package org.apache.lucene.codecs.lucene3x;

/*
 * 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.
 */

import java.io.IOException;

import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.FieldInfos;
import org.apache.lucene.store.IndexInput;

// not an anonymous class so TestTermInfosReaderIndex can instantiate directly
class PreflexRWSegmentTermEnum extends SegmentTermEnum {
  PreflexRWSegmentTermEnum(IndexInput i, FieldInfos fis, boolean isi) throws IOException {
    super(i, fis, isi);
  }
  
  @Override
  protected long readSize(IndexInput input) throws IOException {
    long savedPosition = input.getFilePointer();
    input.seek(input.length() - 16);
    long magic = input.readLong();
    if (magic != TermInfosWriter.MAGIC) {
      throw new CorruptIndexException("this file was not written with PreFlexRWCodec (resource: " + input + ")");
    }
    long size = input.readLong();
    input.seek(savedPosition + 8); // we still left the 'hole'
    return size;
  }
}
