From 4396978d4bebc23b6bf72a8f57fc9bc51a2d78fe Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Mon, 17 Jun 2019 10:48:36 +0900
Subject: [PATCH] jsutil: Refactoring

---
 internal/jsutil/go113_js.go | 38 +++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/internal/jsutil/go113_js.go b/internal/jsutil/go113_js.go
index bacd81cdd..40bb339f4 100644
--- a/internal/jsutil/go113_js.go
+++ b/internal/jsutil/go113_js.go
@@ -34,56 +34,66 @@ func ArrayBufferToSlice(value js.Value) []byte {
 	return Uint8ArrayToSlice(js.Global().Get("Uint8Array").New(value))
 }
 
-func sliceToByteSlice(s interface{}) []byte {
+func sliceToByteSlice(s interface{}) (bs []byte) {
 	switch s := s.(type) {
 	case []int8:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []int16:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 2
 		h.Cap *= 2
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []int32:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 4
 		h.Cap *= 4
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []int64:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 8
 		h.Cap *= 8
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []uint8:
 		return s
 	case []uint16:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 2
 		h.Cap *= 2
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []uint32:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 4
 		h.Cap *= 4
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []uint64:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 8
 		h.Cap *= 8
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []float32:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 4
 		h.Cap *= 4
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	case []float64:
 		h := (*reflect.SliceHeader)(unsafe.Pointer(&s))
 		h.Len *= 8
 		h.Cap *= 8
-		return *(*[]byte)(unsafe.Pointer(h))
+		bs = *(*[]byte)(unsafe.Pointer(h))
+		runtime.KeepAlive(s)
 	default:
 		panic(fmt.Sprintf("jsutil: unexpected value at sliceToBytesSlice: %T", s))
 	}
+	return
 }
 
 func SliceToTypedArray(s interface{}) (js.Value, func()) {
@@ -91,48 +101,40 @@ func SliceToTypedArray(s interface{}) (js.Value, func()) {
 	case []int8:
 		a := js.Global().Get("Uint8Array").New(len(s))
 		js.CopyBytesToJS(a, sliceToByteSlice(s))
-		runtime.KeepAlive(s)
 		buf := a.Get("buffer")
 		return js.Global().Get("Int8Array").New(buf, a.Get("byteOffset"), a.Get("byteLength")), func() {}
 	case []int16:
 		a := js.Global().Get("Uint8Array").New(len(s) * 2)
 		js.CopyBytesToJS(a, sliceToByteSlice(s))
-		runtime.KeepAlive(s)
 		buf := a.Get("buffer")
 		return js.Global().Get("Int16Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/2), func() {}
 	case []int32:
 		a := js.Global().Get("Uint8Array").New(len(s) * 4)
 		js.CopyBytesToJS(a, sliceToByteSlice(s))
-		runtime.KeepAlive(s)
 		buf := a.Get("buffer")
 		return js.Global().Get("Int32Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/4), func() {}
 	case []uint8:
 		a := js.Global().Get("Uint8Array").New(len(s))
 		js.CopyBytesToJS(a, s)
-		runtime.KeepAlive(s)
 		return a, func() {}
 	case []uint16:
 		a := js.Global().Get("Uint8Array").New(len(s) * 2)
 		js.CopyBytesToJS(a, sliceToByteSlice(s))
-		runtime.KeepAlive(s)
 		buf := a.Get("buffer")
 		return js.Global().Get("Uint16Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/2), func() {}
 	case []uint32:
 		a := js.Global().Get("Uint8Array").New(len(s) * 4)
 		js.CopyBytesToJS(a, sliceToByteSlice(s))
-		runtime.KeepAlive(s)
 		buf := a.Get("buffer")
 		return js.Global().Get("Uint32Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/4), func() {}
 	case []float32:
 		a := js.Global().Get("Uint8Array").New(len(s) * 4)
 		js.CopyBytesToJS(a, sliceToByteSlice(s))
-		runtime.KeepAlive(s)
 		buf := a.Get("buffer")
 		return js.Global().Get("Float32Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/4), func() {}
 	case []float64:
 		a := js.Global().Get("Uint8Array").New(len(s) * 8)
 		js.CopyBytesToJS(a, sliceToByteSlice(s))
-		runtime.KeepAlive(s)
 		buf := a.Get("buffer")
 		return js.Global().Get("Float64Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/8), func() {}
 	default: