// TODO - EventSource?
/// <summary>
/// Invokes the logic of the middleware.
/// </summary>
/// <param name="context">The <see cref="HttpContext"/>.</param>
/// <returns>A <see cref="Task"/> that completes when the request leaves.</returns>
public async Task Invoke(HttpContext context)
{
using var lease = await TryAcquireAsync(context);
if (lease.IsAcquired)
{
await _next(context);
}
else
{
RateLimiterLog.RequestRejectedLimitsExceeded(_logger);
// OnRejected "wins" over DefaultRejectionStatusCode - we set DefaultRejectionStatusCode first,
// then call OnRejected in case it wants to do any further modification of the status code.
context.Response.StatusCode = _rejectionStatusCode;
await _onRejected(context, lease);
}
}
private async Task InvokeInternal(HttpContext context, EnableRateLimitingAttribute?enableRateLimitingAttribute)
{
using var leaseContext = await TryAcquireAsync(context);
if (leaseContext.Lease.IsAcquired)
{
await _next(context);
}
else
{
var thisRequestOnRejected = _defaultOnRejected;
RateLimiterLog.RequestRejectedLimitsExceeded(_logger);
// OnRejected "wins" over DefaultRejectionStatusCode - we set DefaultRejectionStatusCode first,
// then call OnRejected in case it wants to do any further modification of the status code.
context.Response.StatusCode = _rejectionStatusCode;
// If this request was rejected by the endpoint limiter, use its OnRejected if available.
if (leaseContext.GlobalRejected == false)
{
DefaultRateLimiterPolicy?policy;
// Use custom policy OnRejected if available, else use OnRejected from the Options if available.
policy = enableRateLimitingAttribute?.Policy;
if (policy is not null)
{
thisRequestOnRejected = policy.OnRejected;
}
else
{
var policyName = enableRateLimitingAttribute?.PolicyName;
if (policyName is not null && _policyMap.TryGetValue(policyName, out policy) && policy.OnRejected is not null)
{
thisRequestOnRejected = policy.OnRejected;
}
}
}
if (thisRequestOnRejected is not null)
{
await thisRequestOnRejected(new OnRejectedContext()
{
HttpContext = context, Lease = leaseContext.Lease
}, context.RequestAborted);
}
}
}