def nextfit(self, joblist, index):
ondeck = []
# we start looking at the last index that we assigned a job
c = index
# we look at each job we have
for job in joblist:
# flag keeps track of if a job has been added or not
flag = True
# we then check each partition starting where we last added a job
# only covers from index to the end of the partition list
while c < len(self.partitions):
# If the job fits inside, then we add it and flag this job to end the inner loop
# moving on to the next job in the list
if job.getsize() <= self.partitions[c].getsize(
) and flag and self.partitions[c].getstatus() != 'Loaded':
self.partitions[c].addjob(job)
if self.partitions[c].getfragmentation() != 0:
self.addpartition(
partition.partition(
name=("P" + str(len(self.partitions))),
size=(self.partitions[c].getsize() -
job.getsize()),
address=str(
int(self.partitions[c].getaddress()) +
job.getsize())))
self.partitions[c].setsize(job.getsize())
# we set a job so now we want to mark the index as this one
index = c
flag = False
c += 1
# reset c to start from the front of the list
c = 0
# while loop covers from 0 to index we last set a job at
while c < index:
# If the job fits inside, then we add it and flag this job to end the inner loop
# moving on to the next job in the list
if job.getsize() <= self.partitions[c].getsize(
) and flag and self.partitions[c].getstatus() != 'Loaded':
self.partitions[c].addjob(job)
if self.partitions[c].getfragmentation() != 0:
self.addpartition(
partition.partition(
name=("P" + str(len(self.partitions))),
size=(self.partitions[c].getsize() -
job.getsize()),
address=str(
int(self.partitions[c].getaddress()) +
job.getsize())))
self.partitions[c].setsize(job.getsize())
index = c
flag = False
c += 1
# Job was not added to any partition, it was too big or all partitions were full
if flag:
# add the job to the list of jobs that are waiting to be executed
ondeck.append(job)
return [ondeck, index]
def createpartitions():
tmp = []
# create and append standard partitions to return
tmp.append(partition.partition(name='P0', size=1500, address='0000'))
tmp.append(partition.partition(name='P1', size=10, address='1500'))
tmp.append(partition.partition(name='P2', size=500, address='1510'))
tmp.append(partition.partition(name='P3', size=100, address='2010'))
tmp.append(partition.partition(name='P4', size=25, address='2110'))
return tmp
def worstfit(self, joblist):
ondeck = []
for job in joblist:
target = ''
fit = -1
for part in self.partitions:
# print(part.getsize() - job.getsize())
if (part.getsize() - job.getsize() > fit) and (
part.getstatus() != 'Loaded') and (job.getsize() <=
part.getsize()):
fit = part.getsize() - job.getsize()
target = part
if target == '':
ondeck.append(job)
else:
target.addjob(job)
if target.getfragmentation() != 0:
self.addpartition(
partition.partition(
name=("P" + str(len(self.partitions))),
size=(target.getsize() - job.getsize()),
address=str(
int(target.getaddress()) + job.getsize())))
target.setsize(job.getsize())
return ondeck
def combinepartitions(self):
total = 0
tmpparts = []
for part in self.partitions:
if part.getstatus() != 'Loaded':
# print(self.partitions[x].getsize())
total += part.getsize()
# self.partitions.remove(part)
else:
tmpparts.append(part)
tmpparts.append(
partition.partition(name=("P" + str(len(self.partitions))),
size=total))
self.partitions = tmpparts
def firstfit(self, joblist):
ondeck = []
# we look at each job we have
for job in joblist:
# flag keeps track of if a job has been added or not
flag = True
# we then check each partition in order
for x in range(len(self.partitions)):
# If the job fits inside, then we add it and flag this job to end the inner loop
# moving on to the next job in the list
if job.getsize() <= self.partitions[x].getsize(
) and flag and self.partitions[x].getstatus() != 'Loaded':
# add the job to the partition
self.partitions[x].addjob(job)
# if our fragmentation is 0, check prevents creating a new partition with 0 size
if self.partitions[x].getfragmentation != 0:
# create a new partition for the empty memory that is caused by the job added add a name
# using the length of the current partition list (length is always one number above the last
# name because it is zero indexed) add a size (the difference between the partition we added
# the job to and the job size itself) the address is just the old address of the partition we
# added the job to plus the job size
self.addpartition(
partition.partition(
name=("P" + str(len(self.partitions))),
size=(self.partitions[x].getsize() -
job.getsize()),
address=str(
int(self.partitions[x].getaddress()) +
job.getsize())))
# because we created a new partition for the unused memory, we need to reset the size of the
# current partition that we added the job to it just becomes the size of the job itself
self.partitions[x].setsize(job.getsize())
# the job was added so we change our flag
flag = False
# Job was not added to any partition, it was too big or all partitions were full
if flag:
# add job to the ondeck list
ondeck.append(job)
# return waiting jobs
return ondeck