Fix LoadCacheImage logic so that when checking for an image in the me…

…mory cache we only perform the last modified checks if it's actually found. This prevents us checking twice for every single image.

Also fix a bug where we loaded an image from the disk cache when we were only supposed to be checking whether it was in the memory cache.

mythtv/libs/libmythui/mythuihelper.cpp

@@ -1508,16 +1508,25 @@ MythImage *MythUIHelper::LoadCacheImage(QString srcfile, QString label,
         }
     }
 
-    QString cachefilepath = GetThemeCacheDir() + '/' + label;
-    QFileInfo fi(cachefilepath);
-
     MythImage *ret = NULL;
 
-    if (!!(cacheMode & kCacheIgnoreDisk) || fi.exists())
+    // Check Memory Cache
+    ret = GetImageFromCache(label);
+
+    // If the image is in the memory or we are not ignoring the disk cache
+    // then proceed to check whether the source file is newer than our cached
+    // copy
+    if (ret || !(cacheMode & kCacheIgnoreDisk))
     {
+        // Create url to image in disk cache
+        QString cachefilepath = GetThemeCacheDir() + '/' + label;
+        QFileInfo cacheFileInfo(cachefilepath);
+
         // Now compare the time on the source versus our cached copy
         QDateTime srcLastModified;
 
+        // For internet images this involves querying the headers of the remote
+        // image. This is slow even without redownloading the whole image
         if ((srcfile.startsWith("http://")) ||
             (srcfile.startsWith("https://")) ||
             (srcfile.startsWith("ftp://")))
@@ -1529,30 +1538,37 @@ MythImage *MythUIHelper::LoadCacheImage(QString srcfile, QString label,
             srcLastModified = RemoteFile::LastModified(srcfile);
         else
         {
-            if (!(cacheMode & kCacheIgnoreDisk))
-            {
-                if (!FindThemeFile(srcfile))
-                    return NULL;
-            }
+            if (!FindThemeFile(srcfile))
+                return NULL;
 
             QFileInfo original(srcfile);
 
             if (original.exists())
                 srcLastModified = original.lastModified();
         }
 
-        if (!!(cacheMode & kCacheIgnoreDisk) ||
-            (fi.lastModified() >= srcLastModified))
+        // Now compare the timestamps, if the cached image is newer than the
+        // source image we can use it, otherwise we want to remove it from the
+        // cache
+        if (cacheFileInfo.lastModified() >= srcLastModified)
         {
-            // Check Memory Cache
-            ret = GetImageFromCache(label);
-
-            if (!ret && (cacheMode == kCacheNormal) && painter)
+            // If we haven't already loaded the image from the memory cache
+            // and we're not ignoring the disk cache, then it's time to load
+            // it from there instead
+            if (!ret && (cacheMode == kCacheNormal))
             {
-                // Load file from disk cache to memory cache
-                ret = painter->GetFormatImage();
 
-                if (!ret->Load(cachefilepath, false))
+                if (painter)
+                    ret = painter->GetFormatImage();
+
+                // Load file from disk cache to memory cache
+                if (ret && ret->Load(cachefilepath, false))
+                {
+                    // Add to ram cache, and skip saving to disk since that is
+                    // where we found this in the first place.
+                    CacheImage(label, ret, true);
+                }
+                else
                 {
                     LOG(VB_GUI | VB_FILE, LOG_WARNING, LOC +
                         QString("LoadCacheImage: Could not load :%1")
@@ -1562,16 +1578,11 @@ MythImage *MythUIHelper::LoadCacheImage(QString srcfile, QString label,
                     ret->DecrRef();
                     ret = NULL;
                 }
-                else
-                {
-                    // Add to ram cache, and skip saving to disk since that is
-                    // where we found this in the first place.
-                    CacheImage(label, ret, true);
-                }
             }
         }
         else
         {
+            ret = NULL;
             // If file has changed on disk, then remove it from the memory
             // and disk cache
             RemoveFromCacheByURL(label);

mythtv/libs/libmythui/mythuiimage.cpp

@@ -981,7 +981,7 @@ bool MythUIImage::Load(bool allowLoadInBackground, bool forceStat)
 
         // Only load in the background if allowed and the image is
         // not already in our mem cache
-        int cacheMode = kCacheCheckMemoryOnly;
+        int cacheMode = kCacheIgnoreDisk;
 
         if (forceStat)
             cacheMode |= (int)kCacheForceStat;