LogFile.java example

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/*
 * (C) 2007-2012 Alibaba Group Holding Limited.
 * 
 * Licensed 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.
 * Authors:
 *   dogun (yuexuqiang at gmail.com)
 */
package com.taobao.common.store.journal;

import java.io.File;
import java.io.IOException;


/**
 * һ����־�ļ�
 * 
 * @author dogun (yuexuqiang at gmail.com)
 */
class LogFile extends DataFile {
    /**
     * Ĭ�Ϲ��캯��
     * 
     * @param file
     * @throws IOException
     */
    LogFile(final File file, final int n) throws IOException {
        this(file, n, false);
    }


    /**
     * ���캯��
     * 
     * @param file
     * @param force
     * @throws IOException
     */
    LogFile(final File file, final int n, final boolean force) throws IOException {
        super(file, n, force);
        // ����ط���Ϊ�˷�ֹ������־�ļ��Ĳ����������������������������������ݡ�
        final long count = fc.size() / OpItem.LENGTH;
        if (count * OpItem.LENGTH < fc.size()) {
            fc.truncate(count * OpItem.LENGTH);
            fc.position(count * OpItem.LENGTH);
        }
    }

}