| /* |
| * 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.encoding.decoder; |
| |
| import org.apache.iotdb.tsfile.encoding.encoder.RegularDataEncoder; |
| import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding; |
| import org.apache.iotdb.tsfile.utils.ReadWriteIOUtils; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.BitSet; |
| |
| /** |
| * This class is a decoder for decoding the byte array that encoded by {@code RegularDataEncoder}. |
| * RegularDataDecoder only supports integer and long values.<br> |
| * . |
| * |
| * @see RegularDataEncoder |
| */ |
| public abstract class RegularDataDecoder extends Decoder { |
| |
| /** the first value in one pack. */ |
| protected int readIntTotalCount = 0; |
| |
| protected int nextReadIndex = 0; |
| /** data number in this pack. */ |
| protected int packNum; |
| |
| public RegularDataDecoder() { |
| super(TSEncoding.REGULAR); |
| } |
| |
| protected abstract void readHeader(ByteBuffer buffer) throws IOException; |
| |
| protected abstract void allocateDataArray(); |
| |
| protected abstract void readValue(int i); |
| |
| @Override |
| public boolean hasNext(ByteBuffer buffer) throws IOException { |
| return (nextReadIndex < readIntTotalCount) || buffer.remaining() > 0; |
| } |
| |
| public static class IntRegularDecoder extends RegularDataDecoder { |
| |
| private int[] data; |
| private int firstValue; |
| private int previous; |
| private boolean isMissingPoint; |
| private BitSet bitmap; |
| private int bitmapIndex; |
| /** minimum value for all difference. */ |
| private int minDeltaBase; |
| |
| public IntRegularDecoder() { |
| super(); |
| } |
| |
| /** |
| * if there's no decoded data left, decode next pack into {@code data}. |
| * |
| * @param buffer ByteBuffer |
| * @return long value |
| */ |
| protected int readT(ByteBuffer buffer) { |
| if (nextReadIndex == readIntTotalCount) { |
| isMissingPoint = ReadWriteIOUtils.readBool(buffer); |
| if (isMissingPoint) { |
| readBitmap(buffer); |
| } |
| return loadIntBatch(buffer); // load first value |
| } |
| if (isMissingPoint) { |
| bitmapIndex++; |
| return loadWithBitmap(buffer); |
| } |
| return data[nextReadIndex++]; |
| } |
| |
| private void readBitmap(ByteBuffer buffer) { |
| int length = ReadWriteIOUtils.readInt(buffer); |
| byte[] byteArr = new byte[length]; |
| buffer.get(byteArr); |
| bitmap = BitSet.valueOf(byteArr); |
| bitmapIndex = 0; |
| } |
| |
| /** |
| * load the data with bitmap (when bitmap denote the element with false, load next element) |
| * |
| * @param buffer |
| * @return long value |
| */ |
| protected int loadWithBitmap(ByteBuffer buffer) { |
| while (!bitmap.get(bitmapIndex)) { |
| bitmapIndex++; |
| } |
| nextReadIndex = bitmapIndex - 1; |
| return data[nextReadIndex]; |
| } |
| |
| /** |
| * if remaining data has been run out, load next pack from InputStream. |
| * |
| * @param buffer ByteBuffer |
| * @return int value |
| */ |
| protected int loadIntBatch(ByteBuffer buffer) { |
| packNum = ReadWriteIOUtils.readInt(buffer); |
| readHeader(buffer); |
| |
| allocateDataArray(); |
| |
| readIntTotalCount = isMissingPoint ? (packNum - 2) : (packNum - 1); |
| previous = firstValue; |
| nextReadIndex = 0; |
| readPack(); |
| return firstValue; |
| } |
| |
| private void readPack() { |
| for (int i = 0; i < data.length; i++) { |
| readValue(i); |
| previous = data[i]; |
| } |
| } |
| |
| @Override |
| public int readInt(ByteBuffer buffer) { |
| return readT(buffer); |
| } |
| |
| @Override |
| protected void readHeader(ByteBuffer buffer) { |
| minDeltaBase = ReadWriteIOUtils.readInt(buffer); |
| firstValue = ReadWriteIOUtils.readInt(buffer); |
| } |
| |
| @Override |
| protected void allocateDataArray() { |
| data = new int[packNum - 1]; |
| } |
| |
| @Override |
| protected void readValue(int i) { |
| data[i] = previous + minDeltaBase; |
| } |
| |
| @Override |
| public void reset() { |
| // do nothing |
| } |
| } |
| |
| public static class LongRegularDecoder extends RegularDataDecoder { |
| |
| private long[] data; |
| private long firstValue; |
| private long previous; |
| private boolean isMissingPoint; |
| private BitSet bitmap; |
| private int bitmapIndex; |
| /** minimum value for all difference. */ |
| private long minDeltaBase; |
| |
| public LongRegularDecoder() { |
| super(); |
| } |
| |
| /** |
| * if there's no decoded data left, decode next pack into {@code data}. |
| * |
| * @param buffer ByteBuffer |
| * @return long value |
| */ |
| protected long readT(ByteBuffer buffer) { |
| if (nextReadIndex == readIntTotalCount) { |
| isMissingPoint = ReadWriteIOUtils.readBool(buffer); |
| if (isMissingPoint) { |
| readBitmap(buffer); |
| } |
| return loadIntBatch(buffer); // load first value |
| } |
| if (isMissingPoint) { |
| bitmapIndex++; |
| return loadWithBitmap(buffer); |
| } |
| return data[nextReadIndex++]; |
| } |
| |
| private void readBitmap(ByteBuffer buffer) { |
| int length = ReadWriteIOUtils.readInt(buffer); |
| byte[] byteArr = new byte[length]; |
| buffer.get(byteArr); |
| bitmap = BitSet.valueOf(byteArr); |
| bitmapIndex = 0; |
| } |
| |
| /** |
| * load the data with bitmap (when bitmap denote the element with false, load next element) |
| * |
| * @param buffer |
| * @return long value |
| */ |
| protected long loadWithBitmap(ByteBuffer buffer) { |
| while (!bitmap.get(bitmapIndex)) { |
| bitmapIndex++; |
| } |
| nextReadIndex = bitmapIndex - 1; |
| return data[nextReadIndex]; |
| } |
| |
| /** |
| * if remaining data has been run out, load next pack from InputStream. |
| * |
| * @param buffer ByteBuffer |
| * @return long value |
| */ |
| protected long loadIntBatch(ByteBuffer buffer) { |
| packNum = ReadWriteIOUtils.readInt(buffer); |
| readHeader(buffer); |
| |
| allocateDataArray(); |
| |
| readIntTotalCount = isMissingPoint ? (packNum - 2) : (packNum - 1); |
| previous = firstValue; |
| nextReadIndex = 0; |
| readPack(); |
| return firstValue; |
| } |
| |
| private void readPack() { |
| for (int i = 0; i < data.length; i++) { |
| readValue(i); |
| previous = data[i]; |
| } |
| } |
| |
| @Override |
| public long readLong(ByteBuffer buffer) { |
| return readT(buffer); |
| } |
| |
| @Override |
| protected void readHeader(ByteBuffer buffer) { |
| minDeltaBase = ReadWriteIOUtils.readLong(buffer); |
| firstValue = ReadWriteIOUtils.readLong(buffer); |
| } |
| |
| @Override |
| protected void allocateDataArray() { |
| data = new long[packNum - 1]; |
| } |
| |
| @Override |
| protected void readValue(int i) { |
| data[i] = previous + minDeltaBase; |
| } |
| |
| @Override |
| public void reset() { |
| // do nothing |
| } |
| } |
| } |