/// <summary>
/// 将 RunContext 的当前实例重设为 null，该方法一般与 InitCurrent 成对使用。
/// </summary>
public static void ResetCurrent()
{
current = null;
}
private static RunContext GetFromRequest()
{
RunContext runContext;
// 经测试，访问 1亿次 HttpContext.Current 用时 6 秒左右，每次 0.6 时间刻度(即2万分之一毫秒)，完全不需要担心判断它是否存在会有性能问题
System.Web.HttpContext httpContext = System.Web.HttpContext.Current;
if (httpContext != null)
{
runContext = httpContext.Items["_RunContext"] as RunContext;
if (runContext == null)
{
runContext = new RunContext();
System.Web.HttpRequest httpRequest = httpContext.TryGetRequest();
if (httpRequest != null)
{
if (httpRequest.Url.DnsSafeHost.StartsWith("demo.", StringComparison.InvariantCultureIgnoreCase))
{
runContext.contextRunMode = RunMode.Demo;
}
}
httpContext.Items["_RunContext"] = runContext;
}
return runContext;
}
// 经测试，访问 1亿次 System.ServiceModel.OperationContext.Current 用时 5 秒左右，每次 0.5 时间刻度(即2万分之一毫秒)，完全不需要担心判断它是否存在会有性能问题
System.ServiceModel.OperationContext operationContext = System.ServiceModel.OperationContext.Current;
if (operationContext != null)
{
runContext = OperationContextExtension.GetItem(operationContext, "_RunContext") as RunContext;
if (runContext == null)
{
runContext = new RunContext();
int headerIndex = operationContext.IncomingMessageHeaders.FindHeader(XMS.Core.WCF.DemoHeader.Name, XMS.Core.WCF.DemoHeader.NameSpace);
if (headerIndex >= 0)
{
if (operationContext.IncomingMessageHeaders.GetHeader<bool>(headerIndex))
{
runContext.contextRunMode = RunMode.Demo;
}
else
{
runContext.contextRunMode = RunMode.Release;
}
}
else
{
if (operationContext.IncomingMessageProperties.ContainsKey(HttpRequestMessageProperty.Name))
{
HttpRequestMessageProperty requestMessageProperty = operationContext.IncomingMessageProperties[HttpRequestMessageProperty.Name] as HttpRequestMessageProperty;
if (requestMessageProperty != null)
{
if ("true".Equals(requestMessageProperty.Headers.Get(XMS.Core.WCF.DemoHeader.Name)))
{
runContext.contextRunMode = RunMode.Demo;
}
else
{
runContext.contextRunMode = RunMode.Release;
}
}
}
}
OperationContextExtension.RegisterItem(operationContext, "_RunContext", runContext);
}
return runContext;
}
// 即不存在服务上下文又不存在http上下文时，返回本地运行上下文（local)。
return local;
}
/// <summary>
/// 从请求中初始化 Current 属性，这可将 RunContext 当前实例初始化化，后续对 Current 属性的访问不再依赖于具体的请求上下文，可避免访问已经释放的 OperationContext.Current 时发生错误，
/// 并可提高后续访问的性能，但必须在执行结束时成对调用 ResetCurrent 方法，以防止在线程被复用时误用之前的上下文实例。
/// </summary>
public static void InitCurrent()
{
current = GetFromRequest();
}
