Fix for Unitary cache strategy support

This patch fixes the population phase of the cache to support
unitary strategy.
It also prevents a possible divide-by-zero error.

Change-Id: I4ab18041f8e908bd60eb581663fe34fbb01c4991
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

2 files changed, 25 insertions, 15 deletions

diff --git a/src/location/maps/qcache3q_p.h b/src/location/maps/qcache3q_p.h
index cd21961a..148c1f8b 100644
--- a/src/location/maps/qcache3q_p.h
+++ b/src/location/maps/qcache3q_p.h
@@ -145,7 +145,7 @@ private:
     QHash<Key, Node *> lookup_;
 
 public:
-    explicit QCache3Q(int maxCost = 100, int minRecent = -1, int maxOldPopular = -1);
+    explicit QCache3Q(int maxCost = 0, int minRecent = -1, int maxOldPopular = -1);
     inline ~QCache3Q() { clear(); delete q1_; delete q2_; delete q3_; delete q1_evicted_; }
 
     inline int maxCost() const { return maxCost_; }
@@ -398,7 +398,7 @@ void QCache3Q<Key,T,EvPolicy>::rebalance()
         } else {
             Node *n = q2_->l;
             unlink(n);
-            if (n->pop > (q2_->pop / q2_->size)) {
+            if (q2_->size && n->pop > (q2_->pop / q2_->size)) {
                 link_front(n, q3_);
             } else {
                 EvPolicy::aboutToBeEvicted(n->k, n->v);
diff --git a/src/location/maps/qgeofiletilecache.cpp b/src/location/maps/qgeofiletilecache.cpp
index 911e9865..49e9dfff 100644
--- a/src/location/maps/qgeofiletilecache.cpp
+++ b/src/location/maps/qgeofiletilecache.cpp
@@ -120,20 +120,26 @@ void QGeoFileTileCache::init()
     QDir::root().mkpath(directory_);
 
     // default values
-    if (costStrategyDisk_ == ByteSize)
-        setMaxDiskUsage(50 * 1024 * 1024);
-    else
-        setMaxDiskUsage(1000);
+    if (!diskCache_.maxCost()) { // If setMaxDiskUsage has not been called yet
+        if (costStrategyDisk_ == ByteSize)
+            setMaxDiskUsage(50 * 1024 * 1024);
+        else
+            setMaxDiskUsage(1000);
+    }
 
-    if (costStrategyMemory_ == ByteSize)
-        setMaxMemoryUsage(3 * 1024 * 1024);
-    else
-        setMaxMemoryUsage(100);
+    if (!memoryCache_.maxCost()) { // If setMaxMemoryUsage has not been called yet
+        if (costStrategyMemory_ == ByteSize)
+            setMaxMemoryUsage(3 * 1024 * 1024);
+        else
+            setMaxMemoryUsage(100);
+    }
 
-    if (costStrategyTexture_ == ByteSize)
-        setExtraTextureUsage(6 * 1024 * 1024);
-    else
-        setExtraTextureUsage(30); // byte size of texture is >> compressed image, hence unitary cost should be lower
+    if (!textureCache_.maxCost()) { // If setExtraTextureUsage has not been called yet
+        if (costStrategyTexture_ == ByteSize)
+            setExtraTextureUsage(6 * 1024 * 1024);
+        else
+            setExtraTextureUsage(30); // byte size of texture is >> compressed image, hence unitary cost should be lower
+    }
 
     loadTiles();
 }
@@ -172,7 +178,11 @@ void QGeoFileTileCache::loadTiles()
                 QFileInfo fi(tileDisk->filename);
                 specs.append(spec);
                 queue.append(tileDisk);
-                costs.append(fi.size());
+                if (costStrategyDisk_ == ByteSize)
+                    costs.append(fi.size());
+                else
+                    costs.append(1);
+
             }
         }