go-netln/copyline.go

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package netln
import (
"errors"
"io"
)
// CopyLine reads in a line from reader and writes that line to writer (without the line terminator).
//
// For CopyLine, a line is terminated by the "\r\n" characters.
//
// So, for example, if from reader CopyLine read in:
//
// "Hello world!\r\n"
//
// Then what CopyLine would write to writer is:
//
// "Hello world!"
//
// (Notice that the "\r\n" at the end is missing.)
//
// Note that n64 represents how many bytes were written, not read.
func CopyLine(writer io.Writer, reader io.Reader) (n64 int64, err error) {
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var eof bool
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for {
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var r0 rune
var size0 int
{
r0, size0, err = readRune(reader)
eof = errors.Is(err, io.EOF)
if nil != err && !eof {
/////////////////////////////// RETURN
return
}
}
if size0 <= 0 {
/////////////// BREAK
break
}
if '\r' != r0 || eof {
err = writeRune(writer, r0, size0)
if nil != err {
/////////////////////////////// RETURN
return
}
n64 += int64(size0)
if eof {
/////////////////////// BREAK
break
} else {
/////////////////////// CONTINUE
continue
}
}
var r1 rune
var size1 int
{
r1, size1, err = readRune(reader)
eof = errors.Is(err, io.EOF)
if nil != err && !eof {
/////////////////////////////// RETURN
return
}
}
if size1 <= 0 {
err = writeRune(writer, r0, size0)
if nil != err {
/////////////////////////////// RETURN
return
}
n64 += int64(size0)
/////////////// BREAK
break
}
if '\n' != r1 {
{
err = writeRune(writer, r0, size0)
if nil != err {
/////////////////////////////////////// RETURN
return
}
n64 += int64(size0)
}
{
err = writeRune(writer, r1, size1)
if nil != err {
/////////////////////////////////////// RETURN
return
}
n64 += int64(size1)
}
if eof {
/////////////////////////////// BREAK
break
} else {
/////////////////////////////// CONTINUE
continue
}
}
/////// BREAK
break
}
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if eof && n64 <= 0 {
return n64, io.EOF
}
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return n64, nil
}