| /* |
| * Copyright 2017 HugeGraph Authors |
| * |
| * 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 com.baidu.hugegraph.computer.core.sort.flusher; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| |
| import com.baidu.hugegraph.computer.core.combiner.PointerCombiner; |
| import com.baidu.hugegraph.computer.core.store.entry.DefaultKvEntry; |
| import com.baidu.hugegraph.computer.core.store.entry.KvEntry; |
| import com.baidu.hugegraph.computer.core.store.entry.Pointer; |
| import com.baidu.hugegraph.util.E; |
| |
| public abstract class CombinableSorterFlusher { |
| |
| private final PointerCombiner combiner; |
| |
| public CombinableSorterFlusher(PointerCombiner combiner) { |
| this.combiner = combiner; |
| } |
| |
| public void flush(Iterator<KvEntry> entries) throws IOException { |
| E.checkArgument(entries.hasNext(), |
| "Parameter entries can't be empty"); |
| |
| KvEntry last = entries.next(); |
| Pointer combineValue = last.value(); |
| |
| while (true) { |
| KvEntry current = null; |
| if (entries.hasNext()) { |
| current = entries.next(); |
| if (last.compareTo(current) == 0) { |
| combineValue = this.combiner.combine(combineValue, |
| current.value()); |
| continue; |
| } |
| } |
| |
| this.writeKvEntry(new DefaultKvEntry(last.key(), combineValue)); |
| |
| if (current == null) { |
| break; |
| } |
| |
| last = current; |
| combineValue = last.value(); |
| } |
| } |
| |
| protected abstract void writeKvEntry(KvEntry entry) throws IOException; |
| } |