/*
* 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.
*/
package org.apache.beam.sdk.io;
import com.google.auto.service.AutoService;
import java.util.ServiceLoader;
import javax.annotation.Nullable;
import org.apache.beam.sdk.annotations.Experimental;
import org.apache.beam.sdk.annotations.Experimental.Kind;
import org.apache.beam.sdk.options.PipelineOptions;
/**
* A registrar that creates {@link FileSystem} instances from {@link PipelineOptions}.
*
* <p>{@link FileSystem} creators have the ability to provide a registrar by creating
* a {@link ServiceLoader} entry and a concrete implementation of this interface.
*
* <p>It is optional but recommended to use one of the many build time tools such as
* {@link AutoService} to generate the necessary META-INF files automatically.
*/
@Experimental(Kind.FILESYSTEM)
public interface FileSystemRegistrar {
/**
* Create zero or more {@link FileSystem filesystems} from the given {@link PipelineOptions}.
*
* <p>Each {@link FileSystem#getScheme() scheme} is required to be unique among all
* {@link FileSystem}s registered by all {@link FileSystemRegistrar}s.
*/
Iterable<FileSystem> fromOptions(@Nullable PipelineOptions options);
}