Added cache for thread opening post

boards/models/post.py

@@ -1,444 +1,451 b''
 from datetime import datetime, timedelta, date
 from datetime import time as dtime
 import os
 from random import random
 import time
 import math
 import re
 import hashlib
 
 from django.core.cache import cache
 from django.core.paginator import Paginator
 from django.core.urlresolvers import reverse
 
 from django.db import models, transaction
 from django.http import Http404
 from django.utils import timezone
 from markupfield.fields import MarkupField
 
 from neboard import settings
 from boards import thumbs
 
 MAX_TITLE_LENGTH = 50
 
 APP_LABEL_BOARDS = 'boards'
 
 CACHE_KEY_PPD = 'ppd'
 CACHE_KEY_POST_URL = 'post_url'
+CACHE_KEY_OPENING_POST = 'opening_post'
 
 POSTS_PER_DAY_RANGE = range(7)
 
 BAN_REASON_AUTO = 'Auto'
 
 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
 IMAGES_DIRECTORY = 'images/'
 FILE_EXTENSION_DELIMITER = '.'
 
 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):
         """
         Create new post
         """
 
         posting_time = timezone.now()
         if not thread:
             thread = Thread.objects.create(bump_time=posting_time,
                                            last_edit_time=posting_time)
         else:
             thread.bump()
             thread.last_edit_time = posting_time
             thread.save()
 
         post = self.create(title=title,
                            text=text,
                            pub_time=posting_time,
                            thread_new=thread,
                            image=image,
                            poster_ip=ip,
                            poster_user_agent=UNKNOWN_UA,  # TODO Get UA at
                            # last!
                            last_edit_time=posting_time,
                            user=user)
 
         thread.replies.add(post)
         if tags:
             linked_tags = []
             for tag in tags:
                 tag_linked_tags = tag.get_linked_tags()
                 if len(tag_linked_tags) > 0:
                     linked_tags.extend(tag_linked_tags)
 
             tags.extend(linked_tags)
             map(thread.add_tag, tags)
 
         self._delete_old_threads()
         self.connect_replies(post)
 
         return post
 
     def delete_post(self, post):
         """
         Delete post and update or delete its thread
         """
 
         thread = post.thread_new
 
         if post.is_opening():
             thread.delete_with_posts()
         else:
             thread.last_edit_time = timezone.now()
             thread.save()
 
             post.delete()
 
     def delete_posts_by_ip(self, ip):
         """
         Delete all posts of the author with same IP
         """
 
         posts = self.filter(poster_ip=ip)
         map(self.delete_post, posts)
 
     # TODO This method may not be needed any more, because django's paginator
     # is used
     def get_threads(self, tag=None, page=ALL_PAGES,
                     order_by='-bump_time', archived=False):
         if tag:
             threads = tag.threads
 
             if not threads.exists():
                 raise Http404
         else:
             threads = Thread.objects.all()
 
         threads = threads.filter(archived=archived).order_by(order_by)
 
         if page != ALL_PAGES:
             threads = Paginator(threads, settings.THREADS_PER_PAGE).page(
                     page).object_list
 
         return threads
 
     # TODO Move this method to thread manager
     def _delete_old_threads(self):
         """
         Preserves maximum thread count. If there are too many threads,
         archive the old ones.
         """
 
         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:]
 
             for thread in old_threads:
                 thread.archived = True
                 thread.last_edit_time = timezone.now()
                 thread.save()
 
     def connect_replies(self, post):
         """
         Connect replies to a post to show them as a reflink map
         """
 
         for reply_number in re.finditer(REGEX_REPLY, post.text.raw):
             post_id = reply_number.group(1)
             ref_post = self.filter(id=post_id)
             if ref_post.count() > 0:
                 referenced_post = ref_post[0]
                 referenced_post.referenced_posts.add(post)
                 referenced_post.last_edit_time = post.pub_time
                 referenced_post.save()
 
                 referenced_thread = referenced_post.thread_new
                 referenced_thread.last_edit_time = post.pub_time
                 referenced_thread.save()
 
     def get_posts_per_day(self):
         """
         Get average count of posts per day for the last 7 days
         """
 
         today = date.today()
         ppd = cache.get(CACHE_KEY_PPD + str(today))
         if ppd:
             return ppd
 
         posts_per_days = []
         for i in POSTS_PER_DAY_RANGE:
             day_end = today - timedelta(i + 1)
             day_start = today - timedelta(i + 2)
 
             day_time_start = timezone.make_aware(datetime.combine(day_start,
                 dtime()), timezone.get_current_timezone())
             day_time_end = timezone.make_aware(datetime.combine(day_end,
                 dtime()), timezone.get_current_timezone())
 
             posts_per_days.append(float(self.filter(
                 pub_time__lte=day_time_end,
                 pub_time__gte=day_time_start).count()))
 
         ppd = (sum(posts_per_day for posts_per_day in posts_per_days) /
                len(posts_per_days))
         cache.set(CACHE_KEY_PPD + str(today), ppd)
         return ppd
 
 
 class Post(models.Model):
     """A post is a message."""
 
