1 files changed, 46 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-rete/src/main/java/tools/refinery/viatra/runtime/rete/matcher/HintConfigurator.java b/subprojects/viatra-runtime-rete/src/main/java/tools/refinery/viatra/runtime/rete/matcher/HintConfigurator.java
new file mode 100644
index 00000000..a4fa4914
--- /dev/null
+++ b/subprojects/viatra-runtime-rete/src/main/java/tools/refinery/viatra/runtime/rete/matcher/HintConfigurator.java
@@ -0,0 +1,46 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Gabor Bergmann, IncQueryLabs Ltd.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package tools.refinery.viatra.runtime.rete.matcher;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import tools.refinery.viatra.runtime.matchers.backend.IQueryBackendHintProvider;
+import tools.refinery.viatra.runtime.matchers.backend.QueryEvaluationHint;
+import tools.refinery.viatra.runtime.matchers.psystem.queries.PQuery;
+
+/**
+ * A configurable hint provider that gathers hints for queries during runtime, and delegates defaults to an external hint provider. 
+ * 
+ * @author Gabor Bergmann
+ * @since 1.5
+ */
+class HintConfigurator implements IQueryBackendHintProvider {
+    
+    private IQueryBackendHintProvider defaultHintProvider;
+    private Map<PQuery, QueryEvaluationHint> storedHints = new HashMap<PQuery, QueryEvaluationHint>();
+
+    public HintConfigurator(IQueryBackendHintProvider defaultHintProvider) {
+        this.defaultHintProvider = defaultHintProvider;
+    }
+
+    @Override
+    public QueryEvaluationHint getQueryEvaluationHint(PQuery query) {
+        return defaultHintProvider.getQueryEvaluationHint(query).overrideBy(storedHints.get(query));
+    }
+    
+    public void storeHint(PQuery query, QueryEvaluationHint hint) {
+        QueryEvaluationHint oldHint = storedHints.get(query);
+        if (oldHint == null)
+            storedHints.put(query, hint);
+        else
+            storedHints.put(query, oldHint.overrideBy(hint));
+    }
+
+}