mcs/class/System.Runtime.Caching/ReferenceSources/CacheExpires.cs

   1 // This file implements the classes ExpiresEntryRef and CacheExpires missing from .NET reference source
   2
   3 using System.Threading;
   4
   5 namespace System.Runtime.Caching
   6 {
   7         class ExpiresEntryRef
   8         {
   9                 public static ExpiresEntryRef INVALID = new ExpiresEntryRef ();
  10
  11                 public bool IsInvalid {
  12                         get { return this == INVALID; }
  13                 }
  14         }
  15
  16         class CacheExpiresHelper : ICacheEntryHelper
  17         {
  18                 public int Compare(MemoryCacheEntry entry1, MemoryCacheEntry entry2)
  19                 {
  20                         return DateTime.Compare (entry1.UtcAbsExp , entry2.UtcAbsExp);
  21                 }
  22
  23                 public DateTime GetDateTime (MemoryCacheEntry entry)
  24                 {
  25                         return entry.UtcAbsExp;
  26                 }
  27         }
  28
  29         class CacheExpires : CacheEntryCollection
  30         {
  31
  32                 public static TimeSpan MIN_UPDATE_DELTA = new TimeSpan (0, 0, 1);
  33                 public static TimeSpan EXPIRATIONS_INTERVAL = new TimeSpan (0, 0, 20);
  34                 public static CacheExpiresHelper helper = new CacheExpiresHelper ();
  35
  36                 Timer timer;
  37
  38                 public CacheExpires (MemoryCacheStore store)
  39                         : base (store, helper)
  40                 {
  41                 }
  42
  43                 public void Add (MemoryCacheEntry entry)
  44                 {
  45                         entry.ExpiresEntryRef = new ExpiresEntryRef ();
  46                         base.Add (entry);
  47                 }
  48
  49                 public void Remove (MemoryCacheEntry entry)
  50                 {
  51                         base.Remove (entry);
  52                         entry.ExpiresEntryRef = ExpiresEntryRef.INVALID;
  53                 }
  54
  55                 public void UtcUpdate (MemoryCacheEntry entry, DateTime utcAbsExp)
  56                 {
  57                         base.Remove (entry);
  58                         entry.UtcAbsExp = utcAbsExp;
  59                         base.Add (entry);
  60                 }
  61
  62                 public void EnableExpirationTimer (bool enable)
  63                 {
  64                         if (enable) {
  65                                 if (timer != null)
  66                                         return;
  67
  68                                 var period = (int) EXPIRATIONS_INTERVAL.TotalMilliseconds;
  69                                 timer = new Timer ((o) => FlushExpiredItems (true), null, period, period);
  70                         } else {
  71                                 timer.Dispose ();
  72                                 timer = null;
  73                         }
  74                 }
  75
  76                 public int FlushExpiredItems (bool blockInsert)
  77                 {
  78                         return base.FlushItems (DateTime.UtcNow, CacheEntryRemovedReason.Expired, blockInsert);
  79                 }
  80         }
  81 }