Function cache

packages/beth-stack/src/cache/render.ts:4–35

(fn: T)

import { BETH_GLOBAL_RENDER_CACHE } from "../shared/global";

export function cache<T extends (...args: any[]) => any>(fn: T): T {
  return ((...args: unknown[]) => {
    const cachedResults = BETH_GLOBAL_RENDER_CACHE.dedupeCache.get(fn);

    if (cachedResults) {
      for (let [keyArgs, cachedValue] of cachedResults.entries()) {
        if (Bun.deepEquals(args, keyArgs, true)) {
          if (cachedValue.type === "error") {
            console.log("throwing cached error");
            throw cachedValue.error;
          } else {
            console.log("returning cached value");
            return cachedValue.value;
          }
        }
      }
    } else {
      const newCache = new Map();

      BETH_GLOBAL_RENDER_CACHE.dedupeCache.set(fn, newCache);

      try {
        const functionResult = fn(...args);
        newCache.set(args, { type: "result", value: functionResult });
        return functionResult;
      } catch (error) {
        newCache.set(args, { type: "error", error });
        throw error;
      }
    }
  }) as T;
}

type CachedValue<T> =
  | { type: "result"; value: T }