     objects = PostManager()
 
     class Meta:
         app_label = APP_LABEL_BOARDS
 
     # TODO Save original file name to some field
     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_pre_width = models.IntegerField(default=0)
     image_pre_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',
                                         preview_width_field='image_pre_width',
                                         preview_height_field='image_pre_height')
     image_hash = models.CharField(max_length=36)
 
     poster_ip = models.GenericIPAddressField()
     poster_user_agent = models.TextField()
 
     thread = models.ForeignKey('Post', null=True, default=None)
     thread_new = models.ForeignKey('Thread', null=True, default=None)
     last_edit_time = models.DateTimeField()
     user = models.ForeignKey('User', null=True, default=None)
 
     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.rendered
 
         return title
 
     def get_sorted_referenced_posts(self):
         return self.referenced_posts.order_by('id')
 
     def is_referenced(self):
         return self.referenced_posts.all().exists()
 
     def is_opening(self):
-        return self.thread_new.get_replies()[0] == self
+        return self.thread_new.get_opening_post() == self
 
     def save(self, *args, **kwargs):
         """
         Save the model and compute the image hash
         """
 
         if not self.pk and self.image:
             md5 = hashlib.md5()
             for chunk in self.image.chunks():
                 md5.update(chunk)
             self.image_hash = md5.hexdigest()
         super(Post, self).save(*args, **kwargs)
 
     @transaction.atomic
     def add_tag(self, tag):
         edit_time = timezone.now()
 
         thread = self.thread_new
         thread.add_tag(tag)
         self.last_edit_time = edit_time
         self.save()
 
         thread.last_edit_time = edit_time
         thread.save()
 
     @transaction.atomic
     def remove_tag(self, tag):
         edit_time = timezone.now()
 
         thread = self.thread_new
         thread.remove_tag(tag)
         self.last_edit_time = edit_time
         self.save()
 
         thread.last_edit_time = edit_time
         thread.save()
 
     def get_url(self):
         """
         Get full url to this post
         """
 
         cache_key = CACHE_KEY_POST_URL + str(self.id)
         link = cache.get(cache_key)
 
         if not link:
             opening_post = self.thread_new.get_opening_post()
             if self != opening_post:
                 link = reverse('thread',
                         kwargs={'post_id': opening_post.id}) + '#' + str(
                                 self.id)
             else:
                 link = reverse('thread', kwargs={'post_id': self.id})
 
             cache.set(cache_key, link)
 
         return link
 
 
 class Thread(models.Model):
 
     class Meta:
         app_label = APP_LABEL_BOARDS
 
     tags = models.ManyToManyField('Tag')
     bump_time = models.DateTimeField()
     last_edit_time = models.DateTimeField()
     replies = models.ManyToManyField('Post', symmetrical=False, null=True,
                                      blank=True, related_name='tre+')
     archived = models.BooleanField(default=False)
 
     def get_tags(self):
         """
         Get a sorted tag list
         """
 
         return self.tags.order_by('name')
 
     def bump(self):
         """
         Bump (move to up) thread
         """
 
         if self.can_bump():
             self.bump_time = timezone.now()
 
     def get_reply_count(self):
         return self.replies.count()
 
     def get_images_count(self):
         return self.replies.filter(image_width__gt=0).count()
 
     def can_bump(self):
         """
         Check if the thread can be bumped by replying
         """
 
         if self.archived:
             return False
 
         post_count = self.get_reply_count()
 
         return post_count < settings.MAX_POSTS_PER_THREAD
 
     def delete_with_posts(self):
         """
         Completely delete thread and all its posts
         """
 
         if self.replies.count() > 0:
             self.replies.all().delete()
 
         self.delete()
 
     def get_last_replies(self):
         """
         Get last replies, not including opening post
         """
 
         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 - 1)
                 last_replies = self.replies.all().order_by('pub_time')[
                                reply_count - reply_count_to_show:]
 
                 return last_replies
 
     def get_skipped_replies_count(self):
         last_replies = self.get_last_replies()
         return self.get_reply_count() - len(last_replies) - 1
 
     def get_replies(self):
         """
         Get sorted thread posts
         """
 
         return self.replies.all().order_by('pub_time')
 
     def add_tag(self, tag):
         """
         Connect thread to a tag and tag to a thread
         """
 
         self.tags.add(tag)
         tag.threads.add(self)
 
     def remove_tag(self, tag):
         self.tags.remove(tag)
         tag.threads.remove(self)
 
     def get_opening_post(self):
         """
         Get first post of the thread
         """
 
-        return self.get_replies()[0]
+        cache_key = CACHE_KEY_OPENING_POST + str(self.id)
+        opening_post = cache.get(cache_key)
+        if not opening_post:
+            opening_post = self.get_replies()[0]
+            cache.set(cache_key, opening_post)
+
+        return opening_post
 
     def __unicode__(self):
         return str(self.id)
 
     def get_pub_time(self):
         """
         Thread does not have its own pub time, so we need to get it from
         the opening post
         """
 
         return self.get_opening_post().pub_time