/// <summary>
/// The number of items in the cache or in a partition, if specified.
/// </summary>
/// <param name="partition">The optional partition.</param>
/// <param name="cacheReadMode">The cache read mode.</param>
/// <returns>The number of items in the cache.</returns>
/// <remarks>Calling this method does not extend sliding items lifetime.</remarks>
protected override long CountInternal(string partition, CacheReadMode cacheReadMode = CacheReadMode.ConsiderExpiryDate)
{
// If partition has not been specified, then we use the GetCount method provided directly
// by the MemoryCache.
if (partition == null)
{
return(_store.GetCount());
}
// Otherwise, we need to count items, which is surely slower. In fact, we also need to
// deserialize the key in order to understand if the item belongs to the partition.
return(_store.Count(x => DeserializeCacheKey(x.Key).Partition == partition));
}
/// <summary>
/// Clears this instance or a partition, if specified.
/// </summary>
/// <param name="partition">The optional partition.</param>
/// <param name="cacheReadMode">The cache read mode.</param>
/// <returns>The number of items that have been removed.</returns>
protected override long ClearInternal(string partition, CacheReadMode cacheReadMode = CacheReadMode.IgnoreExpiryDate)
{
// We need to make a snapshot of the keys, since the cache might be used by other
// processes. Therefore, we start projecting all keys.
var keys = _store.Select(x => x.Key);
// Then, if a partition has been specified, we select only those keys that belong to that partition.
if (partition != null)
{
keys = keys.Where(k => DeserializeCacheKey(k).Partition == partition);
}
// Now we take the snapshot of the keys.
var keysArray = keys.ToArray();
// At last, we can remove them safely from the store itself.
foreach (var key in keys)
{
_store.Remove(key);
}
return(keysArray.LongLength);
}
/// <summary> /// The number of items in the cache or in a partition, if specified. /// </summary> /// <param name="partition">The optional partition.</param> /// <param name="cacheReadMode">The cache read mode.</param> /// <returns>The number of items in the cache.</returns> /// <remarks>Calling this method does not extend sliding items lifetime.</remarks> protected override long CountInternal(string partition, CacheReadMode cacheReadMode = CacheReadMode.ConsiderExpiryDate) => 0L;
/// <summary> /// Clears this instance or a partition, if specified. /// </summary> /// <param name="partition">The optional partition.</param> /// <param name="cacheReadMode">The cache read mode.</param> /// <returns>The number of items that have been removed.</returns> protected override long ClearInternal(string partition, CacheReadMode cacheReadMode = CacheReadMode.IgnoreExpiryDate) => 0L;
