Cache public pages by canonical revision

Author: chubes4

packages/runtime-cloudflare/src/worker.ts

@@ -212,6 +212,12 @@ async function runCoordinatedWordPressRequest(request: Request, env: Env, coordi
       if (!lease.pointer || lease.pointer.revision !== bootstrapped.pointer.revision) throw new Error("Canonical bootstrap promotion was not observed by its next lease.")
       cacheRuntime(lease.pointer, bootstrapped)
     }
+    const cachedPage = route === "wordpress" ? await matchWordPressPageCache(request, lease.pointer) : null
+    if (cachedPage) {
+      await releaseLease(coordinator, request.url, lease)
+      finalized = true
+      return cachedPage
+    }
     runtime = await getRuntime(env, lease.pointer, new URL(request.url).origin)
     const mutatesCanonicalState = isMutation(request, route)
     let response: Response
@@ -236,6 +242,7 @@ async function runCoordinatedWordPressRequest(request: Request, env: Env, coordi
     }
     finalized = true
     if (mutatesCanonicalState) await discardRuntime(runtime)
+    else if (route === "wordpress") response = await cacheWordPressPage(request, lease.pointer, response)
     return response
   } catch (error) {
     if (!finalized) await abortLease(coordinator, request.url, lease)
@@ -244,6 +251,54 @@ async function runCoordinatedWordPressRequest(request: Request, env: Env, coordi
   }
 }
 
+function isCacheableWordPressPageRequest(request: Request): boolean {
+  if (request.method !== "GET" && request.method !== "HEAD") return false
+  if (request.headers.has("authorization") || request.headers.has("cookie")) return false
+  const url = new URL(request.url)
+  if (["/wp-admin", "/wp-login.php", "/wp-json"].some((path) => url.pathname === path || url.pathname.startsWith(`${path}/`))) return false
+  return !url.searchParams.has("preview") && !url.searchParams.has("rest_route")
+}
+
+async function matchWordPressPageCache(request: Request, pointer: MarkdownPointer): Promise<Response | null> {
+  if (!isCacheableWordPressPageRequest(request)) return null
+  const cache = typeof caches === "undefined" ? undefined : (caches as CacheStorage & { default?: Cache }).default
+  if (!cache) return null
+  try {
+    const cached = await cache.match(wordPressPageCacheKey(request, pointer))
+    return cached ? pageCacheResponse(cached, request.method === "HEAD", "hit") : null
+  } catch {
+    return null
+  }
+}
+
+async function cacheWordPressPage(request: Request, pointer: MarkdownPointer, response: Response): Promise<Response> {
+  if (!isCacheableWordPressPageRequest(request) || response.status !== 200 || !response.headers.get("content-type")?.includes("text/html") || response.headers.has("set-cookie")) return response
+  if (request.method === "HEAD") return pageCacheResponse(response, true, "miss")
+  const cache = typeof caches === "undefined" ? undefined : (caches as CacheStorage & { default?: Cache }).default
+  const cacheable = pageCacheResponse(response, false, "miss")
+  if (cache) {
+    try {
+      await cache.put(wordPressPageCacheKey(request, pointer), cacheable.clone())
+    } catch {
+      // Page caching is an optimization; canonical rendering remains authoritative.
+    }
+  }
+  return cacheable
+}
+
+function wordPressPageCacheKey(request: Request, pointer: MarkdownPointer): Request {
+  const url = new URL(request.url)
+  url.searchParams.set("__wp_codebox_revision", pointer.revision)
+  return new Request(url, { method: "GET" })
+}
+
+function pageCacheResponse(response: Response, head: boolean, status: "hit" | "miss"): Response {
+  const headers = new Headers(response.headers)
+  headers.set("cache-control", "public, max-age=60, s-maxage=31536000")
+  headers.set("x-wp-codebox-page-cache", status)
+  return new Response(head ? null : response.body, { status: response.status, statusText: response.statusText, headers })
+}
+
 function isMutation(request: Request, route: "wordpress" | "health" | "r2-mutate"): boolean {
   return route === "r2-mutate" || !["GET", "HEAD", "OPTIONS"].includes(request.method)
 }

