Something went wrong. Try again.
[READ-ONLY] Mirror of https://github.com/openstatusHQ/openstatus. 🫖 Status page with uptime monitoring & API monitoring as code 🫖 openstatus.dev
bun drizzle-orm monitoring monitoring-as-code nextjs observability on-call open-source shadcn-ui status-page statuspage synthetic-monitoring tinybird turso uptime uptime-checker uptime-monitor
Something went wrong. Try again.
3.1 kB · 93 lines
TypeScript
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394import { parseCacheControlHeader } from "../parser/cache-control";import { getHeader } from "./get-header";
export const CACHE_STATUSES = [ "HIT", "MISS", "EXPIRED", "STALE", "BYPASS", "DYNAMIC", "UNKNOWN",] as const;
export type CacheStatus = (typeof CACHE_STATUSES)[number];
export interface NormalizedCacheStatus { status: CacheStatus; /** original header value, e.g. "Hit from cloudfront" */ raw: string | null; /** header name that determined the status, e.g. "cf-cache-status" */ source: string | null;}
function fromToken(value: string): CacheStatus | null { const token = value.toUpperCase(); // order matters: "REFRESH_HIT" and "EXPIRED_MISS" must not match plain HIT/MISS if (token.includes("STALE")) return "STALE"; if (token.includes("UPDATING")) return "STALE"; if (token.includes("EXPIRED")) return "EXPIRED"; if (token.includes("REFRESH")) return "EXPIRED"; if (token.includes("REVALIDATED")) return "HIT"; if (token.includes("PRERENDER")) return "HIT"; if (token.includes("BYPASS")) return "BYPASS"; if (token.includes("DYNAMIC")) return "DYNAMIC"; if (token.includes("HIT")) return "HIT"; if (token.includes("MISS")) return "MISS"; if (token.includes("PASS")) return "BYPASS"; return null;}
// RFC 9211 lists the cache closest to the user last.function fromCacheStatusHeader(value: string): CacheStatus | null { // Quoted strings can contain commas and text that resembles parameters. const unquoted = value.replace(/"(?:[^"\\]|\\.)*"/g, '""'); const lower = unquoted.slice(unquoted.lastIndexOf(",") + 1).toLowerCase(); if (/;\s*hit/.test(lower)) return "HIT"; const fwd = lower.match(/fwd=([a-z-]+)/)?.[1]; if (!fwd) return null; if (fwd === "bypass") return "BYPASS"; if (fwd === "stale") return "EXPIRED"; return "MISS";}
const VENDOR_HEADERS = [ "cf-cache-status", "x-vercel-cache", "cache-status", "x-cache", "x-cache-status", "cdn-cache", "x-cache-lookup",] as const;
export function normalizeCacheStatus( headers: Record<string, string>,): NormalizedCacheStatus { for (const name of VENDOR_HEADERS) { const value = getHeader(headers, name); if (!value) continue; const status = name === "cache-status" ? fromCacheStatusHeader(value) : fromToken(value); if (status) return { status, raw: value, source: name }; }
// no vendor header: infer from standard caching headers const age = getHeader(headers, "age"); const cacheControl = getHeader(headers, "cache-control");
if (cacheControl) { const directives = parseCacheControlHeader(cacheControl); // directive names are case-insensitive per RFC 9111 const has = (name: string) => directives.some((d) => d.name.toLowerCase() === name); if (has("no-store") || has("private")) { return { status: "DYNAMIC", raw: cacheControl, source: "cache-control" }; } if (age && Number.parseInt(age, 10) > 0) { return { status: "HIT", raw: age, source: "age" }; } }
return { status: "UNKNOWN", raw: null, source: null };}