1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | #!/usr/bin/env python # -*- coding: utf-8 -*- from django.template import loader from django.conf import settings template_cache = {} original_get_template = loader.get_template def cached_get_template(template_name): global template_cache t = template_cache.get(template_name,None) if not t or settings.DEBUG: template_cache[template_name] = t = original_get_template(template_name) return t loader.get_template = cached_get_template |
Put this code somewhere in one of your INSTALLED_APPS __init__.py file. This code will replace the django.template.loader.get_template with cached version. Standard get_template function from django reads and parses the template code every time it's called. This version calls (if DEBUG set to False) it only once per template. After that it gets a Template object from template_cache dictionary. On django http server with template code like that:
{% extends "index.html" %}
{% block content %}
{% if form.has_errors %}
<p>Your username and password didn't match. Please try again.</p>
{% endif %}
<form method="post" action=".">
<table>
<tr><td><label for="id_username">Username:</label></td><td>{{ form.username }}</td></tr>
<tr><td><label for="id_password">Password:</label></td><td>{{ form.password }}</td></tr>
</table>
<input type="submit" value="login" />
<input type="hidden" name="next" value="{{ next }}" />
</form>
{% endblock %}
ab -n 100 on mac os x 10.5 core 2 duo 2 ghz with 2 GB of RAM gives
forge-macbook:~ forge$ ab -n 100 http://127.0.0.1:8000/login/
This is ApacheBench, Version 2.0.40-dev <$Revision: 1.146 $> apache-2.0
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright 2006 The Apache Software Foundation, http://www.apache.org/
Benchmarking 127.0.0.1 (be patient).....done
Server Software: WSGIServer/0.1
Server Hostname: 127.0.0.1
Server Port: 8000
Document Path: /login/
Document Length: 934 bytes
Concurrency Level: 1
Time taken for tests: 0.432934 seconds
Complete requests: 100
Failed requests: 0
Write errors: 0
Total transferred: 120200 bytes
HTML transferred: 93400 bytes
Requests per second: 230.98 [#/sec] (mean)
Time per request: 4.329 [ms] (mean)
Time per request: 4.329 [ms] (mean, across all concurrent requests)
Transfer rate: 270.25 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.0 0 0
Processing: 3 3 1.5 4 12
Waiting: 3 3 1.2 3 12
Total: 3 3 1.5 4 12
Percentage of the requests served within a certain time (ms)
50% 4
66% 4
75% 4
80% 4
90% 4
95% 5
98% 10
99% 12
100% 12 (longest request)
without template caching, and
forge-macbook:~ forge$ ab -n 100 http://127.0.0.1:8000/login/
This is ApacheBench, Version 2.0.40-dev <$Revision: 1.146 $> apache-2.0
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright 2006 The Apache Software Foundation, http://www.apache.org/
Benchmarking 127.0.0.1 (be patient).....done
Server Software: WSGIServer/0.1
Server Hostname: 127.0.0.1
Server Port: 8000
Document Path: /login/
Document Length: 934 bytes
Concurrency Level: 1
Time taken for tests: 0.369860 seconds
Complete requests: 100
Failed requests: 0
Write errors: 0
Total transferred: 120200 bytes
HTML transferred: 93400 bytes
Requests per second: 270.37 [#/sec] (mean)
Time per request: 3.699 [ms] (mean)
Time per request: 3.699 [ms] (mean, across all concurrent requests)
Transfer rate: 316.34 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.0 0 0
Processing: 3 3 0.9 3 9
Waiting: 2 3 0.9 3 8
Total: 3 3 0.9 3 9
Percentage of the requests served within a certain time (ms)
50% 3
66% 3
75% 3
80% 3
90% 3
95% 5
98% 8
99% 9
100% 9 (longest request)
with caching enabled. In both cases DEBUG is set to False.
- Author:
- forgems
- Posted:
- December 12, 2007
- Language:
- Python
- Tags:
- cache optimization performance template
- Score:
- 8 (after 8 ratings)
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Comments
Be aware that changes in template require server restart to become visible. Anyway, very nice feature.
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There is a little problem with this since Python 2.4's cache framework couldn't pickle a compiled template object. Without that, a production box will barely benefit from the cached template by fetching it from memcached.
An alternative is to patch the template loader source code with this ticket.
Alex from haokanbu.com
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