ServiceWorker: Support longest-prefix-match for registration scope

content/browser/service_worker/service_worker_utils.cc

Index: content/browser/service_worker/service_worker_utils.cc
diff --git a/content/browser/service_worker/service_worker_utils.cc b/content/browser/service_worker/service_worker_utils.cc
index 165bcbec563e8226494083450aedad1f7a90c9c8..2c3d05b773fcecf90f95841c7e65eb83702fa705 100644
--- a/content/browser/service_worker/service_worker_utils.cc
+++ b/content/browser/service_worker/service_worker_utils.cc
@@ -4,9 +4,12 @@
 
 #include "content/browser/service_worker/service_worker_utils.h"
 
+#include <string>
+
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "content/public/common/content_switches.h"
+#include "url/gurl.h"
 
 namespace content {
 
@@ -30,4 +33,33 @@ bool ServiceWorkerUtils::ScopeMatches(const GURL& scope, const GURL& url) {
   return scope_spec == url_spec;
 }
 
+bool LongestScopeMatcher::MatchLongest(const GURL& scope) {
+  if (!ServiceWorkerUtils::ScopeMatches(scope, url_))
+    return false;
+  if (match_.is_empty()) {
+    match_ = scope;
+    return true;
+  }
+
+  const std::string match_spec = match_.spec();
+  const std::string scope_spec = scope.spec();
+  if (match_spec.size() < scope_spec.size()) {
+    match_ = scope;
+    return true;
+  }
+
+  // If |scope| has the same length with |match_|, they are compared as strings.
+  // For example:
+  //   1) for a document "/foo", "/foo" is prioritized over "/fo*".
+  //   2) for a document "/f(1)", "/f(1*" is prioritized over "/f(1)".
+  // TODO(nhiroki): This isn't in the spec.
+  // (https://github.com/slightlyoff/ServiceWorker/issues/287)
+  if (match_spec.size() == scope_spec.size() && match_spec < scope_spec) {
+    match_ = scope;
+    return true;
+  }
+
+  return false;
+}
+
 }  // namespace content