Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.db.impl / src / org / simantics / db / impl / graph / SingleObjectProcedure.java

diff --git a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/graph/SingleObjectProcedure.java b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/graph/SingleObjectProcedure.java
new file mode 100644 (file)
index 0000000..2080165
--- /dev/null
+++ b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/graph/SingleObjectProcedure.java
@@ -0,0 +1,45 @@
+package org.simantics.db.impl.graph;\r
+\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.exception.NoSingleResultException;\r
+import org.simantics.db.impl.query.IntProcedure;\r
+import org.simantics.db.impl.query.QueryProcessor;\r
+\r
+public class SingleObjectProcedure implements IntProcedure {\r
+\r
+       final private QueryProcessor processor;\r
+       private DatabaseException exception;\r
+       private Resource result;\r
+       \r
+       public SingleObjectProcedure(QueryProcessor processor) {\r
+               this.processor = processor;\r
+       }\r
+       \r
+       @Override\r
+       public void execute(ReadGraphImpl graph, int i) {\r
+               Resource resource = processor.querySupport.getResource(i);\r
+               if(result != null) {\r
+                       exception = new NoSingleResultException("");\r
+               } else {\r
+                       result = resource;\r
+               }\r
+       }\r
+\r
+       @Override\r
+       public void finished(ReadGraphImpl graph) {\r
+               if(result == null) exception = new NoSingleResultException("");\r
+       }\r
+\r
+       @Override\r
+       public void exception(ReadGraphImpl graph, Throwable throwable) {\r
+               if(throwable instanceof DatabaseException) exception = (DatabaseException)throwable;\r
+               else throwable = new DatabaseException(throwable);\r
+       }\r
+       \r
+       public Resource get() throws DatabaseException {\r
+               if(exception != null) throw exception;\r
+               else return result;\r
+       }\r
+\r
+}\r