| /* |
| * 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.iotdb.tsfile.read.reader.page; |
| |
| import org.apache.iotdb.tsfile.read.TimeValuePair; |
| import org.apache.iotdb.tsfile.read.reader.IPointReader; |
| import org.apache.iotdb.tsfile.utils.TsPrimitiveType; |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| /** |
| * This class is used to read data of aligned-series row by row. It won't deserialize all data point |
| * of one page in memory. In contrast, it constructs row one by one as needed |
| */ |
| public class LazyLoadAlignedPagePointReader implements IPointReader { |
| |
| private final TimePageReader timeReader; |
| private final List<ValuePageReader> valueReaders; |
| |
| private boolean hasNextRow = false; |
| |
| private int timeIndex; |
| private long currentTime; |
| private TsPrimitiveType currentRow; |
| |
| public LazyLoadAlignedPagePointReader( |
| TimePageReader timeReader, List<ValuePageReader> valueReaders) throws IOException { |
| this.timeIndex = -1; |
| this.timeReader = timeReader; |
| this.valueReaders = valueReaders; |
| prepareNextRow(); |
| } |
| |
| private void prepareNextRow() throws IOException { |
| while (true) { |
| if (!timeReader.hasNextTime()) { |
| hasNextRow = false; |
| return; |
| } |
| currentTime = timeReader.nextTime(); |
| timeIndex++; |
| boolean someValueNotNull = false; |
| TsPrimitiveType[] valuesInThisRow = new TsPrimitiveType[valueReaders.size()]; |
| for (int i = 0; i < valueReaders.size(); i++) { |
| TsPrimitiveType value = |
| valueReaders.get(i) == null |
| ? null |
| : valueReaders.get(i).nextValue(currentTime, timeIndex); |
| someValueNotNull = someValueNotNull || (value != null); |
| valuesInThisRow[i] = value; |
| } |
| if (someValueNotNull) { |
| currentRow = new TsPrimitiveType.TsVector(valuesInThisRow); |
| hasNextRow = true; |
| break; |
| } |
| } |
| } |
| |
| @Override |
| public boolean hasNextTimeValuePair() throws IOException { |
| return hasNextRow; |
| } |
| |
| @Override |
| public TimeValuePair nextTimeValuePair() throws IOException { |
| TimeValuePair ret = currentTimeValuePair(); |
| prepareNextRow(); |
| return ret; |
| } |
| |
| @Override |
| public TimeValuePair currentTimeValuePair() throws IOException { |
| return new TimeValuePair(currentTime, currentRow); |
| } |
| |
| @Override |
| public long getUsedMemorySize() { |
| // not used |
| return 0; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| // do nothing |
| } |
| } |