runtime/js: impl CopyBytesToGo/CopyBytesToJS

runtime/js/embind/_wrap/emval.cpp

@@ -122,17 +122,14 @@ bool llgo_emval_equals(EM_VAL first, EM_VAL second) {
 EM_VAL llgo_emval_method_call(EM_VAL object, const char* name, EM_VAL args[], int nargs, int *error) {
     std::vector<TYPEID> arr;
     arr.resize(nargs+1);
-    std::vector<val> _args;
-    _args.resize(nargs);
     std::vector<GenericWireType> elements;
     elements.resize(nargs);
     GenericWireType *cursor = elements.data();
     arr[0] = typeid_val;
     for (int i = 0; i < nargs; i++) {
         arr[i+1] = typeid_val;
-        val v = val::take_ownership(args[i]);
-        _args[i] = v;
-        writeGenericWireTypes(cursor, v); 
+        _emval_incref(args[i]);
+        writeGenericWireTypes(cursor, args[i]);
     }
     EM_METHOD_CALLER caller = _emval_get_method_caller(nargs+1,&arr[0],EM_METHOD_CALLER_KIND::FUNCTION);
     EM_GENERIC_WIRE_TYPE ret;
@@ -141,7 +138,7 @@ EM_VAL llgo_emval_method_call(EM_VAL object, const char* name, EM_VAL args[], in
         ret = _emval_call_method(caller, object, name, &destructors, elements.data());        
     } catch(const emscripten::val& jsErr) {
         printf("error\n");
-        *error = 1; 
+        *error = 1;
         return EM_VAL(internal::_EMVAL_UNDEFINED);
     }
     return fromGenericWireType<val>(ret).release_ownership();   
@@ -153,51 +150,36 @@ FUNCTION = 0,
 CONSTRUCTOR = 1,
 */
 EM_VAL llgo_emval_call(EM_VAL fn, EM_VAL args[], int nargs, int kind, int *error) {
-    std::vector<TYPEID> arr;
-    arr.resize(nargs+1);
-    std::vector<val> _args;
-    _args.resize(nargs);
-    std::vector<GenericWireType> elements;
-    elements.resize(nargs);
-    GenericWireType *cursor = elements.data();
-    arr[0] = typeid_val;
-    for (int i = 0; i < nargs; i++) {
-        arr[i+1] = typeid_val;
-        val v = val::take_ownership(args[i]);
-        _args[i] = v;
-        writeGenericWireTypes(cursor, v); 
-    }
-    EM_METHOD_CALLER caller = _emval_get_method_caller(nargs+1,&arr[0],EM_METHOD_CALLER_KIND(kind));
-    EM_GENERIC_WIRE_TYPE ret;
-    try {
-        EM_DESTRUCTORS destructors = nullptr;
-        ret = _emval_call(caller, fn, &destructors, elements.data());
-    } catch(const emscripten::val& jsErr) {
-       *error = 1; 
-        return EM_VAL(internal::_EMVAL_UNDEFINED);
-    }
-    return fromGenericWireType<val>(ret).release_ownership();
-}
-
-/*
-TYPEID llgo_emval_typeid_void() {
-    return take_typeid<void>();
-}
-
-TYPEID llgo_emval_typeid_double() {
-    return take_typeid<double>();
-}
-
-TYPEID llgo_emval_typeid_string() {
-    return take_typeid<std::string>();
+   std::vector<TYPEID> arr;
+   arr.resize(nargs+1);
+   std::vector<GenericWireType> elements;
+   elements.resize(nargs);
+   GenericWireType *cursor = elements.data();
+   arr[0] = typeid_val;
+   for (int i = 0; i < nargs; i++) {
+       arr[i+1] = typeid_val;
+       _emval_incref(args[i]);
+       writeGenericWireTypes(cursor, args[i]);
+   }
+   EM_METHOD_CALLER caller = _emval_get_method_caller(nargs+1,&arr[0],EM_METHOD_CALLER_KIND(kind));
+   EM_GENERIC_WIRE_TYPE ret;
+   try {
+       EM_DESTRUCTORS destructors = nullptr;
+       ret = _emval_call(caller, fn, &destructors, elements.data());
+   } catch(const emscripten::val& jsErr) {
+       *error = 1;
+       return EM_VAL(internal::_EMVAL_UNDEFINED);
+   }
+   return fromGenericWireType<val>(ret).release_ownership();
+}
+
+EM_VAL llgo_emval_memory_view_uint8(size_t length, uint8_t *data) {
+    val view{ typed_memory_view<uint8_t>(length,data) };
+    return view.release_ownership();
 }
 
-TYPEID llgo_emval_typeid_val() {
-    return take_typeid<val>();
-}
-*/
-
 void llgo_emval_dump(EM_VAL v) {
+    _emval_incref(v);
     val console = val::global("console");
     console.call<void>("log", val::take_ownership(v));
 }

runtime/js/emval.go

@@ -83,6 +83,9 @@ func emval_method_call(object Value, name *c.Char, args *Value, nargs c.Int, err
 //go:linkname emval_call C.llgo_emval_call
 func emval_call(fn Value, args *Value, nargs c.Int, kind c.Int, err *c.Int) Value
 
