| /* |
| * 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.ignite.internal.processors.query.h2.opt.join; |
| |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Comparator; |
| import java.util.Map; |
| import org.apache.ignite.internal.processors.query.h2.H2Utils; |
| import org.apache.ignite.internal.processors.query.h2.opt.GridH2IndexBase; |
| import org.h2.index.Cursor; |
| import org.h2.result.Row; |
| import org.h2.result.SearchRow; |
| |
| /** |
| * Merge cursor from multiple nodes. |
| */ |
| @SuppressWarnings("ComparatorNotSerializable") |
| public class BroadcastCursor implements Cursor, Comparator<RangeStream> { |
| /** Index. */ |
| private final GridH2IndexBase idx; |
| |
| /** */ |
| private final int rangeId; |
| |
| /** */ |
| private final RangeStream[] streams; |
| |
| /** */ |
| private boolean first = true; |
| |
| /** */ |
| private int off; |
| |
| /** |
| * @param rangeId Range ID. |
| * @param segmentKeys Remote nodes. |
| * @param rangeStreams Range streams. |
| */ |
| public BroadcastCursor(GridH2IndexBase idx, int rangeId, Collection<SegmentKey> segmentKeys, |
| Map<SegmentKey, RangeStream> rangeStreams) { |
| this.idx = idx; |
| this.rangeId = rangeId; |
| |
| streams = new RangeStream[segmentKeys.size()]; |
| |
| int i = 0; |
| |
| for (SegmentKey segmentKey : segmentKeys) { |
| RangeStream stream = rangeStreams.get(segmentKey); |
| |
| assert stream != null; |
| |
| streams[i++] = stream; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public int compare(RangeStream o1, RangeStream o2) { |
| if (o1 == o2) |
| return 0; |
| |
| // Nulls are at the beginning of array. |
| if (o1 == null) |
| return -1; |
| |
| if (o2 == null) |
| return 1; |
| |
| return idx.compareRows(o1.get(rangeId), o2.get(rangeId)); |
| } |
| |
| /** |
| * Try to fetch the first row. |
| * |
| * @return {@code true} If we were able to find at least one row. |
| */ |
| private boolean goFirst() { |
| // Fetch first row from all the streams and sort them. |
| for (int i = 0; i < streams.length; i++) { |
| if (!streams[i].next(rangeId)) { |
| streams[i] = null; |
| off++; // After sorting this offset will cut off all null elements at the beginning of array. |
| } |
| } |
| |
| if (off == streams.length) |
| return false; |
| |
| Arrays.sort(streams, this); |
| |
| return true; |
| } |
| |
| /** |
| * Fetch next row. |
| * |
| * @return {@code true} If we were able to find at least one row. |
| */ |
| private boolean goNext() { |
| assert off != streams.length; |
| |
| if (!streams[off].next(rangeId)) { |
| // Next row from current min stream was not found -> nullify that stream and bump offset forward. |
| streams[off] = null; |
| |
| return ++off != streams.length; |
| } |
| |
| // Bubble up current min stream with respect to fetched row to achieve correct sort order of streams. |
| H2Utils.bubbleUp(streams, off, this); |
| |
| return true; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public boolean next() { |
| if (first) { |
| first = false; |
| |
| return goFirst(); |
| } |
| |
| return goNext(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public Row get() { |
| return streams[off].get(rangeId); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public SearchRow getSearchRow() { |
| return get(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public boolean previous() { |
| throw new UnsupportedOperationException(); |
| } |
| } |