2 files changed, 32 insertions, 2 deletions
diff --git a/ext/node/polyfills/internal/stream_base_commons.ts b/ext/node/polyfills/internal/stream_base_commons.ts
index d7acf729d..01da0c5e3 100644
--- a/ext/node/polyfills/internal/stream_base_commons.ts
+++ b/ext/node/polyfills/internal/stream_base_commons.ts
@@ -253,7 +253,9 @@ export function onStreamRead(
       }
     } else {
       const offset = streamBaseState[kArrayBufferOffset];
-      const buf = Buffer.from(arrayBuffer, offset, nread);
+      // Performance note: Pass ArrayBuffer to Buffer#from to avoid
+      // copy.
+      const buf = Buffer.from(arrayBuffer.buffer, offset, nread);
       result = stream.push(buf);
     }
 
diff --git a/ext/node/polyfills/internal_binding/stream_wrap.ts b/ext/node/polyfills/internal_binding/stream_wrap.ts
index 27870b20b..95f60fe95 100644
--- a/ext/node/polyfills/internal_binding/stream_wrap.ts
+++ b/ext/node/polyfills/internal_binding/stream_wrap.ts
@@ -40,6 +40,9 @@ import {
 } from "ext:deno_node/internal_binding/async_wrap.ts";
 import { codeMap } from "ext:deno_node/internal_binding/uv.ts";
 
+const core = globalThis.Deno.core;
+const { ops } = core;
+
 interface Reader {
   read(p: Uint8Array): Promise<number | null>;
 }
@@ -54,7 +57,7 @@ export interface Closer {
 
 type Ref = { ref(): void; unref(): void };
 
-enum StreamBaseStateFields {
+const enum StreamBaseStateFields {
   kReadBytesOrError,
   kArrayBufferOffset,
   kBytesWritten,
@@ -195,6 +198,31 @@ export class LibuvStreamWrap extends HandleWrap {
     chunks: Buffer[] | (string | Buffer)[],
     allBuffers: boolean,
   ): number {
+    const supportsWritev = this.provider === providerType.TCPSERVERWRAP;
+    // Fast case optimization: two chunks, and all buffers.
+    if (chunks.length === 2 && allBuffers && supportsWritev) {
+      // String chunks.
+      if (typeof chunks[0] === "string") chunks[0] = Buffer.from(chunks[0]);
+      if (typeof chunks[1] === "string") chunks[1] = Buffer.from(chunks[1]);
+
+      ops.op_raw_write_vectored(
+        this[kStreamBaseField]!.rid,
+        chunks[0],
+        chunks[1],
+      ).then((nwritten) => {
+        try {
+          req.oncomplete(0);
+        } catch {
+          // swallow callback errors.
+        }
+
+        streamBaseState[kBytesWritten] = nwritten;
+        this.bytesWritten += nwritten;
+      });
+
+      return 0;
+    }
+
     const count = allBuffers ? chunks.length : chunks.length >> 1;
     const buffers: Buffer[] = new Array(count);