Add an opt-out header for HTTP throttling. Never throttle for localhost.

net/url_request/url_request_throttler_manager.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_URL_REQUEST_URL_REQUEST_THROTTLER_MANAGER_H_
 #define NET_URL_REQUEST_URL_REQUEST_THROTTLER_MANAGER_H_
 #pragma once
 
 #include <map>
+#include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
 #include "base/singleton.h"
 #include "base/threading/non_thread_safe.h"
 #include "googleurl/src/gurl.h"
 #include "net/url_request/url_request_throttler_entry.h"
 
 namespace net {
@@ skipping 15 matching lines @@
  public:
   static URLRequestThrottlerManager* GetInstance();
 
   // Must be called for every request, returns the URL request throttler entry
   // associated with the URL. The caller must inform this entry of some events.
   // Please refer to url_request_throttler_entry_interface.h for further
   // informations.
   scoped_refptr<URLRequestThrottlerEntryInterface> RegisterRequestUrl(
       const GURL& url);
 
+  // Adds the given host to a list of sites for which exponential back-off
+  // throttling will be disabled.  Subdomains are not included, so they
+  // must be added separately.
+  void AddToOptOutList(const std::string& host);
+
   // Registers a new entry in this service and overrides the existing entry (if
   // any) for the URL. The service will hold a reference to the entry.
   // It is only used by unit tests.
   void OverrideEntryForTests(const GURL& url, URLRequestThrottlerEntry* entry);
 
   // Explicitly erases an entry.
   // This is useful to remove those entries which have got infinite lifetime and
   // thus won't be garbage collected.
   // It is only used by unit tests.
   void EraseEntryForTests(const GURL& url);
@@ skipping 31 matching lines @@
   int GetNumberOfEntriesForTests() const { return url_entries_.size(); }
 
  private:
   friend struct DefaultSingletonTraits<URLRequestThrottlerManager>;
 
   // From each URL we generate an ID composed of the scheme, host, port and path
   // that allows us to uniquely map an entry to it.
   typedef std::map<std::string, scoped_refptr<URLRequestThrottlerEntry> >
       UrlEntryMap;
 
+  // We maintain a set of hosts that have opted out of exponential
+  // back-off throttling.
+  typedef std::set<std::string> OptOutHosts;
+
   // Maximum number of entries that we are willing to collect in our map.
   static const unsigned int kMaximumNumberOfEntries;
   // Number of requests that will be made between garbage collection.
   static const unsigned int kRequestsBetweenCollecting;
 
   // Map that contains a list of URL ID and their matching
   // URLRequestThrottlerEntry.
   UrlEntryMap url_entries_;
 
+  // Set of hosts that have opted out.
+  OptOutHosts opt_out_hosts_;
+
   // This keeps track of how many requests have been made. Used with
   // GarbageCollectEntries.
   unsigned int requests_since_last_gc_;
 
   // Valid after construction.
   GURL::Replacements url_id_replacements_;
 
   // Whether we would like to reject outgoing HTTP requests during the back-off
   // period.
   bool enforce_throttling_;
 
   // Certain tests do not obey the net component's threading policy, so we
   // keep track of whether we're being used by tests, and turn off certain
   // checks.
   //
   // TODO(joi): See if we can fix the offending unit tests and remove this
   // workaround.
   bool enable_thread_checks_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestThrottlerManager);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_THROTTLER_MANAGER_H_