thomasmueller commented on code in PR #1707: URL: https://github.com/apache/jackrabbit-oak/pull/1707#discussion_r1761041004
########## oak-run-commons/src/main/java/org/apache/jackrabbit/oak/index/indexer/document/tree/ParallelTreeStore.java: ########## @@ -0,0 +1,103 @@ +/* + * 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.jackrabbit.oak.index.indexer.document.tree; + +import java.io.IOException; +import java.util.Iterator; +import java.util.concurrent.atomic.AtomicInteger; + +import org.apache.jackrabbit.oak.index.indexer.document.NodeStateEntry; +import org.apache.jackrabbit.oak.index.indexer.document.indexstore.IndexStore; + +/** + * A wrapper around the tree store that only iterates over a subset of the + * nodes. Each parallel tree store for reads the next block (a block is a tiny + * subset of the nodes). Once it has finished iterating over the block, it asks + * the backend for the next block. The result is that the whole range is + * covered, but it doesn't matter much which thread is how fast. + */ +public class ParallelTreeStore implements IndexStore { + + private final TreeStore backend; + private final AtomicInteger openCount; + + ParallelTreeStore(TreeStore backend, AtomicInteger openCount) { + this.backend = backend; + this.openCount = openCount; + } + + @Override + public Iterator<NodeStateEntry> iterator() { + return new Iterator<NodeStateEntry>() { + + private Iterator<NodeStateEntry> currentIterator = backend.nextSubsetIterator(); + + @Override + public boolean hasNext() { + while (currentIterator != null && !currentIterator.hasNext()) { + currentIterator = backend.nextSubsetIterator(); + } + if (currentIterator == null) { + return false; + } + return true; + } + + @Override + public NodeStateEntry next() { + hasNext(); Review Comment: You are right this is not obvious. No, this is not needed. I'll add a comment on why. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
