1 files changed, 33 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-rete/src/main/java/tools/refinery/viatra/runtime/rete/network/indexer/MessageIndexer.java b/subprojects/viatra-runtime-rete/src/main/java/tools/refinery/viatra/runtime/rete/network/indexer/MessageIndexer.java
new file mode 100644
index 00000000..271aaa44
--- /dev/null
+++ b/subprojects/viatra-runtime-rete/src/main/java/tools/refinery/viatra/runtime/rete/network/indexer/MessageIndexer.java
@@ -0,0 +1,33 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, Tamas Szabo, Istvan Rath and Daniel Varro
+ * 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.network.indexer;
+
+import tools.refinery.viatra.runtime.matchers.tuple.Tuple;
+import tools.refinery.viatra.runtime.matchers.util.Clearable;
+import tools.refinery.viatra.runtime.rete.network.mailbox.Mailbox;
+
+/**
+ * A message indexer is used by {@link Mailbox}es to index their contents. 
+ * 
+ * @author Tamas Szabo
+ * @since 2.0
+ */
+public interface MessageIndexer extends Clearable {
+        
+        public void insert(final Tuple update);
+
+        public void delete(final Tuple update);
+
+        public void update(final Tuple update, final int delta);
+        
+        public boolean isEmpty();
+        
+        public int getCount(final Tuple update);
+
+}