From c9226aeaafcc43603a2c4c499622dc6daab5afcd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Thu, 11 Aug 2022 12:41:54 +0800
Subject: [PATCH] Show memory stats in debug

---
 cmd/sing-box/debug.go       | 25 +++++++++++++++++++++++++
 cmd/sing-box/debug_linux.go | 25 +++++++++++++++++++++++++
 cmd/sing-box/debug_stub.go  |  7 +++++++
 common/badjson/object.go    |  2 +-
 go.mod                      |  1 +
 go.sum                      |  1 +
 6 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 cmd/sing-box/debug_linux.go
 create mode 100644 cmd/sing-box/debug_stub.go

diff --git a/cmd/sing-box/debug.go b/cmd/sing-box/debug.go
index 5134ff4c..a27fbbcf 100644
--- a/cmd/sing-box/debug.go
+++ b/cmd/sing-box/debug.go
@@ -5,11 +5,36 @@ package main
 import (
 	"net/http"
 	_ "net/http/pprof"
+	"runtime"
 
 	"github.com/sagernet/sing-box/log"
+
+	"github.com/dustin/go-humanize"
+	"runtime/debug"
+	"encoding/json"
+	"github.com/sagernet/sing-box/common/badjson"
 )
 
 func init() {
+	http.HandleFunc("/debug/gc", func(writer http.ResponseWriter, request *http.Request) {
+		writer.WriteHeader(http.StatusNoContent)
+		go debug.FreeOSMemory()
+	})
+	http.HandleFunc("/debug/memory", func(writer http.ResponseWriter, request *http.Request) {
+		var memStats runtime.MemStats
+		runtime.ReadMemStats(&memStats)
+
+		var memObject badjson.JSONObject
+		memObject.Put("heap", humanize.Bytes(memStats.HeapInuse))
+		memObject.Put("stack", humanize.Bytes(memStats.StackInuse))
+		memObject.Put("idle", humanize.Bytes(memStats.HeapIdle-memStats.HeapReleased))
+		memObject.Put("goroutines", runtime.NumGoroutine())
+		memObject.Put("rss", rusageMaxRSS())
+
+		encoder := json.NewEncoder(writer)
+		encoder.SetIndent("", "  ")
+		encoder.Encode(memObject)
+	})
 	go func() {
 		err := http.ListenAndServe("0.0.0.0:8964", nil)
 		if err != nil {
diff --git a/cmd/sing-box/debug_linux.go b/cmd/sing-box/debug_linux.go
new file mode 100644
index 00000000..ecee3295
--- /dev/null
+++ b/cmd/sing-box/debug_linux.go
@@ -0,0 +1,25 @@
+//go:build debug
+
+package main
+
+import (
+	"runtime"
+	"syscall"
+)
+
+func rusageMaxRSS() float64 {
+	ru := syscall.Rusage{}
+	err := syscall.Getrusage(syscall.RUSAGE_SELF, &ru)
+	if err != nil {
+		return 0
+	}
+
+	rss := float64(ru.Maxrss)
+	if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
+		rss /= 1 << 20 // ru_maxrss is bytes on darwin
+	} else {
+		// ru_maxrss is kilobytes elsewhere (linux, openbsd, etc)
+		rss /= 1 << 10
+	}
+	return rss
+}
diff --git a/cmd/sing-box/debug_stub.go b/cmd/sing-box/debug_stub.go
new file mode 100644
index 00000000..5b16a0d4
--- /dev/null
+++ b/cmd/sing-box/debug_stub.go
@@ -0,0 +1,7 @@
+//go:build debug && !linux
+
+package main
+
+func rusageMaxRSS() float64 {
+	return -1
+}
diff --git a/common/badjson/object.go b/common/badjson/object.go
index ca555971..d9c2a36e 100644
--- a/common/badjson/object.go
+++ b/common/badjson/object.go
@@ -13,7 +13,7 @@ type JSONObject struct {
 	linkedhashmap.Map[string, any]
 }
 
-func (m *JSONObject) MarshalJSON() ([]byte, error) {
+func (m JSONObject) MarshalJSON() ([]byte, error) {
 	buffer := new(bytes.Buffer)
 	buffer.WriteString("{")
 	items := m.Entries()
diff --git a/go.mod b/go.mod
index d7002e8b..bb4ea302 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.18
 
 require (
 	github.com/database64128/tfo-go v1.1.0
+	github.com/dustin/go-humanize v1.0.0
 	github.com/fsnotify/fsnotify v1.5.4
 	github.com/go-chi/chi/v5 v5.0.7
 	github.com/go-chi/cors v1.2.1
diff --git a/go.sum b/go.sum
index 1fa83389..0cb2b80c 100644
--- a/go.sum
+++ b/go.sum
@@ -24,6 +24,7 @@ github.com/database64128/tfo-go v1.1.0/go.mod h1:95pOT8bnV3P2Lmu9upHNWFHz6dYGJ9c
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dustin/go-humanize v1.0.0 h1:VSnTsYCnlFHaM2/igO1h6X3HA71jcobQuxemgkq4zYo=
 github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/eycorsican/go-tun2socks v1.16.11 h1:+hJDNgisrYaGEqoSxhdikMgMJ4Ilfwm/IZDrWRrbaH8=
 github.com/eycorsican/go-tun2socks v1.16.11/go.mod h1:wgB2BFT8ZaPKyKOQ/5dljMG/YIow+AIXyq4KBwJ5sGQ=