stale-while-revalidate experimental implementation.

net/http/http_response_headers_unittest.cc

Index: net/http/http_response_headers_unittest.cc
diff --git a/net/http/http_response_headers_unittest.cc b/net/http/http_response_headers_unittest.cc
index 409a6bddd8a92d2e47428b604db1d2808591c25e..1528615a4e6a6c125aae42ae1ae0034173414c65 100644
--- a/net/http/http_response_headers_unittest.cc
+++ b/net/http/http_response_headers_unittest.cc
@@ -777,9 +777,17 @@ INSTANTIATE_TEST_CASE_P(HttpResponseHeaders,
                         ContentTypeTest,
                         testing::ValuesIn(mimetype_tests));
 
+typedef net::HttpResponseHeaders::ValidationType ValidationType;
+const ValidationType VALIDATION_NONE =
+    net::HttpResponseHeaders::VALIDATION_NONE;
+const ValidationType VALIDATION_SYNCHRONOUS =
+    net::HttpResponseHeaders::VALIDATION_SYNCHRONOUS;
+const ValidationType VALIDATION_ASYNCHRONOUS =
+    net::HttpResponseHeaders::VALIDATION_ASYNCHRONOUS;
+
 struct RequiresValidationTestData {
   const char* headers;
-  bool requires_validation;
+  ValidationType validation_type;
 };
 
 class RequiresValidationTest
@@ -800,41 +808,41 @@ TEST_P(RequiresValidationTest, RequiresValidation) {
   scoped_refptr<net::HttpResponseHeaders> parsed(
       new net::HttpResponseHeaders(headers));
 
-  bool requires_validation =
+  ValidationType validation_type =
       parsed->RequiresValidation(request_time, response_time, current_time);
-  EXPECT_EQ(test.requires_validation, requires_validation);
+  EXPECT_EQ(test.validation_type, validation_type);
 }
 
 const struct RequiresValidationTestData requires_validation_tests[] = {
   // No expiry info: expires immediately.
   { "HTTP/1.1 200 OK\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   // No expiry info: expires immediately.
   { "HTTP/1.1 200 OK\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   // Valid for a little while.
   { "HTTP/1.1 200 OK\n"
     "cache-control: max-age=10000\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Expires in the future.
   { "HTTP/1.1 200 OK\n"
     "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "expires: Wed, 28 Nov 2007 01:00:00 GMT\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Already expired.
   { "HTTP/1.1 200 OK\n"
     "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "expires: Wed, 28 Nov 2007 00:00:00 GMT\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   // Max-age trumps expires.
   { "HTTP/1.1 200 OK\n"
@@ -842,77 +850,77 @@ const struct RequiresValidationTestData requires_validation_tests[] = {
     "expires: Wed, 28 Nov 2007 00:00:00 GMT\n"
     "cache-control: max-age=10000\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Last-modified heuristic: modified a while ago.
   { "HTTP/1.1 200 OK\n"
     "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "last-modified: Wed, 27 Nov 2007 08:00:00 GMT\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   { "HTTP/1.1 203 Non-Authoritative Information\n"
     "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "last-modified: Wed, 27 Nov 2007 08:00:00 GMT\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   { "HTTP/1.1 206 Partial Content\n"
     "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "last-modified: Wed, 27 Nov 2007 08:00:00 GMT\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Last-modified heuristic: modified recently.
   { "HTTP/1.1 200 OK\n"
     "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "last-modified: Wed, 28 Nov 2007 00:40:10 GMT\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   { "HTTP/1.1 203 Non-Authoritative Information\n"
     "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "last-modified: Wed, 28 Nov 2007 00:40:10 GMT\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   { "HTTP/1.1 206 Partial Content\n"
   "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
     "last-modified: Wed, 28 Nov 2007 00:40:10 GMT\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   // Cached permanent redirect.
   { "HTTP/1.1 301 Moved Permanently\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Another cached permanent redirect.
   { "HTTP/1.1 308 Permanent Redirect\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Cached redirect: not reusable even though by default it would be.
   { "HTTP/1.1 300 Multiple Choices\n"
     "Cache-Control: no-cache\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   // Cached forever by default.
   { "HTTP/1.1 410 Gone\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Cached temporary redirect: not reusable.
   { "HTTP/1.1 302 Found\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   // Cached temporary redirect: reusable.
   { "HTTP/1.1 302 Found\n"
     "cache-control: max-age=10000\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Cache-control: max-age=N overrides expires: date in the past.
   { "HTTP/1.1 200 OK\n"
@@ -920,7 +928,7 @@ const struct RequiresValidationTestData requires_validation_tests[] = {
     "expires: Wed, 28 Nov 2007 00:20:11 GMT\n"
     "cache-control: max-age=10000\n"
     "\n",
-    false
+    VALIDATION_NONE
   },
   // Cache-control: no-store overrides expires: in the future.
   { "HTTP/1.1 200 OK\n"
@@ -928,7 +936,7 @@ const struct RequiresValidationTestData requires_validation_tests[] = {
     "expires: Wed, 29 Nov 2007 00:40:11 GMT\n"
     "cache-control: no-store,private,no-cache=\"foo\"\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
   },
   // Pragma: no-cache overrides last-modified heuristic.
   { "HTTP/1.1 200 OK\n"
@@ -936,7 +944,52 @@ const struct RequiresValidationTestData requires_validation_tests[] = {
     "last-modified: Wed, 27 Nov 2007 08:00:00 GMT\n"
     "pragma: no-cache\n"
     "\n",
-    true
+    VALIDATION_SYNCHRONOUS
+  },
+  // max-age has expired, needs synchronous revalidation
+  { "HTTP/1.1 200 OK\n"
+    "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
+    "cache-control: max-age=300\n"
+    "\n",
+    VALIDATION_SYNCHRONOUS
+  },
+  // max-age has expired, stale-while-revalidate has not, eligible for
+  // asynchronous revalidation
+  { "HTTP/1.1 200 OK\n"
+    "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
+    "cache-control: max-age=300, stale-while-revalidate=3600\n"
+    "\n",
+    VALIDATION_ASYNCHRONOUS
+  },
+  // max-age and stale-while-revalidate have expired, needs synchronous
+  // revalidation
+  { "HTTP/1.1 200 OK\n"
+    "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
+    "cache-control: max-age=300, stale-while-revalidate=5\n"
+    "\n",
+    VALIDATION_SYNCHRONOUS
+  },
+  // max-age is 0, stale-while-revalidate is large enough to permit
+  // asynchronous revalidation
+  { "HTTP/1.1 200 OK\n"
+    "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
+    "cache-control: max-age=0, stale-while-revalidate=360\n"
+    "\n",
+    VALIDATION_ASYNCHRONOUS
+  },
+  // stale-while-revalidate must not override no-cache or similar directives.
+  { "HTTP/1.1 200 OK\n"
+    "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
+    "cache-control: no-cache, stale-while-revalidate=360\n"
+    "\n",
+    VALIDATION_SYNCHRONOUS
+  },
+  // max-age has not expired, so no revalidation is needed.
+  { "HTTP/1.1 200 OK\n"
+    "date: Wed, 28 Nov 2007 00:40:11 GMT\n"
+    "cache-control: max-age=3600, stale-while-revalidate=3600\n"
+    "\n",
+    VALIDATION_NONE
   },
 
   // TODO(darin): Add many many more tests here.