Add Has method to HandleMap interface.

fuse/handle.go

@@ -23,6 +23,7 @@ type HandleMap interface {
 	Register(obj *Handled, asInt interface{}) uint64
 	Count() int
 	Forget(uint64) *Handled
+	Has(uint64) bool
 }
 
 type Handled struct {
@@ -44,6 +45,13 @@ func (me *int32HandleMap) Register(obj *Handled, asInt interface{}) uint64 {
 	return uint64(handle)
 }
 
+func (me *int32HandleMap) Has(h uint64) bool {
+	me.mutex.Lock()
+	defer me.mutex.Unlock()
+	return me.handles[uint32(h)] != nil
+}
+
+
 func (me *int32HandleMap) Count() int {
 	me.mutex.Lock()
 	defer me.mutex.Unlock()
@@ -158,6 +166,12 @@ func (me *int64HandleMap) Forget(handle uint64) (val *Handled) {
 	return val
 }
 
+func (me *int64HandleMap) Has(handle uint64) bool {
+	me.mutex.Lock()
+	defer me.mutex.Unlock()
+	return me.handles[handle] != nil
+}
+
 func DecodeHandle(handle uint64) (val *Handled) {
 	var check uint32
 	if unsafe.Sizeof(val) == 8 {

fuse/handle_test.go

@@ -73,6 +73,9 @@ func TestHandleMapBasic(t *testing.T) {
 	hm := NewHandleMap(true)
 	h := hm.Register(v, v)
 	log.Printf("Got handle 0x%x", h)
+	if !hm.Has(h) {
+		t.Fatal("Does not have handle")
+	}
 	if DecodeHandle(h) != v {
 		t.Fatal("address mismatch")
 	}
@@ -83,6 +86,9 @@ func TestHandleMapBasic(t *testing.T) {
 	if hm.Count() != 0 {
 		t.Fatal("count error")
 	}
+	if hm.Has(h) {
+		t.Fatal("Still has handle")
+	}
 }
 
 func TestHandleMapMultiple(t *testing.T) {