/// <summary>
/// Constructor
/// </summary>
/// <param name="cache"></param>
/// <param name="keyList"></param>
/// <param name="bAllowNulls"></param>
public LazyKeysetEnumerator(CacheBase cache, object[] keyList, bool bAllowNulls)
{
_cache = cache;
_keyList = keyList;
_bAllowNulls = bAllowNulls;
((IEnumerator)this).Reset();
}
/// <summary>
/// Tells if the cache is a clustered cache or a local one
/// </summary>
/// <param name="cache"></param>
/// <returns></returns>
#if !CLIENT
public static bool IsClusteredCache(CacheBase cache)
{
if (cache == null)
return false;
else
return cache.GetType().IsSubclassOf(typeof(ClusterCacheBase));
}
/// <summary>
/// Default constructor.
/// </summary>
public LocalCacheImpl(CacheBase cache)
{
if (cache == null)
throw new ArgumentNullException("cache");
_cache = cache;
_context = cache.InternalCache.Context;
}
/// <summary>
/// Default constructor.
/// </summary>
public CacheSyncWrapper(CacheBase cache)
{
if (cache == null)
throw new ArgumentNullException("cache");
_cache = cache;
_context = cache.Context;
_syncObj = _cache.Sync;
}
public void Initialize(EnumerationPointer pointer, IndexedLocalCache cache)
{
_cache = cache;
_pointer = pointer;
if (System.Configuration.ConfigurationSettings.AppSettings.Get("NCacheServer.EnumeratorChunkSize") != null)
_chunkSize = Convert.ToInt32(System.Configuration.ConfigurationSettings.AppSettings.Get("NCacheServer.EnumeratorChunkSize"));
_snapshot = CacheSnapshotPool.Instance.GetSnaphot(pointer.Id, cache);
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or
/// resetting unmanaged resources.
/// </summary>
public override void Dispose()
{
if (_cache != null)
{
_cache.Dispose();
_cache = null;
}
base.Dispose();
}
public void Execute(CacheBase cache, CacheRuntimeContext context, long count)
{
Sync.AcquireWriterLock(Timeout.Infinite);
try
{
_evctPolicy.Execute(cache,context, count);
}
finally
{
Sync.ReleaseWriterLock();
}
}
/// <summary>
/// Returns the thread safe synchronized wrapper over cache.
/// </summary>
/// <param name="cacheStore"></param>
/// <returns></returns>
public static CacheBase Synchronized(CacheBase cache)
{
return(new CacheSyncWrapper(cache));
}
/// <summary>
/// Returns the number of items in local instance of the cache.
/// </summary>
/// <param name="cache"></param>
/// <returns></returns>
public static long GetLocalCount(CacheBase cache)
{
if(cache != null && cache.InternalCache != null)
return (long)cache.InternalCache.Count;
return 0;
}
/// <summary>
/// Get a snaphot from the pool
/// </summary>
/// <param name="pointerID"></param>
/// <param name="cache"></param>
/// <returns></returns>
public Array GetSnaphot(string pointerID, CacheBase cache)
{
CachePool pool = null;
if (_cachePoolMap.Contains(cache.Context.CacheRoot.Name))
{
pool = _cachePoolMap[cache.Context.CacheRoot.Name] as CachePool;
return pool.GetSnaphotInPool(pointerID, cache);
}
else
{
pool = new CachePool(_minSnaphotSizeForPooling, _maxSnapshotsInPool, _newSnapshotCreationThreshold);
_cachePoolMap.Add(cache.Context.CacheRoot.Name, pool);
}
return pool.GetSnaphotInPool(pointerID, cache);
}
/// <summary>
/// Return a snaphot from the snaphot pool to be used by current enumerator
/// </summary>
/// <param name="pointerID">unque id of the enumeration pointer being used by current enumerator.</param>
/// <param name="cache">underlying cache from which snapshot has to be taken.</param>
/// <returns>snaphot as an array.</returns>
public Array GetSnaphotInPool(string pointerID, CacheBase cache)
{
string uniqueID = string.Empty;
if (cache.Count < _minimumSnaphotSizeForPooling)
{
return cache.Keys;
}
else
{
if (_pool.Count == 0)
{
uniqueID = GetNewUniqueID();
_pool.Add(uniqueID, cache.Keys);
_lastSnaphotCreationTime = DateTime.Now;
_currentUsableSnapshot = uniqueID;
}
else if (_pool.Count < _maxNumOfSnapshotsInPool)
{
TimeSpan elapsedTime = DateTime.Now.Subtract(_lastSnaphotCreationTime);
if (elapsedTime.TotalSeconds >= _newSnapshotCreationTimeInSec)
{
uniqueID = GetNewUniqueID();
_pool.Add(uniqueID, cache.Keys);
_lastSnaphotCreationTime = DateTime.Now;
_currentUsableSnapshot = uniqueID;
}
}
if (!_enumeratorSnaphotMap.ContainsKey(pointerID))
{
_enumeratorSnaphotMap.Add(pointerID, uniqueID);
if (!_snapshotRefCountMap.ContainsKey(uniqueID))
{
_snapshotRefCountMap.Add(uniqueID, 1);
}
else
{
int refCount = _snapshotRefCountMap[uniqueID];
refCount++;
_snapshotRefCountMap[uniqueID] = refCount;
}
}
return _pool[_currentUsableSnapshot];
}
}
/// <summary>
/// Get a snaphot from the pool for a particular cache.
