netwerk/cache/nsMemoryCacheDevice.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* vim: set ts=8 sts=4 et sw=4 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef _nsMemoryCacheDevice_h_
   8 #define _nsMemoryCacheDevice_h_
   9
  10 #include "nsCacheDevice.h"
  11 #include "pldhash.h"
  12 #include "nsCacheEntry.h"
  13
  14
  15 class nsMemoryCacheDeviceInfo;
  16
  17 /******************************************************************************
  18  * nsMemoryCacheDevice
  19  ******************************************************************************/
  20 class nsMemoryCacheDevice : public nsCacheDevice
  21 {
  22 public:
  23     nsMemoryCacheDevice();
  24     virtual ~nsMemoryCacheDevice();
  25
  26     virtual nsresult        Init();
  27     virtual nsresult        Shutdown();
  28
  29     virtual const char *    GetDeviceID(void);
  30
  31     virtual nsresult        BindEntry( nsCacheEntry * entry );
  32     virtual nsCacheEntry *  FindEntry( nsCString * key, bool *collision );
  33     virtual void            DoomEntry( nsCacheEntry * entry );
  34     virtual nsresult        DeactivateEntry( nsCacheEntry * entry );
  35
  36     virtual nsresult OpenInputStreamForEntry(nsCacheEntry *     entry,
  37                                              nsCacheAccessMode  mode,
  38                                              uint32_t           offset,
  39                                              nsIInputStream **  result);
  40
  41     virtual nsresult OpenOutputStreamForEntry(nsCacheEntry *     entry,
  42                                               nsCacheAccessMode  mode,
  43                                               uint32_t           offset,
  44                                               nsIOutputStream ** result);
  45
  46     virtual nsresult GetFileForEntry( nsCacheEntry *    entry,
  47                                       nsIFile **        result );
  48
  49     virtual nsresult OnDataSizeChange( nsCacheEntry * entry, int32_t deltaSize );
  50
  51     virtual nsresult Visit( nsICacheVisitor * visitor );
  52
  53     virtual nsresult EvictEntries(const char * clientID);
  54     nsresult EvictPrivateEntries();
  55
  56     void             SetCapacity(int32_t  capacity);
  57     void             SetMaxEntrySize(int32_t  maxSizeInKilobytes);
  58
  59     bool             EntryIsTooBig(int64_t entrySize);
  60
  61     size_t           TotalSize();
  62
  63 private:
  64     friend class nsMemoryCacheDeviceInfo;
  65     enum      { DELETE_ENTRY        = true,
  66                 DO_NOT_DELETE_ENTRY = false };
  67
  68     void      AdjustMemoryLimits( int32_t  softLimit, int32_t  hardLimit);
  69     void      EvictEntry( nsCacheEntry * entry , bool deleteEntry);
  70     void      EvictEntriesIfNecessary();
  71     int       EvictionList(nsCacheEntry * entry, int32_t  deltaSize);
  72
  73     typedef bool (*EvictionMatcherFn)(nsCacheEntry* entry, void* args);
  74     nsresult DoEvictEntries(EvictionMatcherFn matchFn, void* args);
  75
  76 #ifdef DEBUG
  77     void      CheckEntryCount();
  78 #endif
  79     /*
  80      *  Data members
  81      */
  82     enum {
  83         kQueueCount = 24   // entries > 2^23 (8Mb) start in last queue
  84     };
  85
  86     nsCacheEntryHashTable  mMemCacheEntries;
  87     bool                   mInitialized;
  88
  89     PRCList                mEvictionList[kQueueCount];
  90
  91     int32_t                mHardLimit;
  92     int32_t                mSoftLimit;
  93
  94     int32_t                mTotalSize;
  95     int32_t                mInactiveSize;
  96
  97     int32_t                mEntryCount;
  98     int32_t                mMaxEntryCount;
  99     int32_t                mMaxEntrySize; // internal unit is bytes
 100
 101     // XXX what other stats do we want to keep?
 102 };
 103
 104
 105 /******************************************************************************
 106  * nsMemoryCacheDeviceInfo - used to call nsIVisitor for about:cache
 107  ******************************************************************************/
 108 class nsMemoryCacheDeviceInfo : public nsICacheDeviceInfo {
 109 public:
 110     NS_DECL_ISUPPORTS
 111     NS_DECL_NSICACHEDEVICEINFO
 112
 113     explicit nsMemoryCacheDeviceInfo(nsMemoryCacheDevice* device)
 114         :   mDevice(device)
 115     {
 116     }
 117
 118 private:
 119     virtual ~nsMemoryCacheDeviceInfo() {}
 120     nsMemoryCacheDevice* mDevice;
 121 };
 122
 123
 124 #endif // _nsMemoryCacheDevice_h_