Rework APIs of new getChildAssocs with result count limit

- Use regular pattern of get -> select in the DAO
 - All getChildren* batching done after the query
 - Unit tests
 - In progress: Added option (low level select only) to constrain by assoc ID


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@31318 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/domain/node/AbstractNodeDAOImpl.java

@@ -55,9 +55,9 @@ import org.alfresco.repo.domain.usage.UsageDAO;
 import org.alfresco.repo.policy.BehaviourFilter;
 import org.alfresco.repo.security.permissions.AccessControlListProperties;
 import org.alfresco.repo.transaction.AlfrescoTransactionSupport;
+import org.alfresco.repo.transaction.AlfrescoTransactionSupport.TxnReadState;
 import org.alfresco.repo.transaction.TransactionAwareSingleton;
 import org.alfresco.repo.transaction.TransactionListenerAdapter;
-import org.alfresco.repo.transaction.AlfrescoTransactionSupport.TxnReadState;
 import org.alfresco.service.cmr.dictionary.DataTypeDefinition;
 import org.alfresco.service.cmr.dictionary.DictionaryService;
 import org.alfresco.service.cmr.dictionary.InvalidTypeException;
@@ -71,20 +71,20 @@ import org.alfresco.service.cmr.repository.DuplicateChildNodeNameException;
 import org.alfresco.service.cmr.repository.InvalidNodeRefException;
 import org.alfresco.service.cmr.repository.InvalidStoreRefException;
 import org.alfresco.service.cmr.repository.NodeRef;
+import org.alfresco.service.cmr.repository.NodeRef.Status;
 import org.alfresco.service.cmr.repository.Path;
 import org.alfresco.service.cmr.repository.StoreRef;
-import org.alfresco.service.cmr.repository.NodeRef.Status;
 import org.alfresco.service.cmr.repository.datatype.DefaultTypeConverter;
 import org.alfresco.service.namespace.QName;
 import org.alfresco.service.transaction.ReadOnlyServerException;
 import org.alfresco.service.transaction.TransactionService;
 import org.alfresco.util.EqualsHelper;
+import org.alfresco.util.EqualsHelper.MapValueComparison;
 import org.alfresco.util.GUID;
 import org.alfresco.util.Pair;
 import org.alfresco.util.PropertyCheck;
 import org.alfresco.util.ReadWriteLockExecuter;
 import org.alfresco.util.SerializationUtils;
-import org.alfresco.util.EqualsHelper.MapValueComparison;
 import org.apache.commons.lang.mutable.MutableInt;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -2900,7 +2900,6 @@ public abstract class AbstractNodeDAOImpl implements NodeDAO, BatchingDAO
      */
     private class ChildAssocRefBatchingQueryCallback implements ChildAssocRefQueryCallback
     {
-        private static final int BATCH_SIZE = 256 * 4;
         private final ChildAssocRefQueryCallback callback;
         private final boolean preload;
         private final List<NodeRef> nodeRefs;
@@ -2935,18 +2934,10 @@ public abstract class AbstractNodeDAOImpl implements NodeDAO, BatchingDAO
                 Pair<Long, NodeRef> parentNodePair,
                 Pair<Long, NodeRef> childNodePair)
         {
-            if (!preload)
+            if (preload)
             {
-                return callback.handle(childAssocPair, parentNodePair, childNodePair);
+                nodeRefs.add(childNodePair.getSecond());
             }
-            // Batch it
-            if (nodeRefs.size() >= BATCH_SIZE)
-            {
-                cacheNodes(nodeRefs);
-                nodeRefs.clear();
-            }
-            nodeRefs.add(childNodePair.getSecond());
-            
             return callback.handle(childAssocPair, parentNodePair, childNodePair);
         }
         public void done()
@@ -2957,7 +2948,7 @@ public abstract class AbstractNodeDAOImpl implements NodeDAO, BatchingDAO
                 cacheNodes(nodeRefs);
                 nodeRefs.clear();
             }
-            
+            // Done
             callback.done();
         }                               
     }
@@ -2977,6 +2968,23 @@ public abstract class AbstractNodeDAOImpl implements NodeDAO, BatchingDAO
                 new ChildAssocRefBatchingQueryCallback(resultsCallback));
     }
 
