InflateUDF.java example

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incubator-hivemall-master
/*
 * 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
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package hivemall.tools.compress;

import hivemall.utils.codec.DeflateCodec;
import hivemall.utils.hadoop.HiveUtils;
import hivemall.utils.io.IOUtils;

import java.io.IOException;
import java.util.Arrays;

import javax.annotation.Nonnull;

import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.UDFType;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.BinaryObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.Text;

@Description(name = "inflate",
        value = "_FUNC_(BINARY compressedData) - Returns a decompressed STRING by using Inflater")
@UDFType(deterministic = true, stateful = false)
public final class InflateUDF extends GenericUDF {

    private BinaryObjectInspector binaryOI;

    @Nonnull
    private transient DeflateCodec codec;
    @Nonnull
    private transient Text result;

    @Override
    public ObjectInspector initialize(ObjectInspector[] argOIs) throws UDFArgumentException {
        if (argOIs.length != 1) {
            throw new UDFArgumentException("_FUNC_ takes exactly 1 argument");
        }
        this.binaryOI = HiveUtils.asBinaryOI(argOIs[0]);

        return PrimitiveObjectInspectorFactory.writableStringObjectInspector;
    }

    @Override
    public Text evaluate(DeferredObject[] arguments) throws HiveException {
        if (codec == null) {
            this.codec = new DeflateCodec(false, true);
        }

        Object arg0 = arguments[0].get();
        if (arg0 == null) {
            return null;
        }
        BytesWritable b = binaryOI.getPrimitiveWritableObject(arg0);
        byte[] compressed = b.getBytes();
        final int len = b.getLength();
        final byte[] decompressed;
        try {
            decompressed = codec.decompress(compressed, 0, len);
        } catch (IOException e) {
            throw new HiveException("Failed to decompressed. Compressed data format is illegal.", e);
        }
        compressed = null;
        if (result == null) {
            result = new Text(decompressed);
        } else {
            result.set(decompressed, 0, decompressed.length);
        }
        return result;
    }

    @Override
    public void close() throws IOException {
        IOUtils.closeQuietly(codec);
        this.codec = null;
        this.result = null;
    }

    @Override
    public String getDisplayString(String[] children) {
        return "inflate(" + Arrays.toString(children) + ")";
    }

}