Slows down vim startup time significantly

[prashcr]

The plugin is adding 2.5-3.5 seconds to my vim startup time. Startup time returns to normal when I disable the plugin. I can't understand why since the plugin's source code looks pretty simple to me. I'm guessing it possibly has something to do with my shell.

Thank you for your time!

My environment

Mac OS X 10.11.6
zsh 5.2 (x86_64-apple-darwin15.0.0)
iTerm2 3.0.7

Result of running vim --startuptime

(Edited to make bracketed-paste stand out)

times in msec
 clock   self+sourced   self:  sourced script
 clock   elapsed:              other lines

000.009  000.009: --- VIM STARTING ---
000.138  000.129: Allocated generic buffers
001.386  001.248: locale set
001.397  000.011: clipboard setup
001.412  000.015: window checked
002.410  000.998: inits 1
002.421  000.011: parsing arguments
002.423  000.002: expanding arguments
011.825  009.402: shell init
012.281  000.456: Termcap init
012.317  000.036: inits 2
012.613  000.296: init highlight
018.040  004.370  004.370: sourcing /Users/prashanthcr/.vim/autoload/plug.vim
020.452  000.068  000.068: sourcing /usr/local/share/vim/vim80/ftoff.vim
076.872  050.688  050.688: sourcing /usr/local/share/vim/vim80/filetype.vim
080.133  000.139  000.139: sourcing /usr/local/share/vim/vim80/ftplugin.vim
080.673  000.069  000.069: sourcing /usr/local/share/vim/vim80/indent.vim
090.233  004.052  004.052: sourcing /usr/local/share/vim/vim80/syntax/syncolor.vim
091.285  005.921  001.869: sourcing /usr/local/share/vim/vim80/syntax/synload.vim
092.702  009.260  003.339: sourcing /usr/local/share/vim/vim80/syntax/syntax.vim
094.138  000.051  000.051: sourcing /usr/local/share/vim/vim80/filetype.vim
094.348  000.028  000.028: sourcing /usr/local/share/vim/vim80/ftplugin.vim
094.531  000.027  000.027: sourcing /usr/local/share/vim/vim80/filetype.vim
094.710  000.024  000.024: sourcing /usr/local/share/vim/vim80/indent.vim
096.420  001.030  001.030: sourcing /usr/local/Cellar/vim/8.0.0002/share/vim/vim80/syntax/nosyntax.vim
097.139  000.352  000.352: sourcing /usr/local/share/vim/vim80/syntax/syncolor.vim
097.388  000.786  000.434: sourcing /usr/local/share/vim/vim80/syntax/synload.vim
097.465  002.589  000.773: sourcing /usr/local/share/vim/vim80/syntax/syntax.vim
099.531  000.419  000.419: sourcing /usr/local/share/vim/vim80/syntax/syncolor.vim
100.236  000.407  000.407: sourcing /usr/local/share/vim/vim80/syntax/syncolor.vim
132.479  034.168  033.342: sourcing /Users/prashanthcr/.vim/plugged/oceanic-next/colors/OceanicNext.vim
134.493  000.622  000.622: sourcing /usr/local/share/vim/vim80/syntax/syncolor.vim
135.642  000.471  000.471: sourcing /usr/local/share/vim/vim80/syntax/syncolor.vim
153.991  021.273  020.180: sourcing /Users/prashanthcr/.vim/plugged/oceanic-next/colors/OceanicNext.vim
154.120  140.807  018.053: sourcing $HOME/.vimrc
154.446  001.026: sourcing vimrc file(s)
158.051  002.606  002.606: sourcing /Users/prashanthcr/.vim/plugged/auto-pairs/plugin/auto-pairs.vim
==================== BRACKETED PASTE PLUGIN ====================
=> 3280.151  3120.931  3120.931: sourcing /Users/prashanthcr/.vim/plugged/vim-bracketed-paste/plugin/bracketed-paste.vim
3281.637  000.133  000.133: sourcing /usr/local/share/vim/vim80/plugin/getscriptPlugin.vim
3283.830  001.921  001.921: sourcing /usr/local/share/vim/vim80/plugin/gzip.vim
3285.125  000.930  000.930: sourcing /usr/local/share/vim/vim80/plugin/logiPat.vim
3285.428  000.038  000.038: sourcing /usr/local/share/vim/vim80/plugin/manpager.vim
3287.336  001.543  001.543: sourcing /usr/local/share/vim/vim80/plugin/matchparen.vim
3290.513  002.959  002.959: sourcing /usr/local/share/vim/vim80/plugin/netrwPlugin.vim
3290.822  000.053  000.053: sourcing /usr/local/share/vim/vim80/plugin/rrhelper.vim
3291.490  000.121  000.121: sourcing /usr/local/share/vim/vim80/plugin/spellfile.vim
3294.413  000.553  000.553: sourcing /usr/local/share/vim/vim80/plugin/tarPlugin.vim
3295.500  000.408  000.408: sourcing /usr/local/share/vim/vim80/plugin/tohtml.vim
3299.497  000.617  000.617: sourcing /usr/local/share/vim/vim80/plugin/vimballPlugin.vim
3300.406  000.575  000.575: sourcing /usr/local/share/vim/vim80/plugin/zipPlugin.vim
3300.446  012.612: loading plugins
3301.192  000.746: loading packages
3301.258  000.066: loading after plugins
3301.288  000.030: inits 3
3302.709  001.421: reading viminfo
3302.734  000.025: setting raw mode
3302.771  000.037: start termcap
3302.909  000.138: clearing screen
3304.756  001.847: opening buffers
3306.034  001.278: BufEnter autocommands
3306.047  000.013: editing files in windows
3306.459  000.412: VimEnter autocommands
3306.468  000.009: before starting main loop
3310.906  004.438: first screen update
3310.911  000.005: --- VIM STARTED ---

