syscall/js: rename Callback.Close to Release and expose Callback.Value

This makes Callback more in line with TypedArray. The name "Release" is
better than "Close" because the function does not implement io.Closer.

Change-Id: I23829a14b1c969ceb04608afd9505fd5b4b0df2e
Reviewed-on: https://go-review.googlesource.com/121216
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/net/http/roundtrip_js.go b/src/net/http/roundtrip_js.go
index 1e6f83a666b0cd2e0b188fcfcd4b1619c13c3bc8..336c413cea23c8422213b9d51adb37c717645ecc 100644 (file)
--- a/src/net/http/roundtrip_js.go
+++ b/src/net/http/roundtrip_js.go
@@ -110,7 +110,7 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
                case <-req.Context().Done():
                }
        })
-       defer success.Close()
+       defer success.Release()
        failure := js.NewCallback(func(args []js.Value) {
                err := fmt.Errorf("net/http: fetch() failed: %s", args[0].String())
                select {
@@ -118,7 +118,7 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
                case <-req.Context().Done():
                }
        })
-       defer failure.Close()
+       defer failure.Release()
        respPromise.Call("then", success, failure)
        select {
        case <-req.Context().Done():
@@ -171,7 +171,7 @@ func (r *streamReader) Read(p []byte) (n int, err error) {
                        a.Release()
                        bCh <- value
                })
-               defer success.Close()
+               defer success.Release()
                failure := js.NewCallback(func(args []js.Value) {
                        // Assumes it's a TypeError. See
                        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypeError
@@ -180,7 +180,7 @@ func (r *streamReader) Read(p []byte) (n int, err error) {
                        // the read method.
                        errCh <- errors.New(args[0].Get("message").String())
                })
-               defer failure.Close()
+               defer failure.Release()
                r.stream.Call("read").Call("then", success, failure)
                select {
                case b := <-bCh:
@@ -234,7 +234,7 @@ func (r *arrayReader) Read(p []byte) (n int, err error) {
                        a.Release()
                        bCh <- value
                })
-               defer success.Close()
+               defer success.Release()
                failure := js.NewCallback(func(args []js.Value) {
                        // Assumes it's a TypeError. See
                        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypeError
@@ -242,7 +242,7 @@ func (r *arrayReader) Read(p []byte) (n int, err error) {
                        // See https://fetch.spec.whatwg.org/#concept-body-consume-body for reasons this might error.
                        errCh <- errors.New(args[0].Get("message").String())
                })
-               defer failure.Close()
+               defer failure.Release()
                r.arrayPromise.Call("then", success, failure)
                select {
                case b := <-bCh:

diff --git a/src/syscall/js/callback.go b/src/syscall/js/callback.go
index cfcce693cb2ce3a46e1e18a055979e2876a4bf0e..fa8a03ab0c3997210d9c1ecad1a867b179c3b2bf 100644 (file)
--- a/src/syscall/js/callback.go
+++ b/src/syscall/js/callback.go
@@ -46,8 +46,8 @@ var (
 // A Callback can be passed to functions of this package that accept interface{},
 // for example Value.Set and Value.Call.
 type Callback struct {
-       id        uint32
-       enqueueFn Value // the JavaScript function that queues the callback for execution
+       Value // the JavaScript function that queues the callback for execution
+       id    uint32
 }
 
 // NewCallback returns a wrapped callback function. It can be passed to functions of this package
@@ -59,7 +59,7 @@ type Callback struct {
 // As a consequence, if one callback blocks this goroutine, other callbacks will not be processed.
 // A blocking callback should therefore explicitly start a new goroutine.
 //
-// Callback.Close must be called to free up resources when the callback will not be used any more.
+// Callback.Release must be called to free up resources when the callback will not be used any more.
 func NewCallback(fn func(args []Value)) Callback {
        callbackLoopOnce.Do(func() {
                go callbackLoop()
@@ -71,8 +71,8 @@ func NewCallback(fn func(args []Value)) Callback {
        callbacks[id] = fn
        callbacksMu.Unlock()
        return Callback{
-               id:        id,
-               enqueueFn: makeCallbackHelper.Invoke(id, pendingCallbacks, resolveCallbackPromise),
+               Value: makeCallbackHelper.Invoke(id, pendingCallbacks, resolveCallbackPromise),
+               id:    id,
        }
 }
 
@@ -95,17 +95,19 @@ func NewEventCallback(flags EventCallbackFlag, fn func(event Value)) Callback {
                fn(args[0])
        })
        return Callback{
-               id: c.id,
-               enqueueFn: makeEventCallbackHelper.Invoke(
+               Value: makeEventCallbackHelper.Invoke(
                        flags&PreventDefault != 0,
                        flags&StopPropagation != 0,
                        flags&StopImmediatePropagation != 0,
                        c,
                ),
+               id: c.id,
        }
 }
 
-func (c Callback) Close() {
+// Release frees up resources allocated for the callback.
+// The callback must not be invoked after calling Release.
+func (c Callback) Release() {
        callbacksMu.Lock()
        delete(callbacks, c.id)
        callbacksMu.Unlock()

diff --git a/src/syscall/js/js.go b/src/syscall/js/js.go
index a7b1ed8d29263eaef0008273d8168958115d2bd3..7f0a5a1a8a5eec5cebaf9ad95956f25506d5bfbc 100644 (file)
--- a/src/syscall/js/js.go
+++ b/src/syscall/js/js.go
@@ -99,7 +99,7 @@ func ValueOf(x interface{}) Value {
        case TypedArray:
                return x.Value
        case Callback:
-               return x.enqueueFn
+               return x.Value
        case nil:
                return valueNull
        case bool:

diff --git a/src/syscall/js/js_test.go b/src/syscall/js/js_test.go
index 0aaa65d054d5314b218566d59ac894e2abce91f6..497b9467bbeab7b61bb93b0c08933f7ddbd4daa8 100644 (file)
--- a/src/syscall/js/js_test.go
+++ b/src/syscall/js/js_test.go
@@ -214,7 +214,7 @@ func TestCallback(t *testing.T) {
                }
                c <- struct{}{}
        })
-       defer cb.Close()
+       defer cb.Release()
        js.Global().Call("setTimeout", cb, 0, 42)
        <-c
 }
@@ -234,10 +234,10 @@ func TestEventCallback(t *testing.T) {
                cb := js.NewEventCallback(flags, func(event js.Value) {
                        c <- struct{}{}
                })
-               defer cb.Close()
+               defer cb.Release()
 
                event := js.Global().Call("eval", fmt.Sprintf("({ called: false, %s: function() { this.called = true; } })", name))
-               js.ValueOf(cb).Invoke(event)
+               cb.Invoke(event)
                if !event.Get("called").Bool() {
                        t.Errorf("%s not called", name)
                }
@@ -250,7 +250,7 @@ func ExampleNewCallback() {
        var cb js.Callback
        cb = js.NewCallback(func(args []js.Value) {
                fmt.Println("button clicked")
-               cb.Close() // close the callback if the button will not be clicked again
+               cb.Release() // release the callback if the button will not be clicked again
        })
        js.Global().Get("document").Call("getElementById", "myButton").Call("addEventListener", "click", cb)
 }