+    // perform the memory check for 'free mem dependant' profiles only
+    if ( Settings::memoryLevel() == Settings::EnumMemoryLevel::Low )
+        return;
+
+    // for each observer going over 1MB of memory, invoke the manager
+    QMap< int, ObserverData * >::iterator it = d->observers.begin(), end = d->observers.end();
+    for ( ; it != end ; ++ it )
+        if ( (*it)->totalMemory > 1024 )
+            mCleanupMemory( it.key() /*observerId*/ );
+}
+
 void KPDFDocument::slotGeneratedContents( int id, int pageNumber )
 {
+    // notify an observer that its pixmap changed
     if ( d->observers.contains( id ) )
         d->observers[ id ]->observer->notifyPixmapChanged( pageNumber );
 }

kpdf/document.h

@@ -121,6 +121,7 @@ class KPDFDocument : public QObject // only for a private slot..
         class KPDFDocumentPrivate * d;
 
     private slots:
+        void slotCheckMemory();
         void slotGeneratedContents( int id, int pageNumber );
 };
 

kpdf/generator_pdf.cpp

@@ -36,7 +36,7 @@
 
 
 PDFGenerator::PDFGenerator()
-    : pdfdoc( 0 ), kpdfOutputDev( 0 ),
+    : pdfdoc( 0 ), kpdfOutputDev( 0 ), requestOnThread( 0 ),
     docInfoDirty( true ), docSynopsisDirty( true )
 {
     // generate kpdfOutputDev and cache page color
@@ -45,7 +45,14 @@ PDFGenerator::PDFGenerator()
 
 PDFGenerator::~PDFGenerator()
 {
+    // TODO wait for the end of threaded generator too and disable it
     docLock.lock();
+    // remove requests in queue
+    QValueList< PixmapRequest * >::iterator rIt = requestsQueue.begin(), rEnd = requestsQueue.end();
+    for ( ; rIt != rEnd; rIt++ )
+        delete *rIt;
+    requestsQueue.clear();
+    // remove other internal objects
     delete kpdfOutputDev;
     delete pdfdoc;
     docLock.unlock();
@@ -293,10 +300,14 @@ void PDFGenerator::requestPixmap( PixmapRequest * request, bool syncronous )
 
         // pixmap generated
         contentsChanged( request->id, request->pageNumber );
+
+        // free memory (since we took ownership of the request)
+        delete request;
     }
     else
     {
-        // TODO add the pixmaprequest in a queue ...
+        requestsQueue.push_back( request );
+        //startThreadedGeneration();
     }
 }
 

kpdf/generator_pdf.h

@@ -73,8 +73,8 @@ class PDFGenerator : public Generator
         PDFDoc * pdfdoc;
         KPDFOutputDev * kpdfOutputDev;
         QColor paperColor;
-        //PixmapRequest * currentRequest;
-        //QValueList< PixmapRequest * > requests;
+        PixmapRequest * requestOnThread;
+        QValueList< PixmapRequest * > requestsQueue;
         bool docInfoDirty;
         DocumentInfo docInfo;
         bool docSynopsisDirty;