org.apache.lucene.codecs.PointsFormat.java Source code

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Here is the source code for org.apache.lucene.codecs.PointsFormat.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.codecs;

import java.io.IOException;

import org.apache.lucene.index.PointValues;
import org.apache.lucene.index.SegmentReadState;
import org.apache.lucene.index.SegmentWriteState;

/** 
 * Encodes/decodes indexed points.
 *
 * @lucene.experimental */
public abstract class PointsFormat {

    /**
     * Creates a new point format.
     */
    protected PointsFormat() {
    }

    /** Writes a new segment */
    public abstract PointsWriter fieldsWriter(SegmentWriteState state) throws IOException;

    /** Reads a segment.  NOTE: by the time this call
     *  returns, it must hold open any files it will need to
     *  use; else, those files may be deleted. 
     *  Additionally, required files may be deleted during the execution of 
     *  this call before there is a chance to open them. Under these 
     *  circumstances an IOException should be thrown by the implementation. 
     *  IOExceptions are expected and will automatically cause a retry of the 
     *  segment opening logic with the newly revised segments.
     *  */
    public abstract PointsReader fieldsReader(SegmentReadState state) throws IOException;

    /** A {@code PointsFormat} that has nothing indexed */
    public static final PointsFormat EMPTY = new PointsFormat() {
        @Override
        public PointsWriter fieldsWriter(SegmentWriteState state) {
            throw new UnsupportedOperationException();
        }

        @Override
        public PointsReader fieldsReader(SegmentReadState state) {
            return new PointsReader() {
                @Override
                public void close() {
                }

                @Override
                public long ramBytesUsed() {
                    return 0L;
                }

                @Override
                public void checkIntegrity() {
                }

                @Override
                public PointValues getValues(String field) {
                    throw new IllegalArgumentException("field=\"" + field + "\" was not indexed with points");
                }
            };
        }
    };
}