/// <summary>
/// This method must be called from within a writer lock
/// </summary>
private void PurgeStaleItems()
{
if (!(CacheLock.IsWriteLockHeld == true))
{
// we failfast here because if we don't have the lock we could corrupt the cache
Fx.Assert("Cache write lock is not held.");
Environment.FailFast("Cache write lock is not held.");
}
ArrayList expiredItems = new ArrayList();
foreach (object key in _entries.Keys)
{
IExpirableItem item = _entries[key] as IExpirableItem;
if (IsExpired(item))
{
// this is a stale item. Remove!
OnRemove(ExtractItem(item));
expiredItems.Add(key);
}
}
for (int i = 0; i < expiredItems.Count; ++i)
{
_entries.Remove(expiredItems[i]);
}
CancelTimerIfNeeded();
_nextPurgeTimeUtc = DateTime.UtcNow.Add(_purgeInterval);
}
protected object GetItem(object key)
{
bool lockHeld = false;
try
{
try { }
finally
{
CacheLock.EnterReadLock();
lockHeld = true;
}
IExpirableItem item = _entries[key] as IExpirableItem;
if (item == null)
{
return(null);
}
else if (IsExpired(item))
{
// this is a stale item
return(null);
}
else
{
return(ExtractItem(item));
}
}
finally
{
if (lockHeld)
{
CacheLock.ExitReadLock();
}
}
}
protected bool TryRemoveItem(object key)
{
bool lockHeld = false;
try
{
try { }
finally
{
CacheLock.EnterWriteLock();
lockHeld = true;
}
PurgeIfNeeded();
IExpirableItem currentItem = _entries[key] as IExpirableItem;
bool result = (currentItem != null) && !IsExpired(currentItem);
if (currentItem != null)
{
_entries.Remove(key);
if (_doRemoveNotification)
{
OnRemove(ExtractItem(currentItem));
}
CancelTimerIfNeeded();
}
return(result);
}
finally
{
if (lockHeld)
{
CacheLock.ExitWriteLock();
}
}
}
protected bool TryRemoveItem(object key)
{
bool lockHeld = false;
try
{
try { }
finally
{
this.cacheLock.AcquireWriterLock(-1);
lockHeld = true;
}
PurgeIfNeeded();
IExpirableItem currentItem = this.entries[key] as IExpirableItem;
bool result = (currentItem != null) && !IsExpired(currentItem);
if (currentItem != null)
{
this.entries.Remove(key);
if (doRemoveNotification)
{
this.OnRemove(ExtractItem(currentItem));
}
CancelTimerIfNeeded();
}
return(result);
}
finally
{
if (lockHeld)
{
this.cacheLock.ReleaseWriterLock();
}
}
}
protected object GetItem(object key)
{
bool lockHeld = false;
try
{
try { }
finally
{
this.CacheLock.AcquireReaderLock(-1);
lockHeld = true;
}
IExpirableItem item = this.entries[key] as IExpirableItem;
if (item == null)
{
return(null);
}
else if (IsExpired(item))
{
// this is a stale item
return(null);
}
else
{
return(ExtractItem(item));
}
}
finally
{
if (lockHeld)
{
this.CacheLock.ReleaseReaderLock();
}
}
}
protected object GetItem(object key)
{
object obj2;
bool flag = false;
try
{
try
{
}
finally
{
this.cacheLock.AcquireReaderLock(-1);
flag = true;
}
IExpirableItem item = this.entries[key] as IExpirableItem;
if (item == null)
{
return(null);
}
if (this.IsExpired(item))
{
return(null);
}
obj2 = this.ExtractItem(item);
}
finally
{
if (flag)
{
this.cacheLock.ReleaseReaderLock();
}
}
return(obj2);
}
protected object ExtractItem(IExpirableItem val)
{
ExpirableItem item = val as ExpirableItem;
if (item != null)
{
return(item.Item);
}
return(val);
}
protected object ExtractItem(IExpirableItem val)
{
ExpirableItem wrapper = (val as ExpirableItem);
if (wrapper != null)
{
return(wrapper.Item);
}
else
{
return(val);
}
}
