1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROME_BROWSER_NET_TIMED_CACHE_H_ 6 #define CHROME_BROWSER_NET_TIMED_CACHE_H_ 7 8 #include "base/basictypes.h" 9 #include "base/containers/mru_cache.h" 10 #include "base/time/time.h" 11 12 class GURL; 13 14 namespace chrome_browser_net { 15 16 // Define a LRU cache that recalls all navigations within the last N seconds. 17 // When we learn about subresources to possibly preconnect to, it would be a 18 // waste to preconnect when the original navigation was too long ago. Any 19 // connected, but unused TCP/IP connection, will generally be reset by the 20 // server if it is not used quickly (i.e., GET or POST is sent). 21 class TimedCache { 22 public: 23 explicit TimedCache(const base::TimeDelta& max_duration); 24 ~TimedCache(); 25 26 // Evicts any entries that have been in the FIFO "too long," and then checks 27 // to see if the given url is (still) in the FIFO cache. 28 bool WasRecentlySeen(const GURL& url); 29 30 // Adds the given url to the cache, where it will remain for max_duration_. 31 void SetRecentlySeen(const GURL& url); 32 33 private: 34 // Our cache will be keyed on a URL (actually, just a scheme/host/port). 35 // We will always track the time it was last added to the FIFO cache by 36 // remembering a TimeTicks value. 37 typedef base::MRUCache<GURL, base::TimeTicks> UrlMruTimedCache; 38 UrlMruTimedCache mru_cache_; 39 40 // The longest time an entry can persist in the cache, and still be found. 41 const base::TimeDelta max_duration_; 42 43 DISALLOW_COPY_AND_ASSIGN(TimedCache); 44 }; 45 46 } // namespace chrome_browser_net 47 48 #endif // CHROME_BROWSER_NET_TIMED_CACHE_H_ 49