/// </summary>
public void DiposeSnapshot(string pointerID, CacheBase cache)
{
CachePool pool = null;
if (_cachePoolMap.Contains(cache.Context.CacheRoot.Name))
{
pool = _cachePoolMap[cache.Context.CacheRoot.Name] as CachePool;
pool.DiposeSnapshotInPool(pointerID);
}
}
/// <summary>
/// Returns the thread safe synchronized wrapper over cache.
/// </summary>
/// <param name="cacheStore"></param>
/// <returns></returns>
public static CacheBase Synchronized(CacheBase cache)
{
return new CacheSyncWrapper(cache);
}
public void Dispose()
{
CacheSnapshotPool.Instance.DiposeSnapshot(_pointer.Id, _cache); //Disposes the snapshot from pool for this particular pointer
_cache = null;
_pointer = null;
_snapshot = null;
}
void IEvictionPolicy.Execute(CacheBase cache, CacheRuntimeContext context, long evictSize)
{
ILogger NCacheLog = cache.Context.NCacheLog;
if (NCacheLog.IsInfoEnabled) NCacheLog.Info("LocalCache.Evict()", "Cache Size: {0}" + cache.Count.ToString());
//if user has updated the values in configuration file then new values will be reloaded.
_sleepInterval = Convert.ToInt32(ServiceConfiguration.EvictionBulkRemoveDelay);
_removeThreshhold = Convert.ToInt32(ServiceConfiguration.EvictionBulkRemoveSize);
DateTime startTime = DateTime.Now;
ArrayList selectedKeys = this.GetSelectedKeys(cache, (long)Math.Ceiling(evictSize * _ratio));
DateTime endTime = DateTime.Now;
if (NCacheLog.IsInfoEnabled) NCacheLog.Info("LocalCache.Evict()", String.Format("Time Span for {0} Items: " + (endTime - startTime), selectedKeys.Count));
startTime = DateTime.Now;
Cache rootCache = context.CacheRoot;
ArrayList keysTobeRemoved = new ArrayList();
ArrayList dependentItems = new ArrayList();
ArrayList removedItems = null;
IEnumerator e = selectedKeys.GetEnumerator();
int removedThreshhold = _removeThreshhold/300;
int remIteration = 0;
while (e.MoveNext())
{
object key = e.Current;
if (key == null) continue;
keysTobeRemoved.Add(key);
if (keysTobeRemoved.Count % 300 == 0)
{
try
{
OperationContext priorityEvictionOperationContext = new OperationContext();
priorityEvictionOperationContext.Add(OperationContextFieldName.OperationType, OperationContextOperationType.CacheOperation);
removedItems = cache.RemoveSync(keysTobeRemoved.ToArray(), ItemRemoveReason.Underused, false, priorityEvictionOperationContext) as ArrayList;
context.PerfStatsColl.IncrementEvictPerSecStatsBy(keysTobeRemoved.Count);
}
catch (Exception ex)
{
NCacheLog.Error("PriorityEvictionPolicy.Execute", "an error occured while removing items. Error " + ex.ToString());
}
keysTobeRemoved.Clear();
if (removedItems != null && removedItems.Count > 0)
{
dependentItems.AddRange(removedItems);
}
remIteration++;
if (remIteration >= removedThreshhold)
{
//put some delay so that user operations are not affected.
