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# -*- coding: UTF8 -*-
#
# Swordfish database
# Copyright (C) 2009 UUMC, Ltd. <chris@playfire.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# 3. Neither the name of the University nor the names of its contributors
# may be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
import time
import datetime
from django.db import models
from django.contrib.auth.models import User
from django_swordfish.db import Tree
class Following(models.Model):
src = models.ForeignKey(User, related_name='following')
dst = models.ForeignKey(User, related_name='followers')
def save(self, *args, **kwargs):
super(Following, self).save(*args, **kwargs)
Tree('followed-by-%s' % self.src).set(self.dst, self.dst_id)
Tree('follower-of-%s' % self.dst).set(self.src, self.src_id)
class Message(models.Model):
user = models.ForeignKey(User, related_name='messages')
username = models.CharField(max_length=15)
msg = models.CharField(max_length=140)
date = models.DateTimeField(default=datetime.datetime.now)
class Meta:
ordering = ('-date',)
def key(self):
return '%0.10d-%d' % (
2**31 - time.mktime(self.date.timetuple()),
self.pk,
)
def save(self, *args, **kwargs):
created = not self.id
if created:
self.username = self.user.username
super(Message, self).save(*args, **kwargs)
if created:
key = self.key()
# Add the message to the user's message tree.
Tree('messages-for-%s' % self.user).set(key, self.pk)
# Use the follower-of- tree for this user to add the message their
# followers' trees.
#
# This step could be done asynchronously if required - the above call
# could still be made sychronously to maintain the illusion.
Tree('follower-of-%s' % self.user).keys().map('messages-for-%', key, self.pk)
def delete(self, *args, **kwargs):
key = self.key()
# Remove the message to the user's message tree.
Tree('messages-for-%s' % self.user).delete(key)
# Use the follower-of- tree for this user to remove the message their
# followers' trees.
#
# Like the call in save(), this step could be done asynchronously.
Tree('follower-of-%s' % self.user).keys().map('messages-for-%', key)
super(Message, self).delete(*args, **kwargs)
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