私の問題はもともと、かなりありきたりの「最大再帰深度を超えました」というエラーとして現れましたListView。掘り下げた後、対応するページをロードしようとするたびに、dbtemplates に由来する大量のキャッシュ ヒットが見つかりました。これにより、私は独自のテンプレート ローダーを作成するようになりました。その時点でload_template_source、ページが読み込まれるたびに Django が正確に 69 回呼び出していることが明らかになりました。
Django がload_template_source複数回呼び出すのはなぜですか?
Visitor_index (db テンプレート)
<!DOCTYPE html>
<html lang="en">
<head>
<title>{{ site.name }}</title>
</head>
<body id="home">
<pre>
Starting
{% for video in videos %}
{{ video.headline }}
{% endfor %}
</pre>
</body>
</html>
urls.py
from django.conf.urls import include, url
from django.conf.urls.defaults import patterns
from videos.views import *
urlpatterns = patterns('',
url(r'^$', VisitorIndex.as_view(), name='index'),
)
ビュー.py
import logging
from django.views.generic import ListView
from videos.models import Video
logger = logging.getLogger(__name__)
class VisitorIndex(ListView):
context_object_name = 'videos'
template_name = 'visitor_index'
def get_queryset(self):
logger.debug('VisitorIndex.get_queryset()')
return Video.on_site.filter(privacy_mode='PUB')
loader.py
import logging
from django.template import TemplateDoesNotExist
from django.template.loader import BaseLoader
from dbtemplates.models import Template
logger = logging.getLogger(__name__)
class Loader(BaseLoader):
is_usable = True
def load_template_source(self, template_name, template_dirs=None):
try:
logger.debug('Loader.load_template_source(%s, %s)' % (template_name, template_dirs))
template = Template.on_site.get(slug__exact=template_name).template_body
logger.debug('Loaded template.')
return template, template_name
except Template.DoesNotExist:
logger.debug('Template.DoesNotExist caught.')
raise TemplateDoesNotExist, template_name
models.py
import logging
from django.contrib.sites.models import Site
from django.contrib.sites.managers import CurrentSiteManager
from django.db import models
logger = logging.getLogger('__name__')
class Template(models.Model):
slug = models.CharField(max_length=80)
template_body = models.TextField()
site = models.ForeignKey(Site)
objects = models.Manager()
on_site = CurrentSiteManager('site')
def __unicode__(self):
return self.slug
設定.py
TEMPLATE_LOADERS = (
'django.template.loaders.filesystem.Loader',
'django.template.loaders.app_directories.Loader',
'dbtemplates.loader.Loader',
)
app.log (トレースで更新)
2013-05-09 19:15:43,634 [DEBUG] dynamicsites.middleware: ENV_HOSTNAMES lookup subdomain=None domain=mydomain.com domain_unsplit=mydomain.com
2013-05-09 19:15:43,634 [DEBUG] dynamicsites.middleware: Checking database for domain=mydomain.com
2013-05-09 19:15:43,679 [DEBUG] dynamicsites.middleware: Using site id=2 domain=mydomain.com
2013-05-09 19:15:43,714 [DEBUG] videos.views: VisitorIndex.get_queryset()
2013-05-09 19:15:43,716 [DEBUG] django.template.response: SimpleTemplateResponse.rendered_content()
2013-05-09 19:15:43,717 [DEBUG] django.template.response: Start self.resolve_template()
2013-05-09 19:15:43,717 [DEBUG] django.template.response: SimpleTemplateResponse.resolve_template(). Found list or tuple.
