author | Sylvain Thénault <sylvain.thenault@logilab.fr> |
Thu, 17 Sep 2009 17:05:58 +0200 | |
branch | 3.5 |
changeset 3295 | 7e5d0ae8d202 |
parent 1977 | 606923dff11b |
child 3451 | 6b46d73823f5 |
child 4212 | ab6573088b4a |
permissions | -rw-r--r-- |
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"""HTTP cache managers |
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:organization: Logilab |
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1977
606923dff11b
big bunch of copyright / docstring update
Adrien Di Mascio <Adrien.DiMascio@logilab.fr>
parents:
1802
diff
changeset
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:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2. |
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:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr |
1977
606923dff11b
big bunch of copyright / docstring update
Adrien Di Mascio <Adrien.DiMascio@logilab.fr>
parents:
1802
diff
changeset
|
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:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses |
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""" |
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__docformat__ = "restructuredtext en" |
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1016
26387b836099
use datetime instead of mx.DateTime
sylvain.thenault@logilab.fr
parents:
762
diff
changeset
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from datetime import datetime |
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# time delta usable to convert localized time to GMT time |
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1016
26387b836099
use datetime instead of mx.DateTime
sylvain.thenault@logilab.fr
parents:
762
diff
changeset
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GMTOFFSET = - (datetime.now() - datetime.utcnow()) |
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class NoHTTPCacheManager(object): |
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"""default cache manager: set no-cache cache control policy""" |
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def __init__(self, view): |
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self.view = view |
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self.req = view.req |
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self.rset = view.rset |
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def set_headers(self): |
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self.req.set_header('Cache-control', 'no-cache') |
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class MaxAgeHTTPCacheManager(NoHTTPCacheManager): |
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"""max-age cache manager: set max-age cache control policy, with max-age |
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specified with the `cache_max_age` attribute of the view |
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""" |
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def set_headers(self): |
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self.req.set_header('Cache-control', |
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'max-age=%s' % self.view.cache_max_age) |
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class EtagHTTPCacheManager(NoHTTPCacheManager): |
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"""etag based cache manager for startup views |
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* etag is generated using the view name and the user's groups |
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* set policy to 'must-revalidate' and expires to the current time to force |
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revalidation on each request |
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""" |
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# GMT time required |
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date_format = "%a, %d %b %Y %H:%M:%S GMT" |
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def etag(self): |
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return self.view.id + '/' + ','.join(sorted(self.req.user.groups)) |
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1802
d628defebc17
delete-trailing-whitespace + some copyright update
Adrien Di Mascio <Adrien.DiMascio@logilab.fr>
parents:
1149
diff
changeset
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def max_age(self): |
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# 0 to actually force revalidation |
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return 0 |
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1802
d628defebc17
delete-trailing-whitespace + some copyright update
Adrien Di Mascio <Adrien.DiMascio@logilab.fr>
parents:
1149
diff
changeset
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def last_modified(self): |
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return self.view.last_modified() |
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1802
d628defebc17
delete-trailing-whitespace + some copyright update
Adrien Di Mascio <Adrien.DiMascio@logilab.fr>
parents:
1149
diff
changeset
|
53 |
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def set_headers(self): |
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req = self.req |
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try: |
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req.set_header('Etag', '"%s"' % self.etag()) |
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except NoEtag: |
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self.req.set_header('Cache-control', 'no-cache') |
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return |
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req.set_header('Cache-control', |
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'must-revalidate;max-age=%s' % self.max_age()) |
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mdate = self.last_modified() |
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req.set_header('Last-modified', mdate.strftime(self.date_format)) |
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class EntityHTTPCacheManager(EtagHTTPCacheManager): |
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"""etag based cache manager for view displaying a single entity |
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* etag is generated using entity's eid, the view name and the user's groups |
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* get last modified time from the entity definition (this may not be the |
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entity's modification time since a view may include some related entities |
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with a modification time to consider) using the `last_modified` method |
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""" |
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def etag(self): |
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if self.rset is None or len(self.rset) == 0: # entity startup view for instance |
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return super(EntityHTTPCacheManager, self).etag() |
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if len(self.rset) > 1: |
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raise NoEtag() |
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etag = super(EntityHTTPCacheManager, self).etag() |
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eid = self.rset[0][0] |
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if self.req.user.owns(eid): |
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etag += ',owners' |
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return str(eid) + '/' + etag |
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class NoEtag(Exception): |
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"""an etag can't be generated""" |
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__all__ = ('GMTOFFSET', |
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'NoHTTPCacheManager', 'MaxAgeHTTPCacheManager', |
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'EtagHTTPCacheManager', 'EntityHTTPCacheManager') |
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# monkey patching, so view doesn't depends on this module and we have all |
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# http cache related logic here |
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from cubicweb import view as viewmod |
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def set_http_cache_headers(self): |
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self.http_cache_manager(self).set_headers() |
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viewmod.View.set_http_cache_headers = set_http_cache_headers |
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def last_modified(self): |
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"""return the date/time where this view should be considered as |
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modified. Take care of possible related objects modifications. |
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/!\ must return GMT time /!\ |
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""" |
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# XXX check view module's file modification time in dev mod ? |
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1016
26387b836099
use datetime instead of mx.DateTime
sylvain.thenault@logilab.fr
parents:
762
diff
changeset
|
109 |
ctime = datetime.utcnow() |
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if self.cache_max_age: |
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mtime = self.req.header_if_modified_since() |
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if mtime: |
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1016
26387b836099
use datetime instead of mx.DateTime
sylvain.thenault@logilab.fr
parents:
762
diff
changeset
|
113 |
tdelta = (ctime - mtime) |
26387b836099
use datetime instead of mx.DateTime
sylvain.thenault@logilab.fr
parents:
762
diff
changeset
|
114 |
if tdelta.days * 24*60*60 + tdelta.seconds > self.cache_max_age: |
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mtime = ctime |
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else: |
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mtime = ctime |
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else: |
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mtime = ctime |
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# mtime = ctime will force page rerendering |
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return mtime |
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viewmod.View.last_modified = last_modified |
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# configure default caching |
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viewmod.View.http_cache_manager = NoHTTPCacheManager |
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# max-age=0 to actually force revalidation when needed |
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viewmod.View.cache_max_age = 0 |
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viewmod.EntityView.http_cache_manager = EntityHTTPCacheManager |
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viewmod.StartupView.http_cache_manager = MaxAgeHTTPCacheManager |
1802
d628defebc17
delete-trailing-whitespace + some copyright update
Adrien Di Mascio <Adrien.DiMascio@logilab.fr>
parents:
1149
diff
changeset
|
133 |
viewmod.StartupView.cache_max_age = 60*60*2 # stay in http cache for 2 hours by default |