Hook up the background transpiler.

*Triggers the transpilation process upon server startup and at regular intervals (every 5 minutes).

sequencing-server/src/app.ts

@@ -24,6 +24,10 @@ import getLogger from './utils/logger.js';
 import { commandExpansionRouter } from './routes/command-expansion.js';
 import { seqjsonRouter } from './routes/seqjson.js';
 import { getHasuraSession, canUserPerformAction, ENDPOINTS_WHITELIST } from './utils/hasura.js';
+import type { Result } from '@nasa-jpl/aerie-ts-user-code-runner/build/utils/monads';
+import type { CacheItem, UserCodeError } from '@nasa-jpl/aerie-ts-user-code-runner';
+import { PromiseThrottler } from './utils/PromiseThrottler.js';
+import { backgroundTranspiler } from './backgroundTranspiler.js';
 
 const logger = getLogger('app');
 
@@ -36,8 +40,17 @@ app.use(bodyParser.json({ limit: '100mb' }));
 
 DbExpansion.init();
 export const db = DbExpansion.getDb();
+export let graphqlClient = new GraphQLClient(getEnv().MERLIN_GRAPHQL_URL, {
+  headers: { 'x-hasura-admin-secret': getEnv().HASURA_GRAPHQL_ADMIN_SECRET },
+});
+export const piscina = new Piscina({
+  filename: new URL('worker.js', import.meta.url).pathname,
+  minThreads: parseInt(getEnv().SEQUENCING_WORKER_NUM),
+  resourceLimits: { maxOldGenerationSizeMb: parseInt(getEnv().SEQUENCING_MAX_WORKER_HEAP_MB) },
+});
+export const promiseThrottler = new PromiseThrottler(parseInt(getEnv().SEQUENCING_WORKER_NUM) - 2);
+export const typeCheckingCache = new Map<string, Promise<Result<CacheItem, ReturnType<UserCodeError['toJSON']>[]>>>();
 
-export const piscina = new Piscina({ filename: new URL('worker.js', import.meta.url).pathname });
 const temporalPolyfillTypes = fs.readFileSync(new URL('TemporalPolyfillTypes.ts', import.meta.url).pathname, 'utf-8');
 
 export type Context = {
@@ -52,10 +65,6 @@ export type Context = {
 };
 
 app.use(async (req: Request, res: Response, next: NextFunction) => {
-  const graphqlClient = new GraphQLClient(getEnv().MERLIN_GRAPHQL_URL, {
-    headers: { 'x-hasura-admin-secret': getEnv().HASURA_GRAPHQL_ADMIN_SECRET },
-  });
-
   // Check and make sure the user making the request has the required permissions.
   if (
     !ENDPOINTS_WHITELIST.has(req.url) &&
@@ -234,4 +243,23 @@ app.use((err: any, _: Request, res: Response, next: NextFunction) => {
 
 app.listen(PORT, () => {
   logger.info(`connected to port ${PORT}`);
+  logger.info(`Worker pool initialized:
+              Total workers started: ${piscina.threads.length},
+              Heap Size per Worker: ${getEnv().SEQUENCING_MAX_WORKER_HEAP_MB} MB`);
 });
+
+if (getEnv().TRANSPILER_ENABLED === 'true') {
+  //log that the tranpiler is on
+  logger.info(`Background Transpiler is 'on'`);
+  // Immediately call the background transpiler
+  await backgroundTranspiler();
+  // Then continue calling it every 5 minutes
+  let transpilerInProgress: boolean = false;
+  setInterval(async () => {
+    if (!transpilerInProgress) {
+      transpilerInProgress = true;
+      await backgroundTranspiler();
+      transpilerInProgress = false;
+    }
+  }, 60 * 5 * 1000);
+}