Fixed #5791 -- Added early-bailout support for views (ETags and Last-modified).

This provides support for views that can have their ETag and/or Last-modified
values computed much more quickly than the view itself. Supports all HTTP
verbs (not just GET).

Documentation and tests need a little more fleshing out (I'm not happy with the
documentation at the moment, since it's a bit backwards), but the functionality
is correct.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10114 bcc190cf-cafb-0310-a4f2-bffc1f526a37

4 files changed, 126 insertions, 0 deletions

diff --git a/tests/regressiontests/conditional_processing/__init__.py b/tests/regressiontests/conditional_processing/__init__.py
new file mode 100644
index 0000000000..380474e035
--- /dev/null
+++ b/tests/regressiontests/conditional_processing/__init__.py
@@ -0,0 +1 @@
+# -*- coding:utf-8 -*-
diff --git a/tests/regressiontests/conditional_processing/models.py b/tests/regressiontests/conditional_processing/models.py
new file mode 100644
index 0000000000..5c52acbd52
--- /dev/null
+++ b/tests/regressiontests/conditional_processing/models.py
@@ -0,0 +1,100 @@
+# -*- coding:utf-8 -*-
+from datetime import datetime, timedelta
+from calendar import timegm
+
+from django.test import TestCase
+from django.utils.http import parse_etags, quote_etag
+
+FULL_RESPONSE = 'Test conditional get response'
+LAST_MODIFIED = datetime(2007, 10, 21, 23, 21, 47)
+LAST_MODIFIED_STR = 'Sun, 21 Oct 2007 23:21:47 GMT'
+EXPIRED_LAST_MODIFIED_STR = 'Sat, 20 Oct 2007 23:21:47 GMT'
+ETAG = 'b4246ffc4f62314ca13147c9d4f76974'
+EXPIRED_ETAG = '7fae4cd4b0f81e7d2914700043aa8ed6'
+
+class ConditionalGet(TestCase):
+    def assertFullResponse(self, response, check_last_modified=True, check_etag=True):
+        self.assertEquals(response.status_code, 200)
+        self.assertEquals(response.content, FULL_RESPONSE)
+        if check_last_modified:
+            self.assertEquals(response['Last-Modified'], LAST_MODIFIED_STR)
+        if check_etag:
+            self.assertEquals(response['ETag'], '"%s"' % ETAG)
+
+    def assertNotModified(self, response):
+        self.assertEquals(response.status_code, 304)
+        self.assertEquals(response.content, '')
+
+    def testWithoutConditions(self):
+        response = self.client.get('/condition/')
+        self.assertFullResponse(response)
+
+    def testIfModifiedSince(self):
+        self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR
+        response = self.client.get('/condition/')
+        self.assertNotModified(response)
+        self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = EXPIRED_LAST_MODIFIED_STR
+        response = self.client.get('/condition/')
+        self.assertFullResponse(response)
+
+    def testIfNoneMatch(self):
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s"' % ETAG
+        response = self.client.get('/condition/')
+        self.assertNotModified(response)
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s"' % EXPIRED_ETAG
+        response = self.client.get('/condition/')
+        self.assertFullResponse(response)
+
+        # Several etags in If-None-Match is a bit exotic but why not?
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s", "%s"' % (ETAG, EXPIRED_ETAG)
+        response = self.client.get('/condition/')
+        self.assertNotModified(response)
+
+    def testBothHeaders(self):
+        self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s"' % ETAG
+        response = self.client.get('/condition/')
+        self.assertNotModified(response)
+
+        self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = EXPIRED_LAST_MODIFIED_STR
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s"' % ETAG
+        response = self.client.get('/condition/')
+        self.assertFullResponse(response)
+
+        self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s"' % EXPIRED_ETAG
+        response = self.client.get('/condition/')
+        self.assertFullResponse(response)
+
+    def testSingleCondition1(self):
+        self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR
+        response = self.client.get('/condition/last_modified/')
+        self.assertNotModified(response)
+        response = self.client.get('/condition/etag/')
+        self.assertFullResponse(response, check_last_modified=False)
+
+    def testSingleCondition2(self):
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s"' % ETAG
+        response = self.client.get('/condition/etag/')
+        self.assertNotModified(response)
+        response = self.client.get('/condition/last_modified/')
+        self.assertFullResponse(response, check_etag=False)
+
+    def testSingleCondition3(self):
+        self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = EXPIRED_LAST_MODIFIED_STR
+        response = self.client.get('/condition/last_modified/')
+        self.assertFullResponse(response, check_etag=False)
+
+    def testSingleCondition4(self):
+        self.client.defaults['HTTP_IF_NONE_MATCH'] = '"%s"' % EXPIRED_ETAG
+        response = self.client.get('/condition/etag/')
+        self.assertFullResponse(response, check_last_modified=False)
+
+class ETagProcesing(TestCase):
+    def testParsing(self):
+        etags = parse_etags(r'"", "etag", "e\"t\"ag", "e\\tag", W/"weak"')
+        self.assertEquals(etags, ['', 'etag', 'e"t"ag', r'e\tag', 'weak'])
+
+    def testQuoting(self):
+        quoted_etag = quote_etag(r'e\t"ag')
+        self.assertEquals(quoted_etag, r'"e\\t\"ag"')
diff --git a/tests/regressiontests/conditional_processing/urls.py b/tests/regressiontests/conditional_processing/urls.py
new file mode 100644
index 0000000000..938a4e4833
--- /dev/null
+++ b/tests/regressiontests/conditional_processing/urls.py
@@ -0,0 +1,8 @@
+from django.conf.urls.defaults import *
+import views
+
+urlpatterns = patterns('',
+    ('^$', views.index),
+    ('^last_modified/$', views.last_modified),
+    ('^etag/$', views.etag),
+)
diff --git a/tests/regressiontests/conditional_processing/views.py b/tests/regressiontests/conditional_processing/views.py
new file mode 100644
index 0000000000..c88236e21b
--- /dev/null
+++ b/tests/regressiontests/conditional_processing/views.py
@@ -0,0 +1,17 @@
+# -*- coding:utf-8 -*-
+from django.views.decorators.http import condition
+from django.http import HttpResponse
+
+from models import FULL_RESPONSE, LAST_MODIFIED, ETAG
+
+@condition(lambda r: ETAG, lambda r: LAST_MODIFIED)
+def index(request):
+    return HttpResponse(FULL_RESPONSE)
+
+@condition(last_modified_func=lambda r: LAST_MODIFIED)
+def last_modified(request):
+    return HttpResponse(FULL_RESPONSE)
+
+@condition(etag_func=lambda r: ETAG)
+def etag(request):
+    return HttpResponse(FULL_RESPONSE)