110swag / flashy-backend

Commit 5c1348fee89a45afb07f214b9855b0b351009a3a

Authored by Andrew Buss 10 years ago

Exists in master

halfway denormalize score

Showing 2 changed files with 58 additions and 16 deletions Side-by-side Diff

flashcards/migrations/0018_flashcard_score.py
flashcards/models.py

	1	+# -- coding: utf-8 --
	2	+from __future__ import unicode_literals
	3	+from math import log1p, exp
	4	+
	5	+from django.db import models, migrations
	6	+from django.utils.timezone import make_aware
	7	+
	8	+
	9	+def update_scores(apps, schema_editor):
	10	+ Flashcard = apps.get_model("flashcards", "Flashcard")
	11	+ for card in Flashcard.objects.all():
	12	+ def seconds_since_epoch(dt):
	13	+ from datetime import datetime
	14	+
	15	+ epoch = make_aware(datetime.utcfromtimestamp(0))
	16	+ delta = dt - epoch
	17	+ return delta.total_seconds()
	18	+
	19	+ z = 0
	20	+ rate = 1.0 / 3600
	21	+ for vote in card.userflashcard_set.iterator():
	22	+ t = seconds_since_epoch(vote.pulled)
	23	+ u = max(z, rate * t)
	24	+ v = min(z, rate * t)
	25	+ z = u + log1p(exp(v - u))
	26	+ card.score = z
	27	+ card.save()
	28	+
	29	+
	30	+class Migration(migrations.Migration):
	31	+ dependencies = [
	32	+ ('flashcards', '0017_auto_20150601_2001'),
	33	+ ]
	34	+
	35	+ operations = [
	36	+ migrations.AddField(
	37	+ model_name='flashcard',
	38	+ name='score',
	39	+ field=models.FloatField(default=0),
	40	+ preserve_default=False,
	41	+ ),
	42	+ migrations.RunPython(update_scores),
	43	+ ]

...	...	@@ -7,7 +7,7 @@
7	7	from django.contrib.auth.tokens import default_token_generator
8	8	from django.core.cache import cache
9	9	from django.core.exceptions import ValidationError
10		-from django.core.exceptions import PermissionDenied, SuspiciousOperation
	10	+from django.core.exceptions import PermissionDenied
11	11	from django.core.mail import send_mail
12	12	from django.core.validators import MinLengthValidator
13	13	from django.db import IntegrityError
...	...	@@ -23,6 +23,8 @@
23	23
24	24
25	25
	26	+
	27	+
26	28	# Hack to fix AbstractUser before subclassing it
27	29
28	30	AbstractUser._meta.get_field('email')._unique = True
...	...	@@ -127,6 +129,8 @@
127	129	except IntegrityError:
128	130	raise FlashcardAlreadyPulledException()
129	131
	132	+ flashcard.refresh_score()
	133	+
130	134	import flashcards.pushes
131	135
132	136	flashcards.pushes.push_feed_event('score_change', flashcard)
133	137
...	...	@@ -135,13 +139,14 @@
135	139	def unpull(self, flashcard):
136	140	if not self.is_in_section(flashcard.section):
137	141	raise ValueError("User not in the section this flashcard belongs to")
138		-
139	142	try:
140	143	user_card = UserFlashcard.objects.get(user=self, flashcard=flashcard)
141	144	except UserFlashcard.DoesNotExist:
142	145	raise FlashcardNotInDeckException()
143	146	user_card.delete()
144	147
	148	+ flashcard.refresh_score()
	149	+
145	150	import flashcards.pushes
146	151
147	152	flashcards.pushes.push_feed_event('score_change', flashcard)
...	...	@@ -271,6 +276,7 @@
271	276	material_date = DateTimeField(default=now, help_text="The date with which the card is associated")
272	277	previous = ForeignKey('Flashcard', null=True, blank=True, default=None,
273	278	help_text="The previous version of this card, if one exists")
	279	+ score = FloatField(default=0)
274	280	author = ForeignKey(User)
275	281	is_hidden = BooleanField(default=False)
276	282	hide_reason = CharField(blank=True, null=True, max_length=255, default='',
...	...	@@ -284,6 +290,10 @@
284	290	def __unicode__(self):
285	291	return u'<flashcard: %s>' % self.text
286	292
	293	+ def refresh_score(self):
	294	+ self.score = self.calculate_score
	295	+ self.save()
	296	+
287	297	@classmethod
288	298	def push(cls, **kwargs):
289	299	card = cls(**kwargs)
...	...	@@ -311,16 +321,6 @@
311	321	def is_in_deck(self, user):
312	322	return self.userflashcard_set.filter(user=user).exists()
313	323
314		- def add_to_deck(self, user):
315		- if not user.is_in_section(self.section):
316		- raise PermissionDenied("You don't have the permission to add this card")
317		- try:
318		- user_flashcard = UserFlashcard.objects.create(user=user, flashcard=self, mask=self.mask)
319		- except IntegrityError:
320		- raise SuspiciousOperation("The flashcard is already in the user's deck")
321		- user_flashcard.save()
322		- return user_flashcard
323		-
324	324	def edit(self, user, new_data):
325	325	"""
326	326	Creates a new flashcard if a new flashcard should be created when the given user edits this flashcard.
...	...	@@ -347,7 +347,7 @@
347	347	self.pk = None
348	348	self.mask = new_data.get('mask', self.mask)
349	349	self.save()
350		- self.add_to_deck(user)
	350	+ user.pull(self)
351	351	else:
352	352	user_card, created = UserFlashcard.objects.get_or_create(user=user, flashcard=self)
353	353	user_card.mask = new_data.get('mask', user_card.mask)
...	...	@@ -372,7 +372,7 @@
372	372	hide.delete()
373	373
374	374	@cached_property
375		- def score(self):
	375	+ def calculate_score(self):
376	376	def seconds_since_epoch(dt):
377	377	from datetime import datetime
378	378
...	...	@@ -526,8 +526,7 @@
526	526	return '%s %s' % (self.department_abbreviation, self.course_num)
527	527
528	528	def get_feed_for_user(self, user, page=1):
529		- cards = list(self.get_cards_for_user(user)[(page - 1) * self.PAGE_SIZE:page * self.PAGE_SIZE])
530		- cards.sort(key=lambda x: -x.score)
	529	+ cards = self.get_cards_for_user(user).order_by('-score')[(page - 1) * self.PAGE_SIZE:page * self.PAGE_SIZE]
531	530	return cards
532	531
533	532	def get_cards_for_user(self, user):