Adding JMCR-Stable version

[Benchmarks_CSolver.git] / JMCR-Stable / real-world application / MyDerby-10.3 / java / engine / org / apache / derby / impl / store / access / sort / SortBufferScan.java

diff --git a/JMCR-Stable/real-world application/MyDerby-10.3/java/engine/org/apache/derby/impl/store/access/sort/SortBufferScan.java b/JMCR-Stable/real-world application/MyDerby-10.3/java/engine/org/apache/derby/impl/store/access/sort/SortBufferScan.java
new file mode 100644 (file)
index 0000000..9d4c944
--- /dev/null
+++ b/JMCR-Stable/real-world application/MyDerby-10.3/java/engine/org/apache/derby/impl/store/access/sort/SortBufferScan.java
@@ -0,0 +1,113 @@
+/*\r
+\r
+   Derby - Class org.apache.derby.impl.store.access.sort.SortBufferScan\r
+\r
+   Licensed to the Apache Software Foundation (ASF) under one or more\r
+   contributor license agreements.  See the NOTICE file distributed with\r
+   this work for additional information regarding copyright ownership.\r
+   The ASF licenses this file to you under the Apache License, Version 2.0\r
+   (the "License"); you may not use this file except in compliance with\r
+   the License.  You may obtain a copy of the License at\r
+\r
+      http://www.apache.org/licenses/LICENSE-2.0\r
+\r
+   Unless required by applicable law or agreed to in writing, software\r
+   distributed under the License is distributed on an "AS IS" BASIS,\r
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+   See the License for the specific language governing permissions and\r
+   limitations under the License.\r
+\r
+ */\r
+\r
+package org.apache.derby.impl.store.access.sort;\r
+\r
+import org.apache.derby.iapi.services.sanity.SanityManager;\r
+\r
+import org.apache.derby.iapi.error.StandardException;\r
+import org.apache.derby.iapi.store.access.conglomerate.TransactionManager;\r
+\r
+/**\r
+\r
+  A sort scan that just reads rows out of a sorter.\r
+\r
+**/\r
+\r
+public class SortBufferScan extends SortScan\r
+{\r
+       /**\r
+       The sorter we're returning rows from.\r
+       **/\r
+       protected SortBuffer sortBuffer;\r
+\r
+       /*\r
+        * Constructors.\r
+        */\r
+\r
+       SortBufferScan(\r
+    MergeSort           sort, \r
+    TransactionManager  tran, \r
+    SortBuffer          sortBuffer,\r
+    boolean             hold)\r
+       {\r
+               super(sort, tran, hold);\r
+\r
+        if (SanityManager.DEBUG)\r
+            SanityManager.ASSERT(sortBuffer != null);\r
+\r
+               this.sortBuffer = sortBuffer;\r
+       }\r
+\r
+       /*\r
+        * Methods of MergeSortScan\r
+        */\r
+\r
+    /**\r
+    Move to the next position in the scan.\r
+       @see org.apache.derby.iapi.store.access.ScanController#next\r
+    **/\r
+    public boolean next()\r
+               throws StandardException\r
+       {\r
+        if (SanityManager.DEBUG)\r
+        {\r
+            SanityManager.ASSERT(\r
+                sortBuffer != null, \r
+                "next() called on scan after scan was closed.");\r
+        }\r
+\r
+               super.current = sortBuffer.removeFirst();\r
+               return (super.current != null);\r
+       }\r
+\r
+    /**\r
+    Close the scan.\r
+    **/\r
+    public boolean closeForEndTransaction(boolean closeHeldScan)\r
+    {\r
+        if (closeHeldScan || !hold)\r
+        {\r
+            close();\r
+            return(true);\r
+        }\r
+        else\r
+        {\r
+            return(false);\r
+        }\r
+\r
+    }\r
+\r
+    /**\r
+    Close the scan.\r
+       @see org.apache.derby.iapi.store.access.ScanController#close\r
+    **/\r
+    public void close()\r
+       {\r
+               if (super.sort != null)\r
+               {\r
+                       sort.doneScanning(this, sortBuffer);\r
+                       sortBuffer = null;\r
+               }\r
+               super.close();\r
+       }\r
+\r
+}\r