1 files changed, 46 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/backend/IQueryBackendFactoryProvider.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/backend/IQueryBackendFactoryProvider.java
new file mode 100644
index 00000000..8787814e
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/backend/IQueryBackendFactoryProvider.java
@@ -0,0 +1,46 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, Zoltan Ujhelyi, IncQuery Labs 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.matchers.backend;
+
+/**
+ * A provider interface for {@link IQueryBackendFactory} instances.
+ * @since 2.0
+ */
+public interface IQueryBackendFactoryProvider {
+
+    /**
+     * Returns a query backend factory instance. The method should return the same instance in case of repeated calls.
+     */
+    IQueryBackendFactory getFactory();
+    
+    /**
+     * Returns whether the given query backend should be considered as system default. If multiple backends are
+     * registered as system default, it is undefined which one will be chosen.
+     */
+    default boolean isSystemDefaultEngine() {
+        return false;
+    }
+    
+    /**
+     * Returns whether the given query backend should be considered as system default search backend. If multiple
+     * backends are registered as system default, it is undefined which one will be chosen.
+     */
+    default boolean isSystemDefaultSearchBackend() {
+        return false;
+    }
+    
+    
+    /**
+     * Returns whether the given query backend should be considered as system default caching backend. If multiple
+     * backends are registered as system default, it is undefined which one will be chosen.
+     */
+    default boolean isSystemDefaultCachingBackend() {
+        return false;
+    }
+}