QML: Convert the PropertyDependencyMap to a QVarLengthArray.

This is much more efficient than a QHash.

Change-Id: I84752eecb6a456402ae222c4d6543bbb67cbcf63
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

2 files changed, 28 insertions, 5 deletions

diff --git a/src/qml/compiler/qv4compiler.cpp b/src/qml/compiler/qv4compiler.cpp
index 5de29d38fd..3943642146 100644
--- a/src/qml/compiler/qv4compiler.cpp
+++ b/src/qml/compiler/qv4compiler.cpp
@@ -385,15 +385,13 @@ int QV4::Compiler::JSUnitGenerator::writeFunction(char *f, int index, QV4::IR::F
         *writtenDeps++ = id;
 
     writtenDeps = (quint32 *)(f + function->dependingContextPropertiesOffset);
-    for (QV4::IR::PropertyDependencyMap::ConstIterator property = irFunction->contextObjectPropertyDependencies.constBegin(), end = irFunction->contextObjectPropertyDependencies.constEnd();
-         property != end; ++property) {
+    for (auto property : irFunction->contextObjectPropertyDependencies) {
         *writtenDeps++ = property.key(); // property index
         *writtenDeps++ = property.value(); // notify index
     }
 
     writtenDeps = (quint32 *)(f + function->dependingScopePropertiesOffset);
-    for (QV4::IR::PropertyDependencyMap::ConstIterator property = irFunction->scopeObjectPropertyDependencies.constBegin(), end = irFunction->scopeObjectPropertyDependencies.constEnd();
-         property != end; ++property) {
+    for (auto property : irFunction->scopeObjectPropertyDependencies) {
         *writtenDeps++ = property.key(); // property index
         *writtenDeps++ = property.value(); // notify index
     }
diff --git a/src/qml/compiler/qv4jsir_p.h b/src/qml/compiler/qv4jsir_p.h
index 26b06561a8..94fa65cf71 100644
--- a/src/qml/compiler/qv4jsir_p.h
+++ b/src/qml/compiler/qv4jsir_p.h
@@ -1061,7 +1061,32 @@ private:
 };
 
 // Map from meta property index (existence implies dependency) to notify signal index
-typedef QHash<int, int> PropertyDependencyMap;
+struct KeyValuePair
+{
+    quint32 _key;
+    quint32 _value;
+
+    KeyValuePair(): _key(0), _value(0) {}
+    KeyValuePair(quint32 key, quint32 value): _key(key), _value(value) {}
+
+    quint32 key() const { return _key; }
+    quint32 value() const { return _value; }
+};
+
+class PropertyDependencyMap: public QVarLengthArray<KeyValuePair, 8>
+{
+public:
+    void insert(quint32 key, quint32 value)
+    {
+        for (auto it = begin(), eit = end(); it != eit; ++it) {
+            if (it->_key == key) {
+                it->_value = value;
+                return;
+            }
+        }
+        append(KeyValuePair(key, value));
+    }
+};
 
 // The Function owns (manages), among things, a list of basic-blocks. All the blocks have an index,
 // which corresponds to the index in the entry/index in the vector in which they are stored. This