Refactor expvar

cmd/daze/main.go

@@ -1,8 +1,6 @@
 package main
 
 import (
-	"encoding/json"
-	"expvar"
 	"flag"
 	"fmt"
 	"log"
@@ -16,6 +14,7 @@ import (
 
 	"github.com/libraries/daze"
 	"github.com/libraries/daze/lib/doa"
+	"github.com/libraries/daze/lib/expvpp"
 	"github.com/libraries/daze/lib/gracefulexit"
 	"github.com/libraries/daze/lib/rate"
 	"github.com/libraries/daze/protocol/ashe"
@@ -63,31 +62,6 @@ func main() {
 	if os.Getenv("ANDROID_ROOT") != "" {
 		net.DefaultResolver = daze.ResolverDns(daze.ResolverPublic.Cloudflare.Dns)
 	}
-	// Remove cmdline and memstats from expvar default exports.
-	// See: https://github.com/golang/go/issues/29105
-	muxHttp := http.NewServeMux()
-	muxHttp.HandleFunc("/debug/vars", func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json; charset=utf-8")
-		vars := new(expvar.Map).Init()
-		expvar.Do(func(kv expvar.KeyValue) {
-			vars.Set(kv.Key, kv.Value)
-		})
-		vars.Delete("cmdline")
-		vars.Delete("memstats")
-		msg := map[string]any{}
-		err := json.Unmarshal([]byte(vars.String()), &msg)
-		if err != nil {
-			w.WriteHeader(http.StatusBadRequest)
-			w.Write([]byte(err.Error()))
-			return
-		}
-		enc := json.NewEncoder(w)
-		enc.SetIndent("", "    ")
-		enc.Encode(msg)
-	})
-	muxHttp.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		http.DefaultServeMux.ServeHTTP(w, r)
-	})
 	resExec := filepath.Dir(doa.Try(os.Executable()))
 	subCommand := os.Args[1]
 	os.Args = os.Args[1:len(os.Args)]
@@ -148,7 +122,7 @@ func main() {
 		if *flGpprof != "" {
 			_ = pprof.Handler
 			log.Println("main: listen net/http/pprof on", *flGpprof)
-			go func() { doa.Nil(http.ListenAndServe(*flGpprof, muxHttp)) }()
+			go func() { doa.Nil(http.ListenAndServe(*flGpprof, expvpp.ServeMux())) }()
 		}
 		// Hang prevent program from exiting.
 		gracefulexit.Wait()
@@ -226,7 +200,7 @@ func main() {
 		if *flGpprof != "" {
 			_ = pprof.Handler
 			log.Println("main: listen net/http/pprof on", *flGpprof)
-			go func() { doa.Nil(http.ListenAndServe(*flGpprof, muxHttp)) }()
+			go func() { doa.Nil(http.ListenAndServe(*flGpprof, expvpp.ServeMux())) }()
 		}
 		// Hang prevent program from exiting.
 		gracefulexit.Wait()

daze.go

@@ -28,6 +28,7 @@ import (
 	"time"
 
 	"github.com/libraries/daze/lib/doa"
+	"github.com/libraries/daze/lib/expvpp"
 	"github.com/libraries/daze/lib/lru"
 	"github.com/libraries/daze/lib/pretty"
 	"github.com/libraries/daze/lib/rate"
@@ -66,15 +67,15 @@ var Conf = struct {
 var Expv = struct {
 	RouterCacheCall *expvar.Int
 	RouterCacheHits *expvar.Int
-	RouterCacheRate expvar.Func
+	RouterCacheRate *expvar.Func
 	RouterIPNetCall *expvar.Int
-	RouterIPNetTime *ExpvarAverage
+	RouterIPNetTime *expvpp.ExpvarAverage
 }{
 	RouterCacheCall: expvar.NewInt("RouterCache.Call"),
 	RouterCacheHits: expvar.NewInt("RouterCache.Hits"),
-	RouterCacheRate: NewExpvarPercent("RouterCache.Rate", "RouterCache.Hits", "RouterCache.Call"),
+	RouterCacheRate: expvpp.NewExpvarPercent("RouterCache.Rate", "RouterCache.Hits", "RouterCache.Call"),
 	RouterIPNetCall: expvar.NewInt("RouterIPNet.Call"),
-	RouterIPNetTime: NewExpvarAverage("RouterIPNet.Time", 64),
+	RouterIPNetTime: expvpp.NewExpvarAverage("RouterIPNet.Time", 64),
 }
 
 // ResolverDns returns a DNS resolver.
@@ -1059,37 +1060,6 @@ func Dial(network string, address string) (net.Conn, error) {
 	return d.Dial(network, address)
 }
 
