org.apache.druid.segment.writeout.SegmentWriteOutMediumFactory.java Source code

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Here is the source code for org.apache.druid.segment.writeout.SegmentWriteOutMediumFactory.java

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/*
 * 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.druid.segment.writeout;

import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.google.common.collect.ImmutableSet;

import java.io.File;
import java.io.IOException;
import java.util.Set;

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, defaultImpl = TmpFileSegmentWriteOutMediumFactory.class)
@JsonSubTypes(value = { @JsonSubTypes.Type(name = "tmpFile", value = TmpFileSegmentWriteOutMediumFactory.class),
        @JsonSubTypes.Type(name = "offHeapMemory", value = OffHeapMemorySegmentWriteOutMediumFactory.class), })
public interface SegmentWriteOutMediumFactory {
    static Set<SegmentWriteOutMediumFactory> builtInFactories() {
        return ImmutableSet.of(TmpFileSegmentWriteOutMediumFactory.instance(),
                OffHeapMemorySegmentWriteOutMediumFactory.instance());
    }

    /**
     * Creates a new SegmentWriteOutMedium. If this type of SegmentWriteOutMedium needs to create some temprorary files,
     * it creates a *subdirectory* in the given outDir, stores the files there, and removes the files and the subdirectory
     * when closed.
     */
    SegmentWriteOutMedium makeSegmentWriteOutMedium(File outDir) throws IOException;
}