Coverage for scheduler/prioritization.py: 100%
21 statements
« prev ^ index » next coverage.py v7.0.4, created at 2023-03-19 22:02 +0000
1"""
2Collection of prioritization functions.
4For compatibility with the |Scheduler|, the prioritization
5functions have to be of type ``Callable[[float, Job, int, int], float]``.
7Author: Jendrik A. Potyka, Fabian A. Preiss
8"""
10import random
12from scheduler.threading.job import Job
15def constant_weight_prioritization(
16 time_delta: float, job: Job, max_exec: int, job_count: int
17) -> float:
18 r"""
19 Interprets the `Job`'s weight as its priority.
21 Return the |Job|'s weight for overdue
22 |Job|\ s, otherwise return zero:
24 .. math::
25 \left(\mathtt{time\_delta},\mathtt{weight}\right)\ {\mapsto}\begin{cases}
26 0 & :\ \mathtt{time\_delta}<0\\
27 \mathtt{weight} & :\ \mathtt{time\_delta}\geq0
28 \end{cases}
30 Parameters
31 ----------
32 time_delta : float
33 The time in seconds that a |Job| is overdue.
34 job : Job
35 The |Job| instance
36 max_exec : int
37 Limits the number of overdue |Job|\ s that can be executed
38 by calling function `Scheduler.exec_jobs()`.
39 job_count : int
40 Number of scheduled |Job|\ s
42 Returns
43 -------
44 float
45 The weight of a |Job| as priority.
46 """
47 _ = max_exec
48 _ = job_count
49 if time_delta < 0:
50 return 0
51 return job.weight
54def linear_priority_function(time_delta: float, job: Job, max_exec: int, job_count: int) -> float:
55 r"""
56 Compute the |Job|\ s default linear priority.
58 Linear |Job| prioritization such that the priority increases
59 linearly with the amount of time that a |Job| is overdue.
60 At the exact time of the scheduled execution, the priority is equal to the
61 |Job|\ s weight.
63 The function is defined as
65 .. math::
66 \left(\mathtt{time\_delta},\mathtt{weight}\right)\ {\mapsto}\begin{cases}
67 0 & :\ \mathtt{time\_delta}<0\\
68 {\left(\mathtt{time\_delta}+1\right)}\cdot\mathtt{weight} & :\ \mathtt{time\_delta}\geq0
69 \end{cases}
71 Parameters
72 ----------
73 time_delta : float
74 The time in seconds that a |Job| is overdue.
75 job : Job
76 The |Job| instance
77 max_exec : int
78 Limits the number of overdue |Job|\ s that can be executed
79 by calling function `Scheduler.exec_jobs()`.
80 job_count : int
81 Number of scheduled |Job|\ s
83 Returns
84 -------
85 float
86 The time dependant priority for a |Job|
87 """
88 _ = max_exec
89 _ = job_count
91 if time_delta < 0:
92 return 0
93 return (time_delta + 1) * job.weight
96def random_priority_function(time: float, job: Job, max_exec: int, job_count: int) -> float:
97 """
98 Generate random priority values from weights.
100 .. warning:: Not suitable for security relevant purposes.
102 The priority generator will return 1 if the random number
103 is lower then the |Job|'s weight, otherwise it will return 0.
104 """
105 _ = time
106 _ = max_exec
107 _ = job_count
108 if random.random() < job.weight: # nosec
109 return 1
110 return 0