reduce buffer copies (#867)

.changeset/strange-cars-itch.md

@@ -0,0 +1,6 @@
+---
+"@smithy/util-body-length-node": patch
+"@smithy/node-http-handler": patch
+---
+
+reduce buffer copies

packages/node-http-handler/src/node-http-handler.spec.ts

@@ -8,9 +8,11 @@ import { NodeHttpHandler } from "./node-http-handler";
 import { ReadFromBuffers } from "./readable.mock";
 import {
   createContinueResponseFunction,
+  createMirrorResponseFunction,
   createMockHttpServer,
   createMockHttpsServer,
   createResponseFunction,
+  getResponseBody,
 } from "./server.mock";
 
 describe("NodeHttpHandler", () => {
@@ -203,36 +205,39 @@ describe("NodeHttpHandler", () => {
       expect(response.body).toBeDefined();
     });
 
-    it("can send requests with bodies", async () => {
-      const body = Buffer.from("test");
-      const mockResponse = {
-        statusCode: 200,
-        headers: {},
-      };
-      mockHttpServer.addListener("request", createResponseFunction(mockResponse));
-      const spy = jest.spyOn(http, "request").mockImplementationOnce(() => {
-        const calls = spy.mock.calls;
-        const currentIndex = calls.length - 1;
-        return http.request(calls[currentIndex][0], calls[currentIndex][1]);
-      });
-
-      const nodeHttpHandler = new NodeHttpHandler();
-      const { response } = await nodeHttpHandler.handle(
-        new HttpRequest({
-          hostname: "localhost",
-          method: "PUT",
-          port: (mockHttpServer.address() as AddressInfo).port,
-          protocol: "http:",
-          path: "/",
+    [
+      { name: "buffer", body: Buffer.from("Buffering🚀") },
+      { name: "uint8Array", body: Uint8Array.from(Buffer.from("uint8Array 🚀")) },
+      { name: "string", body: Buffer.from("string-test 🚀") },
+      { name: "uint8Array subarray", body: Uint8Array.from(Buffer.from("test")).subarray(1, 3) },
+      { name: "buffer subarray", body: Buffer.from("test").subarray(1, 3) },
+    ].forEach(({ body, name }) => {
+      it(`can send requests with bodies ${name}`, async () => {
+        const mockResponse = {
+          statusCode: 200,
           headers: {},
-          body,
-        }),
-        {}
-      );
+        };
+        mockHttpServer.addListener("request", createMirrorResponseFunction(mockResponse));
+        const nodeHttpHandler = new NodeHttpHandler();
+        const { response } = await nodeHttpHandler.handle(
+          new HttpRequest({
+            hostname: "localhost",
+            method: "PUT",
+            port: (mockHttpServer.address() as AddressInfo).port,
+            protocol: "http:",
+            path: "/",
+            headers: {},
+            body,
+          }),
+          {}
+        );
 
-      expect(response.statusCode).toEqual(mockResponse.statusCode);
-      expect(response.headers).toBeDefined();
-      expect(response.headers).toMatchObject(mockResponse.headers);
+        expect(response.statusCode).toEqual(mockResponse.statusCode);
+        expect(response.headers).toBeDefined();
+        expect(response.headers).toMatchObject(mockResponse.headers);
+        const responseBody = await getResponseBody(response);
+        expect(responseBody).toEqual(Buffer.from(body).toString());
+      });
     });
 
     it("can handle expect 100-continue", async () => {

packages/node-http-handler/src/server.mock.ts

@@ -1,4 +1,4 @@
-import { HeaderBag, HttpResponse } from "@smithy/types";
+import { HeaderBag, HttpResponse, NodeJsRuntimeBlobTypes } from "@smithy/types";
 import { readFileSync } from "fs";
 import { createServer as createHttpServer, IncomingMessage, Server as HttpServer, ServerResponse } from "http";
 import { createServer as createHttp2Server, Http2Server } from "http2";
@@ -14,7 +14,7 @@ const setResponseHeaders = (response: ServerResponse, headers: HeaderBag) => {
   }
 };
 
-const setResponseBody = (response: ServerResponse, body: Readable | string) => {
+const setResponseBody = (response: ServerResponse, body: string | NodeJsRuntimeBlobTypes) => {
   if (body instanceof Readable) {
     body.pipe(response);
   } else {
@@ -67,3 +67,38 @@ export const createMockHttp2Server = (): Http2Server => {
   const server = createHttp2Server();
   return server;
 };
+
+export const createMirrorResponseFunction = (httpResp: HttpResponse) => (
+  request: IncomingMessage,
+  response: ServerResponse
+) => {
+  const bufs: Buffer[] = [];
+  request.on("data", (chunk) => {
+    bufs.push(chunk);
+  });
+  request.on("end", () => {
+    response.statusCode = httpResp.statusCode;
+    setResponseHeaders(response, httpResp.headers);
+    setResponseBody(response, Buffer.concat(bufs));
+  });
+  request.on("error", (err) => {
+    response.statusCode = 500;
+    setResponseHeaders(response, httpResp.headers);
+    setResponseBody(response, err.message);
+  });
+};
+
+export const getResponseBody = (response: HttpResponse) => {
+  return new Promise<string>((resolve, reject) => {
+    const bufs: Buffer[] = [];
+    response.body.on("data", function (d: Buffer) {
+      bufs.push(d);
+    });
+    response.body.on("end", function () {
+      resolve(Buffer.concat(bufs).toString());
+    });
+    response.body.on("error", (err: Error) => {
+      reject(err);
+    });
+  });
+};

packages/node-http-handler/src/write-request-body.ts

@@ -58,9 +58,30 @@ function writeBody(
   if (body instanceof Readable) {
     // pipe automatically handles end
     body.pipe(httpRequest);
-  } else if (body) {
-    httpRequest.end(Buffer.from(body as Parameters<typeof Buffer.from>[0]));
-  } else {
-    httpRequest.end();
+    return;
   }
+
+  if (body) {
+    if (Buffer.isBuffer(body) || typeof body === "string") {
+      httpRequest.end(body);
+      return;
+    }
+
+    const uint8 = body as Uint8Array;
+    if (
+      typeof uint8 === "object" &&
+      uint8.buffer &&
+      typeof uint8.byteOffset === "number" &&
+      typeof uint8.byteLength === "number"
+    ) {
+      // this avoids copying the array.
+      httpRequest.end(Buffer.from(uint8.buffer, uint8.byteOffset, uint8.byteLength));
+      return;
+    }
+
+    httpRequest.end(Buffer.from(body as ArrayBuffer));
+    return;
+  }
+
+  httpRequest.end();
 }

packages/util-body-length-node/src/calculateBodyLength.ts

@@ -8,7 +8,7 @@ export const calculateBodyLength = (body: any): number | undefined => {
     return 0;
   }
   if (typeof body === "string") {
-    return Buffer.from(body).length;
+    return Buffer.byteLength(body);
   } else if (typeof body.byteLength === "number") {
     // handles Uint8Array, ArrayBuffer, Buffer, and ArrayBufferView
     return body.byteLength;