Merge pull request #1203 from ZyX-I/cache-tagbar

Add more precise caching for tagbar segment

powerline/bindings/vim/__init__.py

@@ -124,6 +124,14 @@ else:
 	vim_get_func = VimFunc
 
 
+def vim_get_autoload_func(f, rettype=None):
+	func = vim_get_func(f)
+	if not func:
+		vim.command('runtime! ' + f.replace('#', '/')[:f.rindex('#')] + '.vim')
+		func = vim_get_func(f)
+	return func
+
+
 if hasattr(vim, 'Function'):
 	def vim_func_exists(f):
 		try:
@@ -145,6 +153,7 @@ if type(vim) is object:
 
 
 _getbufvar = vim_get_func('getbufvar')
+_vim_exists = vim_get_func('exists', rettype='int')
 
 
 # It may crash on some old vim versions and I do not remember in which patch 
@@ -171,14 +180,20 @@ if hasattr(vim, 'vvars') and vim.vvars['version'] > 703:
 
 	def vim_getwinvar(segment_info, varname):
 		return _vim_to_python(segment_info['window'].vars[str(varname)])
+
+	def vim_global_exists(name):
+		try:
+			vim.vars[name]
+		except KeyError:
+			return False
+		else:
+			return True
 else:
 	_vim_to_python_types = {
 		dict: (lambda value: dict(((k, _vim_to_python(v)) for k, v in value.items()))),
 		list: (lambda value: [_vim_to_python(i) for i in value]),
 	}
 
-	_vim_exists = vim_get_func('exists', rettype='int')
-
 	def vim_getvar(varname):
 		varname = 'g:' + varname
 		if _vim_exists(varname):
@@ -201,6 +216,13 @@ else:
 				raise KeyError(varname)
 		return result
 
+	def vim_global_exists(name):
+		return int(vim.eval('exists("g:' + name + '")'))
+
+
+def vim_command_exists(name):
+	return _vim_exists(':' + name)
+
 
 if sys.version_info < (3,):
 	getbufvar = _getbufvar

powerline/segments/vim/__init__.py

@@ -62,11 +62,6 @@ vim_modes = {
 }
 
 
-eventfuncs = defaultdict(lambda: [])
-bufeventfuncs = defaultdict(lambda: [])
-defined_events = set()
-
-
 # TODO Remove cache when needed
 def window_cached(func):
 	cache = {}

powerline/segments/vim/plugin/syntastic.py

@@ -7,6 +7,7 @@ except ImportError:
 	vim = object()
 
 from powerline.segments.vim import window_cached
+from powerline.bindings.vim import vim_global_exists
 
 
 @window_cached
@@ -21,8 +22,8 @@ def syntastic(pl, err_format='ERR:  {first_line} ({num}) ', warn_format='WARN
 
 	Highlight groups used: ``syntastic.warning`` or ``warning``, ``syntastic.error`` or ``error``.
 	'''
-	if not int(vim.eval('exists("g:SyntasticLoclist")')):
-		return
+	if not vim_global_exists('SyntasticLoclist'):
+		return None
 	has_errors = int(vim.eval('g:SyntasticLoclist.current().hasErrorsOrWarningsToDisplay()'))
 	if not has_errors:
 		return

powerline/segments/vim/plugin/tagbar.py

@@ -6,11 +6,16 @@ try:
 except ImportError:
 	vim = object()
 
-from powerline.segments.vim import window_cached
+from powerline.bindings.vim import vim_command_exists, vim_get_autoload_func
+from powerline.theme import requires_segment_info
 
 
-@window_cached
-def current_tag(pl, flags='s'):
+currenttag = None
+tag_cache = {}
+
+
+@requires_segment_info
+def current_tag(segment_info, pl, flags='s'):
 	'''Return tag that is near the cursor.
 
 	:param str flags:
@@ -25,6 +30,22 @@ def current_tag(pl, flags='s'):
 
 		.. _`official documentation`: https://github.com/majutsushi/tagbar/blob/master/doc/tagbar.txt
 	'''
-	if not int(vim.eval('exists(":Tagbar")')):
-		return None
-	return vim.eval('tagbar#currenttag("%s", "", "{0}")'.format(flags))
+	global currenttag
+	global tag_cache
+	window_id = segment_info['window_id']
+	if segment_info['mode'] == 'nc':
+		return tag_cache.get(window_id, (None,))[-1]
+	if not currenttag:
+		if vim_command_exists('Tagbar'):
+			currenttag = vim_get_autoload_func('tagbar#currenttag')
+			if not currenttag:
+				return None
+		else:
+			return None
+	prev_key, r = tag_cache.get(window_id, (None, None))
+	key = (int(vim.eval('b:changedtick')), segment_info['window'].cursor[0])
+	if prev_key and key == prev_key:
+		return r
+	r = currenttag('%s', '', flags)
+	tag_cache[window_id] = (key, r)
+	return r

tests/vim.py

@@ -412,9 +412,11 @@ def _emul_bufnr(expr):
 
 
 @_vim
-def _emul_exists(varname):
-	if varname.startswith('g:'):
-		return varname[2:] in vars
+def _emul_exists(ident):
+	if ident.startswith('g:'):
+		return ident[2:] in vars
+	elif ident.startswith(':'):
+		return 0
 	raise NotImplementedError