System.Threading.Thread.Sleep(_sleepInterval*1000);
remIteration = 0;
}
}
}
if (keysTobeRemoved.Count > 0)
{
try
{
OperationContext priorityEvictionOperationContext = new OperationContext();
priorityEvictionOperationContext.Add(OperationContextFieldName.OperationType, OperationContextOperationType.CacheOperation);
removedItems = cache.RemoveSync(keysTobeRemoved.ToArray(), ItemRemoveReason.Underused, false, priorityEvictionOperationContext) as ArrayList;
context.PerfStatsColl.IncrementEvictPerSecStatsBy(keysTobeRemoved.Count);
if (removedItems != null && removedItems.Count > 0)
{
dependentItems.AddRange(removedItems);
}
}
catch (Exception ex)
{
NCacheLog.Error("PriorityEvictionPolicy.Execute", "an error occured while removing items. Error " + ex.ToString());
}
}
if (dependentItems.Count > 0)
{
ArrayList removableList = new ArrayList();
if (rootCache != null)
{
foreach (object depenentItme in dependentItems)
{
if (depenentItme == null) continue;
removableList.Add(depenentItme);
if (removableList.Count % 100 == 0)
{
try
{
OperationContext priorityEvictionOperationContext = new OperationContext();
priorityEvictionOperationContext.Add(OperationContextFieldName.OperationType, OperationContextOperationType.CacheOperation);
rootCache.CascadedRemove(removableList.ToArray(), ItemRemoveReason.Underused, true, priorityEvictionOperationContext);
context.PerfStatsColl.IncrementEvictPerSecStatsBy(removableList.Count);
}
catch (Exception exc)
{
NCacheLog.Error("PriorityEvictionPolicy.Execute", "an error occured while removing dependent items. Error " + exc.ToString());
}
removableList.Clear();
}
}
if (removableList.Count > 0)
{
try
{
OperationContext priorityEvictionOperationContext = new OperationContext();
priorityEvictionOperationContext.Add(OperationContextFieldName.OperationType, OperationContextOperationType.CacheOperation);
rootCache.CascadedRemove(removableList.ToArray(), ItemRemoveReason.Underused, true, priorityEvictionOperationContext);
context.PerfStatsColl.IncrementEvictPerSecStatsBy(removableList.Count);
}
catch (Exception exc)
{
NCacheLog.Error("PriorityEvictionPolicy.Execute", "an error occured while removing dependent items. Error " + exc.ToString());
}
removableList.Clear();
}
}
}
return;
}
/// <summary>
///
/// </summary>
/// <param name="cache"></param>
/// <param name="evictSize"></param>
/// <returns></returns>
private ArrayList GetSelectedKeys(CacheBase cache, long evictSize)
{
ArrayList selectedKeys = new ArrayList(100);
long sizeCount = 0;
int prvsSize = 0;
object key = null;
bool selectionComplete = false;
lock (_index.SyncRoot)
{
for (int i = 0; i < 5; i++)
{
if (!selectionComplete)
{
Hashtable currentIndex = this._index[i];
if (currentIndex != null)
{
IDictionaryEnumerator ide = currentIndex.GetEnumerator();
while (ide.MoveNext())
{
key = ide.Key;
if (key != null)
{
int itemSize = cache.GetItemSize(key);
if (sizeCount + itemSize >= evictSize && sizeCount > 0)
{
if (evictSize - sizeCount > (itemSize + sizeCount) - evictSize)
selectedKeys.Add(key);
selectionComplete = true;
break;
}
else
{
selectedKeys.Add(key);
sizeCount += itemSize;
prvsSize = itemSize;
}
}
}
}
}
else
{
//break the outer loop. we have already picked up
//the keys to be evicited.
break;
}
}
}
return selectedKeys;
}
/// <summary>
/// Returns an array containing list of keys contained in the cache. Null if there are no
/// keys or if timeout occurs.
/// </summary>
/// <param name="cache"></param>
/// <param name="timeout"></param>
/// <returns></returns>
internal static object[] GetKeyset(CacheBase cache, int timeout)
{
ulong index = 0;
object[] objects = null;
cache.Sync.AcquireWriterLock(timeout);
try
{
if (!cache.Sync.IsWriterLockHeld || cache.Count < 1) return objects;
objects = new object[cache.Count];
for (IEnumerator i = cache.GetEnumerator(); i.MoveNext(); )
{
objects[index++] = ((DictionaryEntry)i.Current).Key;
}
}
finally
{
cache.Sync.ReleaseWriterLock();
}
return objects;
}
