private bool IsNotExpired(CacheKey key, CacheEntry entry, bool callOnIdle = true)
{
if (entry.NonExpiring)
{
return(true);
}
var now = GetCurrentDate(0);
if (entry.IsExpired(now))
{
return(false);
}
if (entry.SlidingExpiration > 0)
{
// if Value is saved in Store's key segment, updating this
// field updated the current Value in the Store as they refer
// to the same object at this point.
entry.ExpirationTime = GetCurrentDate(entry.SlidingExpiration);
if (!_store.IsDataInKeySegment)
{
_store.CurrentValue = entry;
}
}
return(true);
}
/// <summary>
/// get will return the cache entry with a given key.
/// set will insert/update the cache entry with a given key.
/// </summary>
/// <param name="key"></param>
/// <returns></returns>
public override object this[string key]
{
get
{
var r = Get(key);
MethodOnIdle();
return(r);
}
set
{
var policy = new CacheItemPolicy {
SlidingExpiration = new TimeSpan(0, 5, 0)
};
var now = GetCurrentDate(0);
var entry = new CacheEntry(policy, GetCurrentDate(0));
var cacheKey = new CacheKey(key)
{
TimeStamp = now
};
var r = _store.Locker.Invoke(() =>
{
if (_store.AddIfNotExist(cacheKey, entry))
{
return(1);
}
// if priotiry is not removable, just update the store w/ value
if (entry.NonExpiring)
{
_store.CurrentValue.Value = value;
return(2);
}
entry = _store.CurrentValue;
entry.Value = value;
if (!entry.IsExpired(now))
{
// slide the expire time...
if (entry.SlidingExpiration > 0)
{
entry.ExpirationTime = GetCurrentDate(entry.SlidingExpiration);
if (!_store.IsDataInKeySegment)
{
_store.CurrentValue = entry;
}
return(0);
}
return(2);
}
// adjust policy (set to slide every 5 mins) of the expired item to accomodate this update...
if (entry.SlidingExpiration == 0)
{
entry.SlidingExpiration = TimeSpan.TicksPerMinute * 5;
}
entry.ExpirationTime = GetCurrentDate(entry.SlidingExpiration);
if (!_store.IsDataInKeySegment)
{
_store.CurrentValue = entry;
}
return(0);
}
);
if (r == 0)
{
UpdateTimeStamp(cacheKey, entry, now);
}
else if (r == 1)
{
AddTimeStamp(cacheKey, entry);
}
else if (r == 2)
{
MethodOnIdle();
}
}
}
/// <summary>
/// Retrievs cached entries given their Keys. If key is not found or expired,
/// null will be returned to this item's Value portion of the KeyValuePair.
/// </summary>
/// <param name="keys"></param>
/// <param name="regionName"></param>
/// <returns></returns>
public override IDictionary <string, object> GetValues(IEnumerable <string> keys, string regionName = null)
{
if (keys == null)
{
throw new ArgumentNullException("keys");
}
var keysList = new List <CacheKey>();
foreach (var k in keys)
{
keysList.Add(new CacheKey(k));
}
Dictionary <string, object> r = new Dictionary <string, object>();
if (keysList.Count == 0)
{
return(r);
}
QueryResult <CacheKey>[] result = null;
if (!_store.Locker.Invoke <bool>(() =>
{
if (!_store.Query(Sop.QueryExpression <CacheKey> .Package(keysList.ToArray()), out result))
{
// just unlock and return, no need to update the TimeStamps as no match was found...
_store.Locker.Unlock();
MethodOnIdle();
return(false);
}
return(true);
}))
{
return(r);
}
// package data Values onto the dictionary for return...
var l = new List <QueryResult <CacheKey> >(result.Length);
var now = GetCurrentDate(0);
foreach (var res in result)
{
r[res.Key.Key] = res.Value;
if (res.Found)
{
CacheEntry ce = res.Value as CacheEntry;
if (ce.IsExpired(now))
{
// try to update the expired entry...
if (CacheEntrySetUpdateCallback != null)
{
CacheEntrySetUpdateCallback(new CacheEntryUpdateArguments[] { new CacheEntryUpdateArguments(this, CacheEntryRemovedReason.Expired, res.Key.Key, null) });
CacheEntry entry;
var resKey = res.Key;
_store.Locker.Invoke(() =>
{
if (_store.TryGetValue(resKey, out entry))
{
if (IsNotExpired(resKey, entry, false))
{
r[resKey.Key] = _store.CurrentValue.Value;
}
}
});
}
}
else if (!ce.NonExpiring)
{
l.Add(res);
}
}
}
UpdateTimeStamp(l.ToArray(), now);
return(r);
}
/// <summary>
/// Set inserts or updates an existing cache entry with the given key.
/// If eviction policy is null, a Sliding Expiration policy with five minute
/// timespan will be used. VirtualCache doesn't support regions thus, regionName
/// will be ignored and defaults to null.
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
/// <param name="policy"></param>
/// <param name="regionName"></param>
public override void Set(string key, object value, CacheItemPolicy policy, string regionName = null)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (value == null)
{
throw new ArgumentNullException("value");
}
if (policy == null)
{
policy = DefaultPolicy;
}
var now = GetCurrentDate(0);
var entry = new CacheEntry(policy, now)
{
Value = value
};
var cacheKey = new CacheKey(key)
{
TimeStamp = now
};
_store.Locker.Invoke(() =>
{
#region update block
if (_store.AddIfNotExist(cacheKey, entry))
{
return;
}
// if priotiry is not removable, just update the store w/ value
if (entry.NonExpiring)
{
_store.CurrentValue.Value = value;
return;
}
entry = _store.CurrentValue;
entry.Value = value;
if (!entry.IsExpired(now))
{
// slide the expire time...
if (entry.SlidingExpiration > 0)
{
entry.ExpirationTime = GetCurrentDate(entry.SlidingExpiration);
if (!_store.IsDataInKeySegment)
{
_store.CurrentValue = entry;
}
}
return;
}
// adjust policy (set to slide every 5 mins) of the expired item to accomodate this update...
if (entry.SlidingExpiration == 0)
{
entry.SlidingExpiration = TimeSpan.TicksPerMinute * 5;
}
entry.ExpirationTime = GetCurrentDate(entry.SlidingExpiration);
if (!_store.IsDataInKeySegment)
{
_store.CurrentValue = entry;
}
return;
#region for removal
//if (_store.AddIfNotExist(cacheKey, ce))
// return;
//// update the store...
//cacheKey.TimeStamp = _store.CurrentKey.TimeStamp;
//_store.CurrentKey.TimeStamp = now;
//var ce2 = new CacheEntry(policy, GetCurrentDate(0));
//ce2.Value = value;
//_store.CurrentValue = ce2;
#endregion
#endregion
});
}
