" If we can use filesize to detect the big file early, we should
function! big_file_options#() abort
" Try and get filesize; if we can't, defer another check attempt until after
" everything's been loaded
let size = getfsize(bufname('%'))
if size == -1
autocmd big_file_options BufReadPost,StdinReadPost <buffer>
\ call s:CheckPost()
\|autocmd! big_file_options BufReadPost,StdinReadPost <buffer>
return
endif
" Set the buffer's big flag to whether the file is verifiably outsize
let b:big_file_options_big = size > s:Limit() || size == -2
" If we found it's a big file, call the early options set
if b:big_file_options_big
call s:SetPre()
autocmd big_file_options BufReadPost,StdinReadPost <buffer>
\ call s:SetPost()
\|autocmd! big_file_options BufReadPost,StdinReadPost <buffer>
endif
endfunction
" If it's still indeterminate (stdin read?), try to check the buffer size
" itself
function! s:CheckPost() abort
" Test buffer size, bail if that doesn't work either
let size = line2byte(line('$') + 1)
if size == -1
return
endif
" Flag the buffer's oversize status; if it's positive, we'll catch up and
" run the early options set now
let b:big_file_options_big = size > s:Limit()
if b:big_file_options_big
call s:SetPre()
call s:SetPost()
endif
endfunction
" Wrapper function to get the configured size limit, default to 10 MiB
function! s:Limit() abort
let limit = get(g:, 'big_file_options_limit', 10 * 1024 * 1024)
return limit
endfunction
" These options can and should be set as early as possible
function! s:SetPre() abort
" These are always set
setlocal noswapfile
setlocal undolevels=-1
if has('persistent_undo')
setlocal noundofile
endif
" Decide whether to set readonly options
let readonly = get(g:, 'big_file_options_readonly', 1)
if readonly
setlocal buftype=nowrite
setlocal nomodifiable
setlocal readonly
endif
endfunction
" These options need to be set later, after the buffer has loaded
function! s:SetPost() abort
" Force filetype off
setlocal filetype=
" Disable syntax highlighting if configured
let syntax = get(g:, 'big_file_options_syntax', 0)
if !syntax
setlocal syntax=OFF
endif
" Force maximum syntax columns down if configured
let synmaxcol = get(g:, 'big_file_options_synmaxcol', 256)
if &synmaxcol > synmaxcol
let &l:synmaxcol = synmaxcol
endif
" Tell the user what we've done
echomsg 'Big file detected, set appropriate options'
endfunction
