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https://github.com/golang/go
synced 2024-11-12 07:10:22 -07:00
bytes, strings: allow Reader.Seek past 1<<31
Fixes #7654 LGTM=rsc R=rsc, dan.kortschak CC=golang-codereviews https://golang.org/cl/81530043
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f074565158
@ -16,17 +16,17 @@ import (
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// Unlike a Buffer, a Reader is read-only and supports seeking.
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type Reader struct {
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s []byte
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i int // current reading index
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prevRune int // index of previous rune; or < 0
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i int64 // current reading index
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prevRune int // index of previous rune; or < 0
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}
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// Len returns the number of bytes of the unread portion of the
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// slice.
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func (r *Reader) Len() int {
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0
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}
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return len(r.s) - r.i
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return int(int64(len(r.s)) - r.i)
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}
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func (r *Reader) Read(b []byte) (n int, err error) {
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@ -34,11 +34,11 @@ func (r *Reader) Read(b []byte) (n int, err error) {
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if len(b) == 0 {
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return 0, nil
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}
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0, io.EOF
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}
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n = copy(b, r.s[r.i:])
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r.i += n
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r.i += int64(n)
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return
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}
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@ -49,7 +49,7 @@ func (r *Reader) ReadAt(b []byte, off int64) (n int, err error) {
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if off >= int64(len(r.s)) {
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return 0, io.EOF
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}
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n = copy(b, r.s[int(off):])
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n = copy(b, r.s[off:])
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if n < len(b) {
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err = io.EOF
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}
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@ -58,7 +58,7 @@ func (r *Reader) ReadAt(b []byte, off int64) (n int, err error) {
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func (r *Reader) ReadByte() (b byte, err error) {
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r.prevRune = -1
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0, io.EOF
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}
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b = r.s[r.i]
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@ -76,17 +76,17 @@ func (r *Reader) UnreadByte() error {
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}
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func (r *Reader) ReadRune() (ch rune, size int, err error) {
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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r.prevRune = -1
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return 0, 0, io.EOF
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}
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r.prevRune = r.i
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r.prevRune = int(r.i)
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if c := r.s[r.i]; c < utf8.RuneSelf {
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r.i++
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return rune(c), 1, nil
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}
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ch, size = utf8.DecodeRune(r.s[r.i:])
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r.i += size
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r.i += int64(size)
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return
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}
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@ -94,7 +94,7 @@ func (r *Reader) UnreadRune() error {
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if r.prevRune < 0 {
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return errors.New("bytes.Reader: previous operation was not ReadRune")
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}
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r.i = r.prevRune
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r.i = int64(r.prevRune)
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r.prevRune = -1
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return nil
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}
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@ -116,17 +116,14 @@ func (r *Reader) Seek(offset int64, whence int) (int64, error) {
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if abs < 0 {
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return 0, errors.New("bytes: negative position")
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}
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if abs >= 1<<31 {
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return 0, errors.New("bytes: position out of range")
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}
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r.i = int(abs)
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r.i = abs
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return abs, nil
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}
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// WriteTo implements the io.WriterTo interface.
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func (r *Reader) WriteTo(w io.Writer) (n int64, err error) {
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r.prevRune = -1
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0, nil
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}
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b := r.s[r.i:]
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@ -134,7 +131,7 @@ func (r *Reader) WriteTo(w io.Writer) (n int64, err error) {
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if m > len(b) {
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panic("bytes.Reader.WriteTo: invalid Write count")
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}
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r.i += m
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r.i += int64(m)
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n = int64(m)
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if m != len(b) && err == nil {
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err = io.ErrShortWrite
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@ -27,8 +27,8 @@ func TestReader(t *testing.T) {
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{seek: os.SEEK_SET, off: 1, n: 1, want: "1"},
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{seek: os.SEEK_CUR, off: 1, wantpos: 3, n: 2, want: "34"},
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{seek: os.SEEK_SET, off: -1, seekerr: "bytes: negative position"},
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{seek: os.SEEK_SET, off: 1<<31 - 1},
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{seek: os.SEEK_CUR, off: 1, seekerr: "bytes: position out of range"},
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{seek: os.SEEK_SET, off: 1 << 33, wantpos: 1 << 33},
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{seek: os.SEEK_CUR, off: 1, wantpos: 1<<33 + 1},
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{seek: os.SEEK_SET, n: 5, want: "01234"},
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{seek: os.SEEK_CUR, n: 5, want: "56789"},
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{seek: os.SEEK_END, off: -1, n: 1, wantpos: 9, want: "9"},
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@ -60,6 +60,16 @@ func TestReader(t *testing.T) {
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}
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}
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func TestReadAfterBigSeek(t *testing.T) {
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r := NewReader([]byte("0123456789"))
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if _, err := r.Seek(1<<31+5, os.SEEK_SET); err != nil {
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t.Fatal(err)
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}
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if n, err := r.Read(make([]byte, 10)); n != 0 || err != io.EOF {
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t.Errorf("Read = %d, %v; want 0, EOF", n, err)
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}
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}
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func TestReaderAt(t *testing.T) {
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r := NewReader([]byte("0123456789"))
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tests := []struct {
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@ -15,17 +15,17 @@ import (
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// from a string.
