public async Task <CommandResult <TResult> > DispatchAsync <TResult>(ICommand <TResult> command, CancellationToken cancellationToken)
{
CacheOptions options = _cacheOptionsProvider.Get(command);
if (options == null)
{
return(await _commandDispatcher.DispatchAsync(command, cancellationToken));
}
var cacheKey = CacheKey(command);
TResult result = await _cacheAdapter.Get <TResult>(cacheKey);
if (result != null)
{
return(new CommandResult <TResult>(result, false));
}
CommandResult <TResult> executedResult;
if (options.Semaphore != null)
{
await options.Semaphore.WaitAsync(cancellationToken);
try
{
result = await _cacheAdapter.Get <TResult>(cacheKey);
if (result != null)
{
return(new CommandResult <TResult>(result, false));
}
else
{
executedResult = await _commandDispatcher.DispatchAsync(command, cancellationToken);
}
}
finally
{
options.Semaphore.Release();
}
}
else
{
executedResult = await _commandDispatcher.DispatchAsync(command, cancellationToken);
}
if (options.LifeTime != null)
{
await _cacheAdapter.Set(cacheKey, executedResult.Result, options.LifeTime());
}
else if (options.ExpiresAtUtc != null)
{
await _cacheAdapter.Set(cacheKey, executedResult.Result, options.ExpiresAtUtc());
}
else
{
// shouldn't happen but lets make sure we spit out a sensible error if it does
throw new CacheConfigurationException("Either a lifetime or expiry date must be set for a cached command");
}
return(executedResult);
}
