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/*
* 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.tsfile.encoding.decoder;
import org.apache.tsfile.exception.encoding.TsFileDecodingException;
import org.apache.tsfile.file.metadata.enums.TSEncoding;
import org.apache.tsfile.utils.Binary;
import org.apache.tsfile.utils.Pair;
import org.apache.tsfile.utils.ReadWriteForEncodingUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.math.BigDecimal;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Decoder switch or enums value using bitmap, bitmap-encoding:. {@code
* }
*
* @deprecated (2019.1.25, The bitmap data type has been removed., We can reserve this class, and
* reuse it later.)
*/
@Deprecated
public class BitmapDecoder extends Decoder {
private static final Logger logger = LoggerFactory.getLogger(BitmapDecoder.class);
/** how many bytes for all encoded data in input stream. */
private int length;
/** number of encoded data. */
private int number;
/** number of data left for reading in current buffer. */
private int currentCount;
/**
* each time decoder receives a inputstream, decoder creates a buffer to save all encoded data.
*/
private ByteBuffer byteCache;
/** decoder reads all bitmap index from byteCache and save in Map(value, bitmap index). */
private Map buffer;
/** BitmapDecoder constructor. */
public BitmapDecoder() {
super(TSEncoding.BITMAP);
this.reset();
logger.debug("tsfile-encoding BitmapDecoder: init bitmap decoder");
}
@Override
public int readInt(ByteBuffer buffer) {
if (currentCount == 0) {
reset();
getLengthAndNumber(buffer);
readNext();
}
int result = 0;
int index = (number - currentCount) / 8;
int offset = 7 - ((number - currentCount) % 8);
for (Map.Entry entry : this.buffer.entrySet()) {
byte[] tmp = entry.getValue();
if (((tmp[index] & 0xff) & ((byte) 1 << offset)) != 0) {
result = entry.getKey();
}
}
currentCount--;
return result;
}
private void getLengthAndNumber(ByteBuffer buffer) {
this.length = ReadWriteForEncodingUtils.readUnsignedVarInt(buffer);
this.number = ReadWriteForEncodingUtils.readUnsignedVarInt(buffer);
// TODO maybe this.byteCache = buffer is faster, but not safe
byte[] tmp = new byte[length];
buffer.get(tmp, 0, length);
this.byteCache = ByteBuffer.wrap(tmp);
}
/** Decode all data from buffer and save them. */
private void readNext() {
int len = (this.number + 7) / 8;
while (byteCache.remaining() > 0) {
int value = ReadWriteForEncodingUtils.readUnsignedVarInt(byteCache);
byte[] tmp = new byte[len];
byteCache.get(tmp, 0, len);
buffer.put(value, tmp);
}
currentCount = number;
}
@Override
public void reset() {
this.length = 0;
this.number = 0;
this.currentCount = 0;
if (this.byteCache == null) {
this.byteCache = ByteBuffer.allocate(0);
} else {
this.byteCache.position(0);
}
if (this.buffer == null) {
this.buffer = new HashMap<>();
} else {
this.buffer.clear();
}
}
/**
* For special value in page list, get its bitmap index.
*
* @param target value to get its bitmap index
* @param pageList input page list
* @return List(Pair of ( length, bitmap index) )
*/
public List> decodeAll(int target, List pageList) {
List> resultList = new ArrayList<>();
for (ByteBuffer bufferPage : pageList) {
reset();
getLengthAndNumber(bufferPage);
int byteArrayLength = (this.number + 7) / 8;
byte[] tmp = new byte[byteArrayLength];
while (byteCache.remaining() > 0) {
int value = ReadWriteForEncodingUtils.readUnsignedVarInt(byteCache);
if (value == target) {
byteCache.get(tmp, 0, byteArrayLength);
break;
} else {
byteCache.position(byteCache.position() + byteArrayLength);
}
}
resultList.add(new Pair<>(this.number, tmp));
logger.debug(
"tsfile-encoding BitmapDecoder: number {} in current page, byte length {}",
this.number,
byteArrayLength);
}
return resultList;
}
/**
* Check whether there is number left for reading.
*
* @param buffer : decoded data saved in InputStream
* @return true or false to indicate whether there is number left
* @throws IOException cannot read next value
*/
@Override
public boolean hasNext(ByteBuffer buffer) {
if (currentCount > 0 || buffer.remaining() > 0) {
return true;
}
return false;
}
/**
* In current version, boolean value is equal to Enums value in schema.
*
* @param buffer : decoded data saved in InputStream
* @throws TsFileDecodingException cannot read next value
*/
@Override
public boolean readBoolean(ByteBuffer buffer) {
throw new TsFileDecodingException("Method readBoolean is not supported by BitmapDecoder");
}
@Override
public short readShort(ByteBuffer buffer) {
throw new TsFileDecodingException("Method readShort is not supported by BitmapDecoder");
}
@Override
public long readLong(ByteBuffer buffer) {
throw new TsFileDecodingException("Method readLong is not supported by BitmapDecoder");
}
@Override
public float readFloat(ByteBuffer buffer) {
throw new TsFileDecodingException("Method readFloat is not supported by BitmapDecoder");
}
@Override
public double readDouble(ByteBuffer buffer) {
throw new TsFileDecodingException("Method readDouble is not supported by BitmapDecoder");
}
@Override
public Binary readBinary(ByteBuffer buffer) {
throw new TsFileDecodingException("Method readBinary is not supported by BitmapDecoder");
}
@Override
public BigDecimal readBigDecimal(ByteBuffer buffer) {
throw new TsFileDecodingException("Method readBigDecimal is not supported by BitmapDecoder");
}
}