package org.apache.flink.api.connector.source.lib;

/**
 * A data source that produces generators N events of an arbitrary type in parallel. This source is useful for
 * testing and for cases that just need a stream of N events of any kind.
 *
 * <p>The source splits the sequence into as many parallel sub-sequences as there are parallel
 * source readers. Each sub-sequence will be produced in order. Consequently, if the parallelism is
 * limited to one, this will produce one sequence in order.
 *
 * <p>This source is always bounded. For very long sequences user may want to consider executing 
 * the application in a streaming manner, because, despite the fact that the produced stream is bounded, 
 * the end bound is pretty far away.
 */

@Public
public class DataGeneratorSource<OUT>
        implements Source<OUT, GeneratorSequenceSplit<OUT>, Collection<GeneratorSequenceSplit<OUT>>>,
                ResultTypeQueryable<OUT> {


    /**
     * Creates a new {@code DataGeneratorSource} that produces {@code count} records in
     * parallel.
     *
     * @param generatorFunction The generator function that receives index numbers and 
	 *                          translates them into events of the output type.
     * @param count The number of events to be produced.
     * @param typeInfo The type information of the returned events.
     */
    public DataGeneratorSource(
            MapFunction<Long, OUT> generatorFunction, long count, TypeInformation<OUT> typeInfo) {
     ...
	}
	
    /** A split of the source, representing a number sub-sequence. */
    public static class GeneratorSequenceSplit<T>
            implements IteratorSourceSplit<T, GeneratorSequenceIterator<T>> {
	 
        public GeneratorSequenceSplit(
                NumberSequenceSplit numberSequenceSplit, MapFunction<Long, T> generatorFunction) {
            this.numberSequenceSplit = numberSequenceSplit;
            this.generatorFunction = generatorFunction;
        }
		...
	}
}