[ConradIrwin]

Hi @prashcr, I can't reproduce this. Can you please give more information about your setup,

which version of the plugin are you using, and which terminal emulator?

times in msec
 clock   self+sourced   self:  sourced script
 clock   elapsed:              other lines

000.010  000.010: --- VIM STARTING ---
000.081  000.071: Allocated generic buffers
000.371  000.290: locale set
000.381  000.010: window checked
000.868  000.487: inits 1
000.877  000.009: parsing arguments
000.878  000.001: expanding arguments
000.894  000.016: shell init
001.157  000.263: Termcap init
001.175  000.018: inits 2
001.280  000.105: init highlight
001.511  000.161  000.161: sourcing $VIM/vimrc
015.841  014.150  014.150: sourcing /usr/share/vim/vim73/filetype.vim
015.992  000.045  000.045: sourcing /usr/share/vim/vim73/ftplugin.vim
016.104  000.037  000.037: sourcing /usr/share/vim/vim73/indent.vim
016.754  000.485  000.485: sourcing /Users/conrad/.vim/autoload/pathogen.vim
020.324  000.989  000.989: sourcing /usr/share/vim/vim73/ftoff.vim
032.969  000.066  000.066: sourcing /Users/conrad/.vim/bundle/vim-cjsx/ftdetect/cjsx.vim
033.177  000.142  000.142: sourcing /Users/conrad/.vim/bundle/vim-coffee-script/ftdetect/coffee.vim
033.360  000.114  000.114: sourcing /Users/conrad/.vim/bundle/vim-go/ftdetect/gofiletype.vim
033.490  013.037  012.715: sourcing /usr/share/vim/vim73/filetype.vim
033.672  032.114  003.371: sourcing $HOME/.vimrc
033.733  000.178: sourcing vimrc file(s)
034.036  000.014  000.014: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/autoloclist.vim
034.073  000.009  000.009: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/balloons.vim
034.110  000.010  000.010: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/checker.vim
034.145  000.009  000.009: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/cursor.vim
034.180  000.009  000.009: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/highlighting.vim
034.214  000.008  000.008: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/loclist.vim
034.249  000.009  000.009: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/modemap.vim
034.283  000.009  000.009: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/notifiers.vim
034.318  000.009  000.009: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/registry.vim
034.353  000.009  000.009: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/signs.vim
034.645  000.186  000.186: sourcing /Users/conrad/.vim/bundle/syntastic/autoload/syntastic/log.vim
035.077  000.317  000.317: sourcing /Users/conrad/.vim/bundle/syntastic/autoload/syntastic/util.vim
069.186  000.051  000.051: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/autoloclist.vim
069.276  000.058  000.058: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/balloons.vim
069.497  000.191  000.191: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/checker.vim
069.624  000.099  000.099: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/cursor.vim
