public DownloadService(IProvideDownloadClient downloadClientProvider,
IRateLimitService rateLimitService,
IEventAggregator eventAggregator,
Logger logger)
{
_downloadClientProvider = downloadClientProvider;
_rateLimitService = rateLimitService;
_eventAggregator = eventAggregator;
_logger = logger;
}
// IMyScopedService is injected into Invoke
public async Task InvokeAsync(HttpContext context, IRateLimitService rateLimitService)
{
// check if rate limiting is enabled
if (_options == null)
{
await _next.Invoke(context);
return;
}
// compute identity from request
var identity = await ClientIdentityHelper.ResolveIdentityAsync(context, _options);
var currentTime = DateTime.UtcNow;
// check if user is already requested
var record = await rateLimitService.GetRateLimitRecordAsync(identity);
if (record == null)
{
record = new RateLimitRecord
{
ClientId = identity.ClientId,
Timestamp = currentTime
}
}
;
// check if user is blocked
if (record.isBlocked)
{
var blockTime = record.BlockedUntillTime - currentTime;
if (blockTime.TotalSeconds > 0)
{
await ReturnQuotaExceededResponse(context, record.BlockedUntillTime);
return;
}
else
{
//reset rateCounter record if time for block is run out
await rateLimitService.ResetUserAsync(identity, context.RequestAborted);
}
}
//find all rules eligibe for request
IEnumerable <RateLimitRule> rules = await rateLimitService.GetMatchingRulesAsync(identity, context.RequestAborted);
foreach (var rule in rules)
{
RateLimitRecord rateCounter = await rateLimitService.ProcessRequestAsync(record, rule, currentTime, context.RequestAborted);
if (rule.Limit > 0)
{
// check if limit is reached
if (rateCounter.Count > rule.Limit)
{
var blockedUser = await rateLimitService.BlockUserByRateLimitAsync(identity, rule);
// break execution
await ReturnQuotaExceededResponse(context, blockedUser.BlockedUntillTime);
return;
}
}
}
// Call the next delegate/middleware in the pipeline
await _next(context);
}
public HttpClient(IEnumerable <IHttpRequestInterceptor> requestInterceptors, ICacheManager cacheManager, IRateLimitService rateLimitService, IHttpDispatcher httpDispatcher, Logger logger)
{
_requestInterceptors = requestInterceptors.ToList();
_rateLimitService = rateLimitService;
_httpDispatcher = httpDispatcher;
_logger = logger;
ServicePointManager.DefaultConnectionLimit = 12;
_cookieContainerCache = cacheManager.GetCache <CookieContainer>(typeof(HttpClient));
}
