alluxio-master-2.x/underfs/cosn/src/main/java/alluxio/underfs/cosn/CosNUnderFileSystemFactory.java
/*
 * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
 * (the "License"). You may not use this work except in compliance with the License, which is
 * available at www.apache.org/licenses/LICENSE-2.0
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied, as more fully set forth in the License.
 *
 * See the NOTICE file distributed with this work for information regarding copyright ownership.
 */

package alluxio.underfs.cosn;

import alluxio.AlluxioURI;
import alluxio.Constants;
import alluxio.CosnUfsConstants;
import alluxio.conf.PropertyKey;
import alluxio.underfs.UnderFileSystem;
import alluxio.underfs.UnderFileSystemConfiguration;
import alluxio.underfs.hdfs.HdfsUnderFileSystemFactory;

import com.google.common.base.Preconditions;

import javax.annotation.concurrent.ThreadSafe;

/**
 * Factory for creating {@link CosnUnderFileSystem}.
 */
@ThreadSafe
public class CosNUnderFileSystemFactory extends HdfsUnderFileSystemFactory {

  @Override
  public UnderFileSystem create(String path, UnderFileSystemConfiguration conf) {
    Preconditions.checkNotNull(path, "path");
    return CosnUnderFileSystem.createInstance(new AlluxioURI(path), conf);
  }

  @Override
  public boolean supportsPath(String path) {
    return path != null && path.startsWith(Constants.HEADER_COSN);
  }

  @Override
  public boolean supportsPath(String path, UnderFileSystemConfiguration conf) {
    if (!supportsPath(path)) {
      return false;
    }
    // If the user has explicitly specified a UFS version,
    // the version also has to match exactly, in addition to path prefix
    if (conf.isSetByUser(PropertyKey.UNDERFS_VERSION)
        && !conf.get(PropertyKey.UNDERFS_VERSION).equals(getVersion())) {
      return false;
    }
    // otherwise, assume the version we ship with Alluxio supports it.
    return true;
  }

  @Override
  public String getVersion() {
    return CosnUfsConstants.UFS_COSN_VERSION;
  }
}
