logtoprocess: rewrite dict building in py3-compatible way

hgext/logtoprocess.py

@@ -1,89 +1,90 b''
 # logtoprocess.py - send ui.log() data to a subprocess
 #
 # Copyright 2016 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 """send ui.log() data to a subprocess (EXPERIMENTAL)
 
 This extension lets you specify a shell command per ui.log() event,
 sending all remaining arguments to as environment variables to that command.
 
 Each positional argument to the method results in a `MSG[N]` key in the
 environment, starting at 1 (so `MSG1`, `MSG2`, etc.). Each keyword argument
 is set as a `OPT_UPPERCASE_KEY` variable (so the key is uppercased, and
 prefixed with `OPT_`). The original event name is passed in the `EVENT`
 environment variable, and the process ID of mercurial is given in `HGPID`.
 
 So given a call `ui.log('foo', 'bar', 'baz', spam='eggs'), a script configured
 for the `foo` event can expect an environment with `MSG1=bar`, `MSG2=baz`, and
 `OPT_SPAM=eggs`.
 
 Scripts are configured in the `[logtoprocess]` section, each key an event name.
 For example::
 
   [logtoprocess]
   commandexception = echo "$MSG2$MSG3" > /var/log/mercurial_exceptions.log
 
 would log the warning message and traceback of any failed command dispatch.
 
 Scripts are run asynchronously as detached daemon processes; mercurial will
 not ensure that they exit cleanly.
 
 """
 
 from __future__ import absolute_import
 
-import itertools
 import os
 
+from mercurial import (
+    pycompat,
+)
 from mercurial.utils import (
     procutil,
 )
 
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
 def uisetup(ui):
 
     class logtoprocessui(ui.__class__):
         def log(self, event, *msg, **opts):
             """Map log events to external commands
 
             Arguments are passed on as environment variables.
 
             """
             script = self.config('logtoprocess', event)
             if script:
                 if msg:
                     # try to format the log message given the remaining
                     # arguments
                     try:
                         # Format the message as blackbox does
                         formatted = msg[0] % msg[1:]
                     except (TypeError, KeyError):
                         # Failed to apply the arguments, ignore
                         formatted = msg[0]
                     messages = (formatted,) + msg[1:]
                 else:
                     messages = msg
+                env = {
+                    b'EVENT': event,
+                    b'HGPID': os.getpid(),
+                }
                 # positional arguments are listed as MSG[N] keys in the
                 # environment
-                msgpairs = (
-                    ('MSG{0:d}'.format(i), m)
-                    for i, m in enumerate(messages, 1))
+                env.update((b'MSG%d' % i, m) for i, m in enumerate(messages, 1))
                 # keyword arguments get prefixed with OPT_ and uppercased
-                optpairs = (
-                    ('OPT_{0}'.format(key.upper()), value)
-                    for key, value in opts.iteritems())
-                env = dict(itertools.chain(msgpairs, optpairs),
-                           EVENT=event, HGPID=os.getpid())
+                env.update((b'OPT_%s' % key.upper(), value)
+                           for key, value in pycompat.byteskwargs(opts).items())
                 fullenv = procutil.shellenviron(env)
                 procutil.runbgcommand(script, fullenv, shell=True)
             return super(logtoprocessui, self).log(event, *msg, **opts)
 
     # Replace the class for this instance and all clones created from it:
     ui.__class__ = logtoprocessui