+    @Override
+    public void getChildAssocs(
+            Long parentNodeId,
+            QName assocTypeQName,
+            QName assocQName,
+            int maxResults,
+            ChildAssocRefQueryCallback resultsCallback)
+    {
+        selectChildAssocs(
+                parentNodeId,
+                assocTypeQName,
+                assocQName,
+                null,
+                maxResults,
+                new ChildAssocRefBatchingQueryCallback(resultsCallback));
+    }
+
     public void getChildAssocs(Long parentNodeId, Set<QName> assocTypeQNames, ChildAssocRefQueryCallback resultsCallback)
     {
         switch (assocTypeQNames.size())
@@ -3926,6 +3934,13 @@ public abstract class AbstractNodeDAOImpl implements NodeDAO, BatchingDAO
             Boolean isPrimary,
             Boolean sameStore,
             ChildAssocRefQueryCallback resultsCallback);
+    protected abstract void selectChildAssocs(
+            Long parentNodeId,
+            QName assocTypeQName,
+            QName assocQName,
+            Long minAssocIdInclusive,
+            int maxResults,
+            ChildAssocRefQueryCallback resultsCallback);
     protected abstract void selectChildAssocs(
             Long parentNodeId,
             Set<QName> assocTypeQNames,

source/java/org/alfresco/repo/domain/node/ChildAssocEntity.java

@@ -185,7 +185,7 @@ public class ChildAssocEntity
      */
     public ChildAssocEntity()
     {
-        ordered = true;
+        ordered = false;
     }
 
     @Override

source/java/org/alfresco/repo/domain/node/NodeDAO.java

@@ -503,15 +503,15 @@ public interface NodeDAO extends NodeBulkLoader
      * @param assocQName            the association qname to filter on; <tt>null</tt> for no filtering
      * @param maxResults            the maximum number of results to return. The query will be terminated efficiently
      *                              after that number of results                             
-     * @param preload          should the child nodes be batch loaded?
+     * @param resultsCallback       the callback that will be called with the results
      * @return a list of child associations
      */
-    public List<ChildAssociationRef> getChildAssocs(
+    public void getChildAssocs(
             Long parentNodeId,
             QName assocTypeQName,
             QName assocQName,
             final int maxResults,
-            boolean preload);
+            ChildAssocRefQueryCallback resultsCallback);
     
    /**
      * Get the child associations of a given parent node, optionally filtering on type <tt>QName</tt>.

source/java/org/alfresco/repo/domain/node/ibatis/NodeDAOImpl.java

@@ -23,7 +23,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -1014,6 +1013,7 @@ public class NodeDAOImpl extends AbstractNodeDAOImpl
         {
             if (!assoc.setTypeQNameAll(qnameDAO, assocTypeQName, false))
             {
+                resultsCallback.done();
                 return;                     // Shortcut
             }
         }
@@ -1022,6 +1022,7 @@ public class NodeDAOImpl extends AbstractNodeDAOImpl
         {
             if (!assoc.setQNameAll(qnameDAO, assocQName, false))
             {
+                resultsCallback.done();
                 return;                     // Shortcut
             }
         }
@@ -1045,25 +1046,29 @@ public class NodeDAOImpl extends AbstractNodeDAOImpl
         resultsCallback.done();
     }
 
-    public List<ChildAssociationRef> getChildAssocs(
+    @Override
+    public void selectChildAssocs(
             Long parentNodeId,
             QName assocTypeQName,
             QName assocQName,
+            Long minAssocIdInclusive,
             final int maxResults,
-            boolean preload)
+            ChildAssocRefQueryCallback resultsCallback)
     {
         ChildAssocEntity assoc = new ChildAssocEntity();
         // Parent
         NodeEntity parentNode = new NodeEntity();
         parentNode.setId(parentNodeId);
         assoc.setParentNode(parentNode);
+        assoc.setId(minAssocIdInclusive);
 
         // Type QName
         if (assocTypeQName != null)
         {
             if (!assoc.setTypeQNameAll(qnameDAO, assocTypeQName, false))
             {
-                return Collections.emptyList();                     // Shortcut
+                resultsCallback.done();
+                return;                 // Shortcut
             }
         }
         // QName
@@ -1071,49 +1076,23 @@ public class NodeDAOImpl extends AbstractNodeDAOImpl
         {
             if (!assoc.setQNameAll(qnameDAO, assocQName, false))
             {
-                return Collections.emptyList();                     // Shortcut
+                resultsCallback.done();
+                return;                 // Shortcut
             }
         }
 
-        final List<ChildAssociationRef> result = new LinkedList<ChildAssociationRef>();
-        final List<NodeRef> toLoad = new LinkedList<NodeRef>();
-
-        // We can't invoke the row handler whilst the limited query is running as it's illegal on some databases (MySQL)
-        List<?> entities = template.selectList(SELECT_CHILD_ASSOCS_OF_PARENT_LIMITED, assoc, new RowBounds(0,
-                maxResults));
-        ChildAssocResultHandler rowHandler = new ChildAssocResultHandler(new ChildAssocRefQueryCallback(){
-
-            @Override
-            public boolean handle(Pair<Long, ChildAssociationRef> childAssocPair, Pair<Long, NodeRef> parentNodePair,
-                    Pair<Long, NodeRef> childNodePair)
-            {
-                result.add(childAssocPair.getSecond());
-                toLoad.add(childNodePair.getSecond());
-                return true;
-            }
-
-            @Override
-            public void done()
-            {
-            }
-
-            @Override
-            public boolean preLoadNodes()
-            {
-                return false;
-            }});
+        ChildAssocResultHandler resultHandler = new ChildAssocResultHandler(resultsCallback);
+        
+        RowBounds rowBounds = new RowBounds(0, maxResults);
+        List<?> entities = template.selectList(SELECT_CHILD_ASSOCS_OF_PARENT_LIMITED, assoc, rowBounds);
         final DefaultResultContext resultContext = new DefaultResultContext();
         for (Object entity : entities)
         {
               resultContext.nextResultObject(entity);
-              rowHandler.handleResult(resultContext);
-        }
-        if (preload && !toLoad.isEmpty())
-        {
-            cacheNodes(toLoad);
+              resultHandler.handleResult(resultContext);
         }
         
-        return result;
+        resultsCallback.done();
     }
 
     @Override

source/java/org/alfresco/repo/node/NodeServiceTest.java

@@ -241,11 +241,16 @@ public class NodeServiceTest extends TestCase
     public void testConcurrentArchive() throws Exception
     {
         final NodeRef workspaceRootNodeRef = nodeService.getRootNode(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE);
+        final NodeRef[] nodesPrimer = new NodeRef[1];
+        buildNodeHierarchy(workspaceRootNodeRef, nodesPrimer);
         final NodeRef[] nodesOne = new NodeRef[10];
         buildNodeHierarchy(workspaceRootNodeRef, nodesOne);
         final NodeRef[] nodesTwo = new NodeRef[10];
         buildNodeHierarchy(workspaceRootNodeRef, nodesTwo);
         
+        // Prime the root of the archive store (first child adds inherited ACL)
+        nodeService.deleteNode(nodesPrimer[0]);
+        
         RetryingTransactionCallback<Void> outerCallback = new RetryingTransactionCallback<Void>()
         {
             @Override
@@ -426,8 +431,41 @@ public class NodeServiceTest extends TestCase
         }
     }
     
+    public void testGetChildren_Limited()
+    {
+        // Create a node and loads of children
+        final NodeRef[] liveNodeRefs = new NodeRef[10];
+        final NodeRef workspaceRootNodeRef = nodeService.getRootNode(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE);
+
+        buildNodeHierarchy(workspaceRootNodeRef, liveNodeRefs);
+        
+        // Hook 3rd and subsequent children into 1st child
+        for (int i = 2; i < liveNodeRefs.length; i++)
+        {
+            nodeService.addChild(
+                    liveNodeRefs[0],
+                    liveNodeRefs[i],
+                    ContentModel.ASSOC_CONTAINS,
+                    QName.createQName(NAMESPACE, "secondary"));
+        }
+        
+        // Do limited queries each time
+        for (int i = 1; i < liveNodeRefs.length; i++)
+        {
+            List<ChildAssociationRef> childAssocRefs = nodeService.getChildAssocs(liveNodeRefs[0], null, null, i, true);
+            assertEquals("Expected exact number of child assocs", i, childAssocRefs.size());
+        }
+        
+        // Repeat, but don't preload
+        for (int i = 1; i < liveNodeRefs.length; i++)
+        {
+            List<ChildAssociationRef> childAssocRefs = nodeService.getChildAssocs(liveNodeRefs[0], null, null, i, false);
+            assertEquals("Expected exact number of child assocs", i, childAssocRefs.size());
+        }
+    }
+    
     /**
-     * Checks that the node caches react correct when a node is deleted
+     * Checks that the node caches react correctly when a node is deleted
      */
     public void testCaches_DeleteNode()
     {

source/java/org/alfresco/repo/node/db/DbNodeServiceImpl.java

@@ -1707,8 +1707,33 @@ public class DbNodeServiceImpl extends AbstractNodeServiceImpl
     {
         // Get the node
         Pair<Long, NodeRef> nodePair = getNodePairNotNull(nodeRef);
+        
+        // We have a callback handler to filter results
+        final List<ChildAssociationRef> results = new ArrayList<ChildAssociationRef>(10);
+        ChildAssocRefQueryCallback callback = new ChildAssocRefQueryCallback()
+        {
+            public boolean preLoadNodes()
+            {
+                return preload;
+            }
+            
+            public boolean handle(
+                    Pair<Long, ChildAssociationRef> childAssocPair,
+                    Pair<Long, NodeRef> parentNodePair,
+                    Pair<Long, NodeRef> childNodePair)
+            {
+                results.add(childAssocPair.getSecond());
+                return true;
+            }
+
+            public void done()
+            {
+            }                               
+        };
         // Get the assocs pointing to it
-        return nodeDAO.getChildAssocs(nodePair.getFirst(), typeQName, qname, maxResults, preload);
+        nodeDAO.getChildAssocs(nodePair.getFirst(), typeQName, qname, maxResults, callback);
+        // Done
+        return results;
     }
 
     public List<ChildAssociationRef> getChildAssocs(NodeRef nodeRef, Set<QName> childNodeTypeQNames)