Add debug http server

debug_http.go

@@ -0,0 +1,67 @@
+package box
+
+import (
+	"net/http"
+	"net/http/pprof"
+	"runtime"
+	"runtime/debug"
+
+	"github.com/sagernet/sing-box/common/badjson"
+	"github.com/sagernet/sing-box/common/json"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+
+	"github.com/dustin/go-humanize"
+	"github.com/go-chi/chi/v5"
+)
+
+var debugHTTPServer *http.Server
+
+func applyDebugListenOption(options option.DebugOptions) {
+	if debugHTTPServer != nil {
+		debugHTTPServer.Close()
+		debugHTTPServer = nil
+	}
+	if options.Listen == "" {
+		return
+	}
+	r := chi.NewMux()
+	r.Route("/debug", func(r chi.Router) {
+		r.Get("/gc", func(writer http.ResponseWriter, request *http.Request) {
+			writer.WriteHeader(http.StatusNoContent)
+			go debug.FreeOSMemory()
+		})
+		r.Get("/memory", func(writer http.ResponseWriter, request *http.Request) {
+			var memStats runtime.MemStats
+			runtime.ReadMemStats(&memStats)
+
+			var memObject badjson.JSONObject
+			memObject.Put("heap", humanize.IBytes(memStats.HeapInuse))
+			memObject.Put("stack", humanize.IBytes(memStats.StackInuse))
+			memObject.Put("idle", humanize.IBytes(memStats.HeapIdle-memStats.HeapReleased))
+			memObject.Put("goroutines", runtime.NumGoroutine())
+			memObject.Put("rss", rusageMaxRSS())
+
+			encoder := json.NewEncoder(writer)
+			encoder.SetIndent("", "  ")
+			encoder.Encode(memObject)
+		})
+		r.HandleFunc("/pprof", pprof.Index)
+		r.HandleFunc("/pprof/*", pprof.Index)
+		r.HandleFunc("/pprof/cmdline", pprof.Cmdline)
+		r.HandleFunc("/pprof/profile", pprof.Profile)
+		r.HandleFunc("/pprof/symbol", pprof.Symbol)
+		r.HandleFunc("/pprof/trace", pprof.Trace)
+	})
+	debugHTTPServer = &http.Server{
+		Addr:    options.Listen,
+		Handler: r,
+	}
+	go func() {
+		err := debugHTTPServer.ListenAndServe()
+		if err != nil && !E.IsClosed(err) {
+			log.Error(E.Cause(err, "serve debug HTTP server"))
+		}
+	}()
+}