diff options
Diffstat (limited to 'mcs/class/System.Web/System.Web.Caching/CacheExpires.cs')
| -rw-r--r-- | mcs/class/System.Web/System.Web.Caching/CacheExpires.cs | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/mcs/class/System.Web/System.Web.Caching/CacheExpires.cs b/mcs/class/System.Web/System.Web.Caching/CacheExpires.cs new file mode 100644 index 00000000000..cad44c36af1 --- /dev/null +++ b/mcs/class/System.Web/System.Web.Caching/CacheExpires.cs @@ -0,0 +1,147 @@ +//
+// System.Web.Caching
+//
+// Author:
+// Patrik Torstensson (Patrik.Torstensson@labs2.com)
+// Changes:
+// Daniel Cazzulino [DHC] (dcazzulino@users.sf.net)
+//
+// (C) Copyright Patrik Torstensson, 2001
+//
+namespace System.Web.Caching
+{
+ /// <summary>
+ /// Class responsible for handling time based flushing of entries in the cache. The class creates
+ /// and manages 60 buckets each holding every item that expires that minute. The bucket calculated
+ /// for an entry is one minute more than the timeout just to make sure that the item end up in the
+ /// bucket where it should be flushed.
+ /// </summary>
+ public class CacheExpires : System.IDisposable
+ {
+ static int _intFlush;
+ /// <summary>
+ /// 1 bucket == 1 minute == 10M ticks (1 second) * 60
+ /// </summary>
+ static long _ticksPerBucket = 600000000;
+ /// <summary>
+ /// 1 cycle == 1 hour
+ /// </summary>
+ static long _ticksPerCycle = _ticksPerBucket * 60;
+
+ private ExpiresBucket[] _arrBuckets;
+ private System.Threading.Timer _objTimer;
+ private Cache _objManager;
+
+ /// <summary>
+ /// Constructor
+ /// </summary>
+ /// <param name="objManager">The cache manager, used when flushing items in a bucket.</param>
+ public CacheExpires(Cache objManager)
+ {
+ _objManager = objManager;
+ Initialize();
+ }
+
+ /// <summary>
+ /// Initializes the class.
+ /// </summary>
+ private void Initialize()
+ {
+ // Create one bucket per minute
+ _arrBuckets = new ExpiresBucket[60];
+
+ byte bytePos = 0;
+ do
+ {
+ _arrBuckets[bytePos] = new ExpiresBucket(bytePos, _objManager);
+ bytePos++;
+ } while (bytePos < 60);
+
+ // GC Bucket controller
+ _intFlush = System.DateTime.Now.Minute - 1;
+ _objTimer = new System.Threading.Timer(new System.Threading.TimerCallback(GarbageCleanup), null, 10000, 60000);
+ }
+
+ /// <summary>
+ /// Adds a Cache entry to the correct flush bucket.
+ /// </summary>
+ /// <param name="objEntry">Cache entry to add.</param>
+ public void Add(CacheEntry objEntry)
+ {
+ lock(this)
+ {
+ // If the entry doesn't have a expires time we assume that the entry is due to expire now.
+ if (objEntry.Expires == 0)
+ {
+ objEntry.Expires = System.DateTime.Now.Ticks;
+ }
+
+ _arrBuckets[GetHashBucket(objEntry.Expires)].Add(objEntry);
+ }
+ }
+
+ public void Remove(CacheEntry objEntry)
+ {
+ lock(this)
+ {
+ // If the entry doesn't have a expires time we assume that the entry is due to expire now.
+ if (objEntry.Expires == 0)
+ {
+ objEntry.Expires = System.DateTime.Now.Ticks;
+ }
+
+ _arrBuckets[GetHashBucket(objEntry.Expires)].Remove(objEntry);
+ }
+ }
+
+ public void Update(CacheEntry objEntry, long ticksExpires)
+ {
+ lock(this)
+ {
+ // If the entry doesn't have a expires time we assume that the entry is due to expire now.
+ if (objEntry.Expires == 0)
+ {
+ objEntry.Expires = System.DateTime.Now.Ticks;
+ }
+
+ _arrBuckets[GetHashBucket(objEntry.Expires)].Update(objEntry, ticksExpires);
+ }
+ }
+
+ public void GarbageCleanup(object State)
+ {
+ ExpiresBucket objBucket;
+
+ lock(this)
+ {
+ // Do cleanup of the bucket
+ objBucket = _arrBuckets[(++_intFlush) % 60];
+ }
+
+ // Flush expired items in the current bucket (defined by _intFlush)
+ objBucket.FlushExpiredItems();
+ }
+
+ private int GetHashBucket(long ticks)
+ {
+ // Get bucket to add expire item into, add one minute to the bucket just to make sure that we get it in the bucket gc
+ return (int) (((((ticks + 60000) % _ticksPerCycle) / _ticksPerBucket) + 1) % 60);
+ }
+
+ /// <summary>
+ /// Called by the cache for cleanup.
+ /// </summary>
+ public void Dispose()
+ {
+ lock(this)
+ {
+ // Cleanup the internal timer
+ if (_objTimer != null)
+ {
+ _objTimer.Dispose();
+ _objTimer = null;
+ }
+ }
+ }
+ }
+}
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