/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * 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.nacos.config.server.service.dump.disk;

/**
 * config disk serve factory.
 *
 * @author zunfei.lzf
 */
public class ConfigDiskServiceFactory {
    
    static ConfigDiskService configDiskService;
    
    private static final String TYPE_RAW_DISK = "rawdisk";
    
    private static final String TYPE_ROCKSDB = "rocksdb";
    
    /**
     * get disk service.
     *
     * @return
     */
    public static ConfigDiskService getInstance() {
        if (configDiskService == null) {
            synchronized (ConfigDiskServiceFactory.class) {
                if (configDiskService == null) {
                    String type = System.getProperty("config_disk_type", TYPE_RAW_DISK);
                    if (type.equalsIgnoreCase(TYPE_ROCKSDB)) {
                        configDiskService = new ConfigRocksDbDiskService();
                    } else {
                        configDiskService = new ConfigRawDiskService();
                    }
                }
                return configDiskService;
            }
        }
        return configDiskService;
    }
    
}
