The outside hooks for AVMSyncService are in place and the implementation

of the simplest method, resetLayer is done.
Also fixed goofy merge induced bug in DbNodeServiceImpl.
Can we make merging a punishment for naughty Alfrescans?


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/BRANCHES/WCM-DEV2/root@3778 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/service/cmr/avmsync/AVMSyncService.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2006 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the
+ * License.
+ */
+
+package org.alfresco.service.cmr.avmsync;
+
+import java.util.List;
+
+/**
+ * This service handles comparisons and synchronizations between
+ * corresponding avm node trees.
+ * @author britt
+ */
+public interface AVMSyncService
+{
+    /**
+     * Get a difference list between two corresponding node trees.
+     * @param srcVersion The version id for the source tree.
+     * @param srcPath The avm path to the source tree.
+     * @param dstVersion The version id for the destination tree.
+     * @param dstPath The avm path to the destination tree.
+     * @return A List of AVMDifference structs which can be used for
+     * the update operation.
+     */
+    public List<AVMDifference> compare(int srcVersion, String srcPath, 
+                                       int dstVersion, String dstPath);
+    
+    /**
+     * Updates the destination nodes in the AVMDifferences
+     * with the source nodes. Normally any conflicts or cases in
+     * which the source of an AVMDifference is older than the destination
+     * will cause the transaction to roll back.
+     * @param diffList A List of AVMDifference structs.
+     * @param ignoreConflicts If this is true the update will skip those 
+     * AVMDifferences which are in conflict or for which the source is older than
+     * the destination.
+     * @param overrideConflicts If this is true the update will override conflicting
+     * AVMDifferences and replace the destination with the conflicting source.
+     * @param overrideOlder If this is true the update will override AVMDifferences
+     * in which the source is older than the destination and overwrite the destination.
+     */
+    public void update(List<AVMDifference> diffList, boolean ignoreConflicts, 
+                       boolean overrideConflicts, boolean overrideOlder);
+    
+    /**
+     * Flattens a layer so that all all nodes under and including
+     * <code>layerPath</code> become translucent to any nodes in the 
+     * corresponding location under and including <code>underlyingPath</code>
+     * that are the same version. 
+     * @param layerPath The overlying layer path.
+     * @param underlyingPath The underlying path.
+     */
+    public void flatten(String layerPath, String underlyingPath);
+    
+    /**
+     * Takes a layer, deletes it and recreates it pointing at the same underlying
+     * node. Any changes in the layer are lost (except to history if the layer has been 
+     * snapshotted.)
+     * @param layerPath
+     */
+    public void resetLayer(String layerPath);
+}