From 43d214b9824b48c3414398f924a98251d74c5e4c Mon Sep 17 00:00:00 2001
From: Yohann D'ANELLO <ynerant@crans.org>
Date: Mon, 2 Aug 2021 19:30:36 +0200
Subject: [PATCH] [WEI] Store seed in WEI Survey to add determinism in RNG
Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>
---
apps/wei/forms/surveys/wei2021.py | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/apps/wei/forms/surveys/wei2021.py b/apps/wei/forms/surveys/wei2021.py
index 6ecf3107..6739772f 100644
--- a/apps/wei/forms/surveys/wei2021.py
+++ b/apps/wei/forms/surveys/wei2021.py
@@ -1,7 +1,7 @@
# Copyright (C) 2018-2021 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later
-
-from random import choice
+import time
+from random import Random
from django import forms
from django.db import transaction
@@ -35,7 +35,18 @@ class WEISurveyForm2021(forms.Form):
"""
Filter the bus selector with the buses of the current WEI.
"""
- words = [choice(WORDS) for _ in range(10)]
+ information = WEISurveyInformation2021(registration)
+ if not information.seed:
+ information.seed = int(1000 * time.time())
+ information.save(registration)
+ registration.save()
+
+ rng = Random(information.seed)
+
+ words = []
+ for _ in range(information.step + 1):
+ # Generate N times words
+ words = [rng.choice(WORDS) for _ in range(10)]
words = [(w, w) for w in words]
if self.data:
self.fields["word"].choices = [(w, w) for w in WORDS]
@@ -59,6 +70,8 @@ class WEISurveyInformation2021(WEISurveyInformation):
We store the id of the selected bus. We store only the name, but is not used in the selection:
that's only for humans that try to read data.
"""
+ # Random seed that is stored at the first time to ensure that words are generated only once
+ seed = 0
step = 0
def __init__(self, registration):
@@ -125,5 +138,6 @@ class WEISurveyAlgorithm2021(WEISurveyAlgorithm):
def run_algorithm(self):
for registration in self.get_registrations():
survey = self.get_survey_class()(registration)
- survey.select_bus(choice(Bus.objects.all()))
+ rng = Random(survey.information.seed)
+ survey.select_bus(rng.choice(Bus.objects.all()))
survey.save()
--
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