perf: memoize blobs requests in the request scope (#2777)

* test: add test case with multiple fetches for same resource and test asserting we only check blobs once per request for same key

* refactor: create simplified key-value store interface to interact with blobs with common tracing pattern

* refactor: create reusable helper to record warnings

* perf: memoize blobs requests in the request scope

* refactor: rename RequestSpecificInMemoryCache to RequestScopedInMemoryCache

* refactor: modulurize blobs storage abstractions

* chore: fix lint

* refactor: move non-CacheHandler related types and utils from cache-types to blob-types module

* fix: add missing implementation for isTagManifest and isHtmlBlob type guards

* chore: drop use of noOpInMemoryCache

---------

Co-authored-by: Mateusz Bocian <[email protected]>

Author: pieh

.eslintrc.cjs

@@ -72,6 +72,14 @@ module.exports = {
                 message: 'Please use `getTracer()` from `./handlers/tracer.cjs` instead',
               },
             ],
+            patterns: [
+              {
+                // only */storage/storage.cjs is allowed to be imported
+                // rest are implementation details that should not be used directly
+                group: ['*/storage/*', '!*/storage/storage.cjs'],
+                message: 'Import public `[...]/storage/storage.cjs` module instead.',
+              },
+            ],
           },
         ],
       },

package-lock.json

@@ -76,6 +76,7 @@
     "fs-monkey": "^1.0.6",
     "get-port": "^7.1.0",
     "lambda-local": "^2.2.0",
+    "lru-cache": "^10.4.3",
     "memfs": "^4.9.2",
     "mock-require": "^3.0.3",
     "msw": "^2.0.7",

package.json

@@ -6,7 +6,7 @@ import { trace } from '@opentelemetry/api'
 import { wrapTracer } from '@opentelemetry/api/experimental'
 import glob from 'fast-glob'
 
-import type { HtmlBlob } from '../../run/next.cjs'
+import type { HtmlBlob } from '../../shared/blob-types.cjs'
 import { encodeBlobKey } from '../../shared/blobkey.js'
 import { PluginContext } from '../plugin-context.js'
 import { verifyNetlifyForms } from '../verification.js'

src/build/content/static.ts

@@ -5,6 +5,7 @@ import { join, resolve } from 'node:path'
 import type { NextConfigComplete } from 'next/dist/server/config-shared.js'
 
 import { PLUGIN_DIR, RUN_CONFIG } from './constants.js'
+import { setInMemoryCacheMaxSizeFromNextConfig } from './storage/storage.cjs'
 
 /**
  * Get Next.js config from the build output
@@ -13,10 +14,27 @@ export const getRunConfig = async () => {
   return JSON.parse(await readFile(resolve(PLUGIN_DIR, RUN_CONFIG), 'utf-8'))
 }
 
+type NextConfigForMultipleVersions = NextConfigComplete & {
+  experimental: NextConfigComplete['experimental'] & {
+    // those are pre 14.1.0 options that were moved out of experimental in // https://github.com/vercel/next.js/pull/57953/files#diff-c49c4767e6ed8627e6e1b8f96b141ee13246153f5e9142e1da03450c8e81e96fL311
+
+    // https://github.com/vercel/next.js/blob/v14.0.4/packages/next/src/server/config-shared.ts#L182-L183
+    // custom path to a cache handler to use
+    incrementalCacheHandlerPath?: string
+    // https://github.com/vercel/next.js/blob/v14.0.4/packages/next/src/server/config-shared.ts#L207-L212
+    /**
+     * In-memory cache size in bytes.
+     *
+     * If `isrMemoryCacheSize: 0` disables in-memory caching.
+     */
+    isrMemoryCacheSize?: number
+  }
+}
+
 /**
  * Configure the custom cache handler at request time
  */
-export const setRunConfig = (config: NextConfigComplete) => {
+export const setRunConfig = (config: NextConfigForMultipleVersions) => {
   const cacheHandler = join(PLUGIN_DIR, '.netlify/dist/run/handlers/cache.cjs')
   if (!existsSync(cacheHandler)) {
     throw new Error(`Cache handler not found at ${cacheHandler}`)
@@ -25,15 +43,17 @@ export const setRunConfig = (config: NextConfigComplete) => {
   // set the path to the cache handler
   config.experimental = {
     ...config.experimental,
-    // @ts-expect-error incrementalCacheHandlerPath was removed from config type
-    // but we still need to set it for older Next.js versions
+    // Before Next.js 14.1.0 path to the cache handler was in experimental section, see NextConfigForMultipleVersions type
     incrementalCacheHandlerPath: cacheHandler,
   }
 
-  // Next.js 14.1.0 moved the cache handler from experimental to stable
-  // https://github.com/vercel/next.js/pull/57953/files#diff-c49c4767e6ed8627e6e1b8f96b141ee13246153f5e9142e1da03450c8e81e96fL311
+  // Next.js 14.1.0 moved the cache handler from experimental to stable, see NextConfigForMultipleVersions type
   config.cacheHandler = cacheHandler
-  config.cacheMaxMemorySize = 0
+
+  // honor the in-memory cache size from next.config (either one set by user or Next.js default)
+  setInMemoryCacheMaxSizeFromNextConfig(
+    config.cacheMaxMemorySize ?? config.experimental?.isrMemoryCacheSize,
+  )
 
   // set config
   process.env.__NEXT_PRIVATE_STANDALONE_CONFIG = JSON.stringify(config)