/* 
 * 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.
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Lucene.Net.Index;
using Lucene.Net.Store;

namespace Lucene.Net
{
    
    public class CorruptionCheckerForPreLucene3
    {
        ///<summary>
        /// Added safety check on last batch of additions for &lt; 3.0 based Lucene implementations
        /// <see cref="https://issues.apache.org/jira/browse/LUCENE-3255"/>
        ///</summary>
        ///<param name="dir">return true if OK false if a potentially corrupted segments file was removed</param>
        public static bool CheckLastCommitOk(FSDirectory dir)
        {
            string latestSeg = SegmentInfos.GetCurrentSegmentFileName(dir);
            IndexInput input = dir.OpenInput(latestSeg);
            int format = input.ReadInt();
            input.Close();
            if (format != SegmentInfos.FORMAT_DIAGNOSTICS)
            {
                dir.DeleteFile(latestSeg);
                return false;
            }
            return true;
        }
    }
}