/*
* Copyright 2004-2013 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.lealone.engine;
import java.util.ArrayList;
import org.lealone.command.CommandInterface;
import org.lealone.result.ResultInterface;
import org.lealone.util.New;
import org.lealone.value.Value;
/**
* The base class for both remote and embedded sessions.
*/
abstract class SessionWithState implements SessionInterface {
protected ArrayList<String> sessionState;
protected boolean sessionStateChanged;
private boolean sessionStateUpdating;
/**
* Re-create the session state using the stored sessionState list.
*/
protected void recreateSessionState() {
if (sessionState != null && sessionState.size() > 0) {
sessionStateUpdating = true;
try {
for (String sql : sessionState) {
CommandInterface ci = prepareCommand(sql, Integer.MAX_VALUE);
ci.executeUpdate();
}
} finally {
sessionStateUpdating = false;
sessionStateChanged = false;
}
}
}
/**
* Read the session state if necessary.
*/
public void readSessionState() {
if (!sessionStateChanged || sessionStateUpdating) {
return;
}
sessionStateChanged = false;
sessionState = New.arrayList();
CommandInterface ci = prepareCommand("SELECT * FROM INFORMATION_SCHEMA.SESSION_STATE", Integer.MAX_VALUE);
ResultInterface result = ci.executeQuery(0, false);
while (result.next()) {
Value[] row = result.currentRow();
sessionState.add(row[1].getString());
}
}
}