readline/history.go

108 lines
2.0 KiB
Go

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
}
current := o.current.Prev()
if current == nil {
return nil
}
o.current = current
return o.showItem(current.Value)
}
func (o *Operation) NextHistory() ([]rune, bool) {
if o.current == nil {
return nil, false
}
current := o.current.Next()
if current == nil {
return nil, false
}
o.current = current
return o.showItem(current.Value), true
}
func (o *Operation) NewHistory(current []rune) {
// if just use last command without modify
// just clean lastest history
if back := o.history.Back(); back != nil {
prev := back.Prev()
if prev != nil {
use := o.current.Value.(*HisItem)
if equalRunes(use.Tmp, prev.Value.(*HisItem).Source) {
o.current = o.history.Back()
o.current.Value.(*HisItem).Clean()
o.historyVer++
return
}
}
}
if len(current) == 0 {
o.current = o.history.Back()
if o.current != nil {
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, commit bool) {
if o.current == nil {
o.PushHistory(s)
return
}
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(&HisItem{Source: newCopy})
o.current = elem
}