Asynchronous diffs in Vim.

autoload/gitgutter/async.vim

@@ -0,0 +1,109 @@
+let s:jobs = {}
+" Async broken on MacVim in GUI mode:
+" https://github.com/macvim-dev/macvim/issues/272
+let s:available = has('nvim') || (has('patch-7-4-1791') && !(has('gui_macvim') && has('gui_running')))
+
+function! gitgutter#async#available()
+  return s:available
+endfunction
+
+function! gitgutter#async#execute(cmd)
+  if has('nvim')
+    let job_id = jobstart([&shell, &shellcmdflag, a:cmd], {
+          \ 'on_stdout': function('gitgutter#async#handle_diff_job_nvim'),
+          \ 'on_stderr': function('gitgutter#async#handle_diff_job_nvim'),
+          \ 'on_exit':   function('gitgutter#async#handle_diff_job_nvim')
+          \ })
+    call gitgutter#debug#log('[nvim job: '.job_id.'] '.a:cmd)
+    if job_id < 1
+      throw 'diff failed'
+    endif
+
+    " Note that when `cmd` doesn't produce any output, i.e. the diff is empty,
+    " the `stdout` event is not fired on the job handler.  Therefore we keep
+    " track of the jobs ourselves so we can spot empty diffs.
+    call s:job_started(job_id)
+
+  else
+    " Pass a handler for stdout but not for stderr so that errors are
+    " ignored (and thus signs are not updated; this assumes that an error
+    " only occurs when a file is not tracked by git).
+    let job = job_start([&shell, &shellcmdflag, a:cmd], {
+          \ 'out_cb': 'gitgutter#async#handle_diff_job_vim'
+          \ })
+          " \ 'close_cb': 'gitgutter#handle_diff_job_vim_close'
+    call gitgutter#debug#log('[vim job: '.string(job_info(job)).'] '.a:cmd)
+  endif
+endfunction
+
+
+function! gitgutter#async#handle_diff_job_nvim(job_id, data, event)
+  call gitgutter#debug#log('job_id: '.a:job_id.', event: '.a:event)
+
+  if a:event == 'stdout'
+    " a:data is a list
+    call s:job_finished(a:job_id)
+    call gitgutter#handle_diff(join(a:data,"\n")."\n")
+
+  elseif a:event == 'exit'
+    " If the exit event is triggered without a preceding stdout event,
+    " the diff was empty.
+    if s:is_job_started(a:job_id)
+      call gitgutter#handle_diff("")
+      call s:job_finished(a:job_id)
+    endif
+
+  else  " a:event is stderr
+    call gitgutter#hunk#reset()
+    call s:job_finished(a:job_id)
+
+  endif
+endfunction
+
+
+" Channel is in NL mode.
+function! gitgutter#async#handle_diff_job_vim(channel, line)
+  call gitgutter#debug#log('channel: '.a:channel.', line: '.a:line)
+
+  " This seems to be the only way to get info about the channel once closed.
+  let channel_id = matchstr(a:channel, '\d\+')
+
+  if a:line ==# 'DETACH'  " End of job output
+    call gitgutter#handle_diff(s:job_output(channel_id))
+    call s:job_finished(channel_id)
+  else
+    call s:accumulate_job_output(channel_id, a:line)
+  endif
+endfunction
+
+
+function! s:job_started(id)
+  let s:jobs[a:id] = 1
+endfunction
+
+function! s:is_job_started(id)
+  return has_key(s:jobs, a:id)
+endfunction
+
+function! s:accumulate_job_output(id, line)
+  if has_key(s:jobs, a:id)
+    let s:jobs[a:id] = add(s:jobs[a:id], a:line)
+  else
+    let s:jobs[a:id] = [a:line]
+  endif
+endfunction
+
+" Returns a string
+function! s:job_output(id)
+  if has_key(s:jobs, a:id)
+    return join(s:jobs[a:id], "\n")."\n"
+  else
+    return ""
+  endif
+endfunction
+
+function! s:job_finished(id)
+  if has_key(s:jobs, a:id)
+    unlet s:jobs[a:id]
+  endif
+endfunction