Merge pull request #76 from apache/fix_27

[IOTDB-27]Bug fix: the writer of LocalTextModificationAccessor is not recycled 

iotdb/src/main/java/org/apache/iotdb/db/engine/modification/io/LocalTextModificationAccessor.java

@@ -87,6 +87,7 @@ public class LocalTextModificationAccessor implements ModificationReader, Modifi
   public void close() throws IOException {
     if (writer != null) {
       writer.close();
+      writer = null;
     }
   }
 

iotdb/src/test/java/org/apache/iotdb/db/integration/IoTDBDeletionIT.java

@@ -20,6 +20,7 @@
 package org.apache.iotdb.db.integration;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 
 import java.sql.Connection;
 import java.sql.DriverManager;
@@ -147,6 +148,31 @@ public class IoTDBDeletionIT {
     cleanData();
   }
 
+  @Test
+  public void testDelAfterFlush() throws SQLException {
+    Connection connection = DriverManager
+        .getConnection(Config.IOTDB_URL_PREFIX + "127.0.0.1:6667/", "root",
+            "root");
+    Statement statement = connection.createStatement();
+
+    statement.execute("SET STORAGE GROUP TO root.ln.wf01.wt01");
+    statement.execute("CREATE TIMESERIES root.ln.wf01.wt01.status WITH DATATYPE=BOOLEAN,"
+        + " ENCODING=PLAIN");
+    statement.execute("INSERT INTO root.ln.wf01.wt01(timestamp,status) "
+        + "values(1509465600000,true)");
+    statement.execute("INSERT INTO root.ln.wf01.wt01(timestamp,status) VALUES(NOW(), false)");
+
+    statement.execute("delete from root.ln.wf01.wt01.status where time < NOW()");
+    statement.execute("flush");
+    statement.execute("delete from root.ln.wf01.wt01.status where time < NOW()");
+    ResultSet resultSet = statement.executeQuery("select status from root.ln.wf01.wt01");
+    assertFalse(resultSet.next());
+
+    statement.close();
+    connection.close();
+  }
+
+
   private static void prepareSeries() throws SQLException {
     Connection connection = null;
     try {