org.apache.lucene.facet.taxonomy.IntAssociationFacetField.java Source code

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Here is the source code for org.apache.lucene.facet.taxonomy.IntAssociationFacetField.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.lucene.facet.taxonomy;

import java.util.Arrays;

import org.apache.lucene.document.Document;
import org.apache.lucene.util.BytesRef;

/** Add an instance of this to your {@link Document} to add
 *  a facet label associated with an int.  Use {@link
 *  TaxonomyFacetSumIntAssociations} to aggregate int values
 *  per facet label at search time.
 * 
 *  @lucene.experimental */
public class IntAssociationFacetField extends AssociationFacetField {

    /** Creates this from {@code dim} and {@code path} and an
     *  int association */
    public IntAssociationFacetField(int assoc, String dim, String... path) {
        super(intToBytesRef(assoc), dim, path);
    }

    /** Encodes an {@code int} as a 4-byte {@link BytesRef},
     *  big-endian. */
    public static BytesRef intToBytesRef(int v) {
        byte[] bytes = new byte[4];
        // big-endian:
        bytes[0] = (byte) (v >> 24);
        bytes[1] = (byte) (v >> 16);
        bytes[2] = (byte) (v >> 8);
        bytes[3] = (byte) v;
        return new BytesRef(bytes);
    }

    /** Decodes a previously encoded {@code int}. */
    public static int bytesRefToInt(BytesRef b) {
        return ((b.bytes[b.offset] & 0xFF) << 24) | ((b.bytes[b.offset + 1] & 0xFF) << 16)
                | ((b.bytes[b.offset + 2] & 0xFF) << 8) | (b.bytes[b.offset + 3] & 0xFF);
    }

    @Override
    public String toString() {
        return "IntAssociationFacetField(dim=" + dim + " path=" + Arrays.toString(path) + " value="
                + bytesRefToInt(assoc) + ")";
    }
}