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

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Here is the source code for io.druid.query.extraction.IdentityExtractionFn.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.google.common.base.Strings;

public class IdentityExtractionFn implements ExtractionFn {
    private static final byte CACHE_TYPE_ID = 0x6;

    @Override
    public byte[] getCacheKey() {
        return new byte[] { CACHE_TYPE_ID };
    }

    @Override
    public String apply(Object value) {
        return value == null ? null : Strings.emptyToNull(value.toString());
    }

    @Override
    public String apply(String value) {
        return Strings.emptyToNull(value);
    }

    @Override
    public String apply(long value) {
        return Long.toString(value);
    }

    @Override
    public boolean preservesOrdering() {
        return true;
    }

    @Override
    public ExtractionType getExtractionType() {
        return ExtractionType.ONE_TO_ONE;
    }
}