2013-05-09 19:15:43,717 [DEBUG] django.template.response: Calling loader.select_template(template=['visitor_index', u'videos/video_list.html'])
2013-05-09 19:15:43,720 [DEBUG] dbtemplates.loader: Loader.load_template_source(visitor_index, None)
2013-05-09 19:15:43,722 [DEBUG] dbtemplates.loader: File "/usr/lib/python2.7/threading.py", line 525, in __bootstrap
self.__bootstrap_inner()
File "/usr/lib/python2.7/threading.py", line 552, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 505, in run
self.__target(*self.__args, **self.__kwargs)
File "/usr/lib/python2.7/SocketServer.py", line 593, in process_request_thread
self.finish_request(request, client_address)
File "/usr/lib/python2.7/SocketServer.py", line 334, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/core/servers/basehttp.py", line 150, in __init__
super(WSGIRequestHandler, self).__init__(*args, **kwargs)
File "/usr/lib/python2.7/SocketServer.py", line 649, in __init__
self.handle()
File "/usr/lib/python2.7/wsgiref/simple_server.py", line 124, in handle
handler.run(self.server.get_app())
File "/usr/lib/python2.7/wsgiref/handlers.py", line 85, in run
self.result = application(self.environ, self.start_response)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/contrib/staticfiles/handlers.py", line 72, in __call__
return self.application(environ, start_response)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 255, in __call__
response = self.get_response(request)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 140, in get_response
response = response.render()
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/response.py", line 121, in render
self.content = self.rendered_content
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/response.py", line 91, in rendered_content
template = self.resolve_template(self.template_name)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/response.py", line 60, in resolve_template
t = loader.select_template(template)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/loader.py", line 188, in select_template
return get_template(template_name)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/loader.py", line 146, in get_template
template, origin = find_template(template_name)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/loader.py", line 135, in find_template
source, display_name = loader(name, dirs)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/loader.py", line 43, in __call__
return self.load_template(template_name, template_dirs)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/loader.py", line 46, in load_template
source, display_name = self.load_template_source(template_name, template_dirs)
File "/home/wesley/howl/dbtemplates/loader.py", line 19, in load_template_source
logger.debug(''.join(traceback.format_stack()))
2013-05-09 19:15:43,885 [DEBUG] dbtemplates.loader: Loaded template.
2013-05-09 19:15:43,886 [DEBUG] django.template.response: Done.
2013-05-09 19:15:43,887 [DEBUG] django.template.response: Done. <django.template.base.Template object at 0x7fbdf8215050>
2013-05-09 19:15:43,887 [DEBUG] django.template.response: Start self.resolve_context()
2013-05-09 19:15:43,920 [DEBUG] django.template.response: Start template.render(context)
2013-05-09 19:15:43,920 [DEBUG] django.template.base: Template.render(context)
2013-05-09 19:15:43,920 [DEBUG] django.template.base: context.render_context.push()
2013-05-09 19:15:43,920 [DEBUG] django.template.base: Done.
2013-05-09 19:15:43,921 [DEBUG] django.template.base: Try self._render(context)
2013-05-09 19:15:43,932 [DEBUG] dbtemplates.loader: Loader.load_template_source(visitor_index, None)
2013-05-09 19:15:43,933 [DEBUG] dbtemplates.loader: File "/usr/lib/python2.7/threading.py", line 525, in __bootstrap
self.__bootstrap_inner()
File "/usr/lib/python2.7/threading.py", line 552, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 505, in run
self.__target(*self.__args, **self.__kwargs)
File "/usr/lib/python2.7/SocketServer.py", line 593, in process_request_thread
self.finish_request(request, client_address)
File "/usr/lib/python2.7/SocketServer.py", line 334, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/core/servers/basehttp.py", line 150, in __init__
super(WSGIRequestHandler, self).__init__(*args, **kwargs)
File "/usr/lib/python2.7/SocketServer.py", line 649, in __init__
self.handle()
File "/usr/lib/python2.7/wsgiref/simple_server.py", line 124, in handle
handler.run(self.server.get_app())
File "/usr/lib/python2.7/wsgiref/handlers.py", line 85, in run
self.result = application(self.environ, self.start_response)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/contrib/staticfiles/handlers.py", line 72, in __call__
return self.application(environ, start_response)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 255, in __call__
response = self.get_response(request)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 140, in get_response
response = response.render()
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/response.py", line 121, in render
self.content = self.rendered_content
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/response.py", line 97, in rendered_content
content = template.render(context)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/base.py", line 146, in render
return self._render(context)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/test/utils.py", line 65, in instrumented_test_render
return self.nodelist.render(context)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/base.py", line 837, in render
bit = self.render_node(node, context)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/debug.py", line 74, in render_node
return node.render(context)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/defaulttags.py", line 148, in render
len_values = len(values)
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/db/models/query.py", line 90, in __len__
self._result_cache = list(self.iterator())
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/db/models/query.py", line 301, in iterator
for row in compiler.results_iter():
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 775, in results_iter
for rows in self.execute_sql(MULTI):
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 840, in execute_sql
cursor.execute(sql, params)
File "/home/wesley/howl/debug_toolbar/utils/tracking/db.py", line 134, in execute
template_info = get_template_info(node.source)
File "/home/wesley/howl/debug_toolbar/utils/__init__.py", line 80, in get_template_info
template_source = origin.reload()
File "/home/wesley/environments/howl/local/lib/python2.7/site-packages/django/template/loader.py", line 80, in reload
return self.loader(self.loadname, self.dirs)[0]
File "/home/wesley/howl/dbtemplates/loader.py", line 19, in load_template_source
logger.debug(''.join(traceback.format_stack()))
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