Package org.apache.ignite.lang

Interface IgniteReducer<E,R>

Type Parameters:
E - Type of collected values.
R - Type of reduced value.
All Superinterfaces:
Serializable
public interface IgniteReducer<E,R> extends Serializable
Defines generic reducer that collects multiple values and reduces them into one. Reducers are useful in computations when results from multiple remote jobs need to be reduced into one, e.g. org.apache.ignite.IgniteCompute#call(Collection, IgniteReducer) method.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    collect(E e)
    Collects given value.
    R
    reduce()
    Reduces collected values into one.

  • Method Details

    • collect

      boolean collect(E e)
      Collects given value. If this method returns false then reduce() will be called right away. Otherwise caller will continue collecting until all values are processed.
      Parameters:
      e - Value to collect.
      Returns:
      true to continue collecting, false to instruct caller to stop collecting and call reduce() method.

    • reduce

      R reduce()
      Reduces collected values into one.
      Returns:
      Reduced value.