1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
# -*- 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.
from operator import attrgetter
from django.db.models import Q
from django.template import RequestContext
from django.core.paginator import Paginator
from django.contrib.auth.models import User
from django.http import HttpResponseRedirect
from django.shortcuts import render_to_response, get_object_or_404
from django_swordfish.db import Tree, TreeIntersection, TreeDifference
from models import Message
from forms import MessageForm
def index(request):
return render_to_response('index.html', {
'users': User.objects.all(),
}, context_instance=RequestContext(request))
def user_page(request, username):
user = get_object_or_404(User, username=username)
# Use SQL to get the User objects out via JOINs
following = User.objects.filter(following__dst=user)
followers = User.objects.filter(followers__src=user)
# Alternatively, use .as_model() to get the User objects out
following = Tree('followed-by-%s' % user).values().as_model(User)
followers = Tree('follower-of-%s' % user).values().as_model(User)
# Or (better still) as our URLs are deterministic, just get the keys out
following = Tree('followed-by-%s' % user).keys()
followers = Tree('follower-of-%s' % user).keys()
msgs = user.messages.all()
return render_to_response('user.html', {
'user': user,
'users': User.objects.exclude(pk=user.pk),
'following': following,
'followers': followers,
'msgs': Paginator(msgs, 10).page(request.GET.get('page', 1)),
}, context_instance=RequestContext(request))
def logged_in(request, username):
user = get_object_or_404(User, username=username)
if request.method == 'POST':
form = MessageForm(request.POST)
if form.is_valid():
Message.objects.create(
user=user,
msg=form.cleaned_data['msg'],
)
return HttpResponseRedirect('?')
else:
form = MessageForm()
# Use SQL to get the Message objects out via JOIN and DISTINCT
msgs = Message.objects.filter(
Q(user=user) | Q(user__following__dst=user)
).distinct()
# Alternatively, use .as_model() to get the User objects out
msgs = Tree('messages-for-%s' % user).values().as_model(Message)
return render_to_response('logged_in.html', {
'user': user,
'form': form,
'msgs': Paginator(msgs, 10).page(request.GET.get('page', 1)),
}, context_instance=RequestContext(request))
def intersection(request):
a = get_object_or_404(User, username=request.GET.get('a', ''))
b = get_object_or_404(User, username=request.GET.get('b', ''))
# SQL intersection (double-JOIN)
users = User.objects.filter(followers__src=a) & \
User.objects.filter(followers__src=b)
# Alternatively, use Swordfish
users = TreeIntersection('followed-by-%s' % a, 'followed-by-%s' % b). \
values().as_model(User)
# Alternatively, as our URLs are deterministic; just use the keys
users = TreeIntersection('followed-by-%s' % a, 'followed-by-%s' % b).keys()
return render_to_response('intersection.html', {
'a': a,
'b': b,
'users': Paginator(users, 10).page(request.GET.get('page', 1)),
}, context_instance=RequestContext(request))
def difference(request):
a = get_object_or_404(User, username=request.GET.get('a', ''))
b = get_object_or_404(User, username=request.GET.get('b', ''))
## SQL/Python difference (memory-bound, requires in-Python sorting)
# users = list(set(User.objects.filter(followers__src=a)) - \
# set(User.objects.filter(followers__src=b)))
#users.sort(key=attrgetter('pk'))
# Alternatively, use Swordfish
users = TreeDifference('followed-by-%s' % a, 'followed-by-%s' % b). \
values().as_model(User)
# Alternatively, as our URLs are deterministic; just use the keys
users = TreeDifference('followed-by-%s' % a, 'followed-by-%s' % b).keys()
return render_to_response('difference.html', {
'a': a,
'b': b,
'users': Paginator(users, 10).page(request.GET.get('page', 1)),
}, context_instance=RequestContext(request))
|
