org.apache.spark.sql.sources.v2.StreamWriteSupport Maven / Gradle / Ivy

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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.spark.sql.sources.v2;

import org.apache.spark.annotation.InterfaceStability;
import org.apache.spark.sql.execution.streaming.BaseStreamingSink;
import org.apache.spark.sql.sources.v2.writer.DataSourceWriter;
import org.apache.spark.sql.sources.v2.writer.streaming.StreamWriter;
import org.apache.spark.sql.streaming.OutputMode;
import org.apache.spark.sql.types.StructType;

/**
 * A mix-in interface for {@link DataSourceV2}. Data sources can implement this interface to
 * provide data writing ability for structured streaming.
 */
@InterfaceStability.Evolving
public interface StreamWriteSupport extends DataSourceV2, BaseStreamingSink {

    /**
     * Creates an optional {@link StreamWriter} to save the data to this data source. Data
     * sources can return None if there is no writing needed to be done.
     *
     * @param queryId A unique string for the writing query. It's possible that there are many
     *                writing queries running at the same time, and the returned
     *                {@link DataSourceWriter} can use this id to distinguish itself from others.
     * @param schema the schema of the data to be written.
     * @param mode the output mode which determines what successive epoch output means to this
     *             sink, please refer to {@link OutputMode} for more details.
     * @param options the options for the returned data source writer, which is an immutable
     *                case-insensitive string-to-string map.
     */
    StreamWriter createStreamWriter(
        String queryId,
        StructType schema,
        OutputMode mode,
        DataSourceOptions options);
}