[PATCH 1 of 9] chgserver: copy to mercurial

[Jun Wu]

# HG changeset patch
# User Jun Wu <quark at fb.com>
# Date 1479070808 0
#      Sun Nov 13 21:00:08 2016 +0000
# Node ID c04847bc1bf1804cc7d8f5e74444c50a653a9526
# Parent  e1d6aa0e4c3aed73e0dc523b8a8fd5f9fe23510a
chgserver: copy to mercurial

The patch moves chgserver.py to mercurial and the chg refactoring (mainly to
avoid calling uisetup) starts here. The movement to core was decided at the
4.0 sprint.

It's inconvenient to change hgext.chgserver directly and then move it to
mercurial because this is a relatively large refactoring and until we have
all the patches, the "mercurial/" version would be incomplete or
incompatible to the current chg client. Maintaining compatibility while
doing the refactoring is hard.

Therefore, in the mean time, the chg client will still use hgext.chgserver.
Once the refactoring is in a good shape, we will make the switch and remove
hgext.chgserver.

"mercurial" was replaced to "." to make the import checker happy.

The motivation behind the refactoring was mainly discussed at:
https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-July/085965.html

The goals of the current planned refactoring are:

  a. do not run uisetup - much better compatibility
  b. long socket path support
  c. better integration with the pager extension
  d. lock-free server start
  e. fix remaining tests

Note that a downside of "a." is things can be slower - With ~50 extensions
enabled, "chg version" may need 0.10 seconds, increased from 0.05 seconds.
However, "a." provides "correctness" that solves some hard issues like
infinite redirection with bundle or the share extension. So the performance
price looks worthwhile. If we do want that 0.05 seconds, we can optimize
later - like by making it possible to pre-run uisetups for part of the
extensions manually.

diff --git a/hgext/chgserver.py b/mercurial/chgserver.py
copy from hgext/chgserver.py
copy to mercurial/chgserver.py
--- a/hgext/chgserver.py
+++ b/mercurial/chgserver.py
@@ -51,7 +51,7 @@ import sys
 import time
 
-from mercurial.i18n import _
+from .i18n import _
 
-from mercurial import (
+from . import (
     cmdutil,
     commands,
@@ -125,5 +125,5 @@ def _getmtimepaths(ui):
     modules = [m for n, m in extensions.extensions(ui)]
     try:
-        from mercurial import __version__
+        from . import __version__
         modules.append(__version__)
     except ImportError: