[gnome-builder] jedi: avoid killing active thread so much

[Christian Hergert <chergert src gnome org>]

commit bb4bfd29b9e9c455903f8c16ac922223fbfabc0e
Author: Christian Hergert <christian hergert me>
Date:   Fri Oct 2 02:48:44 2015 -0700

    jedi: avoid killing active thread so much
    
    If we detect that the previous completion thread is close enough to what
    we are currently looking for, just reuse it rather than ignoring the
    results and wasting cpu.

 plugins/jedi/jedi_plugin.py |   32 +++++++++++++++++---------------
 1 files changed, 17 insertions(+), 15 deletions(-)
---
diff --git a/plugins/jedi/jedi_plugin.py b/plugins/jedi/jedi_plugin.py
index e95f4e4..ab8431c 100644
--- a/plugins/jedi/jedi_plugin.py
+++ b/plugins/jedi/jedi_plugin.py
@@ -199,26 +199,25 @@ class JediCompletionProvider(Ide.Object,
         self.current_word = Ide.CompletionProvider.context_current_word(context)
         self.current_word_lower = self.current_word.lower()
 
-        if self.thread is not None:
-            self.thread.cancelled = True
-        self.thread = None
-
         _, iter = context.get_iter()
 
-        # Make sure the line text matches
-        # what we queried with, or we could
-        # be on the same line, but different
-        # context.
         begin = iter.copy()
         begin.set_line_offset(0)
         line_str = begin.get_slice(iter)
 
-        if iter.get_line() == self.line and \
-           self.results is not None and \
-           line_str.startswith(self.line_str) and \
-           self.results.replay(self.current_word):
-            self.results.present(self, context)
-            return
+        # If we have no results yet, but a thread is active and mostly matches
+        # our line prefix, then we should just let that one continue but tell
+        # it to deliver to our new context.
+        self.context = context
+        if self.thread is not None:
+            if not line_str.startswith(self.line_str):
+                self.thread.cancelled = True
+                self.thread = None
+
+        if iter.get_line() == self.line and line_str.startswith(self.line_str):
+            if self.results and self.results.replay(self.current_word):
+                self.results.present(self, context)
+                return
 
         self.line_str = line_str
 
@@ -366,9 +365,12 @@ class JediCompletionProvider(Ide.Object,
         return 200
 
     def complete(self, context, results):
+        # If context and self.context are not the same, that means
+        # we stole the results of this task for a later completion.
         self.results = results
-        self.results.present(self, context)
+        self.results.present(self, self.context)
         self.thread = None
+        self.context = None
 
 
 class JediCompletionProposal(Ide.CompletionItem, GtkSource.CompletionProposal):