Function makeFlushLock

packages/cloudflare/src/flush.ts:51–81

(context: ExecutionContext)

 * @return {FlushLock} Returns a flusher function if a valid context is provided, otherwise undefined.
 */
export function makeFlushLock(context: ExecutionContext): FlushLock {
  const registry = getOrCreateFlushLockRegistry(context);
  let resolveAllDone: () => void = () => undefined;
  const allDone = new Promise<void>(res => {
    resolveAllDone = res;
  });
  let pending = 0;

  const lock: FlushLockInternal = {
    ready: allDone,
    acquire: () => {
      pending++;
    },
    release: () => {
      if (--pending === 0) {
        registry.locks.delete(lock);
        resolveAllDone();
      }
    },
    finalize: () => {
      if (pending === 0) {
        registry.locks.delete(lock);
        resolveAllDone();
      }
      return allDone;
    },
  };

  registry.locks.add(lock);
  return Object.freeze(lock);
}

function getOrCreateFlushLockRegistry(context: ExecutionContext): FlushLockRegistry {
  // eslint-disable-next-line @typescript-eslint/unbound-method