Add Vary support for ServiceWorkerCache::Match.

content/browser/service_worker/service_worker_cache.cc

Index: content/browser/service_worker/service_worker_cache.cc
diff --git a/content/browser/service_worker/service_worker_cache.cc b/content/browser/service_worker/service_worker_cache.cc
index 6013d827f80c43f2c5ceb3f6be5e6b7b47ab125e..bef13493aa0aafa08e8224cdd6370205249f6ffb 100644
--- a/content/browser/service_worker/service_worker_cache.cc
+++ b/content/browser/service_worker/service_worker_cache.cc
@@ -9,6 +9,7 @@
 #include "base/files/file_path.h"
 #include "base/guid.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/strings/string_util.h"
 #include "content/browser/service_worker/service_worker_cache.pb.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/io_buffer.h"
@@ -371,6 +372,40 @@ void MatchDidOpenEntry(scoped_ptr<ServiceWorkerFetchRequest> request,
   ReadHeaders(tmp_entry_ptr, headers_callback);
 }
 
+bool VaryMatches(const ServiceWorkerHeaderMap& request,
+                 const ServiceWorkerHeaderMap& cached_request,
+                 const ServiceWorkerHeaderMap& response) {

[jsbell, 2014/09/22 19:17:32]

(I'm assuming we lowercase all the header names somewhere...)

[jsbell, 2014/09/22 19:18:18]

... and that'd be https://codereview.chromium.org/576973004/ which I was going
to look at next. :)

[jkarlin, 2014/09/23 11:42:51]

Acknowledged.

+  ServiceWorkerHeaderMap::const_iterator vary_iter = response.find("vary");
+  if (vary_iter == response.end())
+    return true;
+
+  std::vector<std::string> vary_keys;
+  Tokenize(vary_iter->second, ",", &vary_keys);
+  for (size_t i = 0, max = vary_keys.size(); i < max; ++i) {

[jsbell, 2014/09/22 19:17:32]

Why is this an index/size loop instead of an iterator?

[jkarlin, 2014/09/23 11:42:51]

Done.

+    std::string trimmed;
+    base::TrimWhitespaceASCII(vary_keys[i], base::TRIM_ALL, &trimmed);
+    if (trimmed == "*")
+      return false;
+
+    ServiceWorkerHeaderMap::const_iterator request_iter = request.find(trimmed);
+    ServiceWorkerHeaderMap::const_iterator cached_request_iter =
+        cached_request.find(trimmed);
+
+    // If the header exists in one but not the other, no match.
+    if ((request_iter == request.end()) !=
+        (cached_request_iter == cached_request.end()))
+      return false;
+
+    // If the header exists in one, it exists in both. Verify that the values
+    // are equal.
+    if (request_iter != request.end() &&
+        request_iter->second != cached_request_iter->second)
+      return false;
+  }
+
+  return true;
+}
+
 void MatchDidReadHeaderData(
     scoped_ptr<ServiceWorkerFetchRequest> request,
     const ServiceWorkerCache::ResponseCallback& callback,
@@ -397,7 +432,21 @@ void MatchDidReadHeaderData(
     response->headers.insert(std::make_pair(header.name(), header.value()));
   }
 
-  // TODO(jkarlin): Insert vary validation here.
+  ServiceWorkerHeaderMap cached_request_headers;
+  for (int i = 0; i < headers->request_headers_size(); ++i) {
+    const ServiceWorkerRequestResponseHeaders::HeaderMap header =
+        headers->request_headers(i);
+    cached_request_headers.insert(

[jsbell, 2014/09/22 19:17:32]

Shorter to write: cached_request_headers[header.name()] = header.value();

[jkarlin, 2014/09/23 11:42:51]

Done.

+        std::make_pair(header.name(), header.value()));
+  }
+
+  if (!VaryMatches(
+          request->headers, cached_request_headers, response->headers)) {
+    callback.Run(ServiceWorkerCache::ErrorTypeNotFound,
+                 scoped_ptr<ServiceWorkerResponse>(),
+                 scoped_ptr<storage::BlobDataHandle>());
+    return;
+  }
 
   if (entry->GetDataSize(INDEX_RESPONSE_BODY) == 0) {
     callback.Run(ServiceWorkerCache::ErrorTypeOK,