CS 342 Lab 7: Sort Server



Lab date: 28 March-30 March 2000
Due date: Friday 31 March 2000 11:59 pm


Extend/improve your sort program from Lab 6 to do the following:
  1. Support merge sort and at least one other sorting algorithm, in addition to selection sort.

  2. Support distributed sorting. Demonstrate this by reading at least two Sort_Infos from files and merging them together.

    A distributed sort partitions the original Sort_Info into multiple, smaller ones. It sends each small Sort_Info to a remote Sorter, then combines the results using mergesort. Note that we don't actually implement the distribution. We just provide the support for it, through the ability to read Sort_Info from files. And, we provide mergesort, which is appropriate for combining sorted arrays.

  3. Decouple your code from the Sort_Viewer_Client.cc implementation by inserting an Adapter between them. The calls to the "raw" connect_to_viewer (), send_to_viewer (), and disconnect_from_viewer () functions work, but they're not clean. The Adapter class will 1) hide the sockfd and stream objects, and 2) make sure that connect_to_viewer () is called before send_to_viewer (), and disconnect_to_viewer () is called when done. That way, the user won't explicitly setup and teardown the connection to the viewer. If you had done this for Lab 6, make sure that your code is very clean, concise, readable, elegant, and documented. (If you had incorporated your adapter into an Observer, separate it out. Then your Observer code should be very simple.)

Here's a high-level diagram of the sort program collaborators:


  1. Review your Lab 6, specifically the create_sorter Factory Method.
  2. Review the patterns used in this lab, including


  1. Add merge sort and at least one other sorting algorithm. Extend the create_sorter Factory Method to support creation of instances of Merge_Sort and your other Sorter.

    It's best if you structure your mergesort just like any other Sorter. Then, add a constructor that takes in an Array of Sort_Infos. Mergesort will then check each Sort_Info in the Array: if they're all SORTED, then it simply merges them together.

  2. Demonstrate support for distributed sorting by reading at least two Sort_Infos from files and merging them together.

  3. Ensure that Adapter between your code and the Sort_Viewer_Client.cc is robust. The Adapter's constructor should call connect_to_viewer, and its destructor should call disconnect_from_viewer. If connect_to_viewer fails, the Adapter can either assert failure, throw an exception (if you use exception handling), or return a failure status through a reference argument.

Obtaining the Lab 7 distribution:

At a Unix shell prompt, type ~cs342/bin/lab7. That will copy a readme and your Lab 6 Makefile to a new lab7 subdirectory. Then cd lab7 and copy your other Lab 6 files.

What to Submit:

By the due date, submit all source files from your final solution. Include a laboratory writeup file (named readme) documenting what you did to satisfy this assignment. readme contains a minimum list of sections that you must provide. (Please replace the comments in [] with your descriptions.) These files will be submitted automatically when you execute the command:
make turnin
NOTE: there is a Makefile target that allows you to test what you are going to turn in:
make test_turnin

It places the output that will be turned in into the TEST_TURNIN directory. You are responsible for using make test_turnin, and verifying that the files that you will submit are correct.

Please see the Lab 6 assignment for notes on using the Java Sort Viewer.

Please see the Lab 4 assignment for notes on using the History class to help track and count instantiations and deletions of an instrumented class.

Please see the Lab 2 assignment for hints on compiling templates.

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