fix: use new host_api implementation for transactional lookups and inserts (#651)

Replaces the Simple Caches use of the direct caching host-calls with a cpp interface provided by host_api.
Also adds a missing CacheHandle::transaction_lookup method and fixes the CacheHandle::lookup to use a non-transactional lookup (which was the bug that causes the SimpleCache API to freeze an application in version 3.2.0 - 3.3.3). Thank you @acfoltzer for hunting this down 🙇

Author: JakeChampion

integration-tests/js-compute/fixtures/cache-simple/bin/index.js

@@ -1561,6 +1561,17 @@ async function simpleCacheEntryInterfaceTests() {
         if (error) { return error }
         return pass()
     });
+    routes.set("/simple-cache/getOrSet/does-not-freeze-when-called-after-a-get", async () => {
+        let key = String(Math.random())
+        SimpleCache.get(key);
+        await SimpleCache.getOrSet(key, async () => {
+            return {
+                value: key,
+                ttl: 10
+            }
+        });
+        return pass()
+    });
 }
 
 

integration-tests/js-compute/fixtures/cache-simple/tests.json

@@ -838,5 +838,15 @@
     "downstream_response": {
       "status": 200
     }
+  },
+  "GET /simple-cache/getOrSet/does-not-freeze-when-called-after-a-get": {
+    "environments": ["c@e"],
+    "downstream_request": {
+      "method": "GET",
+      "pathname": "/simple-cache/getOrSet/does-not-execute-the-set-method-when-key-is-in-cache"
+    },
+    "downstream_response": {
+      "status": 200
+    }
   }
 }

integration-tests/js-compute/test-harness.js

@@ -14,9 +14,9 @@ export let FASTLY_SERVICE_VERSION;
  */
 async function app(event) {
     let res = new Response('Internal Server Error', { status: 500 });
+    const path = (new URL(event.request.url)).pathname
+    console.log(`path: ${path}`)
     try {
-        const path = (new URL(event.request.url)).pathname
-        console.log(`path: ${path}`)
         FASTLY_SERVICE_VERSION = env('FASTLY_SERVICE_VERSION') || 'local'
         console.log(`FASTLY_SERVICE_VERSION: ${FASTLY_SERVICE_VERSION}`)
         if (routes.has(path)) {
@@ -26,7 +26,7 @@ async function app(event) {
             res = fail(`${path} endpoint does not exist`)
         }
     } catch (error) {
-        res = fail(`The routeHandler threw an error: ${error.message || error}` + '\n' + error.stack)
+        res = fail(`The routeHandler for ${path} threw an error: ${error.message || error}` + '\n' + error.stack)
     } finally {
         res.headers.set('fastly_service_version', FASTLY_SERVICE_VERSION);
     }