org.apache.hadoop.hive.serde2.io.BigDecimalWritable.java Source code

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Here is the source code for org.apache.hadoop.hive.serde2.io.BigDecimalWritable.java

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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.hadoop.hive.serde2.io;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.BigInteger;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.serde2.ByteStream.Output;
import org.apache.hadoop.hive.serde2.lazybinary.LazyBinaryUtils;
import org.apache.hadoop.hive.serde2.lazybinary.LazyBinaryUtils.VInt;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.WritableUtils;

public class BigDecimalWritable implements WritableComparable<BigDecimalWritable> {

    static final private Log LOG = LogFactory.getLog(BigDecimalWritable.class);

    private byte[] internalStorage = new byte[0];
    private int scale;

    private final VInt vInt = new VInt(); // reusable integer

    public BigDecimalWritable() {
    }

    public BigDecimalWritable(byte[] bytes, int scale) {
        set(bytes, scale);
    }

    public BigDecimalWritable(BigDecimalWritable writable) {
        set(writable.getBigDecimal());
    }

    public BigDecimalWritable(BigDecimal value) {
        set(value);
    }

    public void set(BigDecimal value) {
        value = value.stripTrailingZeros();
        if (value.compareTo(BigDecimal.ZERO) == 0) {
            // Special case for 0, because java doesn't strip zeros correctly on that number.
            value = BigDecimal.ZERO;
        }
        set(value.unscaledValue().toByteArray(), value.scale());
    }

    public void set(BigDecimalWritable writable) {
        set(writable.getBigDecimal());
    }

    public void set(byte[] bytes, int scale) {
        this.internalStorage = bytes;
        this.scale = scale;
    }

    public void setFromBytes(byte[] bytes, int offset, int length) {
        LazyBinaryUtils.readVInt(bytes, offset, vInt);
        scale = vInt.value;
        offset += vInt.length;
        LazyBinaryUtils.readVInt(bytes, offset, vInt);
        offset += vInt.length;
        if (internalStorage.length != vInt.value) {
            internalStorage = new byte[vInt.value];
        }
        System.arraycopy(bytes, offset, internalStorage, 0, vInt.value);
    }

    public BigDecimal getBigDecimal() {
        return new BigDecimal(new BigInteger(internalStorage), scale);
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        scale = WritableUtils.readVInt(in);
        int byteArrayLen = WritableUtils.readVInt(in);
        if (internalStorage.length != byteArrayLen) {
            internalStorage = new byte[byteArrayLen];
        }
        in.readFully(internalStorage);
    }

    @Override
    public void write(DataOutput out) throws IOException {
        WritableUtils.writeVInt(out, scale);
        WritableUtils.writeVInt(out, internalStorage.length);
        out.write(internalStorage);
    }

    @Override
    public int compareTo(BigDecimalWritable that) {
        return getBigDecimal().compareTo(that.getBigDecimal());
    }

    public void writeToByteStream(Output byteStream) {
        LazyBinaryUtils.writeVInt(byteStream, scale);
        LazyBinaryUtils.writeVInt(byteStream, internalStorage.length);
        byteStream.write(internalStorage, 0, internalStorage.length);
    }

    @Override
    public String toString() {
        return getBigDecimal().toString();
    }

    @Override
    public boolean equals(Object other) {
        if (other == null || !(other instanceof BigDecimalWritable)) {
            return false;
        }
        BigDecimalWritable bdw = (BigDecimalWritable) other;

        // 'equals' and 'compareTo' are not compatible with BigDecimals. We want 
        // compareTo which returns true iff the numbers are equal (e.g.: 3.14 is 
        // the same as 3.140). 'Equals' returns true iff equal and the same scale 
        // is set in the decimals (e.g.: 3.14 is not the same as 3.140)
        return getBigDecimal().compareTo(bdw.getBigDecimal()) == 0;
    }

    @Override
    public int hashCode() {
        return getBigDecimal().hashCode();
    }
}