| /* |
| * 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.geode.internal.cache.versions; |
| |
| import java.util.BitSet; |
| import java.util.Iterator; |
| |
| /** |
| * An iterator on a bit set that produces {@link RVVException} for gaps |
| * in the set bits in the bitset. |
| */ |
| public class BitSetExceptionIterator implements Iterator<RVVException> { |
| private final BitSet bitSet; |
| private long bitSetVersion; |
| private final long maximumVersion; |
| private long nextClearBit; |
| |
| /** |
| * Create a new bitset iterator |
| * |
| * @param bitSet The bitset to iterate on |
| * @param bitSetVersion An offset of the bitset. If this iterator generates a RVVException, |
| * the previous and next values will include this base value. |
| * @param maximumVersion The value to stop creating exceptions at. This should be greater than |
| * bitSetVersion. This may be within the bitSetVersion+bitSet.size, or it could be much |
| * large. |
| * If this value falls within the bitset, gaps past this value will not be returned as |
| * RVVExceptions |
| * by this iterator. |
| */ |
| public BitSetExceptionIterator(BitSet bitSet, long bitSetVersion, long maximumVersion) { |
| this.bitSet = bitSet; |
| this.bitSetVersion = bitSetVersion; |
| this.maximumVersion = maximumVersion; |
| this.nextClearBit = findNextClearBit(bitSet, 0); |
| } |
| |
| /** |
| * Find the next clear bit from a given index in the bitset, that is less than or |
| * equal to our maximum version for this iterator. |
| * |
| * @return the next clear bit, or -1 if there is no next clear bit within the range. |
| */ |
| private int findNextClearBit(BitSet bitSet, int fromIndex) { |
| int nextClearBit = bitSet.nextClearBit(fromIndex); |
| |
| long maxmimumClearBit = maximumVersion - bitSetVersion; |
| if (nextClearBit >= maxmimumClearBit) { |
| // We found empty bits, but past the offset we are interested in |
| // Ignore these |
| return -1; |
| } |
| |
| return nextClearBit; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return nextClearBit != -1; |
| } |
| |
| @Override |
| public RVVException next() { |
| if (!hasNext()) { |
| return null; |
| } |
| |
| int nextSetBit = bitSet.nextSetBit((int) Math.min(Integer.MAX_VALUE, nextClearBit)); |
| |
| long nextSetVersion = nextSetBit == -1 ? maximumVersion : nextSetBit + bitSetVersion; |
| |
| RVVException exception = |
| RVVException.createException(nextClearBit + bitSetVersion - 1, nextSetVersion); |
| |
| nextClearBit = nextSetBit == -1 ? -1 : findNextClearBit(bitSet, nextSetBit); |
| |
| return exception; |
| } |
| } |