Fixed cache issue with memcached

boards/models.py

@@ -1,421 +1,421 b''
 import os
 from random import random
 import time
 import math
 from django.core.cache import cache
 
 from django.db import models
 from django.db.models import Count
 from django.http import Http404
 from django.utils import timezone
 from markupfield.fields import MarkupField
 from boards import settings as board_settings
 
 from neboard import settings
 import thumbs
 
 import re
 
 IMAGE_THUMB_SIZE = (200, 150)
 
 TITLE_MAX_LENGTH = 50
 
 DEFAULT_MARKUP_TYPE = 'markdown'
 
 NO_PARENT = -1
 NO_IP = '0.0.0.0'
 UNKNOWN_UA = ''
 ALL_PAGES = -1
 OPENING_POST_POPULARITY_WEIGHT = 2
 IMAGES_DIRECTORY = 'images/'
 FILE_EXTENSION_DELIMITER = '.'
 
 RANK_ADMIN = 0
 RANK_MODERATOR = 10
 RANK_USER = 100
 
 SETTING_MODERATE = "moderate"
 
 REGEX_REPLY = re.compile('>>(\d+)')
 
 
 class PostManager(models.Manager):
 
     def create_post(self, title, text, image=None, thread=None,
                     ip=NO_IP, tags=None, user=None):
         post = self.create(title=title,
                            text=text,
                            pub_time=timezone.now(),
                            thread=thread,
                            image=image,
                            poster_ip=ip,
                            poster_user_agent=UNKNOWN_UA,
                            last_edit_time=timezone.now(),
                            bump_time=timezone.now(),
                            user=user)
 
         if tags:
             map(post.tags.add, tags)
             for tag in tags:
                 tag.threads.add(post)
 
         if thread:
             thread.replies.add(post)
             thread.bump()
             thread.last_edit_time = timezone.now()
             thread.save()
 
             cache_key = thread.get_cache_key
             cache.delete(cache_key)
 
         else:
             self._delete_old_threads()
 
         self.connect_replies(post)
 
         return post
 
     def delete_post(self, post):
         if post.replies.count() > 0:
             map(self.delete_post, post.replies.all())
 
         # Update thread's last edit time (used as cache key)
         thread = post.thread
         if thread:
             thread.last_edit_time = timezone.now()
             thread.save()
 
             cache_key = thread.get_cache_key
             cache.delete(cache_key)
 
         post.delete()
 
     def delete_posts_by_ip(self, ip):
         posts = self.filter(poster_ip=ip)
         map(self.delete_post, posts)
 
     def get_threads(self, tag=None, page=ALL_PAGES,
                     order_by='-bump_time'):
         if tag:
             threads = tag.threads
 
             if threads.count() == 0:
                 raise Http404
         else:
             threads = self.filter(thread=None)
 
         threads = threads.order_by(order_by)
 
         if page != ALL_PAGES:
             thread_count = threads.count()
 
             if page < self._get_page_count(thread_count):
                 start_thread = page * settings.THREADS_PER_PAGE
                 end_thread = min(start_thread + settings.THREADS_PER_PAGE,
                                  thread_count)
                 threads = threads[start_thread:end_thread]
 
         return threads
 
     def get_thread(self, opening_post_id):
         try:
             opening_post = self.get(id=opening_post_id, thread=None)
         except Post.DoesNotExist:
             raise Http404
 
         cache_key = opening_post.get_cache_key()
         thread = cache.get(cache_key)
         if thread:
             return thread
 
         if opening_post.replies:
             thread = [opening_post]
             thread.extend(opening_post.replies.all().order_by('pub_time'))
 
             cache.set(cache_key, thread, board_settings.CACHE_TIMEOUT)
 
             return thread
 
     def exists(self, post_id):
         posts = self.filter(id=post_id)
 
         return posts.count() > 0
 
     def get_thread_page_count(self, tag=None):
         if tag:
             threads = self.filter(thread=None, tags=tag)
         else:
             threads = self.filter(thread=None)
 
         return self._get_page_count(threads.count())
 
     def _delete_old_threads(self):
         """
         Preserves maximum thread count. If there are too many threads,
         delete the old ones.
         """
 
