This generates test cases for program 3 in CSc 422 Spring 2014 - Could automate test with this, could use improvements.

csc422_dht_test.py

#!/usr/bin/python
"""
CSc 422
Author: Alex Warren
Program 3 Distributed Hash Table
Test correct key placement.
"""

import subprocess
from random import random, randint, seed

NUM_ITERATIONS = 45
CHECK_INTERVAL = 5
NUM_NODES = 10
MIN_INT = -2147483648
MAX_INT = 2147483647
MAX_ID = MAX_INT
MIN_ID = MIN_INT
MIN_INT = -100
MAX_INT = 100
MAX_ID = 100
MIN_ID = -10
PROB_LOW = 10
PROB_HIGH = 300


def piecemeal_probablities(iteration):
    """
    Function for controlling the probability of Add vs Remove.
    Put probablility is whatever remains.

    Returns tuple: (P(Add), P(Remove))
    """
    if iteration < PROB_LOW:
        return (.4, .58)
    elif iteration < PROB_HIGH:
        return (.6, .38)
    else:
        return (.43, .43)

def dht_test():
    """
    Test the dht with mpirun. Check that values are stored in
    the correct node.
    """
    seed(5)

    put_str = "0 {key} {val}"
    get_str = "1 {key}"
    add_str = "2 {rank} {id}"
    remove_str = "3 {id}"
    output_str = "{val} {id}"

    iteration = 0
    active_nodes = []                    #(rank, id)
    inactive_nodes = range(1, NUM_NODES) # rank
    entries = []                         #(key, value)
    commands = []
    outputs = []

    #Add the first node
    rank = inactive_nodes.pop(randint(1, NUM_NODES-1))
    node_id = randint(MIN_ID, MAX_ID)
    active_nodes.append((rank, node_id))
    commands.append(add_str.format(rank=rank, id=node_id))

    while iteration < NUM_ITERATIONS:
        prob_add, prob_remove = (.4, .5) #piecemeal_probablities(iteration)
        rand = random()
        if rand < prob_add:
            #Add
            if len(inactive_nodes) == 0:
                continue
            elif len(inactive_nodes) == 1:
                rank = inactive_nodes.pop(0)
            else:
                rank = inactive_nodes.pop(randint(1, len(inactive_nodes)-1))
            node_id = randint(MIN_ID, MAX_ID)
            if sum((x[1]==node_id for x in active_nodes)):
                print "WHAT ARE THE CHANCES (add)?"
                #TODO figure out the chances
                print "..."
                continue
            active_nodes.append((rank, node_id))
            commands.append(add_str.format(rank=rank, id=node_id))
        elif rand < prob_add+prob_remove:
            #Remove
            if len(active_nodes) == 1:
                continue
            node = active_nodes.pop(randint(0, len(active_nodes)-1))
            inactive_nodes.append(node[0])
            commands.append(remove_str.format(id=node[1]))
        else:
            #Put
            key = randint(MIN_INT, MAX_INT)
            val = randint(MIN_INT, MAX_INT)
            if (key, val) in entries:
                print "WHAT ARE THE CHANCES (put)?"
                #TODO figure out the chances
                print "..."
                continue
            entries.append((key, val))
            commands.append(put_str.format(key=key, val=val))
        iteration += 1
        if (iteration % CHECK_INTERVAL) == 0:
            active_nodes.sort(key=lambda tup: tup[1]) #sort by id
            entries.sort(key=lambda tup: tup[0]) #sort by key
            node_id = 0
            for entry in entries:
                while (entry[0] > active_nodes[node_id][1] 
                        and not node_id == len(active_nodes) - 1):
                    node_id += 1
                commands.append(get_str.format(key=entry[0]))
                outputs.append(output_str.format(val=entry[1], 
                                                 id=active_nodes[node_id][1]))
    commands.append("4") #end command
    print('\n'.join(commands))
    print "-----------------------------------"
    print('\n'.join(outputs))


def main():
    """
    Run dht_test.py as a script.
    """
    dht_test()

if( __name__ == "__main__"):
    main()