public static Delegate GetReadValueDelegate(Type valueType)
{
// We want to generate the delegate only once even if we cannot insert it
// to s_readerDelegates from the first attempt.
var generatedDelegate = new Lazy <Delegate>(
() => JSValueReaderGenerator.GenerateReadValueDelegate(valueType));
// We try to add the generated ReadValue delegate in a loop
// in a lock-free thread-safe way. We do not change existing s_readerDelegates.
// Instead we clone it, update the clone, then replace the s_readerDelegates with the updated clone.
while (true)
{
var readerDelegates = s_readerDelegates; // Get the local pointer first.
if (readerDelegates.TryGetValue(valueType, out Delegate readDelegate))
{
return(readDelegate);
}
// The ReadValue delegate is not found. Generate it add try to add to the dictionary atomically.
var newDelegate = generatedDelegate.Value; // Generates delegate when we are here a first time.
// This is a quick shortcut in case if s_readerDelegates changed while we generated the value.
// It helps to avoid cloning dictionary in a number of cases.
if (readerDelegates != s_readerDelegates)
{
continue;
}
// Clone the dictionary, update the clone, and try to replace the s_readerDelegates.
var updatedReaderDelegates = new Dictionary <Type, Delegate>(readerDelegates as IDictionary <Type, Delegate>);
updatedReaderDelegates.Add(valueType, newDelegate);
Interlocked.CompareExchange(ref s_readerDelegates, updatedReaderDelegates, readerDelegates);
}
}
/// <summary>
/// Helper extension method to register a reflection
/// </summary>
/// <typeparam name="T">This must be thea type defined in the assembly where the items for the react package should be extracted.</typeparam>
/// <remarks>
/// The common use case of this type is when you have a react library. Then you would call this from the <see cref="IReactPackageBuilder.CreatePackage"/> function in ReactPackageProvider class that implements <see cref="IReactPackageProvider"/> like: <c>
/// public sealed class ReactPackageProvider : IReactPackageProvider
/// {
/// public void CreatePackage(IReactPackageBuilder packageBuilder)
/// {
/// packageBuilder.AddReflectionReactPackageProvider<ReactPackageProvider>();
/// }
/// }
/// </c>.
/// </remarks>
public static void AddReflectionReactPackageProvider <T>(this IReactPackageBuilder packageBuilder)
{
var assembly = typeof(T).Assembly;
packageBuilder.AddAttributedModules(assembly);
packageBuilder.AddViewManagers(assembly);
JSValueReaderGenerator.RegisterAssembly(assembly);
JSValueWriterGenerator.RegisterAssembly(assembly);
}
