net/disk_cache/blockfile/eviction_v3.h

   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_BLOCKFILE_EVICTION_V3_H_
   6 #define NET_DISK_CACHE_BLOCKFILE_EVICTION_V3_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/weak_ptr.h"
  10 #include "net/disk_cache/blockfile/disk_format_v3.h"
  11 #include "net/disk_cache/blockfile/index_table_v3.h"
  12
  13 namespace disk_cache {
  14
  15 class BackendImplV3;
  16 class CacheRankingsBlock;
  17 class EntryImplV3;
  18
  19 namespace Rankings {
  20 typedef int List;
  21 }
  22
  23 // This class implements the eviction algorithm for the cache and it is tightly
  24 // integrated with BackendImpl.
  25 class EvictionV3 {
  26  public:
  27   EvictionV3();
  28   ~EvictionV3();
  29
  30   void Init(BackendImplV3* backend);
  31   void Stop();
  32
  33   // Deletes entries from the cache until the current size is below the limit.
  34   // If empty is true, the whole cache will be trimmed, regardless of being in
  35   // use.
  36   void TrimCache(bool empty);
  37
  38   // Notifications of interesting events for a given entry.
  39   void OnOpenEntry(EntryImplV3* entry);
  40   void OnCreateEntry(EntryImplV3* entry);
  41
  42   // Testing interface.
  43   void SetTestMode();
  44   void TrimDeletedList(bool empty);
  45
  46  private:
  47   void PostDelayedTrim();
  48   void DelayedTrim();
  49   bool ShouldTrim();
  50   bool ShouldTrimDeleted();
  51   bool EvictEntry(CacheRankingsBlock* node, bool empty, Rankings::List list);
  52
  53   void TrimCacheV2(bool empty);
  54   void TrimDeleted(bool empty);
  55
  56   bool NodeIsOldEnough(CacheRankingsBlock* node, int list);
  57   int SelectListByLength();
  58   void ReportListStats();
  59
  60   BackendImplV3* backend_;
  61   IndexTable* index_;
  62   IndexHeaderV3* header_;
  63   int max_size_;
  64   int trim_delays_;
  65   bool lru_;
  66   bool first_trim_;
  67   bool trimming_;
  68   bool delay_trim_;
  69   bool init_;
  70   bool test_mode_;
  71   base::WeakPtrFactory<EvictionV3> ptr_factory_;
  72
  73   DISALLOW_COPY_AND_ASSIGN(EvictionV3);
  74 };
  75
  76 }  // namespace disk_cache
  77
  78 #endif  // NET_DISK_CACHE_BLOCKFILE_EVICTION_V3_H_