Multiple reader thread support for db client

[simantics/platform.git] / bundles / org.simantics.db.impl / src / org / simantics / db / impl / query / UnaryQueryP.java

diff --git a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/UnaryQueryP.java b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/UnaryQueryP.java
new file mode 100644 (file)
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+++ b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/UnaryQueryP.java
@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Semantum Oy - initial API and implementation
+ *******************************************************************************/
+package org.simantics.db.impl.query;
+
+import org.simantics.db.common.exception.DebugException;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.impl.graph.ReadGraphImpl;
+import org.simantics.db.impl.procedure.InternalProcedure;
+
+public abstract class UnaryQueryP<R> extends UnaryQuery<InternalProcedure<R>> implements InternalProcedure<R> {
+
+    public UnaryQueryP(int r) {
+        super(r);
+    }
+
+    public abstract void compute(ReadGraphImpl graph, InternalProcedure<R> procedure) throws DatabaseException;
+
+    @Override
+    public final void recompute(ReadGraphImpl graph) throws DatabaseException {
+
+        compute(graph, new InternalProcedure<R>() {
+
+            @Override
+            public void execute(ReadGraphImpl graph, R result) {
+            }
+
+            @Override
+            public void exception(ReadGraphImpl graph, Throwable t) {
+                if (DebugException.DEBUG)
+                    new DebugException(t).printStackTrace();
+                throw new Error("Error in recompute.", t);
+            }
+
+        });
+
+    }
+
+    @Override
+    public final Object performFromCache(ReadGraphImpl graph, InternalProcedure<R> procedure)
+            throws DatabaseException {
+
+        if (handleException(graph, procedure))
+            return (Throwable) statusOrException;
+
+        procedure.execute(graph, (R)getResult());
+
+        return result;
+
+    }
+
+    @Override
+    public final void execute(ReadGraphImpl graph, R result) throws DatabaseException {
+        setResult(result);
+        setReady();
+    }
+
+    @Override
+    public final void exception(ReadGraphImpl graph, Throwable throwable) throws DatabaseException {
+        except(throwable);
+    }
+
+    @Override
+    final boolean isImmutable(ReadGraphImpl graph) {
+        return graph.processor.isImmutable(id);
+    }
+
+}