device: simplify UAPI helper methods

bufio is not required.

strings.Builder is cheaper than bytes.Buffer for constructing strings.

io.Writer is more flexible than io.StringWriter,
and just as cheap (when used with io.WriteString).

Run gofmt.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

diff --git a/device/uapi.go b/device/uapi.go
index 2843a4c20be37d5d677fae4e30ff8c0b6e9c60f7..370ad4eb8e337cac1bd66836f6e03262069f22d9 100644 (file)
--- a/device/uapi.go
+++ b/device/uapi.go
@@ -7,7 +7,6 @@ package device
 
 import (
        "bufio"
-       "bytes"
        "errors"
        "fmt"
        "io"
@@ -33,7 +32,7 @@ func (s IPCError) ErrorCode() int64 {
        return s.int64
 }
 
-func (device *Device) IpcGetOperation(w io.StringWriter) error {
+func (device *Device) IpcGetOperation(w io.Writer) error {
        lines := make([]string, 0, 100)
        send := func(line string) {
                lines = append(lines, line)
@@ -99,7 +98,7 @@ func (device *Device) IpcGetOperation(w io.StringWriter) error {
        // send lines (does not require resource locks)
 
        for _, line := range lines {
-               _, err := w.WriteString(line + "\n")
+               _, err := io.WriteString(w, line+"\n")
                if err != nil {
                        return &IPCError{ipc.IpcErrorIO}
                }
@@ -397,22 +396,16 @@ func (device *Device) IpcSetOperation(r io.Reader) error {
        return nil
 }
 
-
-
 func (device *Device) IpcGet() (string, error) {
-       buf := new(bytes.Buffer)
-       writer := bufio.NewWriter(buf)
-       if err := device.IpcGetOperation(writer); err != nil {
-               return "", err
-       }
-       if err := writer.Flush(); err != nil {
+       buf := new(strings.Builder)
+       if err := device.IpcGetOperation(buf); err != nil {
                return "", err
        }
        return buf.String(), nil
 }
 
 func (device *Device) IpcSet(uapiConf string) error {
-       return device.IpcSetOperation(bufio.NewReader(strings.NewReader(uapiConf)))
+       return device.IpcSetOperation(strings.NewReader(uapiConf))
 }
 
 func (device *Device) IpcHandle(socket net.Conn) {