Completion suggestions are now fetched async

autoload/youcompleteme.vim

@@ -102,13 +102,27 @@ function! youcompleteme#Complete(findstart, base)
     return start_column
   else
     let s:old_cursor_text = a:base
-    let results = []
     if strlen( a:base ) < g:ycm_min_num_of_chars_for_completion
-      return results
+      return []
     endif
 
+	  py csystem.CandidatesForQueryAsync( vim.eval('a:base') )
+
+		let l:results_ready = 0
+		while !l:results_ready
       py << EOF
-results = csystem.CompletionCandidatesForQuery( vim.eval('a:base') )
+results_ready = csystem.AsyncCandidateRequestReady()
+if results_ready:
+  vim.command( 'let l:results_ready = 1' )
+EOF
+			if complete_check()
+				return { 'words' : [], 'refresh' : 'always'}
+			endif
+		endwhile
+
+    let l:results = []
+    py << EOF
+results = csystem.CandidatesFromStoredRequest()
 if results:
   vim.command( 'let l:results = ' + str( results ) )
 EOF
@@ -117,10 +131,8 @@ EOF
     " keystroke. The problem is still present in vim 7.3.390 but is fixed in
     " 7.3.475. It's possible that patch 404 was the one that fixed this issue,
     " but I haven't tested this assumption.
-    let dict = { 'words' : results }
     " A bug in vim causes the '.' register to break when we use set this... sigh
-    let dict.refresh = 'always'
-    return dict
+		return { 'words' : l:results, 'refresh' : 'always'}
   endif
 endfunction
 

cpp/CMakeLists.txt

@@ -86,7 +86,7 @@ endif()
 
 if( CMAKE_COMPILER_IS_GNUCXX OR COMPILER_IS_CLANG )
   # We want all warnings, and warnings should be treated as errors
-  #add_definitions( -Wall -pedantic -Werror )
+	# TODO: -Wextra?
   add_definitions( -Wall -Werror )
 endif()
 

cpp/Completer.cpp

@@ -19,14 +19,42 @@
 #include "Completer.h"
 #include "Utils.h"
 
+#include <boost/bind.hpp>
+#include <boost/make_shared.hpp>
+#include <algorithm>
+
 using boost::python::len;
 using boost::python::extract;
+using boost::packaged_task;
+using boost::bind;
+using boost::unique_future;
+using boost::make_shared;
+using boost::shared_ptr;
+using boost::bind;
+using boost::thread;
 
 namespace YouCompleteMe
 {
 
+namespace
+{
+
+const unsigned int MAX_ASYNC_THREADS = 4;
+const unsigned int MIN_ASYNC_THREADS = 2;
+
+void ThreadMain( TaskStack &task_stack )
+{
+  while ( true )
+  {
+    ( *task_stack.Pop() )();
+  }
+}
+
+} // unnamed namespace
+
 
 Completer::Completer( const Pylist &candidates )
+  : threading_enabled_( false )
 {
   AddCandidatesToDatabase( candidates, "", "" );
 }
@@ -35,6 +63,7 @@ Completer::Completer( const Pylist &candidates )
 Completer::Completer( const Pylist &candidates,
                       const std::string &filetype,
                       const std::string &filepath )
+  : threading_enabled_( false )
 {
   AddCandidatesToDatabase( candidates, filetype, filepath );
 }
@@ -50,6 +79,15 @@ Completer::~Completer()
 }
 
 
+// We need this mostly so that we can not use it in tests. Apparently the
+// GoogleTest framework goes apeshit on us if we enable threads by default.
+void Completer::EnableThreading()
+{
+  threading_enabled_ = true;
+  InitThreads();
+}
+
+
 void Completer::AddCandidatesToDatabase( const Pylist &new_candidates,
                                          const std::string &filetype,
                                          const std::string &filepath )
@@ -85,13 +123,57 @@ void Completer::CandidatesForQuery( const std::string &query,
 void Completer::CandidatesForQueryAndType( const std::string &query,
                                            const std::string &filetype,
                                            Pylist &candidates ) const
+{
+  std::vector< Result > results;
+  ResultsForQueryAndType( query, filetype, results );
+
+  foreach ( const Result& result, results )
+  {
+    candidates.append( *result.Text() );
+  }
+}
+
+
+Future Completer::CandidatesForQueryAndTypeAsync(
+    const std::string &query,
+    const std::string &filetype ) const
+{
+  // TODO: throw exception when threading is not enabled and this is called
+  if (!threading_enabled_)
+    return Future();
+
+  // Try not to look at this too hard, it may burn your eyes.
+  shared_ptr< packaged_task< AsyncResults > > task =
+    make_shared< packaged_task< AsyncResults > >(
+      bind( &Completer::ResultsForQueryAndType,
+                   boost::cref( *this ),
+                   query,
+                   filetype ) );
+
+  unique_future< AsyncResults > future = task->get_future();
+
+  task_stack_.Push( task );
+  return Future( move( future ) );
+}
+
+AsyncResults Completer::ResultsForQueryAndType(
+    const std::string &query,
+    const std::string &filetype ) const
+{
+  AsyncResults results = boost::make_shared< std::vector< Result > >();
+  ResultsForQueryAndType( query, filetype, *results );
+  return results;
+}
+
+void Completer::ResultsForQueryAndType( const std::string &query,
+                                        const std::string &filetype,
+                                        std::vector< Result > &results ) const
 {
   FiletypeMap::const_iterator it = filetype_map_.find( filetype );
   if ( it == filetype_map_.end() )
     return;
 
