Make caching optional in the omnicompleter

README.md

@@ -877,6 +877,18 @@ Default: `[see next line]`
       \   'erlang' : [':'],
       \ }
 
+### The `g:ycm_cache_omnifunc` option
+
+Some omnicompletion engines do not work well with the YCM cache - in
+particular, they might not produce all possible results for a given prefix. By
+unsetting this option you can ensure that the omnicompletion engine is
+requeried on every keypress. That will ensure all completions will be
+presented, but might cause stuttering and lagginess if the omnifunc is slow.
+
+Default: `1`
+
+    let g:ycm_cache_omnifunc = 1
+
 FAQ
 ---
 

plugin/youcompleteme.vim

@@ -133,6 +133,8 @@ let g:ycm_semantic_triggers =
       \   'erlang' : [':'],
       \ } )
 
+let g:ycm_cache_omnifunc = 1
+
 " On-demand loading. Let's use the autoload folder and not slow down vim's
 " startup procedure.
 augroup youcompletemeStart

python/completers/all/omni_completer.py

@@ -36,12 +36,28 @@ class OmniCompleter( Completer ):
     return []
 
 
+  def ShouldUseCache( self ):
+    return vimsupport.GetBoolValue( "g:ycm_cache_omnifunc" )
+
+
+  def ShouldUseNow( self, start_column ):
+    if self.ShouldUseCache():
+      return super( OmniCompleter, self ).ShouldUseNow( start_column )
+    return self.ShouldUseNowInner( start_column )
+
   def ShouldUseNowInner( self, start_column ):
     if not self.omnifunc:
       return False
     return super( OmniCompleter, self ).ShouldUseNowInner( start_column )
 
 
+  def CandidatesForQueryAsync( self, query, unused_start_column ):
+    if self.ShouldUseCache():
+      return super( OmniCompleter, self ).CandidatesForQueryAsync(
+          query, unused_start_column )
+    else:
+      return self.CandidatesForQueryAsyncInner( query, unused_start_column )
+
   def CandidatesForQueryAsyncInner( self, query, unused_start_column ):
     if not self.omnifunc:
       self.stored_candidates = None
@@ -81,6 +97,12 @@ class OmniCompleter( Completer ):
     self.omnifunc = vim.eval( '&omnifunc' )
 
 
+  def CandidatesFromStoredRequest( self ):
+    if self.ShouldUseCache():
+      return super( OmniCompleter, self ).CandidatesFromStoredRequest()
+    else:
+      return self.CandidatesFromStoredRequestInner()
+
   def CandidatesFromStoredRequestInner( self ):
     return self.stored_candidates if self.stored_candidates else []