Session-temporary LOB's could sometimes accumulate, increasing the size of the…

Session-temporary LOB's could sometimes accumulate, increasing the size of the DB file until shutdown.
Now they are cleared out at every commit.

h2/src/docsrc/html/changelog.html

@@ -47,6 +47,8 @@ Change Log
 </li><li>When the H2 parser fails to parse a SQL statement, throw a more specific exception that
     contains extra information to make it possible for smart editors to do autocomplete. Patch from Nicolas Fortin.
 </li><li>Fix DROP ALL OBJECTS and DROP SCHEMA in the presence of tables with computed column dependencies.
+</li><li>Session-temporary LOB's could sometimes accumulate, increasing the size of the DB file until shutdown.
+    Now they are cleared out at every commit.
 </li></ul>
 
 <h2>Version 1.3.173 (2013-07-28)</h2>

h2/src/main/org/h2/engine/Session.java

@@ -111,6 +111,7 @@ public class Session extends SessionWithState {
     private final int queryCacheSize;
     private SmallLRUCache<String, Command> queryCache;
     private long modificationMetaID = -1;
+    private ArrayList<Value> temporaryLobs;
 
     private Transaction transaction;
     private long startStatement = -1;
@@ -475,6 +476,14 @@ public class Session extends SessionWithState {
             // (create/drop table and so on)
             database.commit(this);
         }
+        if (temporaryLobs != null) {
+            for (Value v : temporaryLobs) {
+                if (!v.isLinked()) {
+                    v.close();
+                }
+            }
+            temporaryLobs.clear();
+        }
         if (undoLog.size() > 0) {
             // commit the rows when using MVCC
             if (database.isMultiVersion()) {
@@ -1382,6 +1391,13 @@ public class Session extends SessionWithState {
         closeTemporaryResults();
     }
     
+    public void addTemporaryLob(Value v) {
+        if (temporaryLobs == null) {
+            temporaryLobs = new ArrayList<Value>();                    
+        }
+        temporaryLobs.add(v);
+    }
+
     /**
      * Represents a savepoint (a position in a transaction to where one can roll
      * back to).

h2/src/main/org/h2/engine/SessionInterface.java

@@ -10,6 +10,7 @@ import java.io.Closeable;
 import org.h2.command.CommandInterface;
 import org.h2.message.Trace;
 import org.h2.store.DataHandler;
+import org.h2.value.Value;
 
 /**
  * A local or remote session. A session represents a database connection.
@@ -117,4 +118,6 @@ public interface SessionInterface extends Closeable {
      */
     void setAutoCommit(boolean autoCommit);
     
+    void addTemporaryLob(Value v);
+
 }

h2/src/main/org/h2/engine/SessionRemote.java

@@ -805,4 +805,9 @@ public class SessionRemote extends SessionWithState implements DataHandler {
         }
         return javaObjectSerializerFQN;
     }
+    
+    @Override
+    public void addTemporaryLob(Value v) {
+        // do nothing
+    }
 }

h2/src/main/org/h2/jdbc/JdbcConnection.java

@@ -1493,6 +1493,7 @@ public class JdbcConnection extends TraceObject implements Connection {
                 Value v = session.getDataHandler().getLobStorage().createClob(
                         new InputStreamReader(
                         new ByteArrayInputStream(Utils.EMPTY_BYTES)), 0);
+                session.addTemporaryLob(v);
                 return new JdbcClob(this, v, id);
             } finally {
                 afterWriting();
@@ -1516,6 +1517,7 @@ public class JdbcConnection extends TraceObject implements Connection {
             try {
                 Value v = session.getDataHandler().getLobStorage().createBlob(
                         new ByteArrayInputStream(Utils.EMPTY_BYTES), 0);
+                session.addTemporaryLob(v);
                 return new JdbcBlob(this, v, id);
             } finally {
                 afterWriting();
@@ -1540,6 +1542,7 @@ public class JdbcConnection extends TraceObject implements Connection {
                 Value v = session.getDataHandler().getLobStorage().createClob(
                         new InputStreamReader(
                         new ByteArrayInputStream(Utils.EMPTY_BYTES)), 0);
+                session.addTemporaryLob(v);
                 return new JdbcClob(this, v, id);
             } finally {
                 afterWriting();
@@ -1723,6 +1726,7 @@ public class JdbcConnection extends TraceObject implements Connection {
             length = -1;
         }
         Value v = session.getDataHandler().getLobStorage().createClob(x, length);
+        session.addTemporaryLob(v);
         return v;
     }
 
@@ -1742,6 +1746,7 @@ public class JdbcConnection extends TraceObject implements Connection {
             length = -1;
         }
         Value v = session.getDataHandler().getLobStorage().createBlob(x, length);
+        session.addTemporaryLob(v);
         return v;
     }
 

h2/src/test/org/h2/test/db/TestLob.java

@@ -81,6 +81,7 @@ public class TestLob extends TestBase {
         testAddLobRestart();
         testLobServerMemory();
         testUpdatingLobRow();
+        testLobCleanupSessionTemporaries();
         if (config.memory) {
             return;
         }
@@ -685,6 +686,33 @@ public class TestLob extends TestBase {
         assertEquals(0, FileUtils.newDirectoryStream(getBaseDir() + "/lob.lobs.db").size());
     }
 
+    private void testLobCleanupSessionTemporaries() throws SQLException {
+        if (!SysProperties.LOB_IN_DATABASE) {
+            return;
+        }
+        deleteDb("lob");
+        Connection conn = getConnection("lob");
+        Statement stat = conn.createStatement();
+        stat.execute("create table test(data clob)");
+        
+        ResultSet rs = stat.executeQuery("select count(*) from INFORMATION_SCHEMA.LOBS");
+        assertTrue(rs.next());
+        assertEquals(0, rs.getInt(1));
+        rs.close();
+        
+        PreparedStatement prep = conn.prepareStatement("INSERT INTO test(data) VALUES(?)");
+        final String name = "A veeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeery long string generated only to insert enough data to reproduce the increasing db size PITA ";
+        prep.setString(1, name);
+        prep.execute();
+        prep.close();
+        
+        rs = stat.executeQuery("select count(*) from INFORMATION_SCHEMA.LOBS");
+        assertTrue(rs.next());
+        assertEquals(1, rs.getInt(1));
+        rs.close();
+        conn.close();
+    }
+    
     private void testLobServerMemory() throws SQLException {
         deleteDb("lob");
         Connection conn = getConnection("lob");