/// <summary>
/// Remove item from cache by key.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="raiseEvents">Indicates whether events should be raised.</param>
/// <param name="action">The action that need to be executed in synchronization with the item cache removal.</param>
/// <returns>The value indicating whether the item was removed.</returns>
private bool RemoveItem(TKey key, bool raiseEvents, Action action = null)
{
// Try to get item, if there is no item by that key then return true to indicate that item was removed.
var item = default(CacheStorageValueInfo <TValue>);
if (!_dictionary.TryGetValue(key, out item))
{
return(true);
}
action?.Invoke();
var cancel = false;
var expirationPolicy = item.ExpirationPolicy;
if (raiseEvents)
{
var expiringEventArgs = new ExpiringEventArgs <TKey, TValue>(key, item.Value, expirationPolicy);
Expiring.SafeInvoke(this, expiringEventArgs);
cancel = expiringEventArgs.Cancel;
expirationPolicy = expiringEventArgs.ExpirationPolicy;
}
if (cancel)
{
if (expirationPolicy == null && _defaultExpirationPolicyInitCode != null)
{
expirationPolicy = _defaultExpirationPolicyInitCode.Invoke();
}
_dictionary[key] = new CacheStorageValueInfo <TValue>(item.Value, expirationPolicy);
return(false);
}
_dictionary.Remove(key);
bool dispose = _disposeValuesOnRemoval;
if (raiseEvents)
{
var expiredEventArgs = new ExpiredEventArgs <TKey, TValue>(key, item.Value, dispose);
Expired.SafeInvoke(this, expiredEventArgs);
dispose = expiredEventArgs.Dispose;
}
if (dispose)
{
item.DisposeValue();
}
return(true);
}
public TValue GetFromCacheOrFetch(TKey key, Func <TValue> code, ExpirationPolicy expirationPolicy, bool @override = false)
{
Argument.IsNotNull("key", key);
Argument.IsNotNull("code", code);
return(ExecuteInLock(key, () =>
{
TValue value;
var containsKey = _dictionary.ContainsKey(key);
if (!containsKey || @override)
{
value = code.Invoke();
if (!ReferenceEquals(value, null) || _storeNullValues)
{
if (expirationPolicy == null && _defaultExpirationPolicyInitCode != null)
{
expirationPolicy = _defaultExpirationPolicyInitCode.Invoke();
}
var valueInfo = new CacheStorageValueInfo <TValue>(value, expirationPolicy);
lock (_syncObj)
{
_dictionary[key] = valueInfo;
}
if (valueInfo.CanExpire)
{
_checkForExpiredItems = true;
}
if (expirationPolicy != null)
{
if (_expirationTimer == null)
{
UpdateTimer();
}
}
}
}
else
{
value = _dictionary[key].Value;
}
return value;
}));
}
/// <summary>
/// Adds a value to the cache associated with to a key asynchronously.
/// <para />
/// Note that this is a wrapper around <see cref="GetFromCacheOrFetch(TKey,System.Func{TValue},ExpirationPolicy,bool)"/>.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="code">The deferred initialization code of the value.</param>
/// <param name="expirationPolicy">The expiration policy.</param>
/// <param name="override">Indicates if the key exists the value will be overridden.</param>
/// <returns>The instance initialized by the <paramref name="code" />.</returns>
/// <exception cref="ArgumentNullException">If <paramref name="key" /> is <c>null</c>.</exception>
/// <exception cref="ArgumentNullException">If <paramref name="code" /> is <c>null</c>.</exception>
public async Task <TValue> GetFromCacheOrFetchAsync(TKey key, Func <Task <TValue> > code, ExpirationPolicy expirationPolicy, bool @override = false)
{
Argument.IsNotNull("key", key);
Argument.IsNotNull("code", code);
lock (GetLockByKey(key))
{
var containsKey = _dictionary.ContainsKey(key);
if (containsKey && !@override)
{
return(_dictionary[key].Value);
}
}
var value = await code.Invoke();
lock (GetLockByKey(key))
{
if (!ReferenceEquals(value, null) || _storeNullValues)
{
if (expirationPolicy == null && _defaultExpirationPolicyInitCode != null)
{
expirationPolicy = _defaultExpirationPolicyInitCode.Invoke();
}
var valueInfo = new CacheStorageValueInfo <TValue>(value, expirationPolicy);
lock (_syncObj)
{
_dictionary[key] = valueInfo;
}
if (valueInfo.CanExpire)
{
_checkForExpiredItems = true;
}
if (expirationPolicy != null)
{
if (_expirationTimer == null)
{
UpdateTimer();
}
}
}
}
return(value);
}
/// <summary>
/// Adds a value to the cache associated with to a key asynchronously.
/// <para />
/// Note that this is a wrapper around <see cref="GetFromCacheOrFetch(TKey,System.Func{TValue},ExpirationPolicy,bool)"/>.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="code">The deferred initialization code of the value.</param>
/// <param name="expirationPolicy">The expiration policy.</param>
/// <param name="override">Indicates if the key exists the value will be overridden.</param>
/// <returns>The instance initialized by the <paramref name="code" />.</returns>
/// <exception cref="ArgumentNullException">If <paramref name="key" /> is <c>null</c>.</exception>
/// <exception cref="ArgumentNullException">If <paramref name="code" /> is <c>null</c>.</exception>
public Task <TValue> GetFromCacheOrFetchAsync(TKey key, Func <Task <TValue> > code, ExpirationPolicy expirationPolicy, bool @override = false)
{
Argument.IsNotNull("key", key);
Argument.IsNotNull("code", code);
return(ExecuteInLockAsync(key, async() =>
{
CacheStorageValueInfo <TValue> cacheStorageValueInfo;
if (!@override && _dictionary.TryGetValue(key, out cacheStorageValueInfo))
{
return cacheStorageValueInfo.Value;
}
var value = await code();
if (!ReferenceEquals(value, null) || _storeNullValues)
{
if (expirationPolicy == null && _defaultExpirationPolicyInitCode != null)
{
expirationPolicy = _defaultExpirationPolicyInitCode();
}
var valueInfo = new CacheStorageValueInfo <TValue>(value, expirationPolicy);
lock (_syncObj)
{
_dictionary[key] = valueInfo;
}
if (valueInfo.CanExpire)
{
_checkForExpiredItems = true;
}
if (expirationPolicy != null)
{
if (_expirationTimer == null)
{
UpdateTimer();
}
}
}
return value;
}));
}