069.735  000.083  000.083: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/highlighting.vim
070.103  000.340  000.340: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/loclist.vim
070.241  000.110  000.110: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/modemap.vim
070.347  000.079  000.079: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/notifiers.vim
070.713  000.339  000.339: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/registry.vim
070.844  000.103  000.103: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic/signs.vim
071.738  037.359  035.403: sourcing /Users/conrad/.vim/bundle/syntastic/plugin/syntastic.vim
071.983  000.134  000.134: sourcing /Users/conrad/.vim/bundle/vim-bracketed-paste/plugin/bracketed-paste.vim
072.163  000.068  000.068: sourcing /Users/conrad/.vim/bundle/vim-comment-object/plugin/comment-object.vim
072.472  000.224  000.224: sourcing /Users/conrad/.vim/bundle/vim-go/plugin/go.vim
072.936  000.375  000.375: sourcing /Users/conrad/.vim/bundle/vim-multiple-cursors/plugin/multiple_cursors.vim
073.123  000.010  000.010: sourcing /usr/share/vim/vim73/filetype.vim
073.518  000.015  000.015: sourcing /usr/share/vim/vim73/ftplugin.vim
073.613  000.010  000.010: sourcing /usr/share/vim/vim73/indent.vim
074.089  000.213  000.213: sourcing /usr/share/vim/vim73/syntax/syncolor.vim
074.178  000.400  000.187: sourcing /usr/share/vim/vim73/syntax/synload.vim
074.206  000.520  000.120: sourcing /usr/share/vim/vim73/syntax/syntax.vim
075.170  000.586  000.586: sourcing /usr/share/vim/vim73/macros/matchit.vim
075.199  002.171  001.030: sourcing /Users/conrad/.vim/bundle/vim-sensible/plugin/sensible.vim
075.497  000.077  000.077: sourcing /usr/share/vim/vim73/plugin/getscriptPlugin.vim
075.697  000.169  000.169: sourcing /usr/share/vim/vim73/plugin/gzip.vim
075.884  000.155  000.155: sourcing /usr/share/vim/vim73/plugin/matchparen.vim
076.437  000.520  000.520: sourcing /usr/share/vim/vim73/plugin/netrwPlugin.vim
076.486  000.014  000.014: sourcing /usr/share/vim/vim73/plugin/rrhelper.vim
076.550  000.033  000.033: sourcing /usr/share/vim/vim73/plugin/spellfile.vim
076.737  000.156  000.156: sourcing /usr/share/vim/vim73/plugin/tarPlugin.vim
076.823  000.054  000.054: sourcing /usr/share/vim/vim73/plugin/tohtml.vim
077.000  000.136  000.136: sourcing /usr/share/vim/vim73/plugin/vimballPlugin.vim
077.142  000.108  000.108: sourcing /usr/share/vim/vim73/plugin/zipPlugin.vim
077.189  001.608: loading plugins
077.193  000.004: inits 3
077.801  000.608: reading viminfo
077.832  000.031: setting raw mode
077.840  000.008: start termcap
077.860  000.020: clearing screen
078.997  001.137: opening buffers
079.747  000.750: BufEnter autocommands
079.750  000.003: editing files in windows
079.840  000.090: VimEnter autocommands
079.842  000.002: before starting main loop
080.227  000.385: first screen update
080.229  000.002: --- VIM STARTED ---

[ConradIrwin]

Oh sorry, you did give that information. I'm on iTerm 2.9 — is it a regression with iTerm 3?

