1 files changed, 119 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/scopes/TabularRuntimeContext.java b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/scopes/TabularRuntimeContext.java
new file mode 100644
index 00000000..e99e24d3
--- /dev/null
+++ b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/scopes/TabularRuntimeContext.java
@@ -0,0 +1,119 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, Gabor Bergmann, 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.scopes;
+
+import java.util.Map;
+import java.util.Optional;
+
+import tools.refinery.viatra.runtime.matchers.context.AbstractQueryRuntimeContext;
+import tools.refinery.viatra.runtime.matchers.context.IInputKey;
+import tools.refinery.viatra.runtime.matchers.context.IQueryRuntimeContextListener;
+import tools.refinery.viatra.runtime.matchers.scopes.tables.IIndexTable;
+import tools.refinery.viatra.runtime.matchers.scopes.tables.ITableContext;
+import tools.refinery.viatra.runtime.matchers.tuple.ITuple;
+import tools.refinery.viatra.runtime.matchers.tuple.Tuple;
+import tools.refinery.viatra.runtime.matchers.tuple.TupleMask;
+import tools.refinery.viatra.runtime.matchers.util.Accuracy;
+import tools.refinery.viatra.runtime.matchers.util.CollectionsFactory;
+
+/**
+ * An abstract runtime context that serves enumerable input key instances from tables.
+ * 
+ * <p>
+ * Usage: first, instantiate {@link IIndexTable} tables with this as the 'tableContext' argument. Call
+ * {@link #registerIndexTable(IIndexTable)} to register them; this may happen either during a coalesced indexing, or on
+ * external initiation. Afterwards, they will be visible to the query backends.
+ * <p>
+ * <strong>EXPERIMENTAL</strong>. This class or interface has been added as
+ * part of a work in progress. There is no guarantee that this API will
+ * work or that it will remain the same.
+ * 
+ * @author Gabor Bergmann
+ * @since 2.0
+ */
+public abstract class TabularRuntimeContext extends AbstractQueryRuntimeContext implements ITableContext {
+
+    private Map<IInputKey, IIndexTable> instanceTables = CollectionsFactory.createMap();
+
+    public void registerIndexTable(IIndexTable table) {
+        IInputKey inputKey = table.getInputKey();
+        instanceTables.put(inputKey, table);
+    }
+
+    /**
+     * @return null if the table is not registered
+     */
+    public IIndexTable peekIndexTable(IInputKey key) {
+        return instanceTables.get(key);
+    }
+
+    /**
+     * If the table is not registered, {@link #handleUnregisteredTableRequest(IInputKey)} is invoked; it may handle it
+     * by raising an error or e.g. on-demand index construction
+     */
+    public IIndexTable getIndexTable(IInputKey key) {
+        IIndexTable table = instanceTables.get(key);
+        if (table != null)
+            return table;
+        else
+            return handleUnregisteredTableRequest(key);
+    }
+
+    /**
+     * Override this to provide on-demand table registration
+     */
+    protected IIndexTable handleUnregisteredTableRequest(IInputKey key) {
+        throw new IllegalArgumentException(key.getPrettyPrintableName());
+    }
+
+    @Override
+    public int countTuples(IInputKey key, TupleMask seedMask, ITuple seed) {
+        return getIndexTable(key).countTuples(seedMask, seed);
+    }
+    
+    @Override
+    public Optional<Long> estimateCardinality(IInputKey key, TupleMask groupMask, Accuracy requiredAccuracy) {
+        return getIndexTable(key).estimateProjectionSize(groupMask, requiredAccuracy);
+    }
+
+    @Override
+    public Iterable<Tuple> enumerateTuples(IInputKey key, TupleMask seedMask, ITuple seed) {
+        return getIndexTable(key).enumerateTuples(seedMask, seed);
+    }
+
+    @Override
+    public Iterable<? extends Object> enumerateValues(IInputKey key, TupleMask seedMask, ITuple seed) {
+        return getIndexTable(key).enumerateValues(seedMask, seed);
+    }
+
+    @Override
+    public boolean containsTuple(IInputKey key, ITuple seed) {
+        if (key.isEnumerable()) {
+            return getIndexTable(key).containsTuple(seed);
+        } else {
+            return isContainedInStatelessKey(key, seed);
+        }
+    }
+    
+    @Override
+    public void addUpdateListener(IInputKey key, Tuple seed, IQueryRuntimeContextListener listener) {
+        getIndexTable(key).addUpdateListener(seed, listener);
+    }
+    @Override
+    public void removeUpdateListener(IInputKey key, Tuple seed, IQueryRuntimeContextListener listener) {
+        getIndexTable(key).removeUpdateListener(seed, listener);
+    }
+    
+    /**
+     * Handles non-enumerable input keys that are not backed by a table
+     */
+    protected abstract boolean isContainedInStatelessKey(IInputKey key, ITuple seed);
+
+}