improve history

history.go

@@ -1,5 +1,24 @@
 package readline
 
+type HisItem struct {
+	Source  []rune
+	Version int64
+	Tmp     []rune
+}
+
+func (h *HisItem) Clean() {
+	h.Source = nil
+	h.Tmp = nil
+}
+
+func (o *Operation) showItem(obj interface{}) []rune {
+	item := obj.(*HisItem)
+	if item.Version == o.historyVer {
+		return item.Tmp
+	}
+	return item.Source
+}
+
 func (o *Operation) PrevHistory() []rune {
 	if o.current == nil {
 		return nil
@@ -9,48 +28,69 @@ func (o *Operation) PrevHistory() []rune {
 		return nil
 	}
 	o.current = current
-	return current.Value.([]rune)
+	return o.showItem(current.Value)
 }
 
-func (o *Operation) NextHistory() []rune {
+func (o *Operation) NextHistory() ([]rune, bool) {
 	if o.current == nil {
-		return nil
+		return nil, false
 	}
 	current := o.current.Next()
 	if current == nil {
-		return nil
+		return nil, false
 	}
+
 	o.current = current
-	return current.Value.([]rune)
+	return o.showItem(current.Value), true
 }
 
 func (o *Operation) NewHistory(current []rune) {
-	o.UpdateHistory(current)
-	if o.current != o.history.Back() {
-		// move history item to current command
-		o.history.Remove(o.current)
-		use := o.current.Value.([]rune)
-		o.current = o.history.Back()
-		o.UpdateHistory(use)
+	// if just use last command without modify
+	// just clean lastest history
+	if o.current == o.history.Back().Prev() {
+		use := o.current.Value.(*HisItem)
+		if equalRunes(use.Tmp, use.Source) {
+			o.current = o.history.Back()
+			o.current.Value.(*HisItem).Clean()
+			o.historyVer++
+			return
+		}
 	}
 
+	if o.current != o.history.Back() {
+		// move history item to current command
+		use := o.current.Value.(*HisItem)
+		o.current = o.history.Back()
+		current = use.Tmp
+	}
+
+	o.UpdateHistory(current, true)
+
 	// push a new one to commit current command
+	o.historyVer++
 	o.PushHistory(nil)
 }
 
-func (o *Operation) UpdateHistory(s []rune) {
+func (o *Operation) UpdateHistory(s []rune, commit bool) {
 	if o.current == nil {
 		o.PushHistory(s)
 		return
 	}
-	r := o.current.Value.([]rune)
-	o.current.Value = append(r[:0], s...)
+	r := o.current.Value.(*HisItem)
+	r.Version = o.historyVer
+	if commit {
+		r.Source = make([]rune, len(s))
+		copy(r.Source, s)
+	} else {
+		r.Tmp = append(r.Tmp[:0], s...)
+	}
+	o.current.Value = r
 }
 
 func (o *Operation) PushHistory(s []rune) {
 	// copy
 	newCopy := make([]rune, len(s))
 	copy(newCopy, s)
-	elem := o.history.PushBack(newCopy)
+	elem := o.history.PushBack(&HisItem{Source: newCopy})
 	o.current = elem
 }

operation.go

@@ -12,8 +12,9 @@ type Operation struct {
 	buf     *RuneBuffer
 	outchan chan []rune
 
-	history *list.List
-	current *list.Element
+	history    *list.List
+	historyVer int64
+	current    *list.Element
 }
 
 const (
@@ -23,7 +24,7 @@ const (
 	CharPrev      = 0x10
 	CharBackward  = 0x2
 	CharForward   = 0x6
-	CharEscape    = 0x7f
+	CharBackspace = 0x7f
 	CharEnter     = 0xd
 	CharEnter2    = 0xa
 )
@@ -69,14 +70,17 @@ func (l *Operation) ioloop() {
 			l.buf.MoveToLineEnd()
 		case KeyDelete:
 			l.buf.Delete()
-		case CharEscape:
-			l.buf.BackEscape()
+		case CharBackspace:
+			l.buf.Backspace()
+		case MetaBackspace:
+			l.buf.BackEscapeWord()
 		case CharEnter, CharEnter2:
 			l.buf.WriteRune('\n')
 			data := l.buf.Reset()
 			data = data[:len(data)-1] // trim \n
 			l.outchan <- data
 			l.NewHistory(data)
+			debugList(l.history)
 		case CharBackward:
 			l.buf.MoveBackward()
 		case CharForward:
@@ -87,8 +91,8 @@ func (l *Operation) ioloop() {
 				l.buf.Set(buf)
 			}
 		case CharNext:
-			buf := l.NextHistory()
-			if buf != nil {
+			buf, ok := l.NextHistory()
+			if ok {
 				l.buf.Set(buf)
 			}
 		case KeyInterrupt:
@@ -97,7 +101,7 @@ func (l *Operation) ioloop() {
 		default:
 			l.buf.WriteRune(r)
 		}
-		l.UpdateHistory(l.buf.Runes())
+		l.UpdateHistory(l.buf.Runes(), false)
 	}
 }
 

