| /** |
| * 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 |
| * <p> |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * <p> |
| * 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.storm.state; |
| |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.TreeSet; |
| import org.apache.storm.shade.com.google.common.collect.Iterators; |
| import org.apache.storm.shade.com.google.common.primitives.UnsignedBytes; |
| |
| /** |
| * Base implementation of iterator over {@link KeyValueState} which encoded types of key and value are both binary type. |
| */ |
| public abstract class BaseBinaryStateIterator<K, V> extends BaseStateIterator<K, V, byte[], byte[]> { |
| |
| /** |
| * Constructor. |
| * |
| * @param pendingPrepareIterator The iterator of pendingPrepare |
| * @param pendingCommitIterator The iterator of pendingCommit |
| */ |
| public BaseBinaryStateIterator(Iterator<Map.Entry<byte[], byte[]>> pendingPrepareIterator, |
| Iterator<Map.Entry<byte[], byte[]>> pendingCommitIterator) { |
| super(Iterators.peekingIterator(pendingPrepareIterator), Iterators.peekingIterator(pendingCommitIterator), |
| new TreeSet<>(UnsignedBytes.lexicographicalComparator())); |
| } |
| |
| /** |
| * Load some part of state KVs from storage and returns iterator of cached data from storage. |
| * |
| * @return Iterator of loaded state KVs |
| */ |
| @Override |
| protected abstract Iterator<Map.Entry<byte[], byte[]>> loadChunkFromStateStorage(); |
| |
| /** |
| * Check whether end of data is reached from storage state KVs. |
| * |
| * @return whether end of data is reached from storage state KVs |
| */ |
| @Override |
| protected abstract boolean isEndOfDataFromStorage(); |
| |
| /** |
| * Decode key to convert byte array to state key type. |
| * |
| * @param key byte array encoded key |
| * @return Decoded value of key |
| */ |
| @Override |
| protected abstract K decodeKey(byte[] key); |
| |
| /** |
| * Decode value to convert byte array to state value type. |
| * |
| * @param value byte array encoded value |
| * @return Decoded value of value |
| */ |
| @Override |
| protected abstract V decodeValue(byte[] value); |
| |
| /** |
| * Check whether the value is tombstone (deletion mark) value. |
| * |
| * @param value the value to check |
| * @return true if the value is tombstone, false otherwise |
| */ |
| @Override |
| protected abstract boolean isTombstoneValue(byte[] value); |
| |
| } |