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type Reader struct {
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s string
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i int // current reading index
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prevRune int // index of previous rune; or < 0
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i int64 // current reading index
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prevRune int // index of previous rune; or < 0
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}
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// Len returns the number of bytes of the unread portion of the
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// string.
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func (r *Reader) Len() int {
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0
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}
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return len(r.s) - r.i
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return int(int64(len(r.s)) - r.i)
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}
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func (r *Reader) Read(b []byte) (n int, err error) {
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@ -33,11 +33,11 @@ func (r *Reader) Read(b []byte) (n int, err error) {
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if len(b) == 0 {
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return 0, nil
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}
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0, io.EOF
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}
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n = copy(b, r.s[r.i:])
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r.i += n
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r.i += int64(n)
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return
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}
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@ -48,7 +48,7 @@ func (r *Reader) ReadAt(b []byte, off int64) (n int, err error) {
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if off >= int64(len(r.s)) {
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return 0, io.EOF
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}
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n = copy(b, r.s[int(off):])
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n = copy(b, r.s[off:])
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if n < len(b) {
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err = io.EOF
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}
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@ -57,7 +57,7 @@ func (r *Reader) ReadAt(b []byte, off int64) (n int, err error) {
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func (r *Reader) ReadByte() (b byte, err error) {
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r.prevRune = -1
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0, io.EOF
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}
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b = r.s[r.i]
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@ -75,17 +75,17 @@ func (r *Reader) UnreadByte() error {
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}
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func (r *Reader) ReadRune() (ch rune, size int, err error) {
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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r.prevRune = -1
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return 0, 0, io.EOF
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}
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r.prevRune = r.i
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r.prevRune = int(r.i)
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if c := r.s[r.i]; c < utf8.RuneSelf {
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r.i++
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return rune(c), 1, nil
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}
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ch, size = utf8.DecodeRuneInString(r.s[r.i:])
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r.i += size
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r.i += int64(size)
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return
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}
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@ -93,7 +93,7 @@ func (r *Reader) UnreadRune() error {
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if r.prevRune < 0 {
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return errors.New("strings.Reader: previous operation was not ReadRune")
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}
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r.i = r.prevRune
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r.i = int64(r.prevRune)
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r.prevRune = -1
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return nil
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}
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@ -115,17 +115,14 @@ func (r *Reader) Seek(offset int64, whence int) (int64, error) {
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if abs < 0 {
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return 0, errors.New("strings: negative position")
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}
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if abs >= 1<<31 {
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return 0, errors.New("strings: position out of range")
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}
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r.i = int(abs)
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r.i = abs
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return abs, nil
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}
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// WriteTo implements the io.WriterTo interface.
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func (r *Reader) WriteTo(w io.Writer) (n int64, err error) {
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r.prevRune = -1
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if r.i >= len(r.s) {
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if r.i >= int64(len(r.s)) {
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return 0, nil
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}
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s := r.s[r.i:]
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@ -133,7 +130,7 @@ func (r *Reader) WriteTo(w io.Writer) (n int64, err error) {
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if m > len(s) {
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panic("strings.Reader.WriteTo: invalid WriteString count")
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}
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r.i += m
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r.i += int64(m)
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n = int64(m)
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if m != len(s) && err == nil {
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err = io.ErrShortWrite
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@ -27,8 +27,8 @@ func TestReader(t *testing.T) {
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{seek: os.SEEK_SET, off: 1, n: 1, want: "1"},
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{seek: os.SEEK_CUR, off: 1, wantpos: 3, n: 2, want: "34"},
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{seek: os.SEEK_SET, off: -1, seekerr: "strings: negative position"},
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{seek: os.SEEK_SET, off: 1<<31 - 1},
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{seek: os.SEEK_CUR, off: 1, seekerr: "strings: position out of range"},
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{seek: os.SEEK_SET, off: 1 << 33, wantpos: 1 << 33},
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{seek: os.SEEK_CUR, off: 1, wantpos: 1<<33 + 1},
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{seek: os.SEEK_SET, n: 5, want: "01234"},
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{seek: os.SEEK_CUR, n: 5, want: "56789"},
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{seek: os.SEEK_END, off: -1, n: 1, wantpos: 9, want: "9"},
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@ -60,6 +60,16 @@ func TestReader(t *testing.T) {
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}
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}
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func TestReadAfterBigSeek(t *testing.T) {
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r := strings.NewReader("0123456789")
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if _, err := r.Seek(1<<31+5, os.SEEK_SET); err != nil {
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t.Fatal(err)
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}
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if n, err := r.Read(make([]byte, 10)); n != 0 || err != io.EOF {
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t.Errorf("Read = %d, %v; want 0, EOF", n, err)
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}
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}
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func TestReaderAt(t *testing.T) {
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r := strings.NewReader("0123456789")
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tests := []struct {
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