Part of MOB-436: Cluster-wide Locking Service: Implement DB Changes and Service

- Unit test not checked in as it requires some schema change work that has been done manually
 - Moved activities DAO code and renamed data services to DAOs (as per iBatis and Wikipedia, etc)
 - DAO code should now go into org.alfresco.repo.domain...
 - DAO components are bean:xyzDAO and class:XyzDAO
 - Entity beans are XyzEntity, etc

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@13922 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/domain/locks/LockDAO.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2005-2009 Alfresco Software Limited.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+ * As a special exception to the terms and conditions of version 2.0 of 
+ * the GPL, you may redistribute this Program in connection with Free/Libre 
+ * and Open Source Software ("FLOSS") applications as described in Alfresco's 
+ * FLOSS exception.  You should have recieved a copy of the text describing 
+ * the FLOSS exception, and it is also available here: 
+ * http://www.alfresco.com/legal/licensing"
+ */
+package org.alfresco.repo.domain.locks;
+
+import org.alfresco.service.namespace.QName;
+
+/**
+ * DAO services for <b>alf_lock</b> and related tables
+ * 
+ * @author Derek Hulley
+ * @since 3.2
+ */
+public interface LockDAO
+{
+    /**
+     * Aquire a given exclusive lock, assigning it (and any implicitly shared locks) a
+     * timeout.  All shared locks are implicitly taken as well.
+     * 
+     * @param lockQName             the unique name of the lock to acquire
+     * @param lockApplicant         the potential lock holder's identifier (max 36 chars)
+     * @param timeToLive            the time (in milliseconds) that the lock must remain 
+     * @return                      Returns <tt>true</tt> if the lock was taken, 
+     *                              otherwise <tt>false</tt>
+     */
+    boolean getLock(QName lockQName, String lockApplicant, long timeToLive);
+}