detect-clipboard is slow on startup

[blayz3r]

Describe the bug
A clear description of what the bug is.
detect-clipboard is slow on startup

To Reproduce
Steps to reproduce the behavior, for example:
start zsh with profiler on

Expected behavior
A brief description of what should happen.
Start normally
Screenshots and/or Recordings

If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS / Distro: [Ubunutu 20.04/wsl2]
• Latest ohmyzsh Update?: [e.g. Yes]
• ZSH Version: [5.8]
• WSL2

Additional context
Add any other context about the problem here. This can be themes, plugins, custom configs.
num calls time self name

1) 1 196.85 196.85 85.97% 196.85 196.85 85.97% detect-clipboard
2) 1 11.32 11.32 4.94% 11.32 11.32 4.94% compinit
3) 1 9.18 9.18 4.01% 9.18 9.18 4.01% handle_completion_insecurities
4) 1 4.79 4.79 2.09% 4.71 4.71 2.06% _zsh_highlight_load_highlighters
5) 1 4.09 4.09 1.78% 4.09 4.09 1.78% _zsh_highlight_bind_widgets
6) 8 0.75 0.09 0.33% 0.75 0.09 0.33% add-zsh-hook
7) 1 0.66 0.66 0.29% 0.66 0.66 0.29% colors
8) 9 0.52 0.06 0.23% 0.52 0.06 0.23% compdef
9) 3 0.48 0.16 0.21% 0.48 0.16 0.21% is-at-least
10) 1 0.13 0.13 0.06% 0.13 0.13 0.06% (anon)
11) 5 0.09 0.02 0.04% 0.09 0.02 0.04% spaceship::deprecated
12) 6 0.09 0.01 0.04% 0.09 0.01 0.04% is_plugin
13) 1 0.27 0.27 0.12% 0.06 0.06 0.03% prompt_spaceship_setup
14) 2 0.04 0.02 0.02% 0.04 0.02 0.02% env_default
15) 1 0.01 0.01 0.01% 0.01 0.01 0.01% bashcompinit

[mcornella]

@rwe can we do anything to make it faster?

[rwe]

Relevant function is located here:

ohmyzsh/lib/clipboard.zsh

Lines 51 to 107 in 3f245ed

	function detect-clipboard() {
	emulate -L zsh
	if [[ "${OSTYPE}" == darwin* ]] && (( ${+commands[pbcopy]} )) && (( ${+commands[pbpaste]} )); then
	function clipcopy() { pbcopy < "${1:-/dev/stdin}"; }
	function clippaste() { pbpaste; }
	elif [[ "${OSTYPE}" == (cygwin|msys)* ]]; then
	function clipcopy() { cat "${1:-/dev/stdin}" > /dev/clipboard; }
	function clippaste() { cat /dev/clipboard; }
	elif [ -n "${WAYLAND_DISPLAY:-}" ] && (( ${+commands[wl-copy]} )) && (( ${+commands[wl-paste]} )); then
	function clipcopy() { wl-copy < "${1:-/dev/stdin}"; }
	function clippaste() { wl-paste; }
	elif [ -n "${DISPLAY:-}" ] && (( ${+commands[xclip]} )); then
	function clipcopy() { xclip -in -selection clipboard < "${1:-/dev/stdin}"; }
	function clippaste() { xclip -out -selection clipboard; }
	elif [ -n "${DISPLAY:-}" ] && (( ${+commands[xsel]} )); then
	function clipcopy() { xsel --clipboard --input < "${1:-/dev/stdin}"; }
	function clippaste() { xsel --clipboard --output; }
	elif (( ${+commands[lemonade]} )); then
	function clipcopy() { lemonade copy < "${1:-/dev/stdin}"; }
	function clippaste() { lemonade paste; }
	elif (( ${+commands[doitclient]} )); then
	function clipcopy() { doitclient wclip < "${1:-/dev/stdin}"; }
	function clippaste() { doitclient wclip -r; }
	elif (( ${+commands[win32yank]} )); then
	function clipcopy() { win32yank -i < "${1:-/dev/stdin}"; }
	function clippaste() { win32yank -o; }
	elif [[ $OSTYPE == linux-android* ]] && (( $+commands[termux-clipboard-set] )); then
	function clipcopy() { termux-clipboard-set "${1:-/dev/stdin}"; }
	function clippaste() { termux-clipboard-get; }
	elif [ -n "${TMUX:-}" ] && (( ${+commands[tmux]} )); then
	function clipcopy() { tmux load-buffer "${1:--}"; }
	function clippaste() { tmux save-buffer -; }
	elif [[ $(uname -r) = *icrosoft* ]]; then
	function clipcopy() { clip.exe < "${1:-/dev/stdin}"; }
	function clippaste() { powershell.exe -noprofile -command Get-Clipboard; }
	else
	function _retry_clipboard_detection_or_fail() {
	local clipcmd="${1}"; shift
	if detect-clipboard; then
	"${clipcmd}" "$@"
	else
	print "${clipcmd}: Platform $OSTYPE not supported or xclip/xsel not installed" >&2
	return 1
	fi
	}
	function clipcopy() { _retry_clipboard_detection_or_fail clipcopy "$@"; }
	function clippaste() { _retry_clipboard_detection_or_fail clippaste "$@"; }
	return 1
	fi
	}
	# Detect at startup. A non-zero exit here indicates that the dummy clipboards were set,
	# which is not really an error. If the user calls them, they will attempt to redetect
	# (for example, perhaps the user has now installed xclip) and then either print an error
	# or proceed successfully.
	detect-clipboard || true

