diff mercurial/worker.py @ 37844:8fb9985382be

pycompat: export queue module instead of symbols in module (API)

Previously, pycompat and util re-exported individual symbols from the
queue module. This had the side-effect of forcing the loading of the
queue module whenever pycompat/util was imported.

These symbols aren't used very often. So importing the module to
get a handle on the symbols is wasteful.

This commit changes pycompat so it no longer exports the individual
symbols in the queue module. Instead, we make the imported module
a "public" symbol. We drop the individual symbol aliases from the
util module. All consumers are updated to use pycompat.queue.* instead.

This change makes 300 invocations of `hg log -r. -T '{rev}\n'` a little
faster:

before: 18.44s
after:  17.87s

Differential Revision: https://phab.mercurial-scm.org/D3441

--- a/mercurial/worker.py	Sat May 05 18:41:51 2018 -0700
+++ b/mercurial/worker.py	Sat May 05 18:35:16 2018 -0700
@@ -235,7 +235,7 @@
                             # iteration.
                             if self._interrupted:
                                 return
-                    except util.empty:
+                    except pycompat.queue.Empty:
                         break
             except Exception as e:
                 # store the exception such that the main thread can resurface
@@ -262,8 +262,8 @@
                 return
 
     workers = _numworkers(ui)
-    resultqueue = util.queue()
-    taskqueue = util.queue()
+    resultqueue = pycompat.queue.Queue()
+    taskqueue = pycompat.queue.Queue()
     # partition work to more pieces than workers to minimize the chance
     # of uneven distribution of large tasks between the workers
     for pargs in partition(args, workers * 20):