Beefed up the tests for multi-cache handling of the cache middleware and view decorators, and made a couple of tweaks for edge cases as a result.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15021 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/middleware/cache.py

@@ -85,7 +85,7 @@ class UpdateCacheMiddleware(object):
             return response
         patch_response_headers(response, timeout)
         if timeout:
-            cache_key = learn_cache_key(request, response, timeout, self.key_prefix)
+            cache_key = learn_cache_key(request, response, timeout, self.key_prefix, cache=self.cache)
             self.cache.set(cache_key, response, timeout)
         return response
 
@@ -120,17 +120,14 @@ class FetchFromCacheMiddleware(object):
             return None # Don't cache requests from authenticated users.
 
         # try and get the cached GET response
-        cache_key = get_cache_key(request, self.key_prefix, 'GET')
-
+        cache_key = get_cache_key(request, self.key_prefix, 'GET', cache=self.cache)
         if cache_key is None:
             request._cache_update_cache = True
             return None # No cache information available, need to rebuild.
-
         response = self.cache.get(cache_key, None)
-
         # if it wasn't found and we are looking for a HEAD, try looking just for that
         if response is None and request.method == 'HEAD':
-            cache_key = get_cache_key(request, self.key_prefix, 'HEAD')
+            cache_key = get_cache_key(request, self.key_prefix, 'HEAD', cache=self.cache)
             response = self.cache.get(cache_key, None)
 
         if response is None:
@@ -149,28 +146,33 @@ class CacheMiddleware(UpdateCacheMiddleware, FetchFromCacheMiddleware):
     using the decorator-from-middleware utility.
     """
     def __init__(self, cache_timeout=None, cache_anonymous_only=None, **kwargs):
-        self.cache_timeout = cache_timeout
-        if cache_timeout is None:
-            self.cache_timeout = settings.CACHE_MIDDLEWARE_SECONDS
-
         # We need to differentiate between "provided, but using default value",
         # and "not provided". If the value is provided using a default, then
         # we fall back to system defaults. If it is not provided at all,
         # we need to use middleware defaults.
+
+        cache_kwargs = {}
+        try:
+            self.key_prefix = kwargs.get('key_prefix')
+            if self.key_prefix is not None:
+                cache_kwargs['KEY_PREFIX'] = self.key_prefix
+            else:
+                self.key_prefix = ''
+        except KeyError:
+            self.key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
+            cache_kwargs['KEY_PREFIX'] = self.key_prefix
         try:
             cache_alias = kwargs.get('cache_alias')
             if cache_alias is None:
                 cache_alias = DEFAULT_CACHE_ALIAS
+            if cache_timeout is not None:
+                cache_kwargs['TIMEOUT'] = cache_timeout
         except KeyError:
             cache_alias = settings.CACHE_MIDDLEWARE_ALIAS
-
-        cache_kwargs = {}
-        try:
-            key_prefix = kwargs.get('key_prefix')
-            if key_prefix is not None:
-                cache_kwargs['KEY_PREFIX'] = key_prefix
-        except KeyError:
-            cache_kwargs['KEY_PREFIX'] = settings.CACHE_MIDDLEWARE_KEY_PREFIX
+            if cache_timeout is None:
+                cache_kwargs['TIMEOUT'] = settings.CACHE_MIDDLEWARE_SECONDS
+            else:
+                cache_kwargs['TIMEOUT'] = cache_timeout
 
         if cache_anonymous_only is None:
             self.cache_anonymous_only = getattr(settings, 'CACHE_MIDDLEWARE_ANONYMOUS_ONLY', False)
@@ -178,3 +180,4 @@ class CacheMiddleware(UpdateCacheMiddleware, FetchFromCacheMiddleware):
             self.cache_anonymous_only = cache_anonymous_only
 
         self.cache = get_cache(cache_alias, **cache_kwargs)
+        self.cache_timeout = self.cache.default_timeout

django/utils/cache.py

@@ -21,7 +21,7 @@ import re
 import time
 
 from django.conf import settings
-from django.core.cache import cache
+from django.core.cache import get_cache
 from django.utils.encoding import smart_str, iri_to_uri
 from django.utils.http import http_date
 from django.utils.hashcompat import md5_constructor
@@ -162,7 +162,7 @@ def _generate_cache_header_key(key_prefix, request):
         key_prefix, path.hexdigest())
     return _i18n_cache_key_suffix(request, cache_key)
 
