TsgcWSRateLimiter › Events › OnStateChange

OnStateChange Event

Fired when the Token Bucket size changes for a key.

Syntax

property OnStateChange: TsgcRateLimitOnStateChange;
// TsgcRateLimitOnStateChange = procedure(Sender: TObject; const aKey: string; aOldBucketSize, aNewBucketSize: Integer) of object

Default Value

—

Remarks

Fired after a Token Bucket consume or refill operation updates the bucket size for a key. The aKey parameter identifies the bucket owner and aOldBucketSize / aNewBucketSize report the token counts before and after the change. Useful for telemetry, debugging and real-time visualizations (for example, a chart that shows each client's bucket fill level). The event is not fired for Sliding Window or Fixed Window strategies — only for Token Bucket. Runs synchronously on the thread that invoked the allowance check; keep the handler fast and non-blocking.

Example

procedure TForm1.RateLimiterStateChange(Sender: TObject;
  const aKey: string; aOldBucketSize, aNewBucketSize: Integer);
begin
  // Stream bucket-level telemetry to the dashboard
  Log(Format('Bucket %s: %d -> %d', [aKey, aOldBucketSize, aNewBucketSize]));
end;

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