Commit 06ee80d6 authored by Evan Shaw's avatar Evan Shaw Committed by Russ Cox

bufio: Write and WriteString cleanup

Write never writes less than the buffer size and WriteString takes advantage
of the copy built-in to improve write efficiency.

R=rsc, ality, rog
CC=golang-dev
https://golang.org/cl/4344060
parent 5fd0a749
......@@ -415,38 +415,27 @@ func (b *Writer) Buffered() int { return b.n }
// If nn < len(p), it also returns an error explaining
// why the write is short.
func (b *Writer) Write(p []byte) (nn int, err os.Error) {
if b.err != nil {
return 0, b.err
}
nn = 0
for len(p) > 0 {
n := b.Available()
if n <= 0 {
if b.Flush(); b.err != nil {
break
}
n = b.Available()
}
if b.Buffered() == 0 && len(p) >= len(b.buf) {
for len(p) > b.Available() && b.err == nil {
var n int
if b.Buffered() == 0 {
// Large write, empty buffer.
// Write directly from p to avoid copy.
n, b.err = b.wr.Write(p)
} else {
n = copy(b.buf[b.n:], p)
b.n += n
b.Flush()
}
nn += n
p = p[n:]
if b.err != nil {
break
}
continue
}
if n > len(p) {
n = len(p)
if b.err != nil {
return nn, b.err
}
copy(b.buf[b.n:b.n+n], p[0:n])
n := copy(b.buf[b.n:], p)
b.n += n
nn += n
p = p[n:]
}
return nn, b.err
return nn, nil
}
// WriteByte writes a single byte.
......@@ -496,24 +485,21 @@ func (b *Writer) WriteRune(rune int) (size int, err os.Error) {
// If the count is less than len(s), it also returns an error explaining
// why the write is short.
func (b *Writer) WriteString(s string) (int, os.Error) {
if b.err != nil {
return 0, b.err
}
// Common case, worth making fast.
if b.Available() >= len(s) || len(b.buf) >= len(s) && b.Flush() == nil {
for i := 0; i < len(s); i++ { // loop over bytes, not runes.
b.buf[b.n] = s[i]
b.n++
}
return len(s), nil
nn := 0
for len(s) > b.Available() && b.err == nil {
n := copy(b.buf[b.n:], s)
b.n += n
nn += n
s = s[n:]
b.Flush()
}
for i := 0; i < len(s); i++ { // loop over bytes, not runes.
b.WriteByte(s[i])
if b.err != nil {
return i, b.err
}
return nn, b.err
}
return len(s), nil
n := copy(b.buf[b.n:], s)
b.n += n
nn += n
return nn, nil
}
// buffered input and output
......
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