public async Task <T> Run <T>(Func <T> method, CancellationToken cancellationToken = default)
{
var future = new SynchronousFuture <T>(method, cancellationToken);
await _channel.Writer.WriteAsync(future, cancellationToken).ConfigureAwait(false);
return(await future.Completed.ConfigureAwait(false));
}
public override Future <T> loadStructuredData <T>(string key, Func <string, Future <T> > parser)
{
D.assert(key != null);
D.assert(parser != null);
if (_structuredDataCache.ContainsKey(key))
{
return(_structuredDataCache[key].to <T>());
}
Completer completer = null;
Future <T> result = null;
loadString(key, cache: false).then_ <T>(value => parser(value)).then_ <object>((T value) => {
result = new SynchronousFuture <T>(value);
_structuredDataCache[key] = result;
if (completer != null)
{
// We already returned from the loadStructuredData function, which means
// we are in the asynchronous mode. Pass the value to the completer. The
// completer's future is what we returned.
completer.complete(FutureOr.value(value));
}
return(FutureOr.nil);
});
if (result != null)
{
// The code above ran synchronously, and came up with an answer.
// Return the SynchronousFuture that we created above.
return(result);
}
// The code above hasn't yet run its "then" handler yet. Let's prepare a
// completer for it to use when it does run.
completer = Completer.create();
_structuredDataCache[key] = result = completer.future.to <T>();
return(result);
}
public override Future <_SizeAwareCacheKey> obtainKey(ImageConfiguration configuration)
{
Completer completer = null;
SynchronousFuture <_SizeAwareCacheKey> result = null;
imageProvider.obtainKey(configuration).then((object key) => {
// TODO: completer is always null?
if (completer == null)
{
result = new SynchronousFuture <_SizeAwareCacheKey>(new _SizeAwareCacheKey(key, width, height));
}
else
{
completer.complete(FutureOr.value(new _SizeAwareCacheKey(key, width, height)));
}
});
if (result != null)
{
return(result);
}
completer = Completer.create();
return(completer.future.to <_SizeAwareCacheKey>());
}