[prashcr]

I just realized that it only occurs inside tmux, so iTerm is unlikely to be the culprit.

I got rid of my .tmux.conf and it still occurs so it should be env-related.

[ConradIrwin]

If you run this outside of tmux is it fast?

There's a whole load of tmux specific code in here, but I don't use tmux myself.

[ConradIrwin]

It's probably this line: system('tmux -V')[5] >= '2 which shells out to tmux — do you know a better way of getting the tmux version?

[prashcr]

Yep, it is fast outside tmux.
You're right, I tried adding a few echo commands, and system('tmux -V')[5] >= '2' is the culprit.

I'm curious, why does the function need to return early for tmux major version >= 2? Couldn't find that bit in the coderwall snippet. And what does return a:s mean?

[ConradIrwin]

@Ekleog added this a while back — maybe he can shed some more insight.

[Ekleog]

I use tmux 2.2, no slowdown here. If you run time sh -c "tmux -V", what do you get as an output?

I just noticed that with the upgrade to tmux 2, having vim-bracketed-paste output these Ptmux; etc. triggered an error in tmux. The PR is available at #21 ; I must say I don't remember exactly which error it was.

[prashcr]

Outside tmux

tmux 2.2
sh -c "tmux -V"  0.00s user 0.01s system 58% cpu 0.016 total

Inside tmux

tmux 2.2
sh -c "tmux -V"  0.00s user 0.00s system 72% cpu 0.009 total

Both are pretty fast, and take identical time (+- 10ms). I think it is an issue with vim's system command.

According to vim profiling, system('tmux -V')[5] >= '2' is taking at least 1s every call

vim --cmd 'profile start vimrc.profile' --cmd 'profile! file ~/.vimrc'

For testing purposes, instead of loading this plugin I simply pasted its source code into my .vimrc.
I removed all unrelated profiling output.

SCRIPT  /Users/prashanthcr/.vimrc
Sourced 1 time
Total time:   2.108143
 Self time:   0.002578

count  total (s)   self (s)
    1              0.000003 function! WrapForTmux(s)
                              if !g:bracketed_paste_tmux_wrap || !exists('$TMUX') || system('tmux -V')[5] >= '2'
                                return a:s
                              endif
                              let tmux_start = "\<Esc>Ptmux;"
                              let tmux_end = "\<Esc>\\"
                              return tmux_start . substitute(a:s, "\<Esc>", "\<Esc>\<Esc>", 'g') . tmux_end
                            endfunction
    1   1.025126   0.000055 let &t_ti .= WrapForTmux("\<Esc>[?2004h")
    1   1.001463   0.000091 let &t_te .= WrapForTmux("\<Esc>[?2004l")


FUNCTION  WrapForTmux()
Called 2 times
Total time:   2.026439
 Self time:   0.003712

count  total (s)   self (s)
    2   2.026400   0.003673   if !g:bracketed_paste_tmux_wrap || !exists('$TMUX') || system('tmux -V')[5] >= '2'
    2              0.000029     return a:s
                              endif
                              let tmux_start = "\<Esc>Ptmux;"
                              let tmux_end = "\<Esc>\\"
                              return tmux_start . substitute(a:s, "\<Esc>", "\<Esc>\<Esc>", 'g') . tmux_end


FUNCTIONS SORTED ON TOTAL TIME
count  total (s)   self (s)  function
    2   2.026439   0.003712  WrapForTmux()

FUNCTIONS SORTED ON SELF TIME
count  total (s)   self (s)  function
    2   2.026439   0.003712  WrapForTmux()

Here is my vim version. It's basically the latest version from Homebrew, and the only configuration I remember adding to the build is to enable lua/ruby/python.

