RunningFlags.java

/**
 * Copyright (C) 2010-2013 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.
 */
package com.alibaba.rocketmq.store;

/**
 * 存储模型运行过程的状态位
 * 
 * @author shijia.wxr<vintage.wang@gmail.com>
 * @since 2013-7-21
 */
public class RunningFlags {
    // 禁止读权限
    private static final int NotReadableBit = 1;
    // 禁止写权限
    private static final int NotWriteableBit = 1 << 1;
    // 逻辑队列是否发生错误
    private static final int WriteLogicsQueueErrorBit = 1 << 2;
    // 索引文件是否发生错误
    private static final int WriteIndexFileErrorBit = 1 << 3;
    // 磁盘空间不足
    private static final int DiskFullBit = 1 << 4;
    private volatile int flagBits = 0;


    public RunningFlags() {
    }


    public int getFlagBits() {
        return flagBits;
    }


    public boolean getAndMakeReadable() {
        boolean result = this.isReadable();
        if (!result) {
            this.flagBits &= ~NotReadableBit;
        }
        return result;
    }


    public boolean isReadable() {
        if ((this.flagBits & NotReadableBit) == 0) {
            return true;
        }

        return false;
    }


    public boolean getAndMakeNotReadable() {
        boolean result = this.isReadable();
        if (result) {
            this.flagBits |= NotReadableBit;
        }
        return result;
    }


    public boolean getAndMakeWriteable() {
        boolean result = this.isWriteable();
        if (!result) {
            this.flagBits &= ~NotWriteableBit;
        }
        return result;
    }


    public boolean isWriteable() {
        if ((this.flagBits & (NotWriteableBit | WriteLogicsQueueErrorBit | DiskFullBit | WriteIndexFileErrorBit)) == 0) {
            return true;
        }

        return false;
    }


    public boolean getAndMakeNotWriteable() {
        boolean result = this.isWriteable();
        if (result) {
            this.flagBits |= NotWriteableBit;
        }
        return result;
    }


    public void makeLogicsQueueError() {
        this.flagBits |= WriteLogicsQueueErrorBit;
    }


    public boolean isLogicsQueueError() {
        if ((this.flagBits & WriteLogicsQueueErrorBit) == WriteLogicsQueueErrorBit) {
            return true;
        }

        return false;
    }


    public void makeIndexFileError() {
        this.flagBits |= WriteIndexFileErrorBit;
    }


    public boolean isIndexFileError() {
        if ((this.flagBits & WriteIndexFileErrorBit) == WriteIndexFileErrorBit) {
            return true;
        }

        return false;
    }


    /**
     * 返回Disk是否正常
     */
    public boolean getAndMakeDiskFull() {
        boolean result = !((this.flagBits & DiskFullBit) == DiskFullBit);
        this.flagBits |= DiskFullBit;
        return result;
    }


    /**
     * 返回Disk是否正常
     */
    public boolean getAndMakeDiskOK() {
        boolean result = !((this.flagBits & DiskFullBit) == DiskFullBit);
        this.flagBits &= ~DiskFullBit;
        return result;
    }
}