   Bitset query_bitset = LetterBitsetFromString( query );
-  std::vector< Result > results;
 
   foreach ( const FilepathToCandidates::value_type &path_and_candidates,
             *it->second )
@@ -108,11 +190,6 @@ void Completer::CandidatesForQueryAndType( const std::string &query,
   }
 
   std::sort( results.begin(), results.end() );
-
-  foreach ( const Result& result, results )
-  {
-    candidates.append( *result.Text() );
-  }
 }
 
 
@@ -136,4 +213,17 @@ std::vector< Candidate* >& Completer::GetCandidateVector(
 }
 
 
+void Completer::InitThreads()
+{
+  int threads_to_create =
+    std::max( MIN_ASYNC_THREADS,
+      std::min( MAX_ASYNC_THREADS, thread::hardware_concurrency() ) );
+
+  for ( int i = 0; i < threads_to_create; ++i )
+  {
+    threads_.create_thread( bind( ThreadMain, boost::ref( task_stack_ ) ) );
+  }
+}
+
+
 } // namespace YouCompleteMe

cpp/Completer.h

@@ -19,6 +19,8 @@
 #define COMPLETER_H_7AR4UGXE
 
 #include "Candidate.h"
+#include "ConcurrentStack.h"
+#include "Future.h"
 
 #include <boost/utility.hpp>
 #include <boost/python.hpp>
@@ -28,6 +30,7 @@
 #include <vector>
 #include <string>
 
+
 namespace YouCompleteMe
 {
 
@@ -44,10 +47,12 @@ typedef boost::unordered_map< std::string,
 typedef boost::unordered_map< std::string,
           boost::shared_ptr< FilepathToCandidates > > FiletypeMap;
 
+typedef ConcurrentStack<
+          boost::shared_ptr<
+            boost::packaged_task< AsyncResults > > > TaskStack;
 
-// TODO: resolve problems with noncopyable
-// class Completer : boost::noncopyable
-class Completer
+
+class Completer : boost::noncopyable
 {
 public:
   Completer() {}
@@ -57,6 +62,8 @@ public:
              const std::string &filepath );
   ~Completer();
 
+  void EnableThreading();
+
   void AddCandidatesToDatabase( const Pylist &new_candidates,
                                 const std::string &filetype,
                                 const std::string &filepath );
@@ -69,27 +76,41 @@ public:
                                   const std::string &filetype,
                                   Pylist &candidates ) const;
 
+	Future CandidatesForQueryAndTypeAsync( const std::string &query,
+                                         const std::string &filetype ) const;
+
 private:
 
+  AsyncResults ResultsForQueryAndType( const std::string &query,
+                                       const std::string &filetype ) const;
+
+  void ResultsForQueryAndType( const std::string &query,
+                               const std::string &filetype,
+                               std::vector< Result > &results ) const;
+
   std::vector< Candidate* >& GetCandidateVector(
       const std::string &filetype,
       const std::string &filepath );
 
-  struct CandidatePointerLess
-  {
-    bool operator() ( const Candidate *first, const Candidate *second )
-    {
-      return first->Text() < second->Text();
-    }
-  };
+  void InitThreads();
+
+
+  /////////////////////////////
+  // PRIVATE MEMBER VARIABLES
+  /////////////////////////////
 
   // This data structure owns all the Candidate pointers
   CandidateRepository candidate_repository_;
 
   FiletypeMap filetype_map_;
+
+  mutable TaskStack task_stack_;
+
+  bool threading_enabled_;
+
+  boost::thread_group threads_;
 };
 
 } // namespace YouCompleteMe
 
 #endif /* end of include guard: COMPLETER_H_7AR4UGXE */
-

cpp/ConcurrentStack.h

@@ -0,0 +1,66 @@
+// Copyright (C) 2011, 2012  Strahinja Val Markovic  <val@markovic.io>
+//
+// This file is part of YouCompleteMe.
+//
+// YouCompleteMe is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// YouCompleteMe is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef CONCURRENTSTACK_H_SYF1JPPG
+#define CONCURRENTSTACK_H_SYF1JPPG
+
+#include <stack>
+#include <boost/thread.hpp>
+#include <boost/utility.hpp>
+
+namespace YouCompleteMe
+{
+
+template <typename T>
+class ConcurrentStack : boost::noncopyable
+{
+public:
+
+  void Push( const T& data )
+  {
+    {
+      boost::unique_lock< boost::mutex > lock( mutex_ );
+      stack_.push( data );
+    }
+
+    condition_variable_.notify_one();
+  }
+
+  T Pop()
+  {
+    boost::unique_lock< boost::mutex > lock( mutex_ );
+
+    while ( stack_.empty() )
+    {
+      condition_variable_.wait( lock );
+    }
+
+    T result = stack_.top();
+    stack_.pop();
+    return result;
+  }
+
+private:
+  std::stack<T> stack_;
+  boost::mutex mutex_;
+  boost::condition_variable condition_variable_;
+
+};
+
+} // namespace YouCompleteMe
+
+#endif /* end of include guard: CONCURRENTSTACK_H_SYF1JPPG */

