feat: WIP kittens

apps/gateway/src/lib/fetch-cache.ts

@@ -11,8 +11,8 @@ export async function fetchCache(
     cacheKey?: string
     fetchResponse: () => Promise<Response>
   }
-) {
-  let response
+): Promise<Response> {
+  let response: Response | undefined
 
   if (cacheKey) {
     response = await cache.match(cacheKey)

apps/gateway/src/lib/get-request-cache-key.ts

@@ -0,0 +1,100 @@
+import contentType from 'content-type'
+import stableJsonStringify from 'fast-json-stable-stringify'
+
+import { normalizeUrl } from './normalize-url'
+import * as sha256 from './sha256'
+
+export async function getFaasRequestCacheKey(request) {
+  try {
+    const pragma = request.headers.get('pragma')
+    if (pragma === 'no-cache') {
+      return null
+    }
+
+    const cacheControl = request.headers.get('cache-control')
+    if (cacheControl) {
+      const directives = new Set(cacheControl.split(',').map((s) => s.trim()))
+      if (directives.has('no-store') || directives.has('no-cache')) {
+        return null
+      }
+    }
+
+    if (request.method === 'POST' || request.method === 'PUT') {
+      // useful for debugging since getting all the headers is awkward
+      // console.log(Object.fromEntries(request.headers.entries()))
+
+      const contentLength = parseInt(request.headers.get('content-length'))
+
+      // TODO: what is a reasonable upper bound for hashing the POST body size?
+      if (contentLength && contentLength < 10000) {
+        const ct = contentType.parse(
+          request.headers.get('content-type') || 'application/octet-stream'
+        )
+        const type = ct && ct.type
+        let hash
+
+        // TODO: gracefully handle content-encoding compression
+        // TODO: more robust content-type detection
+
+        if (type && type.indexOf('json') >= 0) {
+          const bodyJson = await request.clone().json()
+          const bodyString = stableJsonStringify(bodyJson)
+          hash = await sha256.fromString(bodyString)
+        } else if (type && type.indexOf('text/') >= 0) {
+          const bodyString = await request.clone().text()
+          hash = await sha256.fromString(bodyString)
+        } else {
+          const bodyBuffer = await request.clone().arrayBuffer()
+          hash = await sha256.fromBuffer(bodyBuffer)
+        }
+
+        const cacheUrl = new URL(request.url)
+        cacheUrl.pathname = cacheUrl.pathname + '/' + hash
+
+        const normalizedUrl = normalizeUrl(cacheUrl.toString())
+
+        const newReq = normalizeRequestHeaders(
+          new Request(normalizedUrl, {
+            headers: request.headers,
+            method: 'GET'
+          })
+        )
+
+        return newReq
+      }
+
+      return null
+    } else if (request.method === 'GET' || request.method === 'HEAD') {
+      const url = request.url
+      const normalizedUrl = normalizeUrl(url)
+
+      if (url !== normalizedUrl) {
+        return normalizeRequestHeaders(
+          new Request(normalizedUrl, {
+            method: request.method
+          })
+        )
+      }
+    }
+
+    return normalizeRequestHeaders(new Request(request))
+  } catch (err) {
+    console.error('error computing cache key', request.method, request.url, err)
+    return null
+  }
+}
+
+const requestHeaderWhitelist = new Set(['cache-control'])
+
+function normalizeRequestHeaders(request) {
+  const headers = Object.fromEntries(request.headers.entries())
+  const keys = Object.keys(headers)
+
+  for (const key of keys) {
+    if (!requestHeaderWhitelist.has(key)) {
+      request.headers.delete(key)
+    }
+  }
+
+  return request
+}

packages/core/src/__snapshots__/utils.test.ts.snap

@@ -0,0 +1,3 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`sha256 1`] = `"9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"`;

packages/core/src/utils.test.ts

@@ -1,6 +1,6 @@
 import { expect, test } from 'vitest'
 
-import { omit, pick } from './utils'
+import { omit, pick, sha256 } from './utils'
 
 test('pick', () => {
   expect(pick({ a: 1, b: 2, c: 3 }, 'a', 'c')).toEqual({ a: 1, c: 3 })
@@ -17,3 +17,24 @@ test('omit', () => {
   })
   expect(omit({ a: 1, b: 2, c: 3 }, 'foo', 'bar', 'c')).toEqual({ a: 1, b: 2 })
 })
+
+test('sha256', async () => {
+  // Test default behavior (random UUID)
+  const hash1 = await sha256()
+  const hash2 = await sha256()
+  expect(hash1).toHaveLength(64) // SHA-256 produces 64 character hex string
+  expect(hash2).toHaveLength(64)
+  expect(hash1).not.toBe(hash2) // Different UUIDs should produce different hashes
+
+  const hash3 = await sha256('foo')
+  const hash4 = await sha256('foo')
+  expect(hash3).toBe(hash4) // Same input should produce the same hash
+
+  const hash5 = await sha256('foo1')
+  expect(hash1).not.toBe(hash5)
+  expect(hash2).not.toBe(hash5)
+  expect(hash3).not.toBe(hash5)
+  expect(hash4).not.toBe(hash5)
+
+  expect(await sha256('test')).toMatchSnapshot()
+})

packages/core/src/utils.ts

@@ -1,5 +1,3 @@
-import { createHash, randomUUID } from 'node:crypto'
-
 import type { ContentfulStatusCode } from 'hono/utils/http-status'
 import type { ZodSchema, ZodTypeDef } from 'zod'
 import hashObjectImpl, { type Options as HashObjectOptions } from 'hash-object'
@@ -99,8 +97,19 @@ export function parseZodSchema<
   }
 }
 
-export function sha256(input: string = randomUUID()) {
-  return createHash('sha256').update(input).digest('hex')
+// import { createHash, randomUUID } from 'node:crypto'
+// export function sha256Node(input: string = randomUUID()) {
+//   return createHash('sha256').update(input).digest('hex')
+// }
+
+export async function sha256(input: string = crypto.randomUUID()) {
+  const textBuffer = new TextEncoder().encode(input)
+  const hashBuffer = await crypto.subtle.digest('SHA-256', textBuffer)
+  const hashArray = Array.from(new Uint8Array(hashBuffer))
+  const hashHex = hashArray
+    .map((b) => ('00' + b.toString(16)).slice(-2))
+    .join('')
+  return hashHex
 }
 
 /**

packages/core/tsconfig.json

@@ -1,5 +1,8 @@
 {
   "extends": "@fisch0920/config/tsconfig-node",
+  "compilerOptions": {
+    "lib": ["ES2022"]
+  },
   "include": ["src", "*.config.ts"],
   "exclude": ["node_modules"]
 }

packages/openapi-utils/src/utils.ts

@@ -21,6 +21,7 @@ export function mergeJsonSchemaObjects(
     label: string
   }
 ) {
+  // TODO: Support cookie parameters
   assert(
     source !== 'cookie',
     'Cookie parameters for OpenAPI operations are not yet supported. If you need cookie parameter support, please contact support@agentic.so.'