         # TODO Move old threads to the archive instead of deleting them.
         # Maybe make some 'old' field in the model to indicate the thread
         # must not be shown and be able for replying.
 
         threads = self.get_threads()
         thread_count = threads.count()
 
         if thread_count > settings.MAX_THREAD_COUNT:
             num_threads_to_delete = thread_count - settings.MAX_THREAD_COUNT
             old_threads = threads[thread_count - num_threads_to_delete:]
 
             map(self.delete_post, old_threads)
 
     def connect_replies(self, post):
         """Connect replies to a post to show them as a refmap"""
 
         for reply_number in re.finditer(REGEX_REPLY, post.text.raw):
             id = reply_number.group(1)
             ref_post = self.filter(id=id)
             if ref_post.count() > 0:
                 ref_post[0].referenced_posts.add(post)
 
     def _get_page_count(self, thread_count):
         return int(math.ceil(thread_count / float(settings.THREADS_PER_PAGE)))
 
 
 class TagManager(models.Manager):
 
     def get_not_empty_tags(self):
         tags = self.annotate(Count('threads')) \
             .filter(threads__count__gt=0).order_by('name')
 
         return tags
 
 
 class Tag(models.Model):
     """
     A tag is a text node assigned to the post. The tag serves as a board
     section. There can be multiple tags for each message
     """
 
     objects = TagManager()
 
     name = models.CharField(max_length=100)
     threads = models.ManyToManyField('Post', null=True,
                                      blank=True, related_name='tag+')
     linked = models.ForeignKey('Tag', null=True, blank=True)
 
     def __unicode__(self):
         return self.name
 
     def is_empty(self):
         return self.get_post_count() == 0
 
     def get_post_count(self):
         return self.threads.count()
 
     def get_popularity(self):
         posts_with_tag = Post.objects.get_threads(tag=self)
         reply_count = 0
         for post in posts_with_tag:
             reply_count += post.get_reply_count()
             reply_count += OPENING_POST_POPULARITY_WEIGHT
 
         return reply_count
 
     def get_linked_tags(self):
         tag_list = []
         self.get_linked_tags_list(tag_list)
 
         return tag_list
 
     def get_linked_tags_list(self, tag_list=[]):
         """
         Returns the list of tags linked to current. The list can be got
         through returned value or tag_list parameter
         """
 
         linked_tag = self.linked
 
         if linked_tag and not (linked_tag in tag_list):
             tag_list.append(linked_tag)
 
             linked_tag.get_linked_tags_list(tag_list)
 
 
 class Post(models.Model):
     """A post is a message."""
 
     objects = PostManager()
 
     def _update_image_filename(self, filename):
         """Get unique image filename"""
 
         path = IMAGES_DIRECTORY
         new_name = str(int(time.mktime(time.gmtime())))
         new_name += str(int(random() * 1000))
         new_name += FILE_EXTENSION_DELIMITER
         new_name += filename.split(FILE_EXTENSION_DELIMITER)[-1:][0]
 
         return os.path.join(path, new_name)
 
     title = models.CharField(max_length=TITLE_MAX_LENGTH)
     pub_time = models.DateTimeField()
     text = MarkupField(default_markup_type=DEFAULT_MARKUP_TYPE,
                        escape_html=False)
 
     image_width = models.IntegerField(default=0)
     image_height = models.IntegerField(default=0)
 
     image = thumbs.ImageWithThumbsField(upload_to=_update_image_filename,
                                         blank=True, sizes=(IMAGE_THUMB_SIZE,),
                                         width_field='image_width',
                                         height_field='image_height')
 
     poster_ip = models.GenericIPAddressField()
     poster_user_agent = models.TextField()
 
     thread = models.ForeignKey('Post', null=True, default=None)
     tags = models.ManyToManyField(Tag)
     last_edit_time = models.DateTimeField()
     bump_time = models.DateTimeField()
     user = models.ForeignKey('User', null=True, default=None)
 