-def get_cache_key(request, key_prefix=None, method='GET'):
+def get_cache_key(request, key_prefix=None, method='GET', cache=None):
     """
     Returns a cache key based on the request path. It can be used in the
     request phase because it pulls the list of headers to take into account
@@ -175,13 +175,15 @@ def get_cache_key(request, key_prefix=None, method='GET'):
     if key_prefix is None:
         key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
     cache_key = _generate_cache_header_key(key_prefix, request)
+    if cache is None:
+        cache = get_cache(settings.CACHE_MIDDLEWARE_ALIAS)
     headerlist = cache.get(cache_key, None)
     if headerlist is not None:
         return _generate_cache_key(request, method, headerlist, key_prefix)
     else:
         return None
 
-def learn_cache_key(request, response, cache_timeout=None, key_prefix=None):
+def learn_cache_key(request, response, cache_timeout=None, key_prefix=None, cache=None):
     """
     Learns what headers to take into account for some request path from the
     response object. It stores those headers in a global path registry so that
@@ -199,6 +201,8 @@ def learn_cache_key(request, response, cache_timeout=None, key_prefix=None):
     if cache_timeout is None:
         cache_timeout = settings.CACHE_MIDDLEWARE_SECONDS
     cache_key = _generate_cache_header_key(key_prefix, request)
+    if cache is None:
+        cache = get_cache(settings.CACHE_MIDDLEWARE_ALIAS)
     if response.has_header('Vary'):
         headerlist = ['HTTP_'+header.upper().replace('-', '_')
                       for header in cc_delim_re.split(response['Vary'])]

tests/regressiontests/cache/tests.py

@@ -14,12 +14,14 @@ from django.core import management
 from django.core.cache import get_cache, DEFAULT_CACHE_ALIAS
 from django.core.cache.backends.base import InvalidCacheBackendError, CacheKeyWarning
 from django.http import HttpResponse, HttpRequest
-from django.middleware.cache import FetchFromCacheMiddleware, UpdateCacheMiddleware
+from django.middleware.cache import FetchFromCacheMiddleware, UpdateCacheMiddleware, CacheMiddleware
+from django.test import RequestFactory
 from django.test.utils import get_warnings_state, restore_warnings_state
 from django.utils import translation
 from django.utils import unittest
 from django.utils.cache import patch_vary_headers, get_cache_key, learn_cache_key
 from django.utils.hashcompat import md5_constructor
+from django.views.decorators.cache import cache_page
 from regressiontests.cache.models import Poll, expensive_calculation
 
 # functions/classes for complex data type tests
@@ -759,6 +761,15 @@ class LocMemCacheTests(unittest.TestCase, BaseCacheTests):
         self.cache = get_cache('locmem://?max_entries=30&cull_frequency=0')
         self.perform_cull_test(50, 19)
 
+    def test_multiple_caches(self):
+        "Check that multiple locmem caches are isolated"
+        mirror_cache = get_cache('django.core.cache.backends.locmem.LocMemCache')
+        other_cache = get_cache('django.core.cache.backends.locmem.LocMemCache', LOCATION='other')
+
+        self.cache.set('value1', 42)
+        self.assertEquals(mirror_cache.get('value1'), 42)
+        self.assertEquals(other_cache.get('value1'), None)
+
 # memcached backend isn't guaranteed to be available.
 # To check the memcached backend, the test settings file will
 # need to contain a cache backend setting that points at
@@ -1117,5 +1128,146 @@ class PrefixedCacheI18nTest(CacheI18nTest):
         else:
             settings.CACHES['default']['KEY_PREFIX'] = self.old_cache_key_prefix
 
