Improve use of QHash to minimize double hashing

Avoid looking up by key twice in a row in various locations, but instead
using iterators and index lookup.

Change-Id: I61a079115199ab9c041ad3a26d36b45ee3f775e0
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/src/gui/image/qpixmapcache.cpp b/src/gui/image/qpixmapcache.cpp
index 6d03332367..73448943e1 100644
--- a/src/gui/image/qpixmapcache.cpp
+++ b/src/gui/image/qpixmapcache.cpp
@@ -324,26 +324,23 @@ QPixmap *QPMCache::object(const QPixmapCache::Key &key) const
 
 bool QPMCache::insert(const QString& key, const QPixmap &pixmap, int cost)
 {
-    QPixmapCache::Key cacheKey;
-    QPixmapCache::Key oldCacheKey = cacheKeys.value(key);
+    QPixmapCache::Key &cacheKey = cacheKeys[key];
     //If for the same key we add already a pixmap we should delete it
-    if (oldCacheKey.d) {
-        QCache<QPixmapCache::Key, QPixmapCacheEntry>::remove(oldCacheKey);
-        cacheKeys.remove(key);
-    }
+    if (cacheKey.d)
+        QCache<QPixmapCache::Key, QPixmapCacheEntry>::remove(cacheKey);
 
     //we create a new key the old one has been removed
     cacheKey = createKey();
 
     bool success = QCache<QPixmapCache::Key, QPixmapCacheEntry>::insert(cacheKey, new QPixmapCacheEntry(cacheKey, pixmap), cost);
     if (success) {
-        cacheKeys.insert(key, cacheKey);
         if (!theid) {
             theid = startTimer(flush_time);
             t = false;
         }
     } else {
         //Insertion failed we released the new allocated key
+        cacheKeys.remove(key);
         releaseKey(cacheKey);
     }
     return success;
@@ -389,12 +386,12 @@ bool QPMCache::replace(const QPixmapCache::Key &key, const QPixmap &pixmap, int
 
 bool QPMCache::remove(const QString &key)
 {
-    QPixmapCache::Key cacheKey = cacheKeys.value(key);
+    auto cacheKey = cacheKeys.constFind(key);
     //The key was not in the cache
-    if (!cacheKey.d)
+    if (cacheKey == cacheKeys.constEnd())
         return false;
-    cacheKeys.remove(key);
-    return QCache<QPixmapCache::Key, QPixmapCacheEntry>::remove(cacheKey);
+    cacheKeys.erase(cacheKey);
+    return QCache<QPixmapCache::Key, QPixmapCacheEntry>::remove(cacheKey.value());
 }
 
 bool QPMCache::remove(const QPixmapCache::Key &key)