[Mulgara-svn] r1996 - trunk/src/jar/store-stringpool-xa11/java/org/mulgara/store/stringpool/xa11

[pag at mulgara.org]

Author: pag
Date: 2011-07-15 03:22:27 +0000 (Fri, 15 Jul 2011)
New Revision: 1996

Modified:
   trunk/src/jar/store-stringpool-xa11/java/org/mulgara/store/stringpool/xa11/XA11StringPoolImpl.java
Log:
Now handling full transaction rollback

Modified: trunk/src/jar/store-stringpool-xa11/java/org/mulgara/store/stringpool/xa11/XA11StringPoolImpl.java
===================================================================
--- trunk/src/jar/store-stringpool-xa11/java/org/mulgara/store/stringpool/xa11/XA11StringPoolImpl.java	2011-07-15 03:21:49 UTC (rev 1995)
+++ trunk/src/jar/store-stringpool-xa11/java/org/mulgara/store/stringpool/xa11/XA11StringPoolImpl.java	2011-07-15 03:22:27 UTC (rev 1996)
@@ -99,7 +99,7 @@
   /** The index file for mapping data to a gNode. */
   private AVLFile dataToGNode;
 
-  /** The file file reader for mapping gNodes to data. */
+  /** The file reader for mapping gNodes to data. */
   private LBufferedFile gNodeToDataFile;
 
   /** The object for creating the output appender. */
@@ -540,7 +540,9 @@
             nextGNodeValue = committedNextGNode;
             long offset = DataStruct.toOffset(nextGNodeValue);
             gNodeToDataAppender.position(offset);
-            // gNodeToDataAppender.truncate(offset);  // can't truncate since it's mapped
+            // tell the read-only access to prepare for truncation
+            gNodeToDataFile.truncate(offset);
+            forceTruncate(gNodeToDataAppender, offset);
           } catch (IOException ioe) {
             throw new SimpleXAResourceException("I/O error while performing rollback (new committed phase)", ioe);
           }
@@ -799,6 +801,31 @@
 
 
   /**
+   * Force a file truncation. If memory maps prevent this, attempt to clean them up, and retry the truncation.
+   * @param fc A channel to the file to be truncated.
+   * @param size The new size of the file.
+   * @throws IOException If the file is open beyond the truncation point, and this cannot be overridden.
+   */
+  private void forceTruncate(FileChannel fc, long size) throws IOException {
+    long s = fc.size();
+    if (s <= size) return;
+    int retries = 10;
+    for (;;) {
+      try {
+        fc.truncate(size);
+        break;
+      } catch (IOException e) {
+        // on failure, attempt to clean up all resources keeping the file open
+        if (retries-- == 0) throw e;
+        System.gc();
+        try { Thread.sleep(100); } catch (InterruptedException ie) { }
+        System.runFinalization();
+      }
+    }
+  }
+
+
+  /**
    * Closes all the files involved with a data pool
    * @param deleteFiles Remove files after closing them.
    * @throws IOException There was an error accessing the filesystem.