remove unnecessary indirection in semaphore

irc/utils/semaphores.go

@@ -12,21 +12,21 @@ import (
 // A semaphore of capacity 1 can be used as a trylock.
 type Semaphore (chan empty)
 
-// Initialize initializes a semaphore to a given capacity.
-func (semaphore *Semaphore) Initialize(capacity int) {
-	*semaphore = make(chan empty, capacity)
+// NewSemaphore creates and initializes a semaphore to a given capacity.
+func NewSemaphore(capacity int) Semaphore {
+	return make(chan empty, capacity)
 }
 
 // Acquire acquires a semaphore, blocking if necessary.
-func (semaphore *Semaphore) Acquire() {
-	(*semaphore) <- empty{}
+func (semaphore Semaphore) Acquire() {
+	semaphore <- empty{}
 }
 
 // TryAcquire tries to acquire a semaphore, returning whether the acquire was
 // successful. It never blocks.
-func (semaphore *Semaphore) TryAcquire() (acquired bool) {
+func (semaphore Semaphore) TryAcquire() (acquired bool) {
 	select {
-	case (*semaphore) <- empty{}:
+	case semaphore <- empty{}:
 		return true
 	default:
 		return false
@@ -36,14 +36,14 @@ func (semaphore *Semaphore) TryAcquire() (acquired bool) {
 // AcquireWithTimeout tries to acquire a semaphore, blocking for a maximum
 // of approximately `d` while waiting for it. It returns whether the acquire
 // was successful.
-func (semaphore *Semaphore) AcquireWithTimeout(timeout time.Duration) (acquired bool) {
+func (semaphore Semaphore) AcquireWithTimeout(timeout time.Duration) (acquired bool) {
 	if timeout < 0 {
 		return semaphore.TryAcquire()
 	}
 
 	timer := time.NewTimer(timeout)
 	select {
-	case (*semaphore) <- empty{}:
+	case semaphore <- empty{}:
 		acquired = true
 	case <-timer.C:
 		acquired = false
@@ -55,9 +55,9 @@ func (semaphore *Semaphore) AcquireWithTimeout(timeout time.Duration) (acquired
 // AcquireWithContext tries to acquire a semaphore, blocking at most until
 // the context expires. It returns whether the acquire was successful.
 // Note that if the context is already expired, the acquire may succeed anyway.
-func (semaphore *Semaphore) AcquireWithContext(ctx context.Context) (acquired bool) {
+func (semaphore Semaphore) AcquireWithContext(ctx context.Context) (acquired bool) {
 	select {
-	case (*semaphore) <- empty{}:
+	case semaphore <- empty{}:
 		acquired = true
 	case <-ctx.Done():
 		acquired = false
@@ -66,6 +66,6 @@ func (semaphore *Semaphore) AcquireWithContext(ctx context.Context) (acquired bo
 }
 
 // Release releases a semaphore.
-func (semaphore *Semaphore) Release() {
-	<-(*semaphore)
+func (semaphore Semaphore) Release() {
+	<-semaphore
 }

irc/utils/semaphores_test.go

@@ -10,8 +10,7 @@ import (
 
 func TestTryAcquire(t *testing.T) {
 	count := 3
-	var sem Semaphore
-	sem.Initialize(count)
+	sem := NewSemaphore(count)
 
 	for i := 0; i < count; i++ {
 		assertEqual(sem.TryAcquire(), true, t)
@@ -24,8 +23,7 @@ func TestTryAcquire(t *testing.T) {
 }
 
 func TestAcquireWithTimeout(t *testing.T) {
-	var sem Semaphore
-	sem.Initialize(1)
+	sem := NewSemaphore(1)
 
 	assertEqual(sem.TryAcquire(), true, t)