Github user eribeiro commented on a diff in the pull request:
https://github.com/apache/zookeeper/pull/136#discussion_r93960053
--- Diff: src/java/main/org/apache/zookeeper/server/PathIterator.java ---
@@ -0,0 +1,89 @@
+/**
+ * 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.
+ */
+
+package org.apache.zookeeper.server;
+
+import java.util.Iterator;
+
+/**
+ * Iterates over a ZooKeeper path. Each iteration goes up one parent path.
Thus, the
+ * effect of the iterator is to iterate over the initial path and then all
of its parents.
+ */
+public class PathIterator implements Iterator<String> {
+ private String path;
+ private int level = -1;
+
+ /**
+ * @param path initial path
+ */
+ public PathIterator(String path) {
+ // NOTE: asserts that the path has already been validated
+ this.path = path;
+ }
+
+ /**
+ * Return an Iterable view so that this Iterator can be used in for
each
+ * statements. IMPORTANT: the returned Iterable is single use only
+ * @return Iterable
+ */
+ public Iterable<String> asIterable() {
+ return new Iterable<String>() {
+ @Override
+ public Iterator<String> iterator() {
+ return PathIterator.this;
+ }
+ };
+ }
+
+ @Override
+ public boolean hasNext() {
+ return !path.isEmpty();
+ }
+
+ /**
+ * Returns true if this iterator is currently at a parent path as
opposed
+ * to the initial path given to the constructor
+ *
+ * @return true/false
+ */
+ public boolean atParentPath() {
+ return level > 0;
+ }
+
+ @Override
+ public String next() {
+ String localPath = path;
+ if (hasNext()) {
+ ++level;
+ if (path.equals("/")) {
+ path = "";
+ } else {
+ path = path.substring(0, path.lastIndexOf('/'));
+ if (path.length() == 0) {
+ path = "/";
+ }
+ }
+ }
--- End diff --
@Randgalt I had written about this previously, but I think it got lost in
my comment flood yesterday, excuse me:
By the ``Iterator#next()`` contract, if we call next() and there's no next
element it should throw a ``NoSuchElementException``, so an ``else`` clause
throwing this exception would be nice. ;)
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