vim --version

VIM - Vi IMproved 8.0 (2016 Sep 12, compiled Sep 13 2016 03:35:58)
MacOS X (unix) version
Included patches: 1-2
Compiled by Homebrew
Huge version without GUI.  Features included (+) or not (-):
+acl             +file_in_path    +mouse_sgr       +tag_old_static
+arabic          +find_in_path    -mouse_sysmouse  -tag_any_white
+autocmd         +float           +mouse_urxvt     -tcl
-balloon_eval    +folding         +mouse_xterm     +termguicolors
-browse          -footer          +multi_byte      +terminfo
++builtin_terms  +fork()          +multi_lang      +termresponse
+byte_offset     -gettext         -mzscheme        +textobjects
+channel         -hangul_input    +netbeans_intg   +timers
+cindent         +iconv           +num64           +title
-clientserver    +insert_expand   +packages        -toolbar
+clipboard       +job             +path_extra      +user_commands
+cmdline_compl   +jumplist        +perl            +vertsplit
+cmdline_hist    +keymap          +persistent_undo +virtualedit
+cmdline_info    +lambda          +postscript      +visual
+comments        +langmap         +printer         +visualextra
+conceal         +libcall         +profile         +viminfo
+cryptv          +linebreak       +python          +vreplace
+cscope          +lispindent      -python3         +wildignore
+cursorbind      +listcmds        +quickfix        +wildmenu
+cursorshape     +localmap        +reltime         +windows
+dialog_con      +lua             +rightleft       +writebackup
+diff            +menu            +ruby            -X11
+digraphs        +mksession       +scrollbind      -xfontset
-dnd             +modify_fname    +signs           -xim
-ebcdic          +mouse           +smartindent     -xpm
+emacs_tags      -mouseshape      +startuptime     -xsmp
+eval            +mouse_dec       +statusline      -xterm_clipboard
+ex_extra        -mouse_gpm       -sun_workshop    -xterm_save
+extra_search    -mouse_jsbterm   +syntax
+farsi           +mouse_netterm   +tag_binary
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
  fall-back for $VIM: "/usr/local/share/vim"
Compilation: clang -c -I. -Iproto -DHAVE_CONFIG_H   -DMACOS_X_UNIX  -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: clang   -L. -L/usr/local/lib  -L/usr/local/lib -o vim        -lm  -lncurses -liconv -framework Cocoa  -L/usr/local/lib -llua -fstack-protector  -L/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE -lperl -F/usr/local/Cellar/python/2.7.12/Frameworks -framework Python   -lruby.2.0.0 -lobjc

[prashcr]

Also, I just realized that if I emptied my .vimrc and only included these 3 lines, it takes 800-900ms on my computer.

if system('')
endif

Then it is slow outside of tmux as well. Maybe this is expected performance, I'm not sure. Could you replacing your .vimrc with this as well and see if you can reproduce?

[ConradIrwin]

How quickly do tmux users upgrade? Assuming most people will be using tmux 2, we could remove the check entirely.

If not, is there an environment variable to get the tmux version?

[ConradIrwin]

calls to system() are around 100ms for me in .vimrc

[prashcr]

It's taking me 800-900ms, which is certainly strange.

Hmm, tmux 2.0 was released May 2015. Almost everybody using Homebrew/building from source will be on tmux 2. However, apt on Debian/Ubuntu still lists 1.8 as the latest, though most stuff on apt is known to be at least 1-2 years behind. I'm pretty certain people using this plugin on the latest apt version should be a minority.

Everyone on tmux 2 will enjoy a ~100ms speedup in that case, but it won't work for those < 2

It's your call.

[ConradIrwin]

The other thing I'm not sure about is is it actually broken on tmux < 2 ?

I don't suppose you have a machine around you could test it on?

[prashcr]

I tested against a DigitalOcean VPS running Debian 8.5 and tmux 1.9, and it works just fine actually.

We could reduce the plugin to this

" Auto-toggle paste mode for xterm
let &t_SI .= "\<Esc>[?2004h"
let &t_EI .= "\<Esc>[?2004l"
inoremap <special> <expr> <Esc>[200~ XTermPasteBegin()
function! XTermPasteBegin()
  set pastetoggle=<Esc>[201~
  set paste
  return ""
endfunction