| /* |
| * 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; |
| |
| import org.apache.iotdb.tsfile.exception.TsFileRuntimeException; |
| import org.apache.iotdb.tsfile.file.metadata.IDeviceID; |
| import org.apache.iotdb.tsfile.file.metadata.MetadataIndexNode; |
| import org.apache.iotdb.tsfile.utils.Pair; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| import java.util.Queue; |
| |
| public class TsFileDeviceIterator implements Iterator<Pair<IDeviceID, Boolean>> { |
| private final TsFileSequenceReader reader; |
| |
| // device -> firstMeasurmentNode offset |
| private final Queue<Pair<IDeviceID, long[]>> queue; |
| private Pair<IDeviceID, Boolean> currentDevice = null; |
| private MetadataIndexNode measurementNode; |
| |
| // <startOffset, endOffset>, device leaf node offset in this file |
| private final List<long[]> leafDeviceNodeOffsetList; |
| |
| public TsFileDeviceIterator( |
| TsFileSequenceReader reader, |
| List<long[]> leafDeviceNodeOffsetList, |
| Queue<Pair<IDeviceID, long[]>> queue) { |
| this.reader = reader; |
| this.queue = queue; |
| this.leafDeviceNodeOffsetList = leafDeviceNodeOffsetList; |
| } |
| |
| public Pair<IDeviceID, Boolean> current() { |
| return currentDevice; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| if (!queue.isEmpty()) { |
| return true; |
| } else if (leafDeviceNodeOffsetList.isEmpty()) { |
| // device queue is empty and all device leaf node has been read |
| return false; |
| } else { |
| // queue is empty but there are still some devices on leaf node not being read yet |
| long[] nextDeviceLeafNodeOffset = leafDeviceNodeOffsetList.remove(0); |
| try { |
| reader.getDevicesAndEntriesOfOneLeafNode( |
| nextDeviceLeafNodeOffset[0], nextDeviceLeafNodeOffset[1], queue); |
| } catch (IOException e) { |
| throw new RuntimeException(e); |
| } |
| return true; |
| } |
| } |
| |
| @Override |
| public Pair<IDeviceID, Boolean> next() { |
| if (!hasNext()) { |
| throw new NoSuchElementException(); |
| } |
| Pair<IDeviceID, long[]> startEndPair = queue.remove(); |
| try { |
| // get the first measurement node of this device, to know if the device is aligned |
| this.measurementNode = |
| reader.readMetadataIndexNode(startEndPair.right[0], startEndPair.right[1], false); |
| boolean isAligned = reader.isAlignedDevice(measurementNode); |
| currentDevice = new Pair<>(startEndPair.left, isAligned); |
| return currentDevice; |
| } catch (IOException e) { |
| throw new TsFileRuntimeException( |
| "Error occurred while reading a time series metadata block."); |
| } |
| } |
| |
| public MetadataIndexNode getFirstMeasurementNodeOfCurrentDevice() { |
| return measurementNode; |
| } |
| } |