gob: slightly simpler decodeUint

R=r
CC=golang-dev
https://golang.org/cl/5089048

diff --git a/src/pkg/gob/decode.go b/src/pkg/gob/decode.go
index 60c0e10ceae6317736b4884a2beb4f5e93a7504d..9d8d9058747a190092cd5c1729c7e2d35beaeac6 100644 (file)
--- a/src/pkg/gob/decode.go
+++ b/src/pkg/gob/decode.go
@@ -70,13 +70,12 @@ func decodeUintReader(r io.Reader, buf []byte) (x uint64, width int, err os.Erro
        if b <= 0x7f {
                return uint64(b), width, nil
        }
-       nb := -int(int8(b))
-       if nb > uint64Size {
+       n := -int(int8(b))
+       if n > uint64Size {
                err = errBadUint
                return
        }
-       var n int
-       n, err = io.ReadFull(r, buf[0:nb])
+       width, err = io.ReadFull(r, buf[0:n])
        if err != nil {
                if err == os.EOF {
                        err = io.ErrUnexpectedEOF
@@ -84,11 +83,10 @@ func decodeUintReader(r io.Reader, buf []byte) (x uint64, width int, err os.Erro
                return
        }
        // Could check that the high byte is zero but it's not worth it.
-       for i := 0; i < n; i++ {
-               x <<= 8
-               x |= uint64(buf[i])
-               width++
+       for _, b := range buf[0:width] {
+               x = x<<8 | uint64(b)
        }
+       width++ // +1 for length byte
        return
 }
 
@@ -102,19 +100,18 @@ func (state *decoderState) decodeUint() (x uint64) {
        if b <= 0x7f {
                return uint64(b)
        }
-       nb := -int(int8(b))
-       if nb > uint64Size {
+       n := -int(int8(b))
+       if n > uint64Size {
                error(errBadUint)
        }
-       n, err := state.b.Read(state.buf[0:nb])
+       width, err := state.b.Read(state.buf[0:n])
        if err != nil {
                error(err)
        }
        // Don't need to check error; it's safe to loop regardless.
        // Could check that the high byte is zero but it's not worth it.
-       for i := 0; i < n; i++ {
-               x <<= 8
-               x |= uint64(state.buf[i])
+       for _, b := range state.buf[0:width] {
+               x = x<<8 | uint64(b)
        }
        return x
 }