feat: introduce new option requestsPerForcedGC

Author: usualoma

src/listener.ts

@@ -203,9 +203,14 @@ export const getRequestListener = (
     errorHandler?: CustomErrorHandler
     overrideGlobalObjects?: boolean
     autoCleanupIncoming?: boolean
+    requestsPerForcedGC?: number
   } = {}
 ) => {
   const autoCleanupIncoming = options.autoCleanupIncoming ?? true
+  const requestsPerForcedGC = options.requestsPerForcedGC ?? 0
+  let requestCount = 0
+  const gc = global.gc as () => void
+
   if (options.overrideGlobalObjects !== false && global.Request !== LightweightRequest) {
     Object.defineProperty(global, 'Request', {
       value: LightweightRequest,
@@ -214,6 +219,9 @@ export const getRequestListener = (
       value: LightweightResponse,
     })
   }
+  if (requestsPerForcedGC && !gc) {
+    throw new Error('`global.gc` is not available. Please run node with `--expose-gc` flag.')
+  }
 
   return async (
     incoming: IncomingMessage | Http2ServerRequest,
@@ -281,6 +289,14 @@ export const getRequestListener = (
             }
           })
         }
+
+        if (requestsPerForcedGC) {
+          requestCount++
+          if (requestCount >= requestsPerForcedGC) {
+            gc()
+            requestCount = 0
+          }
+        }
       })
 
       res = fetchCallback(req, { incoming, outgoing } as HttpBindings) as

src/server.ts

@@ -9,6 +9,7 @@ export const createAdaptorServer = (options: Options): ServerType => {
     hostname: options.hostname,
     overrideGlobalObjects: options.overrideGlobalObjects,
     autoCleanupIncoming: options.autoCleanupIncoming,
+    requestsPerForcedGC: options.requestsPerForcedGC,
   })
   // ts will complain about createServerHTTP and createServerHTTP2 not being callable, which works just fine
   // eslint-disable-next-line @typescript-eslint/no-explicit-any

src/types.ts

@@ -71,6 +71,7 @@ export type Options = {
   fetch: FetchCallback
   overrideGlobalObjects?: boolean
   autoCleanupIncoming?: boolean
+  requestsPerForcedGC?: number
   port?: number
   hostname?: string
 } & ServerOptions