add relase call

bridge.go

@@ -18,9 +18,14 @@ import (
 	"github.com/wasmerio/go-ext-wasm/wasmer"
 )
 
-var undefined = &struct{}{}
-var bridges = map[string]*Bridge{}
-var mu sync.RWMutex // to protect bridges
+const release_call = "_release_"
+
+var (
+	undefined = &struct{}{}
+	bridges   = map[string]*Bridge{}
+	mu        sync.RWMutex // to protect bridges
+)
+
 type bctx struct{ n string }
 
 func getCtxData(b *Bridge) (unsafe.Pointer, error) {
@@ -55,6 +60,30 @@ type Bridge struct {
 	cancF    context.CancelFunc
 }
 
+// releaseRef removes the ref from the refs.
+// Returns the  idx and true if remove was successful.
+func (b *Bridge) releaseRef(v interface{}) (int, bool) {
+	idx, ok := b.refs[v]
+	if !ok {
+		return 0, false
+	}
+
+	delete(b.refs, v)
+	return idx, true
+}
+
+// releaseVal removes val from the valueMap
+// Returns the value and true if remove was successful
+func (b *Bridge) releaseVal(idx int) (interface{}, bool) {
+	v, ok := b.valueMap[idx]
+	if !ok {
+		return nil, false
+	}
+
+	delete(b.valueMap, idx)
+	return v, true
+}
+
 func BridgeFromBytes(name string, bytes []byte, imports *wasmer.Imports) (*Bridge, error) {
 	b := new(Bridge)
 	if imports == nil {
@@ -513,6 +542,21 @@ func (b *Bridge) SetFunc(fname string, fn Func) error {
 	return nil
 }
 
+func (b *Bridge) releaseFunc(v interface{}) Func {
+	return Func(func(args []interface{}) (interface{}, error) {
+		b.valuesMu.Lock()
+		defer b.valuesMu.Unlock()
+
+		idx, ok := b.releaseRef(v)
+		if !ok {
+			return nil, nil
+		}
+
+		b.releaseVal(idx)
+		return nil, nil
+	})
+}
+
 func Bytes(v interface{}) ([]byte, error) {
 	arr, ok := v.(*array)
 	if !ok {

go-converts/wasm.go

@@ -7,8 +7,14 @@ import "syscall/js"
 func ToBytes(v js.Value) []byte {
 	buf := make([]byte, v.Length(), v.Length())
 	for i := 0; i < v.Length(); i++ {
-		buf[i] = byte(v.Index(i).Int())
+		sv := v.Index(i)
+		buf[i] = byte(sv.Int())
 	}
 
 	return buf
 }
+
+// Free frees the value for GC
+func free(v js.Value) {
+	v.Call("_release_")
+}

imports.go

@@ -156,13 +156,19 @@ func valueSetIndex(_ unsafe.Pointer, _ int32) {
 func valueCall(ctx unsafe.Pointer, sp int32) {
 	b := getBridge(ctx)
 	v := b.loadValue(sp + 8)
+	var f Func
+	var args []interface{}
 	str := b.loadString(sp + 16)
-	args := b.loadSliceOfValues(sp + 32)
-	f, ok := v.(*object).props[str].(Func)
-	if !ok {
-		panic(fmt.Sprintln("valueCall: prop not found in ", v, str))
+	if str == release_call {
+		f = b.releaseFunc(v)
+	} else {
+		args = b.loadSliceOfValues(sp + 32)
+		var ok bool
+		f, ok = v.(*object).props[str].(Func)
+		if !ok {
+			panic(fmt.Sprintln("valueCall: prop not found in ", v, str))
+		}
 	}
-
 	sp = b.getSP()
 	res, err := f(args)
 	if err != nil {