Debounce CursorMoved handler (autozimu#1152)

Author: martskins

autoload/LanguageClient.vim

@@ -1312,6 +1312,9 @@ endfunction
 " there will Mutex poison error.
 let s:last_cursor_line = -1
 function! LanguageClient#handleCursorMoved() abort
+ call s:timer_stop('LanguageClient#handleCursorMoved')
+
+ function! DebounceHandleCursorMoved() abort
  let l:cursor_line = getcurpos()[1] - 1
  if l:cursor_line == s:last_cursor_line
  return
@@ -1328,6 +1331,9 @@ function! LanguageClient#handleCursorMoved() abort
  catch
  call s:Debug('LanguageClient caught exception: ' . string(v:exception))
  endtry
+ endfunction
+
+ call s:timer_start_store(100, { -> DebounceHandleCursorMoved() }, 'LanguageClient#handleCursorMoved')
 endfunction
 
 function! LanguageClient#handleCompleteDone() abort
@@ -1711,14 +1717,18 @@ endfunction
 
 " receives the v:event from the CompleteChanged autocmd
 function! LanguageClient#handleCompleteChanged(event) abort
- " this timer is just to stop textlock from locking our changes
- call timer_start(0, funcref('s:ClosePopups'))
-
- if has_key(s:timers, 'LanguageClient#handleCompleteChanged')
- call timer_stop(s:timers['LanguageClient#handleCompleteChanged'])
+ " this function needs timer_start because by the time it is called the
+ " `textlock` lock is set, so calling something (ClosePopups in this case) in
+ " a timer basically unsets that lock.
+ if !exists('*timer_start')
+ return
  endif
 
- function! Debounced(event) abort
+ " this timer is just to stop textlock from locking our changes
+ call s:timer_start(0, funcref('s:ClosePopups'))
+ call s:timer_stop('LanguageClient#handleCompleteChanged')
+
+ function! DebounceHandleCompleteChanged(event) abort
  let l:user_data = get(v:completed_item, 'user_data', '')
  if len(l:user_data) ==# 0
  return
@@ -1751,7 +1761,7 @@ function! LanguageClient#handleCompleteChanged(event) abort
  endif
  endfunction
 
- let s:timers['LanguageClient#handleCompleteChanged'] = timer_start(100, { -> Debounced(a:event) })
+ call s:timer_start_store(100, { -> DebounceHandleCompleteChanged(a:event) }, 'LanguageClient#handleCompleteChanged')
 endfunction
 
 function! s:ShowCompletionItemDocumentation(doc, completion_event) abort
@@ -1785,4 +1795,34 @@ function! s:ShowCompletionItemDocumentation(doc, completion_event) abort
  call s:OpenHoverPreview('CompletionItemDocumentation', l:lines, l:kind, l:x_pos, l:pos['row'])
 endfunction
 
+" s:timer_stop tries to stop the timer with the given name by calling vim's
+" timer_stop. If vim's timer_stop function does not exist it just returns.
+function! s:timer_stop(name) abort
+if !exists('*timer_stop')
+return
+endif
+
+if has_key(s:timers, a:name)
+ call timer_stop(s:timers[a:name])
+endif
+endfunction
+
+" s:timer_start tries to start a timer by calling vim's timer_start function,
+" if it does not exist it just calls the function given in the second
+" argument.
+function! s:timer_start(delay, func) abort
+if !exists('*timer_start')
+return a:func()
+endif
+
+ return timer_start(a:delay, a:func)
+endfunction
+
+" s:timer_start_store calls s:timer_start and stores the returned timer_id in
+" a script scoped s:timers variable that we can use to debounce function
+" calls.
+function! s:timer_start_store(delay, func, name) abort
+ let s:timers[a:name] = s:timer_start(a:delay, a:func)
+endfunction
+
 let g:LanguageClient_loaded = s:Launch()