@snap/camera-kit/dist/handlers/rateLimitingHandler.d.ts

Camera Kit Web

import type { PageVisibility } from "../common/pageVisibility";
import type { ChainableHandler, RequestMetadata } from "./HandlerChainBuilder";
/**
 * Limit the rate at which requests are passed to the next handler in the chain.
 *
 * During any page transitions to "hidden" – possibly indicating the page is about to terminate – requests will not be
 * rate limited, to ensure that they are not lost.
 *
 * TODO: If there are requests in the queue waiting to be sent when the page transitions to "hidden," these will not
 * be immediately sent. This means there still is an edge case in which a request may be lost on page termination. This
 * can be fixed with changes to `createMappingHandler`.
 *
 * **NOTE:** Under the hood, requests that come in faster than the set `duration` are placed in an unbounded buffer.
 * If many requests are made quickly and `duration` is long, this could result in high memory usage. Keep this in mind
 * when using this handler.
 *
 * @param duration In milliseconds. Requests will be passed to the next handler in the chain no faster than this. That
 * is, if `duration` is `1000`, the next handler will be called at most once per second.
 * @param pageVisibility Determines whether to flush buffered requests when the page becomes hidden.
 * `false` value indicates that page visibility handling is avoided, while
 * a {@link PageVisibility} instance is used to subscribe to page visibility change events.
 * @returns {@link ChainableHandler}, suitable for use in {@link HandlerChainBuilder.map}
 */
export declare const createRateLimitingHandler: <Req, Res, Meta extends RequestMetadata>(duration: number, pageVisibility: PageVisibility | false) => ChainableHandler<Req, Res, Req, Res, Meta>;
//# sourceMappingURL=rateLimitingHandler.d.ts.map