The report shows a single call (ie it's not doing anything crazy like re-running detection).

detect-clipboard basically does two things: it checks env/paths and defines (but doesn't run) functions. The only external command it will possibly run (uname -r) does not show up in the profiler list (and should be extremely fast anyway).

I can't easily repro this locally, but my guess is: when detect-clipboard checks ${+commands[…]} to see which clipboard is available, it is possible this is the first time the command hash table special parameter gets filled in.

To verify this, @blayz3r could try temporarily modifying lib/clipboard.zsh like so and see if it gives similar timing results.

+# Still slow?
+function detect-clipboard() {
+  emulate -L zsh
+  (( ${+commands[wl-copy]} )) || true
+}
 
-function detect-clipboard() {
+function _disabled_detect-clipboard() {
   emulate -L zsh
 
   if [[ "${OSTYPE}" == darwin* ]] && (( ${+commands[pbcopy]} )) && (( ${+commands[pbpaste]} )); then

If the timing looks roughly similar, then it's just zsh instantiating that parameter for the first time, which would happen normally anyway. (If the timing is not similar, at least this shows how to narrow down the hotspot!).

Alternatively, my open PR #8000 (Enhanced clipboard detection and management) permits users to set ZSH_CLIPBOARD to skip detection altogether.

[0x7d7b]

I was wondering if there are any updates on this? I still have the same issue on the current master branch.

[MostHated]

Edit : I got it all worked out, nevermind.

---

I am wondering about this as well ^.

[Crazy-Ginger]

Encountering this as well. Moved to powerlevel10k but the problem seems to be at startup.

The speed was still about the same after:

+# Still slow?
+function detect-clipboard() {
+  emulate -L zsh
+  (( ${+commands[wl-copy]} )) || true
+}
  
-function detect-clipboard() {
+function _disabled_detect-clipboard() {

trying this change

Though it only affects WSL2, my arch laptop and headless Debian server (which uses the same dotfiles) are still just as fast, if a bit faster thanks to powerlevel10k.

Why is it so slow for wsl2?

[carlosala]

Hi! Could someone using WSL2 please post the output of which clipcopy and which clippaste after sourcing oh-my-zsh.sh. Let's see where's the issue!

[Crazy-Ginger]

Plain zsh:

$ source ~/.oh-my-zsh/oh-my-zsh.sh
$ which clipcopy
clipcopy () {
        cat "${1:-/dev/stdin}" | clip.exe
}
$ which clippaste
clippaste () {
        powershell.exe -noprofile -command Get-Clipboard
}

Sourcing inside a tmux session:

$ tmux
$ source ~/.oh-my-zsh/oh-my-zsh.sh
$ which clipcopy
clipcopy () {
        tmux load-buffer "${1:--}"
}
$ which clippaste
clippaste () {
        tmux save-buffer -
}

I included the tmux as I normally do everything inside a tmux session