runebuf.go

@@ -126,7 +126,25 @@ func (r *RuneBuffer) MoveToNextWord() {
 	r.Refresh(0, r.SetIdx(len(r.buf)))
 }
 
-func (r *RuneBuffer) BackEscape() {
+func (r *RuneBuffer) BackEscapeWord() {
+	if r.idx == 0 {
+		return
+	}
+	for i := r.idx - 1; i > 0; i-- {
+		if r.buf[i] != ' ' && r.buf[i-1] == ' ' {
+			change := i - r.idx
+			r.buf = append(r.buf[:i], r.buf[r.idx:]...)
+			r.Refresh(change, r.SetIdx(i))
+			return
+		}
+	}
+
+	length := len(r.buf)
+	r.buf = r.buf[:0]
+	r.Refresh(-length, r.SetIdx(0))
+}
+
+func (r *RuneBuffer) Backspace() {
 	if r.idx == 0 {
 		return
 	}
@@ -153,12 +171,8 @@ func (r *RuneBuffer) RefreshSet(originLength, originIdx int) {
 
 func (r *RuneBuffer) Output(originLength, originIdx int) []byte {
 	buf := bytes.NewBuffer(nil)
-	if r.printPrompt {
-		r.printPrompt = false
-		buf.Write(r.prompt)
-	}
-
-	buf.Write(bytes.Repeat([]byte{'\b'}, originIdx))
+	buf.Write(bytes.Repeat([]byte{'\b'}, originIdx+len(r.prompt)))
+	buf.Write(r.prompt)
 	buf.Write([]byte(string(r.buf)))
 	if originLength > len(r.buf) {
 		buf.Write(bytes.Repeat([]byte{' '}, originLength-len(r.buf)))

terminal.go

@@ -14,6 +14,7 @@ const (
 	MetaPrev = -iota - 1
 	MetaNext
 	MetaDelete
+	MetaBackspace
 )
 
 const (

utils.go

@@ -1,8 +1,11 @@
 package readline
 
 import (
+	"container/list"
 	"fmt"
 	"os"
+	"syscall"
+	"unsafe"
 
 	"golang.org/x/crypto/ssh/terminal"
 )
@@ -33,6 +36,8 @@ func prefixKey(r rune) rune {
 		r = MetaNext
 	case 'd':
 		r = MetaDelete
+	case CharBackspace:
+		r = MetaBackspace
 	case KeyEsc:
 
 	}
@@ -44,3 +49,44 @@ func Debug(o ...interface{}) {
 	fmt.Fprintln(f, o...)
 	f.Close()
 }
+
+type winsize struct {
+	Row    uint16
+	Col    uint16
+	Xpixel uint16
+	Ypixel uint16
+}
+
+func getWidth() int {
+	ws := &winsize{}
+	retCode, _, errno := syscall.Syscall(syscall.SYS_IOCTL,
+		uintptr(syscall.Stdin),
+		uintptr(syscall.TIOCGWINSZ),
+		uintptr(unsafe.Pointer(ws)))
+
+	Debug(ws)
+	if int(retCode) == -1 {
+		panic(errno)
+	}
+	return int(ws.Col)
+}
+
+func debugList(l *list.List) {
+	idx := 0
+	for e := l.Front(); e != nil; e = e.Next() {
+		Debug(idx, fmt.Sprintf("%+v", e.Value))
+		idx++
+	}
+}
+
+func equalRunes(a, b []rune) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := 0; i < len(a); i++ {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}