[KPhotoAlbum] Bug in image cache size computation

[Robert Krawitz]

The number of items in the image cache is computed incorrectly if the
image cache size is 2048 MB or greater; it's effectively zero due to
signedness problems.  Performance is much better with this fix.

Also, why the hard upper limit of 4096 MB?  I have 16 GB of RAM in my
laptop, and might as well take advantage of it.

diff --git a/Viewer/ImageDisplay.cpp b/Viewer/ImageDisplay.cpp
index 1775efb..77be9a9 100644
--- a/Viewer/ImageDisplay.cpp
+++ b/Viewer/ImageDisplay.cpp
@@ -567,7 +567,7 @@ void Viewer::ImageDisplay::setImageList( const DB::FileNameList& list )
 
 void Viewer::ImageDisplay::updatePreload()
 {
-    const int cacheSize = ( Settings::SettingsData::instance()->viewerCacheSize() * 1024 * 1024 ) / (width()*height()*4);
+    const int cacheSize = (int) ((long long) ( Settings::SettingsData::instance()->viewerCacheSize() * 1024ll * 1024ll ) / (width()*height()*4));
     bool cacheFull = (m_cache.count() > cacheSize);
 
     int incr = ( m_forward ? 1 : -1 );


-- 
Robert Krawitz                                     <rlk at alum.mit.edu>

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