Package demos.QuickSort

Package demos.QuickSort Description

This package implements the QuickSort algorithm. The approach adopted is to split the data to be sorted into a number of different partitions, the parallel owrkers. The workers each then undertake a QuickSort on their partition. The workers then out put their sorted order to a merge process that merges all the input streams into a final sorted order.

This is achieved by using the spreader OneDirectedList, the reducer N_WayMerge and a group of ThreePhaseWorkers. The emit process creates a large number of QSData objects; such that one property, index, will be the key value used to sort that objects. Another property, batch, indicates to which of the ThreePhaseWorkers the objects should be directed by the OneDirectedList process.

The ThreePhaseWorkers each read a number of the QSData objects into a local worker object called QSWorker. This object implements the required inFunction, workFunction and outFunction methods. Internally, once all the input objects have been read, the workFunction is called, which carries out the QuickSort. Once the sort finishes the outFunction method is repeatedly called to outout the data held in the local data store. The output data objects are also QSData objects.

The output data objects are read by a N_WayMerge process that a method called mergeChoice that determines which of the available data objects that have been read will be chosen and written to the output channel of the process, where they can be Collected.

 Author, Licence and Copyright statement
 author  Jon Kerridge
 		   School of Computing
 		   Edinburgh Napier University
 		   Merchiston Campus,
 		   Colinton Road
 		   Edinburgh EH10 5DT

 Author contact: j.kerridge (at) napier.ac.uk

 Copyright  Jon Kerridge Edinburgh Napier University *

 Licensed 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.