Cleanup code for writev.

fuse/misc.go

@@ -243,33 +243,35 @@ func CopyFileInfo(fi *os.FileInfo, attr *Attr) {
 
 
 func writev(fd int, iovecs *syscall.Iovec, cnt int) (n int, errno int) {
-	n1, _, e1 := syscall.Syscall(syscall.SYS_WRITEV, uintptr(fd), uintptr(unsafe.Pointer(iovecs)), uintptr(cnt))
-	n = int(n1)
-	errno = int(e1)
-	return
+	n1, _, e1 := syscall.Syscall(
+		syscall.SYS_WRITEV,
+		uintptr(fd), uintptr(unsafe.Pointer(iovecs)), uintptr(cnt))
+	return int(n1), int(e1)
 }
 
 func Writev(fd int, packet [][]byte) (n int, err os.Error) {
-	if len(packet) == 0 {
-		return
-	}
-	iovecs := make([]syscall.Iovec, len(packet))
+	iovecs := make([]syscall.Iovec, 0, len(packet))
 
-	j := 0
-	for i, v := range packet {
+	for _, v := range packet {
 		if v == nil || len(v) == 0 {
 			continue
 		}
-		iovecs[j].Base = (*byte)(unsafe.Pointer(&packet[i][0]))
-		iovecs[j].SetLen(len(packet[i]))
-		j++
+		vec := syscall.Iovec{
+		Base: &v[0],
+		}
+		vec.SetLen(len(v))
+		iovecs = append(iovecs, vec) 
+	}
+	
+	if len(iovecs) == 0 {
+		return 0, nil
 	}
-	n, errno := writev(fd, (*syscall.Iovec)(unsafe.Pointer(&iovecs[0])), j)
 
+	n, errno := writev(fd, &iovecs[0], len(iovecs))
 	if errno != 0 {
 		err = os.NewSyscallError("writev", errno)
 	}
-	return
+	return n, err
 }
 
 func CountCpus() int {