public static CallSite Get(int skipFrames)
{
// Account for ourselves
skipFrames++;
if (_stackFrameFast == null)
{
// This is terribad, this session is going to be soooo sloooooooooooow.
// This will eventually happen when the .NET framework authors
// excercise their right to change the private implementation we're
// depending on.
// Fall back to expensive full frame
return new CallSite(new StackFrame(skipFrames, true));
}
// Don't exactly know why we need to skip 2 and not 1 here.
// I suspect expression tree trickery.
var key = _stackFrameFast(skipFrames + 2);
CallSite cached;
if (_cache.TryGetValue(key, out cached))
return cached;
var frame = new StackFrame(skipFrames, true);
var callSite = new CallSite(frame);
return _cache.GetOrAdd(key, callSite);
}
internal OperatorInfo(CallSite callSite, MethodInfo operatorMethod)
{
_id = Interlocked.Increment(ref idCounter);
_callSite = callSite;
_operatorMethod = operatorMethod;
_name = _operatorMethod.Name;
_friendlyName = _name + "#" + _id;
_anonymous = false;
}
Func<IMethodCallMessage, IMethodReturnMessage> GetHandler(IMethodCallMessage call, System.Reflection.MethodInfo method, CallSite callSite)
{
if (call.MethodName == "GetAwaiter")
{
return ForwardCall;
}
var handler = _methodHandlerCache.GetOrAdd(
method,
_ => new Lazy<Func<IMethodCallMessage, IMethodReturnMessage>>(
() => CreateHandler(call, method, callSite), LazyThreadSafetyMode.ExecutionAndPublication));
return handler.Value;
}
Func<IMethodCallMessage, IMethodReturnMessage> CreateHandler(IMethodCallMessage call, System.Reflection.MethodInfo method, CallSite callSite)
{
// IConnectableObservable parameters
if (call.MethodName == "RefCount")
{
return CreateRefCountHandler(call, method, CreateOperatorInfo(method, callSite));
}
// IConnectableObservable return types
if (Array.IndexOf(_connectableCandidates, call.MethodName) >= 0 &&
IsGenericTypeDefinition(method.ReturnType, typeof(IConnectableObservable<>)))
{
return c => HandleConnectableReturnType(c, method, CreateOperatorInfo(method, callSite));
}
else if (IsGenericTypeDefinition(method.ReturnType, typeof(IObservable<>)))
{
return c => HandleObservableReturnType(c, method, CreateOperatorInfo(method, callSite));
}
return ForwardCall;
}
private static OperatorInfo CreateOperatorInfo(System.Reflection.MethodInfo method, CallSite callsite)
{
return new OperatorInfo(callsite, new MethodInfo(method));
}