public async Task Invoke(HttpContext httpContext)
{
// check if rate limiting is enabled
if (_options == null)
{
await _next.Invoke(httpContext);
return;
}
// get request details
var clientRequest = httpContext.GetClientRequest(_options.ClientIdHeader);
// check white list
if (_processor.IsWhitelisted(clientRequest))
{
await _next.Invoke(httpContext);
return;
}
var rules = _processor.GetMatchingRules(clientRequest);
RateLimitResult result = null;
foreach (var rule in rules)
{
// if limit is zero or less, block the request.
if (rule.Limit <= 0)
{
// log blocked request
LogBlockedRequest(httpContext, clientRequest, rule);
// return quote exceeded
await ReturnQuotaExceededResponse(httpContext, rule);
return;
}
// process request
result = await _processor.ProcessRequestAsync(clientRequest, rule);
// check if limit is exceeded
if (!result.Success)
{
//compute retry after value
var retryAfter = Convert.ToInt32((result.Expiry - DateTime.UtcNow).TotalSeconds).ToString(CultureInfo.InvariantCulture);
// log blocked request
LogBlockedRequest(httpContext, clientRequest, rule);
// return quote exceeded
await ReturnQuotaExceededResponse(httpContext, rule, retryAfter);
return;
}
}
// set X-Rate-Limit headers
if (result != null && !_options.DisableRateLimitHeaders)
{
var rule = rules.Last();
var headers = new RateLimitHeaders
{
Reset = result.Expiry.ToString("o", DateTimeFormatInfo.InvariantInfo),
Limit = rule.Period,
Remaining = result.Remaining.ToString()
};
httpContext.Response.OnStarting(state => {
try
{
var context = (HttpContext)state;
context.Response.Headers["X-Rate-Limit-Limit"] = headers.Limit;
context.Response.Headers["X-Rate-Limit-Remaining"] = headers.Remaining;
context.Response.Headers["X-Rate-Limit-Reset"] = headers.Reset;
}
catch
{
// ignore exception adding headers
}
return(Task.FromResult(0));
}, httpContext);
}
await _next.Invoke(httpContext);
}
public async Task Invoke(HttpContext httpContext)
{
// check if rate limiting is enabled
if (_options == null)
{
await _next.Invoke(httpContext);
return;
}
// compute identity from request
var identity = SetIdentity(httpContext);
// check white list
if (_processor.IsWhitelisted(identity))
{
await _next.Invoke(httpContext);
return;
}
var rules = _processor.GetMatchingRules(identity);
foreach (var rule in rules)
{
if (rule.Limit > 0)
{
// increment counter
var counter = _processor.ProcessRequest(identity, rule);
// check if key expired
if (counter.Timestamp + rule.PeriodTimespan.Value < DateTime.UtcNow)
{
continue;
}
// check if limit is reached
if (counter.TotalRequests > rule.Limit)
{
//compute retry after value
var retryAfter = _processor.RetryAfterFrom(counter.Timestamp, rule);
// log blocked request
LogBlockedRequest(httpContext, identity, counter, rule);
// break execution
await ReturnQuotaExceededResponse(httpContext, rule, retryAfter);
return;
}
}
// if limit is zero or less, block the request.
else
{
// process request count
var counter = _processor.ProcessRequest(identity, rule);
// log blocked request
LogBlockedRequest(httpContext, identity, counter, rule);
// break execution (Int32 max used to represent infinity)
await ReturnQuotaExceededResponse(httpContext, rule, Int32.MaxValue.ToString(System.Globalization.CultureInfo.InvariantCulture));
return;
}
}
//set X-Rate-Limit headers for the longest period
if (rules.Any() && !_options.DisableRateLimitHeaders)
{
var rule = rules.OrderByDescending(x => x.PeriodTimespan.Value).First();
var headers = _processor.GetRateLimitHeaders(identity, rule);
headers.Context = httpContext;
httpContext.Response.OnStarting(SetRateLimitHeaders, state: headers);
}
await _next.Invoke(httpContext);
}
public async Task Invoke(HttpContext httpContext)
{
// check if rate limiting is enabled
if (_options == null)
{
await _next.Invoke(httpContext);
return;
}
// compute identity from request
var identity = SetIdentity(httpContext);
_logger.LogInformation($"Identity; User:[{identity.ClientId}]; IP:[{identity.ClientIp}]");
// check white list
if (_processor.IsWhitelisted(identity))
{
await _next.Invoke(httpContext);
return;
}
var rules = _processor.GetMatchingRules(identity);
foreach (var rule in rules)
{
if (rule.Limit > 0)
{
// increment counter
var counter = _processor.ProcessRequest(identity, rule);
// check if key expired
if (counter.Timestamp + rule.PeriodTimespan.Value < DateTime.UtcNow)
{
continue;
}
// check if limit is reached
if (counter.TotalRequests > rule.Limit)
{
//compute retry after value
var retryAfter = _processor.RetryAfterFrom(counter.Timestamp, rule);
// log blocked request
LogBlockedRequest(httpContext, identity, counter, rule);
// break execution
await ReturnQuotaExceededResponse(httpContext, rule, retryAfter);
return;
}
}
}
//set X-Rate-Limit headers for the longest period
if (rules.Any() && !_options.DisableRateLimitHeaders)
{
var rule = rules.OrderByDescending(x => x.PeriodTimespan.Value).First();
var headers = _processor.GetRateLimitHeaders(identity, rule);
headers.Context = httpContext;
httpContext.Response.OnStarting(SetRateLimitHeaders, state: headers);
}
await _next.Invoke(httpContext);
}