/**
* Applies the given window function to each window. The window function is called for each
* evaluation of the window for each key individually. The output of the window function is
* interpreted as a regular non-windowed stream.
*
* <p>Arriving data is pre-aggregated using the given pre-aggregation reducer.
*
* @param preAggregator The reduce function that is used for pre-aggregation
* @param function The window function.
* @return The data stream that is the result of applying the window function to the window.
*/
public <R> SingleOutputStreamOperator<R, ?> apply(
ReduceFunction<T> preAggregator, AllWindowFunction<T, R, W> function) {
TypeInformation<T> inType = input.getType();
TypeInformation<R> resultType =
TypeExtractor.getUnaryOperatorReturnType(
function, AllWindowFunction.class, true, true, inType, null, false);
return apply(preAggregator, function, resultType);
}
/**
* Applies a window function to the window. The window function is called for each evaluation of
* the window for each key individually. The output of the window function is interpreted as a
* regular non-windowed stream.
*
* <p>Not that this function requires that all data in the windows is buffered until the window is
* evaluated, as the function provides no means of pre-aggregation.
*
* @param function The window function.
* @return The data stream that is the result of applying the window function to the window.
*/
public <R> SingleOutputStreamOperator<R, ?> apply(AllWindowFunction<Iterable<T>, R, W> function) {
@SuppressWarnings("unchecked, rawtypes")
TypeInformation<Iterable<T>> iterTypeInfo = new GenericTypeInfo<>((Class) Iterable.class);
TypeInformation<R> resultType =
TypeExtractor.getUnaryOperatorReturnType(
function, AllWindowFunction.class, true, true, iterTypeInfo, null, false);
return apply(function, resultType);
}
