[nfc] kj::HttpHeaders parse simple benchmark

src/workerd/tests/BUILD.bazel

@@ -8,7 +8,7 @@ wd_cc_library(
     visibility = ["//visibility:public"],
     deps = [
         "@capnp-cpp//src/kj:kj-test",
-         "@com_google_benchmark//:benchmark",
+        "@com_google_benchmark//:benchmark",
     ],
 )
 
@@ -34,8 +34,8 @@ wd_cc_benchmark(
     name = "bench-json",
     srcs = ["bench-json.c++"],
     deps = [
-        "@capnp-cpp//src/kj",
         "//src/workerd/api:r2-api_capnp",
+        "@capnp-cpp//src/kj",
     ],
 )
 
@@ -46,3 +46,11 @@ wd_cc_benchmark(
         "//src/workerd/util",
     ],
 )
+
+wd_cc_benchmark(
+    name = "bench-headers",
+    srcs = ["bench-headers.c++"],
+    deps = [
+        "@capnp-cpp//src/kj/compat:kj-http",
+    ],
+)

src/workerd/tests/bench-headers.c++

@@ -0,0 +1,46 @@
+// Copyright (c) 2023 Cloudflare, Inc.
+// Licensed under the Apache 2.0 license found in the LICENSE file or at:
+//     https://opensource.org/licenses/Apache-2.0
+
+#include <workerd/tests/bench-tools.h>
+#include <kj/compat/http.h>
+
+namespace workerd {
+namespace {
+
+struct Fixture: public benchmark::Fixture {
+  virtual ~Fixture() noexcept(true) {}
+
+  void SetUp(benchmark::State& state) noexcept(true) override {
+    kj::HttpHeaderTable::Builder builder;
+    builder.add("Host");
+    builder.add("Accept");
+    builder.add("Content-Type");
+    builder.add("Last-Modified");
+    table = builder.build();
+  }
+
+  kj::Own<kj::HttpHeaderTable> table;
+};
+
+BENCHMARK_F(Fixture, Parse)(benchmark::State& state) {
+  for (auto _ : state) {
+    kj::HttpHeaders headers(*table);
+
+    auto in = kj::heapString(
+          "GET /favicon.ico HTTP/1.1\r\n"
+          "Host: 0.0.0.0=5000\r\n"
+          "User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9) Gecko/2008061015 Firefox/3.0\r\n"
+          "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n"
+          "Accept-Language: en-us,en;q=0.5\r\n"
+          "Accept-Encoding: gzip,deflate\r\n"
+          "Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7\r\n"
+          "Keep-Alive: 300\r\n"
+          "Connection: keep-alive\r\n"
+          "\r\n");
+    KJ_EXPECT(headers.tryParseRequest(in.asArray()).is<kj::HttpHeaders::Request>());
+  }
+}
+
+} // namespace
+} // namespace workerd