Skip to content

Optimise writeString for Windows with vtEnabled #772

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jul 10, 2025
Merged

Optimise writeString for Windows with vtEnabled #772

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 21 additions & 8 deletions console_win.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -655,12 +655,15 @@ var vkKeys = map[uint16]Key{
func getu32(v []byte) uint32 {
return uint32(v[0]) + (uint32(v[1]) << 8) + (uint32(v[2]) << 16) + (uint32(v[3]) << 24)
}

func geti32(v []byte) int32 {
return int32(getu32(v))
}

func getu16(v []byte) uint16 {
return uint16(v[0]) + (uint16(v[1]) << 8)
}

func geti16(v []byte) int16 {
return int16(getu16(v))
}
Expand Down Expand Up @@ -938,7 +941,7 @@ func (s *cScreen) mapStyle(style Style) uint16 {
return attr
}

func (s *cScreen) sendVtStyle(style Style) {
func (s *cScreen) makeVtStyle(style Style) string {
esc := &strings.Builder{}

fg, bg, attrs := style.fg, style.bg, style.attrs
Expand Down Expand Up @@ -998,30 +1001,40 @@ func (s *cScreen) sendVtStyle(style Style) {
esc.WriteString(vtExitUrl)
}

s.emitVtString(esc.String())
return esc.String()
}

func (s *cScreen) writeString(x, y int, style Style, ch []uint16) {
func (s *cScreen) sendVtStyle(style Style) {
s.emitVtString(s.makeVtStyle(style))
}

func (s *cScreen) writeString(x, y int, style Style, vtBuf, ch []uint16) {
// we assume the caller has hidden the cursor
if len(ch) == 0 {
return
}
s.setCursorPos(x, y, s.vten)

if s.vten {
s.sendVtStyle(style)
vtBuf = append(vtBuf, utf16.Encode([]rune(fmt.Sprintf(vtCursorPos, y+1, x+1)))...)
styleStr := s.makeVtStyle(style)
vtBuf = append(vtBuf, utf16.Encode([]rune(styleStr))...)
vtBuf = append(vtBuf, ch...)
_ = syscall.WriteConsole(s.out, &vtBuf[0], uint32(len(vtBuf)), nil, nil)
vtBuf = vtBuf[:0]
} else {
s.setCursorPos(x, y, s.vten)
_, _, _ = procSetConsoleTextAttribute.Call(
uintptr(s.out),
uintptr(s.mapStyle(style)))
_ = syscall.WriteConsole(s.out, &ch[0], uint32(len(ch)), nil, nil)
}
_ = syscall.WriteConsole(s.out, &ch[0], uint32(len(ch)), nil, nil)
}

func (s *cScreen) draw() {
// allocate a scratch line bit enough for no combining chars.
// if you have combining characters, you may pay for extra allocations.
buf := make([]uint16, 0, s.w)
var vtBuf []uint16
wcs := buf[:]
lstyle := styleInvalid

Expand All @@ -1040,7 +1053,7 @@ func (s *cScreen) draw() {
// write out any data queued thus far
// because we are going to skip over some
// cells, or because we need to change styles
s.writeString(lx, ly, lstyle, wcs)
s.writeString(lx, ly, lstyle, vtBuf, wcs)
wcs = buf[0:0]
lstyle = StyleDefault
if !dirty {
Expand All @@ -1067,7 +1080,7 @@ func (s *cScreen) draw() {
}
x += width - 1
}
s.writeString(lx, ly, lstyle, wcs)
s.writeString(lx, ly, lstyle, vtBuf, wcs)
wcs = buf[0:0]
lstyle = styleInvalid
}
Expand Down