Project 4

## Assignment: Project 4
## Date: 11/18/2017
## Course: CSC 431
## Professor: Dr. Bhattacharya
## Programmer: Josh Adams


LOWER_CYLINDER = 0
UPPER_CYLINDER = 4999
SPEED = 1 # distance per unit time, where unit of distance = distance between cylinders of hard drive

requests = [2069, 1212, 2296, 2800, 544, 1618, 356, 1523, 4965, 3681]
deadlines = [2300, 2000, 80, 10, 1800, 7000, 3600, 8900, 97, 8800]
initialPosition = 2500

def SSTF_RT(requests, deadlines, initialPosition):
    localRequests = list(requests)
    request_deadline = dict(zip(requests, deadlines)) # combining  the list of requests with deadlines into a dictionary
    position = initialPosition
    movement = 0
    time = 0
    while localRequests:
        #find the closest request to the current cylinder
        closest = abs(position - localRequests[0])
        closestIndex = 0
        for x in range(1, len(localRequests)):
            if abs(position - localRequests[x]) < closest:
                closest = abs(position - localRequests[x])
                closestIndex = x

        distance = abs(position - localRequests[closestIndex]) #how much to move

        if (time > request_deadline[localRequests[closestIndex]] or (distance > request_deadline[localRequests[closestIndex]]) or ((time+distance)>request_deadline[localRequests[closestIndex]])):
            print("Dropping service request ", localRequests[closestIndex], ",time =", time, sep="")
            del localRequests[closestIndex]         # delete the element in localRequests that correspondes to closestIndex
            continue
        else:
            movement += distance        # increment movement by itself and distance
            time += distance / SPEED        # increment time by itself and (distance / SPEED)
            position = localRequests[closestIndex]      # set position to the request that is processed
            print ("Servicing request " + str(position) + ",time = " + str(time), sep="")
            del localRequests[closestIndex]         # delete the element in localRequests that correspondes to closestIndex


    return movement


def EDF(requests, deadlines, initialPositions):
    localRequests = list(requests)
    request_deadline = dict(zip(requests, deadlines))       # combining  the list of requests with deadlines into a dictionary
    position = initialPosition
    movement = 0
    time = 0
    sortedByValueDict = sorted(request_deadline.items(), key = lambda t: t[1])      # "sort" the dictionary by value and creating a new array of the "sorted" key:value combinations
    for i in sortedByValueDict:         # loop through the elements in the sorted array of key:values
        distance = abs(position - i[0])         # set distance equal to the absolute value of the current position - the request
        if(i[0] in range(LOWER_CYLINDER,UPPER_CYLINDER)):
            if((distance > i[1]) or (time > i[1]) or ((time + distance) > i[1])):       # check if the distance is greater than the deadline or time greater than the deadline, or time + distance greater than the deadline
                print("Dropping service request ", i[0], ",time = ", time, sep="")
            else:
                movement += distance        # increment movement by itself and distance
                time += distance / SPEED        # increment time by itself and (distance / SPEED)
                position = i[0]         # set the current position to the request processed
                print("Servicing request ", i[0], ",time = ", time, sep ="")
        else:
            print("The given cylinder number of: ", i[0], " was greater than our cylinder range of: ",
                  LOWER_CYLINDER, " : ", UPPER_CYLINDER, sep="")
    return movement



print ("Total movement in SSTF_RT = " + str(SSTF_RT(requests, deadlines, initialPosition)), "\n")
print ("Total movement in EDF = " + str(EDF(requests, deadlines, initialPosition)), "\n")