Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.db.common / src / org / simantics / db / common / procedure / single / wrapper / DeepSingleOrErrorProcedure.java

diff --git a/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/wrapper/DeepSingleOrErrorProcedure.java b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/wrapper/DeepSingleOrErrorProcedure.java
new file mode 100644 (file)
index 0000000..3a78245
--- /dev/null
+++ b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/wrapper/DeepSingleOrErrorProcedure.java
@@ -0,0 +1,89 @@
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.db.common.procedure.single.wrapper;\r
+\r
+import java.util.concurrent.atomic.AtomicBoolean;\r
+import java.util.concurrent.atomic.AtomicInteger;\r
+\r
+import org.simantics.db.AsyncReadGraph;\r
+import org.simantics.db.common.utils.Logger;\r
+import org.simantics.db.exception.NoSingleResultException;\r
+import org.simantics.db.procedure.AsyncProcedure;\r
+\r
+final public class DeepSingleOrErrorProcedure<Result> {\r
+    \r
+       private Result result = null;\r
+       final AsyncProcedure<Result> procedure;\r
+    final AtomicBoolean done = new AtomicBoolean(false);\r
+    final AtomicBoolean found = new AtomicBoolean(false);\r
+    final AtomicInteger ready = new AtomicInteger(1);\r
+    \r
+    public DeepSingleOrErrorProcedure(AsyncProcedure<Result> procedure) {\r
+        \r
+        this.procedure = procedure;\r
+        \r
+    }\r
+    \r
+    public void inc() {\r
+        \r
+        ready.incrementAndGet();\r
+        \r
+    }\r
+    \r
+    public void dec(AsyncReadGraph graph) {\r
+\r
+        if(ready.decrementAndGet() == 0) {\r
+                       // Shall fire exactly once!\r
+            if(done.compareAndSet(false, true)) {\r
+               try {\r
+                       if(found.compareAndSet(false, true)) {\r
+                                       procedure.exception(graph, new NoSingleResultException("No results."));\r
+                       } else {\r
+                                       procedure.execute(graph, result);\r
+                       }\r
+               } catch (Throwable t) {\r
+                       Logger.defaultLogError(t);\r
+               }\r
+            }\r
+        }\r
+        \r
+    }\r
+\r
+    public void offer(AsyncReadGraph graph, Result result) {\r
+        \r
+               if(found.compareAndSet(false, true)) {\r
+                       this.result = result;\r
+               } else {\r
+                       // Shall fire exactly once!\r
+                       if(done.compareAndSet(false, true)) {\r
+                               try {\r
+                                       procedure.exception(graph, new NoSingleResultException(this.result + " and " + result));\r
+                               } catch (Throwable t) {\r
+                               Logger.defaultLogError(t);\r
+                               }\r
+                       }\r
+               }\r
+        \r
+    }\r
+    \r
+    public void exception(AsyncReadGraph graph, Throwable t) {\r
+               // Shall fire exactly once!\r
+               if(done.compareAndSet(false, true)) {\r
+                       try {\r
+                               procedure.exception(graph, t);\r
+                       } catch (Throwable t2) {\r
+                       Logger.defaultLogError(t2);\r
+                       }\r
+               }\r
+    }\r
+       \r
+}\r