summaryrefslogtreecommitdiffstats
path: root/src/net/textproto/writer.go
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
commit73df946d56c74384511a194dd01dbe099584fd1a (patch)
treefd0bcea490dd81327ddfbb31e215439672c9a068 /src/net/textproto/writer.go
parentInitial commit. (diff)
downloadgolang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.tar.xz
golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.zip
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/net/textproto/writer.go')
-rw-r--r--src/net/textproto/writer.go119
1 files changed, 119 insertions, 0 deletions
diff --git a/src/net/textproto/writer.go b/src/net/textproto/writer.go
new file mode 100644
index 0000000..33c146c
--- /dev/null
+++ b/src/net/textproto/writer.go
@@ -0,0 +1,119 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package textproto
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+)
+
+// A Writer implements convenience methods for writing
+// requests or responses to a text protocol network connection.
+type Writer struct {
+ W *bufio.Writer
+ dot *dotWriter
+}
+
+// NewWriter returns a new Writer writing to w.
+func NewWriter(w *bufio.Writer) *Writer {
+ return &Writer{W: w}
+}
+
+var crnl = []byte{'\r', '\n'}
+var dotcrnl = []byte{'.', '\r', '\n'}
+
+// PrintfLine writes the formatted output followed by \r\n.
+func (w *Writer) PrintfLine(format string, args ...interface{}) error {
+ w.closeDot()
+ fmt.Fprintf(w.W, format, args...)
+ w.W.Write(crnl)
+ return w.W.Flush()
+}
+
+// DotWriter returns a writer that can be used to write a dot-encoding to w.
+// It takes care of inserting leading dots when necessary,
+// translating line-ending \n into \r\n, and adding the final .\r\n line
+// when the DotWriter is closed. The caller should close the
+// DotWriter before the next call to a method on w.
+//
+// See the documentation for Reader's DotReader method for details about dot-encoding.
+func (w *Writer) DotWriter() io.WriteCloser {
+ w.closeDot()
+ w.dot = &dotWriter{w: w}
+ return w.dot
+}
+
+func (w *Writer) closeDot() {
+ if w.dot != nil {
+ w.dot.Close() // sets w.dot = nil
+ }
+}
+
+type dotWriter struct {
+ w *Writer
+ state int
+}
+
+const (
+ wstateBegin = iota // initial state; must be zero
+ wstateBeginLine // beginning of line
+ wstateCR // wrote \r (possibly at end of line)
+ wstateData // writing data in middle of line
+)
+
+func (d *dotWriter) Write(b []byte) (n int, err error) {
+ bw := d.w.W
+ for n < len(b) {
+ c := b[n]
+ switch d.state {
+ case wstateBegin, wstateBeginLine:
+ d.state = wstateData
+ if c == '.' {
+ // escape leading dot
+ bw.WriteByte('.')
+ }
+ fallthrough
+
+ case wstateData:
+ if c == '\r' {
+ d.state = wstateCR
+ }
+ if c == '\n' {
+ bw.WriteByte('\r')
+ d.state = wstateBeginLine
+ }
+
+ case wstateCR:
+ d.state = wstateData
+ if c == '\n' {
+ d.state = wstateBeginLine
+ }
+ }
+ if err = bw.WriteByte(c); err != nil {
+ break
+ }
+ n++
+ }
+ return
+}
+
+func (d *dotWriter) Close() error {
+ if d.w.dot == d {
+ d.w.dot = nil
+ }
+ bw := d.w.W
+ switch d.state {
+ default:
+ bw.WriteByte('\r')
+ fallthrough
+ case wstateCR:
+ bw.WriteByte('\n')
+ fallthrough
+ case wstateBeginLine:
+ bw.Write(dotcrnl)
+ }
+ return bw.Flush()
+}