io.druid.query.extraction.LookupExtractionFn.java Source code

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Here is the source code for io.druid.query.extraction.LookupExtractionFn.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  Metamarkets 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 io.druid.query.extraction;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Function;
import com.google.common.base.Strings;
import com.google.common.base.Throwables;
import com.metamx.common.StringUtils;

import javax.annotation.Nullable;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class LookupExtractionFn extends FunctionalExtraction {
    private static final byte CACHE_TYPE_ID = 0x5;

    private final LookupExtractor lookup;

    @JsonCreator
    public LookupExtractionFn(@JsonProperty("lookup") final LookupExtractor lookup,
            @JsonProperty("retainMissingValue") final boolean retainMissingValue,
            @Nullable @JsonProperty("replaceMissingValueWith") final String replaceMissingValueWith,
            @JsonProperty("injective") final boolean injective) {
        super(new Function<String, String>() {
            @Nullable
            @Override
            public String apply(String input) {
                return lookup.apply(Strings.nullToEmpty(input));
            }
        }, retainMissingValue, replaceMissingValueWith, injective);
        this.lookup = lookup;
    }

    @JsonProperty
    public LookupExtractor getLookup() {
        return lookup;
    }

    @Override
    @JsonProperty
    public boolean isRetainMissingValue() {
        return super.isRetainMissingValue();
    }

    @Override
    @JsonProperty
    public String getReplaceMissingValueWith() {
        return super.getReplaceMissingValueWith();
    }

    @Override
    @JsonProperty
    public boolean isInjective() {
        return super.isInjective();
    }

    @Override
    public byte[] getCacheKey() {
        try {
            final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            outputStream.write(CACHE_TYPE_ID);
            outputStream.write(lookup.getCacheKey());
            if (getReplaceMissingValueWith() != null) {
                outputStream.write(StringUtils.toUtf8(getReplaceMissingValueWith()));
            }
            outputStream.write(isInjective() ? 1 : 0);
            outputStream.write(isRetainMissingValue() ? 1 : 0);
            return outputStream.toByteArray();
        } catch (IOException ex) {
            // If ByteArrayOutputStream.write has problems, that is a very bad thing
            throw Throwables.propagate(ex);
        }
    }
}