Commit 56f94847 authored by Andrew Gerrand's avatar Andrew Gerrand

bufio: handle a "\r\n" that straddles the buffer.

Fixes #2164.

R=r, rsc
CC=golang-dev
https://golang.org/cl/4927043
parent de20cec9
......@@ -54,11 +54,11 @@ type Reader struct {
}
// NewReaderSize creates a new Reader whose buffer has the specified size,
// which must be greater than zero. If the argument io.Reader is already a
// which must be greater than one. If the argument io.Reader is already a
// Reader with large enough size, it returns the underlying Reader.
// It returns the Reader and any error.
func NewReaderSize(rd io.Reader, size int) (*Reader, os.Error) {
if size <= 0 {
if size <= 1 {
return nil, BufSizeError(size)
}
// Is it already a Reader?
......@@ -298,6 +298,17 @@ func (b *Reader) ReadSlice(delim byte) (line []byte, err os.Error) {
func (b *Reader) ReadLine() (line []byte, isPrefix bool, err os.Error) {
line, err = b.ReadSlice('\n')
if err == ErrBufferFull {
// Handle the case where "\r\n" straddles the buffer.
if len(line) > 0 && line[len(line)-1] == '\r' {
// Put the '\r' back on buf and drop it from line.
// Let the next call to ReadLine check for "\r\n".
if b.r == 0 {
// should be unreachable
panic("bufio: tried to rewind past start of buffer")
}
b.r--
line = line[:len(line)-1]
}
return line, true, nil
}
......@@ -307,10 +318,11 @@ func (b *Reader) ReadLine() (line []byte, isPrefix bool, err os.Error) {
err = nil
if line[len(line)-1] == '\n' {
line = line[:len(line)-1]
}
if len(line) > 0 && line[len(line)-1] == '\r' {
line = line[:len(line)-1]
drop := 1
if len(line) > 1 && line[len(line)-2] == '\r' {
drop = 2
}
line = line[:len(line)-drop]
}
return
}
......
......@@ -137,7 +137,7 @@ var bufreaders = []bufReader{
}
var bufsizes = []int{
1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
2, 3, 4, 5, 6, 7, 8, 9, 10,
23, 32, 46, 64, 93, 128, 1024, 4096,
}
......@@ -697,3 +697,71 @@ func TestLinesAfterRead(t *testing.T) {
t.Errorf("expected EOF from ReadLine, got '%s' %t %s", line, isPrefix, err)
}
}
type readLineResult struct {
line []byte
isPrefix bool
err os.Error
}
var readLineNewlinesTests = []struct {
input string
bufSize int
expect []readLineResult
}{
{"h\r\nb\r\n", 2, []readLineResult{
{[]byte("h"), true, nil},
{nil, false, nil},
{[]byte("b"), true, nil},
{nil, false, nil},
{nil, false, os.EOF},
}},
{"hello\r\nworld\r\n", 6, []readLineResult{
{[]byte("hello"), true, nil},
{nil, false, nil},
{[]byte("world"), true, nil},
{nil, false, nil},
{nil, false, os.EOF},
}},
{"hello\rworld\r", 6, []readLineResult{
{[]byte("hello"), true, nil},
{[]byte("\rworld"), true, nil},
{[]byte("\r"), false, nil},
{nil, false, os.EOF},
}},
{"h\ri\r\n\r", 2, []readLineResult{
{[]byte("h"), true, nil},
{[]byte("\ri"), true, nil},
{nil, false, nil},
{[]byte("\r"), false, nil},
{nil, false, os.EOF},
}},
}
func TestReadLineNewlines(t *testing.T) {
for _, e := range readLineNewlinesTests {
testReadLineNewlines(t, e.input, e.bufSize, e.expect)
}
}
func testReadLineNewlines(t *testing.T, input string, bufSize int, expect []readLineResult) {
b, err := NewReaderSize(strings.NewReader(input), bufSize)
if err != nil {
t.Fatal(err)
}
for i, e := range expect {
line, isPrefix, err := b.ReadLine()
if bytes.Compare(line, e.line) != 0 {
t.Errorf("%q call %d, line == %q, want %q", input, i, line, e.line)
return
}
if isPrefix != e.isPrefix {
t.Errorf("%q call %d, isPrefix == %v, want %v", input, i, isPrefix, e.isPrefix)
return
}
if err != e.err {
t.Errorf("%q call %d, err == %v, want %v", input, i, err, e.err)
return
}
}
}
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