cpp/Future.cpp

@@ -0,0 +1,55 @@
+// Copyright (C) 2011, 2012  Strahinja Val Markovic  <val@markovic.io>
+//
+// This file is part of YouCompleteMe.
+//
+// YouCompleteMe is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// YouCompleteMe is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "standard.h"
+#include "Future.h"
+#include "Result.h"
+
+namespace YouCompleteMe
+{
+
+Future::Future( boost::shared_future< AsyncResults > future )
+  : future_( boost::move( future ) )
+{
+}
+
+bool Future::ResultsReady()
+{
+  return future_.is_ready();
+}
+
+void Future::GetResults( Pylist &candidates )
+{
+  AsyncResults results;
+
+  try
+  {
+    results = future_.get();
+  }
+
+  catch ( boost::future_uninitialized & )
+  {
+    return;
+  }
+
+  foreach ( const Result& result, *results )
+  {
+    candidates.append( *result.Text() );
+  }
+}
+
+} // namespace YouCompleteMe

cpp/Future.h

@@ -0,0 +1,47 @@
+// Copyright (C) 2011, 2012  Strahinja Val Markovic  <val@markovic.io>
+//
+// This file is part of YouCompleteMe.
+//
+// YouCompleteMe is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// YouCompleteMe is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef FUTURE_H_NR1U6MZS
+#define FUTURE_H_NR1U6MZS
+
+#include <boost/thread.hpp>
+#include <boost/python.hpp>
+#include <boost/shared_ptr.hpp>
+
+namespace YouCompleteMe
+{
+
+class Result;
+
+typedef boost::python::list Pylist;
+typedef boost::shared_ptr< std::vector< Result > > AsyncResults;
+
+class Future
+{
+public:
+  Future() {}
+  Future( boost::shared_future< AsyncResults > future );
+  bool ResultsReady();
+  void GetResults( Pylist &candidates );
+
+private:
+  boost::shared_future< AsyncResults > future_;
+};
+
+} // namespace YouCompleteMe
+
+#endif /* end of include guard: FUTURE_H_NR1U6MZS */

cpp/indexer.cpp

@@ -16,15 +16,23 @@
 // along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "Completer.h"
+#include "Future.h"
 
 #include <boost/python.hpp>
+#include <boost/utility.hpp>
 
 BOOST_PYTHON_MODULE(indexer)
 {
   using namespace boost::python;
   using namespace YouCompleteMe;
 
-  class_<Completer>( "Completer" )
+  class_< Future >( "Future" )
+    .def( "ResultsReady", &Future::ResultsReady )
+    .def( "GetResults", &Future::GetResults );
+
+  class_< Completer, boost::noncopyable >( "Completer" )
+    .def( "EnableThreading", &Completer::EnableThreading )
     .def( "AddCandidatesToDatabase", &Completer::AddCandidatesToDatabase )
-    .def( "CandidatesForQueryAndType", &Completer::CandidatesForQueryAndType );
+    .def( "CandidatesForQueryAndTypeAsync",
+          &Completer::CandidatesForQueryAndTypeAsync );
 }

python/ycm.py

@@ -26,15 +26,26 @@ min_num_chars = int( vim.eval( "g:ycm_min_num_of_chars_for_completion" ) )
 class CompletionSystem( object ):
   def __init__( self ):
     self.completer = indexer.Completer()
+    self.completer.EnableThreading()
     self.pattern = re.compile( r"[_a-zA-Z]\w*" )
+    self.future = None
 
-  def CompletionCandidatesForQuery( self, query ):
-    candidates = []
+  def CandidatesForQueryAsync( self, query ):
     filetype = vim.eval( "&filetype" )
-    self.completer.CandidatesForQueryAndType( SanitizeQuery( query ),
-                                              filetype,
-                                              candidates )
-    return candidates
+    self.future = self.completer.CandidatesForQueryAndTypeAsync(
+      SanitizeQuery( query ),
+      filetype )
+
+  def AsyncCandidateRequestReady( self ):
+    return self.future.ResultsReady()
+
+  def CandidatesFromStoredRequest( self ):
+    if not self.future:
+      return []
+
+    results = []
+    self.future.GetResults( results )
+    return results
 
   def AddBufferIdentifiers( self ):
     text = "\n".join( vim.current.buffer )