public PendingValue(TKey key, MissingValueFactory <TKey, TValue> factory)
{
_key = key;
_factory = factory ?? DefaultMissingValueFactory;
_source = new TaskCompletionSource <TValue>();
}
public Task <TValue> GetOrAdd(TKey key, MissingValueFactory <TKey, TValue> missingValueFactory)
{
if (TryGetValue(key, out var cacheValue))
{
return(cacheValue.HasValue
? cacheValue.Value
: cacheValue.GetValue(() => new PendingValue <TKey, TValue>(key, missingValueFactory)));
}
void RemoveValue()
{
_values.TryRemove(key, out _);
}
cacheValue = _policy.CreateValue(RemoveValue);
if (!_values.TryAdd(key, cacheValue))
{
return(GetOrAdd(key, missingValueFactory));
}
_metrics.Miss();
async Task <TValue> Added()
{
await _tracker.Add(cacheValue).ConfigureAwait(false);
return(await cacheValue.GetValue(() => new PendingValue <TKey, TValue>(key, missingValueFactory)).ConfigureAwait(false));
}
return(Added());
}
public PendingValue(TKey key, MissingValueFactory <TKey, TValue> factory)
{
_key = key;
_factory = factory ?? DefaultMissingValueFactory;
_value = new TaskCompletionSource <TValue>(TaskCreationOptions.RunContinuationsAsynchronously);
}
public IIndex <TKey, TValue> AddIndex <TKey>(string indexName, KeyProvider <TKey, TValue> keyProvider,
MissingValueFactory <TKey, TValue> missingValueFactory = null)
{
if (_indices.ContainsKey(indexName))
{
throw new ArgumentException($"An index with the same name was already added: {indexName}", nameof(indexName));
}
var index = new Index <TKey, TValue>(_nodeTracker, keyProvider);
_indices[indexName] = index;
return(index);
}
public Task <TValue> Get(TKey key, MissingValueFactory <TKey, TValue> missingValueFactory)
{
lock (_lock)
{
INode <TValue> existingNode;
if (TryGetExistingNode(key, out existingNode))
{
if (existingNode.HasValue)
{
_nodeTracker.Statistics.Hit();
return(existingNode.Value);
}
var pending = new PendingValue <TKey, TValue>(key, missingValueFactory);
return(existingNode.GetValue(pending));
}
if (missingValueFactory == null)
{
_nodeTracker.Statistics.Miss();
throw new KeyNotFoundException($"Key not found: {key}");
}
var pendingValue = new PendingValue <TKey, TValue>(key, missingValueFactory);
var nodeValueFactory = new NodeValueFactory <TValue>(pendingValue, 0);
var node = new FactoryNode <TValue>(nodeValueFactory);
_index[key] = new WeakReference <INode <TValue> >(node, false);
_nodeTracker.Add(nodeValueFactory);
return(pendingValue.Value);
}
}