scripts/cloudflare-local-gate.mjs

@@ -21,8 +21,8 @@ try {
   const coldHome = await timedWordPressPage(origin, "cold explanatory homepage")
   const warmHome = await timedWordPressPage(origin, "warm explanatory homepage")
   await assertExplanatoryHomepage(warmHome.body)
-  if (warmHome.elapsedMs >= coldHome.elapsedMs || warmHome.elapsedMs > 2_000) {
-    throw new Error(`Warm explanatory homepage did not reuse the canonical runtime: cold=${coldHome.elapsedMs}ms warm=${warmHome.elapsedMs}ms.`)
+  if (coldHome.cacheStatus !== "miss" || warmHome.cacheStatus !== "hit" || warmHome.elapsedMs >= coldHome.elapsedMs || warmHome.elapsedMs > 500) {
+    throw new Error(`Warm explanatory homepage did not use its revision cache: cold=${coldHome.elapsedMs}ms/${coldHome.cacheStatus} warm=${warmHome.elapsedMs}ms/${warmHome.cacheStatus}.`)
   }
   console.log(`Explanatory homepage timing: cold=${coldHome.elapsedMs}ms warm=${warmHome.elapsedMs}ms.`)
   const adminHtml = await login()
@@ -44,7 +44,7 @@ try {
   await assertLinkedAssets(restartedAdmin, "admin after cold restart")
   cookies.length = 0
   await login()
-  console.log("Cloudflare local runtime gate passed: explanatory homepage, complete block styles, warm runtime reuse, login, dashboard, post editor, concurrent canonical mutations, authenticated REST post creation, frontend/admin/editor assets, and cold-restart session persistence.")
+  console.log("Cloudflare local runtime gate passed: explanatory homepage, complete block styles, revision page cache, login, dashboard, post editor, concurrent canonical mutations, authenticated REST post creation, frontend/admin/editor assets, and cold-restart session persistence.")
 } finally {
   await stopWorker()
   await rm(stateDirectory, { recursive: true, force: true })
@@ -164,8 +164,11 @@ async function assertWordPressPage(target, label) {
 
 async function timedWordPressPage(target, label) {
   const startedAt = performance.now()
-  const body = await assertWordPressPage(target, label)
-  return { body, elapsedMs: Math.round(performance.now() - startedAt) }
+  const response = await request(target)
+  const body = await response.text()
+  assertNoPhpDiagnostics(body, label)
+  if (response.status !== 200 || !response.headers.get("content-type")?.includes("text/html") || !/<html[\s>]/i.test(body)) throw new Error(`Expected an HTML ${label}, received ${response.status}: ${body}`)
+  return { body, elapsedMs: Math.round(performance.now() - startedAt), cacheStatus: response.headers.get("x-wp-codebox-page-cache") }
 }
 
 async function assertExplanatoryHomepage(html) {

tests/cloudflare-runtime.test.ts

@@ -250,6 +250,11 @@ test("Cloudflare keeps PHP-WASM in the entry Worker and uses the Durable Object
   assert.match(worker, /"x-wp-codebox-static": "wordpress-archive"/)
   assert.match(worker, /cache\.match\(request\)/)
   assert.match(worker, /cache\.put\(request, response\.clone\(\)\)/)
+  assert.match(worker, /matchWordPressPageCache\(request, lease\.pointer\)/)
+  assert.match(worker, /cacheWordPressPage\(request, lease\.pointer, response\)/)
+  assert.match(worker, /__wp_codebox_revision/)
+  assert.match(worker, /"x-wp-codebox-page-cache"/)
+  assert.match(worker, /"public, max-age=60, s-maxage=31536000"/)
   assert.match(materializer, /materializeWordPressRuntimeArtifact\(php, bucket, wordpressRuntimeArtifactManifest/)
   assert.doesNotMatch(materializer, /decodeRemoteZip\(WORDPRESS_ARCHIVE_URL/)
   assert.match(corpus, /path\.endsWith\("\.map"\)/)