+class CacheMiddlewareTest(unittest.TestCase):
+
+    def setUp(self):
+        self.orig_cache_middleware_alias = settings.CACHE_MIDDLEWARE_ALIAS
+        self.orig_cache_middleware_key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
+        self.orig_caches = settings.CACHES
+
+        settings.CACHE_MIDDLEWARE_ALIAS = 'other'
+        settings.CACHE_MIDDLEWARE_KEY_PREFIX = 'middlewareprefix'
+        settings.CACHES = {
+            'default': {
+                'BACKEND': 'django.core.cache.backends.locmem.LocMemCache'
+            },
+            'other': {
+                'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
+                'LOCATION': 'other',
+                'TIMEOUT': '1'
+            }
+        }
+
+    def tearDown(self):
+        settings.CACHE_MIDDLEWARE_ALIAS = self.orig_cache_middleware_alias
+        settings.CACHE_MIDDLEWARE_KEY_PREFIX = self.orig_cache_middleware_key_prefix
+        settings.CACHES = self.orig_caches
+
+    def test_middleware(self):
+        def view(request, value):
+            return HttpResponse('Hello World %s' % value)
+
+        factory = RequestFactory()
+
+        middleware = CacheMiddleware()
+        prefix_middleware = CacheMiddleware(key_prefix='prefix1')
+        timeout_middleware = CacheMiddleware(cache_timeout=1)
+
+        request = factory.get('/view/')
+
+        # Put the request through the request middleware
+        result = middleware.process_request(request)
+        self.assertEquals(result, None)
+
+        response = view(request, '1')
+
+        # Now put the response through the response middleware
+        response = middleware.process_response(request, response)
+
+        # Repeating the request should result in a cache hit
+        result = middleware.process_request(request)
+        self.assertNotEquals(result, None)
+        self.assertEquals(result.content, 'Hello World 1')
+
+        # The same request through a different middleware won't hit
+        result = prefix_middleware.process_request(request)
+        self.assertEquals(result, None)
+
+        # The same request with a timeout _will_ hit
+        result = timeout_middleware.process_request(request)
+        self.assertNotEquals(result, None)
+        self.assertEquals(result.content, 'Hello World 1')
+
+    def test_view_decorator(self):
+        def view(request, value):
+            return HttpResponse('Hello World %s' % value)
+
+        # decorate the same view with different cache decorators
+        default_view = cache_page(view)
+        default_with_prefix_view = cache_page(key_prefix='prefix1')(view)
+
+        explicit_default_view = cache_page(cache='default')(view)
+        explicit_default_with_prefix_view = cache_page(cache='default', key_prefix='prefix1')(view)
+
+        other_view = cache_page(cache='other')(view)
+        other_with_prefix_view = cache_page(cache='other', key_prefix='prefix2')(view)
+
+        factory = RequestFactory()
+        request = factory.get('/view/')
+
+        # Request the view once
+        response = default_view(request, '1')
+        self.assertEquals(response.content, 'Hello World 1')
+
+        # Request again -- hit the cache
+        response = default_view(request, '2')
+        self.assertEquals(response.content, 'Hello World 1')
+
+        # Requesting the same view with the explicit cache should yield the same result
+        response = explicit_default_view(request, '3')
+        self.assertEquals(response.content, 'Hello World 1')
+
+        # Requesting with a prefix will hit a different cache key
+        response = explicit_default_with_prefix_view(request, '4')
+        self.assertEquals(response.content, 'Hello World 4')
+
+        # Hitting the same view again gives a cache hit
+        response = explicit_default_with_prefix_view(request, '5')
+        self.assertEquals(response.content, 'Hello World 4')
+
+        # And going back to the implicit cache will hit the same cache
+        response = default_with_prefix_view(request, '6')
+        self.assertEquals(response.content, 'Hello World 4')
+
+        # Requesting from an alternate cache won't hit cache
+        response = other_view(request, '7')
+        self.assertEquals(response.content, 'Hello World 7')
+
+        # But a repeated hit will hit cache
+        response = other_view(request, '8')
+        self.assertEquals(response.content, 'Hello World 7')
+
+        # And prefixing the alternate cache yields yet another cache entry
+        response = other_with_prefix_view(request, '9')
+        self.assertEquals(response.content, 'Hello World 9')
+
+        # But if we wait a couple of seconds...
+        time.sleep(2)
+
+        # ... the default cache will still hit
+        cache = get_cache('default')
+        response = default_view(request, '10')
+        self.assertEquals(response.content, 'Hello World 1')
+
+        # ... the default cache with a prefix will still hit
+        response = default_with_prefix_view(request, '11')
+        self.assertEquals(response.content, 'Hello World 4')
+
+        # ... the explicit default cache will still hit
+        response = explicit_default_view(request, '12')
+        self.assertEquals(response.content, 'Hello World 1')
+
+        # ... the explicit default cache with a prefix will still hit
+        response = explicit_default_with_prefix_view(request, '13')
+        self.assertEquals(response.content, 'Hello World 4')
+
+        # .. but a rapidly expiring cache won't hit
+        response = other_view(request, '14')
+        self.assertEquals(response.content, 'Hello World 14')
+
+        # .. even if it has a prefix
+        response = other_with_prefix_view(request, '15')
+        self.assertEquals(response.content, 'Hello World 15')
+
 if __name__ == '__main__':
     unittest.main()