| /* |
| * 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.segment; |
| |
| import static com.google.common.collect.Maps.newHashMap; |
| import static java.lang.System.arraycopy; |
| import static java.util.Arrays.binarySearch; |
| |
| import java.util.Map; |
| |
| /** |
| * A memory optimised set of {@link RecordId}s. |
| * |
| * The set doesn't keep references to the actual record ids |
| * it contains. |
| */ |
| public class RecordIdSet { |
| private final Map<String, IntSet> seenIds = newHashMap(); |
| |
| /** |
| * Add {@code id} to this set if not already present |
| * @param id the record id to add |
| * @return {@code true} if added, {@code false} if already present |
| */ |
| public boolean addIfNotPresent(RecordId id) { |
| String segmentId = id.getSegmentId().toString(); |
| IntSet offsets = seenIds.get(segmentId); |
| if (offsets == null) { |
| offsets = new IntSet(); |
| seenIds.put(segmentId, offsets); |
| } |
| return offsets.add(id.getRecordNumber()); |
| } |
| |
| /** |
| * Check whether {@code id} is present is this set. |
| * @param id the record id to check for |
| * @return {@code true} iff {@code id} is present. |
| */ |
| public boolean contains(RecordId id) { |
| String segmentId = id.getSegmentId().toString(); |
| IntSet offsets = seenIds.get(segmentId); |
| return offsets != null && offsets.contains(id.getRecordNumber()); |
| } |
| |
| static class IntSet { |
| int[] elements; |
| |
| boolean add(int n) { |
| if (elements == null) { |
| elements = new int[1]; |
| elements[0] = n; |
| return true; |
| } else { |
| int k = binarySearch(elements, n); |
| if (k < 0) { |
| int l = -k - 1; |
| int[] e = new int[elements.length + 1]; |
| arraycopy(elements, 0, e, 0, l); |
| e[l] = n; |
| int c = elements.length - l; |
| if (c > 0) { |
| arraycopy(elements, l, e, l + 1, c); |
| } |
| elements = e; |
| return true; |
| } else { |
| return false; |
| } |
| } |
| } |
| |
| boolean contains(int n) { |
| return elements != null && binarySearch(elements, n) >= 0; |
| } |
| } |
| |
| } |