From d34e5d4b8e4c3d9ab9311d43492fe0bded560ccc Mon Sep 17 00:00:00 2001
From: Anmol Sethi <hi@nhooyr.io>
Date: Fri, 20 Oct 2023 07:47:25 -0700
Subject: [PATCH] wsjson: Add json.Encoder vs json.Marshal benchmark

json.Encoder is 42% faster than json.Marshal thanks to the memory reuse.

goos: linux
goarch: amd64
pkg: nhooyr.io/websocket/wsjson
cpu: 12th Gen Intel(R) Core(TM) i5-1235U
BenchmarkJSON/json.Encoder-12            3517579           340.2 ns/op        24 B/op          1 allocs/op
BenchmarkJSON/json.Marshal-12            2374086           484.3 ns/op       728 B/op          2 allocs/op

Closes #409
---
 wsjson/wsjson_test.go | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 wsjson/wsjson_test.go

diff --git a/wsjson/wsjson_test.go b/wsjson/wsjson_test.go
new file mode 100644
index 00000000..a70e808c
--- /dev/null
+++ b/wsjson/wsjson_test.go
@@ -0,0 +1,24 @@
+package wsjson_test
+
+import (
+	"encoding/json"
+	"io"
+	"strings"
+	"testing"
+)
+
+func BenchmarkJSON(b *testing.B) {
+	msg := []byte(strings.Repeat("1234", 128))
+	b.SetBytes(int64(len(msg)))
+	b.ReportAllocs()
+	b.Run("json.Encoder", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			json.NewEncoder(io.Discard).Encode(msg)
+		}
+	})
+	b.Run("json.Marshal", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			json.Marshal(msg)
+		}
+	})
+}