-// ExpvarAverage is a structure to maintain a running average using expvar.Float.
-type ExpvarAverage struct {
-	F *expvar.Float
-	L float64
-}
-
-// Adds a new value to the running average. This is not strictly concurrency-safe, but it won't have much impact on the
-// data.
-func (e *ExpvarAverage) Add(value float64) {
-	e.F.Add((value - e.F.Value()) / e.L)
-}
-
-// NewExpvarAverage creates and initializes a new ExpvarAverage instance.
-func NewExpvarAverage(name string, length int) *ExpvarAverage {
-	return &ExpvarAverage{
-		F: expvar.NewFloat(name),
-		L: float64(length),
-	}
-}
-
-// NewExpvarPercent creates a new expvar.Func that calculates the ratio of two expvar.Int or expvar.Float metrics.
-func NewExpvarPercent(name string, n string, d string) expvar.Func {
-	f := expvar.Func(func() any {
-		v := doa.Try(strconv.ParseFloat(expvar.Get(n).String(), 64))
-		w := doa.Try(strconv.ParseFloat(expvar.Get(d).String(), 64))
-		return float64(v) / float64(max(1, w))
-	})
-	expvar.Publish(name, f)
-	return f
-}
-
 // GravityReader wraps an io.Reader with RC4 crypto.
 func GravityReader(r io.Reader, k []byte) io.Reader {
 	cr := doa.Try(rc4.NewCipher(k))

lib/expvpp/expvpp.go

@@ -0,0 +1,68 @@
+package expvpp
+
+import (
+	"encoding/json"
+	"expvar"
+	"net/http"
+	"strconv"
+)
+
+// ExpvarAverage is a structure to maintain a running average using expvar.Float.
+type ExpvarAverage struct {
+	F *expvar.Float
+	L float64
+}
+
+// Adds a new value to the running average. This is not strictly concurrency-safe, but it won't have much impact on the
+// data.
+func (e *ExpvarAverage) Add(value float64) {
+	e.F.Add((value - e.F.Value()) / e.L)
+}
+
+// NewExpvarAverage creates and initializes a new ExpvarAverage instance.
+func NewExpvarAverage(name string, length int) *ExpvarAverage {
+	return &ExpvarAverage{
+		F: expvar.NewFloat(name),
+		L: float64(length),
+	}
+}
+
+// NewExpvarPercent creates a new expvar.Func that calculates the ratio of two expvar.Int or expvar.Float metrics.
+func NewExpvarPercent(name string, n string, d string) *expvar.Func {
+	f := expvar.Func(func() any {
+		v, _ := strconv.ParseFloat(expvar.Get(n).String(), 64)
+		w, _ := strconv.ParseFloat(expvar.Get(d).String(), 64)
+		return float64(v) / float64(max(1, w))
+	})
+	expvar.Publish(name, f)
+	return &f
+}
+
+// ServeMux returns a new http.ServeMux that removes cmdline and memstats from expvar default exports.
+// See: https://github.com/golang/go/issues/29105
+func ServeMux() *http.ServeMux {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/debug/vars", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		vars := new(expvar.Map).Init()
+		expvar.Do(func(kv expvar.KeyValue) {
+			vars.Set(kv.Key, kv.Value)
+		})
+		vars.Delete("cmdline")
+		vars.Delete("memstats")
+		msg := map[string]any{}
+		err := json.Unmarshal([]byte(vars.String()), &msg)
+		if err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			w.Write([]byte(err.Error()))
+			return
+		}
+		enc := json.NewEncoder(w)
+		enc.SetIndent("", "    ")
+		enc.Encode(msg)
+	})
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		http.DefaultServeMux.ServeHTTP(w, r)
+	})
+	return mux
+}

protocol/ashe/engine.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/libraries/daze"
 	"github.com/libraries/daze/lib/doa"
+	"github.com/libraries/daze/lib/expvpp"
 	"github.com/libraries/daze/lib/rate"
 )
 
@@ -56,9 +57,9 @@ var Conf = struct {
 
 // Expv is a simple wrapper around the expvars package.
 var Expv = struct {
-	ServerClockSkew *daze.ExpvarAverage
+	ServerClockSkew *expvpp.ExpvarAverage
 }{
-	ServerClockSkew: daze.NewExpvarAverage("Protocol.Ashe.Server.ClockSkew", 64),
+	ServerClockSkew: expvpp.NewExpvarAverage("Protocol.Ashe.Server.ClockSkew", 64),
 }
 
 // TCPConn is an implementation of the Conn interface for tcp network connections.