     replies = models.ManyToManyField('Post', symmetrical=False, null=True,
                                      blank=True, related_name='re+')
-    referenced_posts = models.ManyToManyField('Post', symmetrical=False, null=True,
-                                     blank=True, related_name='rfp+')
+    referenced_posts = models.ManyToManyField('Post', symmetrical=False,
+                                              null=True,
+                                              blank=True, related_name='rfp+')
 
     def __unicode__(self):
         return '#' + str(self.id) + ' ' + self.title + ' (' + \
                self.text.raw[:50] + ')'
 
     def get_title(self):
         title = self.title
         if len(title) == 0:
             title = self.text.raw[:20]
 
         return title
 
     def get_reply_count(self):
         return self.replies.count()
 
     def get_images_count(self):
         images_count = 1 if self.image else 0
         images_count += self.replies.filter(image_width__gt=0).count()
 
         return images_count
 
     def can_bump(self):
         """Check if the thread can be bumped by replying"""
 
         post_count = self.get_reply_count() + 1
 
         return post_count <= settings.MAX_POSTS_PER_THREAD
 
     def bump(self):
         """Bump (move to up) thread"""
 
         if self.can_bump():
             self.bump_time = timezone.now()
 
-
     def get_last_replies(self):
         if settings.LAST_REPLIES_COUNT > 0:
             reply_count = self.get_reply_count()
 
             if reply_count > 0:
                 reply_count_to_show = min(settings.LAST_REPLIES_COUNT,
                                           reply_count)
-                last_replies = self.replies.all().order_by('pub_time')[reply_count -
-                                                  reply_count_to_show:]
+                last_replies = self.replies.all().order_by('pub_time')[
+                            reply_count - reply_count_to_show:]
 
                 return last_replies
 
     def get_tags(self):
         """Get a sorted tag list"""
 
         return self.tags.order_by('name')
 
     def get_cache_key(self):
-        return str(self.id) + str(self.last_edit_time)
+        return str(self.id) + str(self.last_edit_time.microsecond)
 
 
 class User(models.Model):
 
     user_id = models.CharField(max_length=50)
     rank = models.IntegerField()
 
     registration_time = models.DateTimeField()
 
     fav_tags = models.ManyToManyField(Tag, null=True, blank=True)
     fav_threads = models.ManyToManyField(Post, related_name='+', null=True,
                                          blank=True)
 
     def save_setting(self, name, value):
         setting, created = Setting.objects.get_or_create(name=name, user=self)
         setting.value = str(value)
         setting.save()
 
         return setting
 
     def get_setting(self, name):
         if Setting.objects.filter(name=name, user=self).exists():
             setting = Setting.objects.get(name=name, user=self)
             setting_value = setting.value
         else:
             setting_value = None
 
         return setting_value
 
     def is_moderator(self):
         return RANK_MODERATOR >= self.rank
 
     def get_sorted_fav_tags(self):
         cache_key = self._get_tag_cache_key()
         fav_tags = cache.get(cache_key)
         if fav_tags:
             return fav_tags
 
         tags = self.fav_tags.annotate(Count('threads'))\
             .filter(threads__count__gt=0).order_by('name')
 
         if tags:
             cache.set(cache_key, tags, board_settings.CACHE_TIMEOUT)
 
         return tags
 
     def get_post_count(self):
         return Post.objects.filter(user=self).count()
 
     def __unicode__(self):
         return self.user_id + '(' + str(self.rank) + ')'
 
     def get_last_access_time(self):
         posts = Post.objects.filter(user=self)
         if posts.count() > 0:
             return posts.latest('pub_time').pub_time
 
     def add_tag(self, tag):
         self.fav_tags.add(tag)
         cache.delete(self._get_tag_cache_key())
 
     def remove_tag(self, tag):
         self.fav_tags.remove(tag)
         cache.delete(self._get_tag_cache_key())
 
     def _get_tag_cache_key(self):
         return self.user_id + '_tags'
 
 
 class Setting(models.Model):
 
     name = models.CharField(max_length=50)
     value = models.CharField(max_length=50)
     user = models.ForeignKey(User)
 
 
 class Ban(models.Model):
 
     ip = models.GenericIPAddressField()
 
     def __unicode__(self):
         return self.ip