ServiceWorker: Support longest-prefix-match for registration scope

content/browser/service_worker/service_worker_utils.h

Index: content/browser/service_worker/service_worker_utils.h
diff --git a/content/browser/service_worker/service_worker_utils.h b/content/browser/service_worker/service_worker_utils.h
index 38669c4317648145870670961284df7a64f50aed..c0d7f6e4149b1ee7fa8c0d2b4484178aa086aa3b 100644
--- a/content/browser/service_worker/service_worker_utils.h
+++ b/content/browser/service_worker/service_worker_utils.h
@@ -13,6 +13,12 @@ namespace content {
 
 class ServiceWorkerUtils {
  public:
+  enum MatchResult {
+    SCOPE_NO_MATCH = 0,
+    SCOPE_EXACT_MATCH,
+    SCOPE_WILDCARD_MATCH,
+  };
+
   static bool IsMainResourceType(ResourceType::Type type) {
     return ResourceType::IsFrame(type) ||
            ResourceType::IsSharedWorker(type);
@@ -29,8 +35,26 @@ class ServiceWorkerUtils {
   // A helper for creating a do-nothing status callback.
   static void NoOpStatusCallback(ServiceWorkerStatusCode status) {}
 
-  // Returns true if |scope| matches |url|.
-  CONTENT_EXPORT static bool ScopeMatches(const GURL& scope, const GURL& url);
+  // Returns SCOPE_EXACT_MATCH if |scope| exactly matches |url|. Returns

[dominicc (has gone to gerrit), 2014/05/22 05:03:31]

I expect sometimes people call this with a URL and sometimes with a scope. Is it
dangerous to represent these two things with different meanings with the same
type?
(I know the existing code did this, and cleaning it up would be a separate
patch, just want to know what you think.)

+  // SCOPE_WILDCARD_MATCH if the scope matches the url with a wildcard.
+  // Otherwise, returns SCOPE_NO_MATCH.
+  CONTENT_EXPORT static MatchResult ScopeMatches(
+      const GURL& scope, const GURL& url);
+
+  // Compares given scopes' priorities in the longest-prefix-match way.
+  //  - Returns a positive number if |scope1| has a higher priority.
+  //  - Returns 0 if |scope1| and |scope2| are the same scope.
+  //  - Returns a negative number if |scope2| has a higher priority.
+  //
+  // NOTE: Assumes that both scopes match a target document URL. You have to
+  // make sure it using ScopeMatches() in advance.
+  //
+  // Eg. if a document url is "/foo" and a pair of |scope1| and |scope2| is
+  //  1) ("/fo*",  "/*"),   returns a positive because |scope1| matches longer.
+  //  2) ("/fo*",  "/fo*"), returns 0 because both scopes are same.
+  //  3) ("/foo*", "/foo"), returns a negative because |scope2| matches exactly.
+  CONTENT_EXPORT static int CompareScopePriorities(
+      const GURL& scope1, const GURL& scope2);
 };
 
 }  // namespace content