improve performance of responses

Author: anonrig

packages/open-next/src/core/routing/util.ts

@@ -105,14 +105,11 @@ export function convertRes(res: OpenNextNodeResponse): InternalResult {
   const isBase64Encoded =
     isBinaryContentType(headers["content-type"]) ||
     !!headers["content-encoding"];
-  // We cannot convert the OpenNextNodeResponse to a ReadableStream directly
-  // You can look in the `aws-lambda.ts` file for some context
-  const body = Readable.toWeb(Readable.from(res.getBody()));
   return {
     type: "core",
     statusCode,
     headers,
-    body,
+    body: Readable.from(res._chunks),
     isBase64Encoded,
   };
 }

packages/open-next/src/http/openNextResponse.ts

@@ -39,7 +39,7 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
   }
   writeEarlyHints(
     _hints: Record<string, string | string[]>,
-    _callback?: (() => void) | undefined,
+    _callback?: (() => void) | undefined
   ): void {
     throw new Error(CANNOT_BE_USED);
   }
@@ -61,7 +61,7 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
     throw new Error(CANNOT_BE_USED);
   }
   addTrailers(
-    _headers: OutgoingHttpHeaders | readonly [string, string][],
+    _headers: OutgoingHttpHeaders | readonly [string, string][]
   ): void {
     throw new Error(CANNOT_BE_USED);
   }
@@ -71,7 +71,7 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
     private onEnd: (headers: OutgoingHttpHeaders) => Promise<void>,
     private streamCreator?: StreamCreator,
     private initialHeaders?: OutgoingHttpHeaders,
-    statusCode?: number,
+    statusCode?: number
   ) {
     super();
     // We only set the status code if it is not a NaN and it is a number
@@ -171,7 +171,7 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
               ...this.headers,
             };
       const initialCookies = parseSetCookieHeader(
-        this.initialHeaders[SET_COOKIE_HEADER]?.toString(),
+        this.initialHeaders[SET_COOKIE_HEADER]?.toString()
       );
       this._cookies =
         mergeHeadersPriority === "middleware"
@@ -217,16 +217,16 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
   writeHead(
     statusCode: number,
     statusMessage?: string | undefined,
-    headers?: OutgoingHttpHeaders | OutgoingHttpHeader[] | undefined,
+    headers?: OutgoingHttpHeaders | OutgoingHttpHeader[] | undefined
   ): this;
   writeHead(
     statusCode: number,
-    headers?: OutgoingHttpHeaders | OutgoingHttpHeader[] | undefined,
+    headers?: OutgoingHttpHeaders | OutgoingHttpHeader[] | undefined
   ): this;
   writeHead(
     statusCode: unknown,
     statusMessage?: unknown,
-    headers?: unknown,
+    headers?: unknown
   ): this {
     let _headers = headers as
       | OutgoingHttpHeaders
@@ -282,6 +282,14 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
     return Buffer.concat(this._chunks);
   }
 
+  getBodyLength(): number {
+    let size = 0;
+    for (const chunk of this._chunks) {
+      size += chunk.length;
+    }
+    return size;
+  }
+
   private _internalWrite(chunk: any, encoding: BufferEncoding) {
     this._chunks.push(Buffer.from(chunk, encoding));
     this.push(chunk, encoding);
@@ -291,7 +299,7 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
   _transform(
     chunk: any,
     encoding: BufferEncoding,
-    callback: TransformCallback,
+    callback: TransformCallback
   ): void {
     if (!this.headersSent) {
       this.flushHeaders();
@@ -310,7 +318,7 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
     globalThis.__openNextAls
       ?.getStore()
       ?.pendingPromiseRunner.add(this.onEnd(this.headers));
-    const bodyLength = this.getBody().length;
+    const bodyLength = this.getBodyLength();
     this.streamCreator?.onFinish?.(bodyLength);
 
     //This is only here because of aws broken streaming implementation.
@@ -338,7 +346,7 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
    */
 
   setHeaders(
-    headers: Headers | Map<string, number | string | readonly string[]>,
+    headers: Headers | Map<string, number | string | readonly string[]>
   ): this {
     headers.forEach((value, key) => {
       this.setHeader(key, Array.isArray(value) ? value : value.toString());
@@ -361,13 +369,15 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
     if (values === undefined) return undefined;
 
     return (Array.isArray(values) ? values : [values]).map((value) =>
-      value.toString(),
+      value.toString()
     );
   }
 
   send() {
-    const body = this.getBody();
-    this.end(body);
+    for (const chunk of this._chunks) {
+      this.write(chunk);
+    }
+    this.end();
   }
 
   body(value: string) {