/*
 * 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.memory;


import java.io.IOException;

import org.apache.lucene.codecs.DocValuesConsumer;
import org.apache.lucene.codecs.DocValuesFormat;
import org.apache.lucene.codecs.DocValuesProducer;
import org.apache.lucene.document.SortedSetDocValuesField; // javadocs
import org.apache.lucene.index.SegmentReadState;
import org.apache.lucene.index.SegmentWriteState;
import org.apache.lucene.util.ArrayUtil;

In-memory docvalues format that does no (or very little)
 compression.  Indexed values are stored on disk, but
 then at search time all values are loaded into memory as
 simple java arrays.  For numeric values, it uses
 byte[], short[], int[], long[] as necessary to fit the
 range of the values.  For binary values, there is an int
 (4 bytes) overhead per value.
 
Limitations:
 

   
For binary and sorted fields the total space
       required for all binary values cannot exceed about
       2.1 GB (see #MAX_TOTAL_BYTES_LENGTH).
   
For sorted set fields, the sum of the size of each document's set of values cannot exceed about 2.1 B values (see #MAX_SORTED_SET_ORDS). For example, if every document has 10 values (10 instances of SortedSetDocValuesField) added, then no more than ~210 M documents can be added to one segment. 
 
 /** In-memory docvalues format that does no (or very little)
 *  compression.  Indexed values are stored on disk, but
 *  then at search time all values are loaded into memory as
 *  simple java arrays.  For numeric values, it uses
 *  byte[], short[], int[], long[] as necessary to fit the
 *  range of the values.  For binary values, there is an int
 *  (4 bytes) overhead per value.
 *
 *  <p>Limitations:
 *  <ul>
 *    <li>For binary and sorted fields the total space
 *        required for all binary values cannot exceed about
 *        2.1 GB (see #MAX_TOTAL_BYTES_LENGTH).</li>
 *
 *    <li>For sorted set fields, the sum of the size of each
 *        document's set of values cannot exceed about 2.1 B
 *        values (see #MAX_SORTED_SET_ORDS).  For example,
 *        if every document has 10 values (10 instances of
 *        {@link SortedSetDocValuesField}) added, then no
 *        more than ~210 M documents can be added to one
 *        segment. </li>
 *  </ul> */

public class DirectDocValuesFormat extends DocValuesFormat {

  
The sum of all byte lengths for binary field, or for
 the unique values in sorted or sorted set fields, cannot
 exceed this. /** The sum of all byte lengths for binary field, or for
   *  the unique values in sorted or sorted set fields, cannot
   *  exceed this. */
  public final static int MAX_TOTAL_BYTES_LENGTH = ArrayUtil.MAX_ARRAY_LENGTH;

  
The sum of the number of values across all documents
 in a sorted set field cannot exceed this. /** The sum of the number of values across all documents
   *  in a sorted set field cannot exceed this. */
  public final static int MAX_SORTED_SET_ORDS = ArrayUtil.MAX_ARRAY_LENGTH;

  
Sole constructor. /** Sole constructor. */
  public DirectDocValuesFormat() {
    super("Direct");
  }
  
  @Override
  public DocValuesConsumer fieldsConsumer(SegmentWriteState state) throws IOException {
    return new DirectDocValuesConsumer(state, DATA_CODEC, DATA_EXTENSION, METADATA_CODEC, METADATA_EXTENSION);
  }
  
  @Override
  public DocValuesProducer fieldsProducer(SegmentReadState state) throws IOException {
    return new DirectDocValuesProducer(state, DATA_CODEC, DATA_EXTENSION, METADATA_CODEC, METADATA_EXTENSION);
  }
  
  static final String DATA_CODEC = "DirectDocValuesData";
  static final String DATA_EXTENSION = "dvdd";
  static final String METADATA_CODEC = "DirectDocValuesMetadata";
  static final String METADATA_EXTENSION = "dvdm";
}