+//go:linkname emval_memory_view_uint8 C.llgo_emval_memory_view_uint8
+func emval_memory_view_uint8(length c.SizeT, data *c.Uint8T) Value
+
 //go:linkname emval_dump C.llgo_emval_dump
 func emval_dump(v Value)
 

runtime/js/func.go

@@ -8,7 +8,6 @@
 package js
 
 import (
-	"strconv"
 	"sync"
 )
 
@@ -48,7 +47,8 @@ func FuncOf(fn func(this Value, args []Value) any) Func {
 	nextFuncID++
 	funcs[id] = fn
 	funcsMu.Unlock()
-	sid := strconv.Itoa(int(id))
+	var buf [20]byte
+	sid := string(itoa(buf[:], uint64(id)))
 	wrap := functionConstructor.New(ValueOf(`
 		const event = { id:` + sid + `, this: this, args: arguments };
 		Module._llgo_invoke(event);
@@ -60,6 +60,17 @@ func FuncOf(fn func(this Value, args []Value) any) Func {
 	}
 }
 
+func itoa(buf []byte, val uint64) []byte {
+	i := len(buf) - 1
+	for val >= 10 {
+		buf[i] = byte(val%10 + '0')
+		i--
+		val /= 10
+	}
+	buf[i] = byte(val + '0')
+	return buf[i:]
+}
+
 // Release frees up resources allocated for the function.
 // The function must not be invoked after calling Release.
 // It is allowed to call Release while the function is still running.

runtime/js/js.go

@@ -666,7 +666,13 @@ func (e *ValueError) Error() string {
 // It panics if src is not a Uint8Array or Uint8ClampedArray.
 // It returns the number of bytes copied, which will be the minimum of the lengths of src and dst.
 func CopyBytesToGo(dst []byte, src Value) int {
-	return 0
+	if !(emval_instanceof(src, uint8Array) || emval_instanceof(src, uint8ClampedArray)) {
+		return 0
+	}
+	toCopy := src.Call("subarray", 0, len(dst))
+	view := emval_memory_view_uint8(uintptr(len(dst)), *(**byte)(unsafe.Pointer(&dst)))
+	view.Call("set", toCopy)
+	return toCopy.Length()
 	// n, ok := copyBytesToGo(dst, src.ref)
 	// runtime.KeepAlive(src)
 	// if !ok {
@@ -675,6 +681,23 @@ func CopyBytesToGo(dst []byte, src Value) int {
 	// return n
 }
 
+/*
+	// func copyBytesToGo(dst []byte, src ref) (int, bool)
+	"syscall/js.copyBytesToGo": (sp) => {
+		sp >>>= 0;
+		const dst = loadSlice(sp + 8);
+		const src = loadValue(sp + 32);
+		if (!(src instanceof Uint8Array || src instanceof Uint8ClampedArray)) {
+			this.mem.setUint8(sp + 48, 0);
+			return;
+		}
+		const toCopy = src.subarray(0, dst.length);
+		dst.set(toCopy);
+		setInt64(sp + 40, toCopy.length);
+		this.mem.setUint8(sp + 48, 1);
+	},
+*/
+
 // copyBytesToGo copies bytes from src to dst.
 //
 // Using go:noescape is safe because the dst byte slice is only used as a dst
@@ -688,7 +711,13 @@ func CopyBytesToGo(dst []byte, src Value) int {
 // It panics if dst is not a Uint8Array or Uint8ClampedArray.
 // It returns the number of bytes copied, which will be the minimum of the lengths of src and dst.
 func CopyBytesToJS(dst Value, src []byte) int {
-	return 0
+	if !(emval_instanceof(dst, uint8Array) || emval_instanceof(dst, uint8ClampedArray)) {
+		return 0
+	}
+	view := emval_memory_view_uint8(uintptr(len(src)), *(**byte)(unsafe.Pointer(&src)))
+	toCopy := view.Call("subarray", 0, dst.Length())
+	dst.Call("set", toCopy)
+	return toCopy.Length()
 	// n, ok := copyBytesToJS(dst.ref, src)
 	// runtime.KeepAlive(dst)
 	// if !ok {
@@ -697,6 +726,28 @@ func CopyBytesToJS(dst Value, src []byte) int {
 	// return n
 }
 
+/*
+	// func copyBytesToJS(dst ref, src []byte) (int, bool)
+	"syscall/js.copyBytesToJS": (sp) => {
+		sp >>>= 0;
+		const dst = loadValue(sp + 8);
+		const src = loadSlice(sp + 16);
+		if (!(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)) {
+			this.mem.setUint8(sp + 48, 0);
+			return;
+		}
+		const toCopy = src.subarray(0, dst.length);
+		dst.set(toCopy);
+		setInt64(sp + 40, toCopy.length);
+		this.mem.setUint8(sp + 48, 1);
+	},
+*/
+
+var (
+	uint8Array        = emval_get_global(c.Str("Uint8Array"))
+	uint8ClampedArray = emval_get_global(c.Str("Uint8ClampedArray"))
+)
+
 // copyBytesToJS copies bytes from src to dst.
 //
 // Using go:noescape is safe because the src byte slice is only used as a src