pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / queryparser / src / java / org / apache / lucene / queryParser / core / processors / RemoveDeletedQueryNodesProcessor.java

diff --git a/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/core/processors/RemoveDeletedQueryNodesProcessor.java b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/core/processors/RemoveDeletedQueryNodesProcessor.java
new file mode 100644 (file)
index 0000000..dcb3335
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/core/processors/RemoveDeletedQueryNodesProcessor.java
@@ -0,0 +1,113 @@
+package org.apache.lucene.queryParser.core.processors;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+import java.util.Iterator;
+import java.util.List;
+
+import org.apache.lucene.queryParser.core.QueryNodeException;
+import org.apache.lucene.queryParser.core.nodes.DeletedQueryNode;
+import org.apache.lucene.queryParser.core.nodes.MatchNoDocsQueryNode;
+import org.apache.lucene.queryParser.core.nodes.QueryNode;
+
+/**
+ * A {@link QueryNodeProcessorPipeline} class removes every instance of
+ * {@link DeletedQueryNode} from a query node tree. If the resulting root node
+ * is a {@link DeletedQueryNode}, {@link MatchNoDocsQueryNode} is returned.
+ * 
+ */
+public class RemoveDeletedQueryNodesProcessor extends QueryNodeProcessorImpl {
+
+  public RemoveDeletedQueryNodesProcessor() {
+    // empty constructor
+  }
+
+  @Override
+  public QueryNode process(QueryNode queryTree) throws QueryNodeException {
+    queryTree = super.process(queryTree);
+
+    if (queryTree instanceof DeletedQueryNode
+        && !(queryTree instanceof MatchNoDocsQueryNode)) {
+
+      return new MatchNoDocsQueryNode();
+
+    }
+
+    return queryTree;
+
+  }
+
+  @Override
+  protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
+
+    if (!node.isLeaf()) {
+      List<QueryNode> children = node.getChildren();
+      boolean removeBoolean = false;
+
+      if (children == null || children.size() == 0) {
+        removeBoolean = true;
+
+      } else {
+        removeBoolean = true;
+
+        for (Iterator<QueryNode> it = children.iterator(); it.hasNext();) {
+
+          if (!(it.next() instanceof DeletedQueryNode)) {
+            removeBoolean = false;
+            break;
+
+          }
+
+        }
+
+      }
+
+      if (removeBoolean) {
+        return new DeletedQueryNode();
+      }
+
+    }
+
+    return node;
+
+  }
+
+  @Override
+  protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
+      throws QueryNodeException {
+
+    for (int i = 0; i < children.size(); i++) {
+
+      if (children.get(i) instanceof DeletedQueryNode) {
+        children.remove(i--);
+      }
+
+    }
+
+    return children;
+
+  }
+
+  @Override
+  protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
+
+    return node;
+
+  }
+
+}