protected bool TryAddItem(object key, IExpirableItem item, bool replaceExistingEntry)
{
bool flag2;
bool flag = false;
try
{
try
{
}
finally
{
this.cacheLock.AcquireWriterLock(-1);
flag = true;
}
this.PurgeIfNeeded();
this.EnforceQuota();
IExpirableItem item2 = this.entries[key] as IExpirableItem;
if ((item2 == null) || this.IsExpired(item2))
{
this.entries[key] = item;
}
else
{
if (!replaceExistingEntry)
{
return(false);
}
this.entries[key] = item;
}
if ((item2 != null) && this.doRemoveNotification)
{
this.OnRemove(this.ExtractItem(item2));
}
this.StartTimerIfNeeded();
flag2 = true;
}
finally
{
if (flag)
{
this.cacheLock.ReleaseWriterLock();
}
}
return(flag2);
}
protected bool TryAddItem(object key, IExpirableItem item, bool replaceExistingEntry)
{
bool lockHeld = false;
try
{
try { }
finally
{
CacheLock.EnterWriteLock();
lockHeld = true;
}
PurgeIfNeeded();
EnforceQuota();
IExpirableItem currentItem = _entries[key] as IExpirableItem;
if (currentItem == null || IsExpired(currentItem))
{
_entries[key] = item;
}
else if (!replaceExistingEntry)
{
return(false);
}
else
{
_entries[key] = item;
}
if (currentItem != null && _doRemoveNotification)
{
OnRemove(ExtractItem(currentItem));
}
StartTimerIfNeeded();
return(true);
}
finally
{
if (lockHeld)
{
CacheLock.ExitWriteLock();
}
}
}
protected bool TryReplaceItem(object key, object item, DateTime expirationTime)
{
bool lockHeld = false;
try
{
try { }
finally
{
CacheLock.EnterWriteLock();
lockHeld = true;
}
PurgeIfNeeded();
EnforceQuota();
IExpirableItem currentItem = _entries[key] as IExpirableItem;
if (currentItem == null || IsExpired(currentItem))
{
return(false);
}
else
{
_entries[key] = new ExpirableItem(item, expirationTime);
if (currentItem != null && _doRemoveNotification)
{
OnRemove(ExtractItem(currentItem));
}
StartTimerIfNeeded();
return(true);
}
}
finally
{
if (lockHeld)
{
CacheLock.ExitWriteLock();
}
}
}
protected bool TryRemoveItem(object key)
{
bool flag3;
bool flag = false;
try
{
try
{
}
finally
{
this.cacheLock.AcquireWriterLock(-1);
flag = true;
}
this.PurgeIfNeeded();
IExpirableItem item = this.entries[key] as IExpirableItem;
bool flag2 = (item != null) && !this.IsExpired(item);
if (item != null)
{
this.entries.Remove(key);
if (this.doRemoveNotification)
{
this.OnRemove(this.ExtractItem(item));
}
this.CancelTimerIfNeeded();
}
flag3 = flag2;
}
finally
{
if (flag)
{
this.cacheLock.ReleaseWriterLock();
}
}
return(flag3);
}
private void PurgeStaleItems()
{
if (!this.cacheLock.IsWriterLockHeld)
{
DiagnosticUtility.FailFast("Cache write lock is not held.");
}
ArrayList list = new ArrayList();
foreach (object obj2 in this.entries.Keys)
{
IExpirableItem item = this.entries[obj2] as IExpirableItem;
if (this.IsExpired(item))
{
this.OnRemove(this.ExtractItem(item));
list.Add(obj2);
}
}
for (int i = 0; i < list.Count; i++)
{
this.entries.Remove(list[i]);
}
this.CancelTimerIfNeeded();
this.nextPurgeTimeUtc = DateTime.UtcNow.Add(this.purgeInterval);
}
private bool IsExpired(IExpirableItem item)
{
Fx.Assert(item.ExpirationTime == DateTime.MaxValue || item.ExpirationTime.Kind == DateTimeKind.Utc, "");
return(item.ExpirationTime <= DateTime.UtcNow);
}
internal void SetExpiration(IExpirableItem expirableItem)
=> this.expirableItem = expirableItem;
private bool IsExpired(IExpirableItem item)
{
return(item.ExpirationTime <= DateTime.UtcNow);
}
