1 // Copyright (c) 2012 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 NET_DISK_CACHE_EVICTION_H_ 6 #define NET_DISK_CACHE_EVICTION_H_ 7 8 #include "base/basictypes.h" 9 #include "base/memory/weak_ptr.h" 10 #include "net/disk_cache/disk_format.h" 11 #include "net/disk_cache/rankings.h" 12 13 namespace disk_cache { 14 15 class BackendImpl; 16 class EntryImpl; 17 18 // This class implements the eviction algorithm for the cache and it is tightly 19 // integrated with BackendImpl. 20 class Eviction { 21 public: 22 Eviction(); 23 ~Eviction(); 24 25 void Init(BackendImpl* backend); 26 void Stop(); 27 28 // Deletes entries from the cache until the current size is below the limit. 29 // If empty is true, the whole cache will be trimmed, regardless of being in 30 // use. 31 void TrimCache(bool empty); 32 33 // Notifications of interesting events for a given entry. 34 void OnOpenEntry(EntryImpl* entry); 35 void OnCreateEntry(EntryImpl* entry); 36 37 // Testing interface. 38 void SetTestMode(); 39 void TrimDeletedList(bool empty); 40 41 private: 42 void PostDelayedTrim(); 43 void DelayedTrim(); 44 bool ShouldTrim(); 45 bool ShouldTrimDeleted(); 46 bool EvictEntry(CacheRankingsBlock* node, bool empty, Rankings::List list); 47 48 void TrimCacheV2(bool empty); 49 void TrimDeleted(bool empty); 50 51 bool NodeIsOldEnough(CacheRankingsBlock* node, int list); 52 int SelectListByLength(Rankings::ScopedRankingsBlock* next); 53 void ReportListStats(); 54 55 BackendImpl* backend_; 56 Rankings* rankings_; 57 IndexHeader* header_; 58 int max_size_; 59 int trim_delays_; 60 int index_size_; 61 bool new_eviction_; 62 bool first_trim_; 63 bool trimming_; 64 bool delay_trim_; 65 bool init_; 66 bool test_mode_; 67 base::WeakPtrFactory<Eviction> ptr_factory_; 68 69 DISALLOW_COPY_AND_ASSIGN(Eviction); 70 }; 71 72 } // namespace disk_cache 73 74 #endif // NET_DISK_CACHE_EVICTION_H_ 75