public void Initialize_Repairs_Handler_Collection_If_RequestTracer_Inserted()
{
// Arrange
HttpConfiguration config = new HttpConfiguration();
config.Services.Replace(typeof(ITraceWriter), new TestTraceWriter());
TestTraceWriter traceWriter = new TestTraceWriter();
DelegatingHandler messageHandler = new Mock <DelegatingHandler>().Object;
DelegatingHandler msgHandlerTracer = new MessageHandlerTracer(messageHandler, traceWriter);
RequestMessageHandlerTracer requestMsgtracer = new RequestMessageHandlerTracer(traceWriter);
List <DelegatingHandler> handlerList = new List <DelegatingHandler>()
{
messageHandler, msgHandlerTracer, requestMsgtracer
};
foreach (var eachHandler in handlerList)
{
config.MessageHandlers.Add(eachHandler);
}
TraceManager traceManager = new TraceManager();
traceManager.Initialize(config);
Collection <DelegatingHandler> expectedMessageHandlers = config.MessageHandlers;
// Act
config.MessageHandlers.Insert(0, requestMsgtracer);
traceManager.Initialize(config);
// Assert
Collection <DelegatingHandler> actualMessageHandlers = config.MessageHandlers;
Assert.Equal(expectedMessageHandlers, actualMessageHandlers);
Assert.True(IsMessageHandlerCollectionValid(config.MessageHandlers));
}
private static void CreateMessageHandlerTracers(
HttpConfiguration configuration,
ITraceWriter traceWriter
)
{
int handlerCount = configuration.MessageHandlers.Count;
// If message handlers have already been wired into the pipeline,
// we do not install tracing message handlers. This scenario occurs
// when initialization is attempted twice, such as per-controller configuration.
if (handlerCount > 0 && configuration.MessageHandlers[0].InnerHandler != null)
{
return;
}
// RequestMessageHandlerTracer will be the first tracer to get executed and each messageHandlerTracer
// will execute before its respective handler. For the MessageHandlerTracers to be registered,
// the message handler list must be of the form:
// requestMessageHandlerTracer
// messageHandler1Tracer
// messageHandler1
// ...
// ...
// messageHandlerNTracer
// messageHandlerN
// Where "N" is a non-negative integer. That is, there could be zero or more pairs of handlers/tracers, plus a
// request tracer at the beginning. If the state does not match this pattern, the tracer list is recreated.
if (!AreMessageHandlerTracersRegistered(configuration.MessageHandlers))
{
// Removing the MessageHandlerTracer and RequestMessageHandlerTracer in the reverse order.
for (int i = handlerCount - 1; i >= 0; i--)
{
if (
configuration.MessageHandlers[i] is RequestMessageHandlerTracer ||
configuration.MessageHandlers[i] is MessageHandlerTracer
)
{
configuration.MessageHandlers.RemoveAt(i);
}
}
handlerCount = configuration.MessageHandlers.Count;
// Insert a tracing handler before each existing message handler (in execution order)
for (int i = 0; i < handlerCount * 2; i += 2)
{
DelegatingHandler innerHandler = configuration.MessageHandlers[i];
DelegatingHandler handlerTracer = new MessageHandlerTracer(
innerHandler,
traceWriter
);
configuration.MessageHandlers.Insert(i, handlerTracer);
}
configuration.MessageHandlers.Insert(
0,
new RequestMessageHandlerTracer(traceWriter)
);
}
}
public ClientHandler(MessageHandlerTracer tracer, IDictionary <string, string> properties)
{
_tracer = tracer ?? throw new ArgumentNullException(nameof(tracer));
_ = properties ?? throw new ArgumentNullException(nameof(properties));
foreach (var kv in properties)
{
Properties[kv.Key] = kv.Value;
}
}
private static void CreateMessageHandlerTracers(HttpConfiguration configuration, ITraceWriter traceWriter)
{
// Insert a tracing handler before each existing message handler (in execution order)
int handlerCount = configuration.MessageHandlers.Count;
for (int i = 0; i < handlerCount * 2; i += 2)
{
DelegatingHandler innerHandler = configuration.MessageHandlers[i];
DelegatingHandler handlerTracer = new MessageHandlerTracer(innerHandler, traceWriter);
configuration.MessageHandlers.Insert(i + 1, handlerTracer);
}
configuration.MessageHandlers.Add(new RequestMessageHandlerTracer(traceWriter));
}
private static void CreateMessageHandlerTracers(HttpConfiguration configuration, ITraceWriter traceWriter)
{
int handlerCount = configuration.MessageHandlers.Count;
// If message handlers have already been wired into the pipeline,
// we do not install tracing message handlers. This scenario occurs
// when initialization is attempted twice, such as per-controller configuration.
if (handlerCount > 0 && configuration.MessageHandlers[0].InnerHandler != null)
{
return;
}
// Insert a tracing handler before each existing message handler (in execution order)
for (int i = 0; i < handlerCount * 2; i += 2)
{
DelegatingHandler innerHandler = configuration.MessageHandlers[i];
DelegatingHandler handlerTracer = new MessageHandlerTracer(innerHandler, traceWriter);
configuration.MessageHandlers.Insert(i + 1, handlerTracer);
}
configuration.MessageHandlers.Add(new RequestMessageHandlerTracer(traceWriter));
}
public CustomDelegatingHandler2(MessageHandlerTracer tracer)
{
_tracer = tracer ?? throw new ArgumentNullException(nameof(tracer));
}
