perf(ext/fetch): consume body using ops (#16038)

This commit adds a fast path to `Request` and `Response` that
make consuming request bodies much faster when using `Body#text`,
`Body#arrayBuffer`, and `Body#blob`, if the body is a FastStream.
Because the response bodies for `fetch` are FastStream, this speeds up
consuming `fetch` response bodies significantly.

1 files changed, 19 insertions, 0 deletions

diff --git a/cli/bench/http/deno_post_bin.js b/cli/bench/http/deno_post_bin.js
new file mode 100644
index 000000000..33ffeed1b
--- /dev/null
+++ b/cli/bench/http/deno_post_bin.js
@@ -0,0 +1,19 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+const addr = Deno.args[0] || "127.0.0.1:4500";
+const [hostname, port] = addr.split(":");
+const listener = Deno.listen({ hostname, port: Number(port) });
+console.log("Server listening on", addr);
+
+for await (const conn of listener) {
+  (async () => {
+    const requests = Deno.serveHttp(conn);
+    for await (const { respondWith, request } of requests) {
+      if (request.method == "POST") {
+        const buffer = await request.arrayBuffer();
+        respondWith(new Response(buffer.byteLength))
+          .catch((e) => console.log(e));
+      }
+    }
+  })();
+}