diff mercurial/upgrade.py @ 33438:8056481caa81

codemod: simplify nested withs

This is the result of running:

  python codemod_nestedwith.py **/*.py

where codemod_nestedwith.py looks like this:

#!/usr/bin/env python
# codemod_nestedwith.py - codemod tool to rewrite nested with
#
# Copyright 2017 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.
from __future__ import absolute_import, print_function

import sys

import redbaron

def readpath(path):
    with open(path) as f:
        return f.read()

def writepath(path, content):
    with open(path, 'w') as f:
        f.write(content)

def main(argv):
    if not argv:
        print('Usage: codemod_nestedwith.py FILES')

    for i, path in enumerate(argv):
        print('(%d/%d) scanning %s' % (i + 1, len(argv), path))
        changed = False
        red = redbaron.RedBaron(readpath(path))
        processed = set()
        for node in red.find_all('with'):
            if node in processed or node.type != 'with':
                continue
            top = node
            child = top[0]
            while True:
                if len(top) > 1 or child.type != 'with':
                    break
                # estimate line length after merging two "with"s
                new = '%swith %s:' % (top.indentation, top.contexts.dumps())
                new += ', %s' % child.contexts.dumps()
                # only do the rewrite if the end result is within 80 chars
                if len(new) > 80:
                    break
                processed.add(child)
                top.contexts.extend(child.contexts)
                top.value = child.value
                top.value.decrease_indentation(4)
                child = child[0]
                changed = True
        if changed:
            print('updating %s' % path)
            writepath(path, red.dumps())

if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))


Differential Revision: https://phab.mercurial-scm.org/D77

--- a/mercurial/upgrade.py	Mon Aug 08 18:14:42 2016 +0200
+++ b/mercurial/upgrade.py	Thu Jul 13 18:31:35 2017 -0700
@@ -792,35 +792,33 @@
     upgradeactions = [a.name for a in actions]
 
     ui.write(_('beginning upgrade...\n'))
-    with repo.wlock():
-        with repo.lock():
-            ui.write(_('repository locked and read-only\n'))
-            # Our strategy for upgrading the repository is to create a new,
-            # temporary repository, write data to it, then do a swap of the
-            # data. There are less heavyweight ways to do this, but it is easier
-            # to create a new repo object than to instantiate all the components
-            # (like the store) separately.
-            tmppath = tempfile.mkdtemp(prefix='upgrade.', dir=repo.path)
-            backuppath = None
-            try:
-                ui.write(_('creating temporary repository to stage migrated '
-                           'data: %s\n') % tmppath)
-                dstrepo = localrepo.localrepository(repo.baseui,
-                                                    path=tmppath,
-                                                    create=True)
+    with repo.wlock(), repo.lock():
+        ui.write(_('repository locked and read-only\n'))
+        # Our strategy for upgrading the repository is to create a new,
+        # temporary repository, write data to it, then do a swap of the
+        # data. There are less heavyweight ways to do this, but it is easier
+        # to create a new repo object than to instantiate all the components
+        # (like the store) separately.
+        tmppath = tempfile.mkdtemp(prefix='upgrade.', dir=repo.path)
+        backuppath = None
+        try:
+            ui.write(_('creating temporary repository to stage migrated '
+                       'data: %s\n') % tmppath)
+            dstrepo = localrepo.localrepository(repo.baseui,
+                                                path=tmppath,
+                                                create=True)
 
-                with dstrepo.wlock():
-                    with dstrepo.lock():
-                        backuppath = _upgraderepo(ui, repo, dstrepo, newreqs,
-                                                  upgradeactions)
+            with dstrepo.wlock(), dstrepo.lock():
+                backuppath = _upgraderepo(ui, repo, dstrepo, newreqs,
+                                          upgradeactions)
 
-            finally:
-                ui.write(_('removing temporary repository %s\n') % tmppath)
-                repo.vfs.rmtree(tmppath, forcibly=True)
+        finally:
+            ui.write(_('removing temporary repository %s\n') % tmppath)
+            repo.vfs.rmtree(tmppath, forcibly=True)
 
-                if backuppath:
-                    ui.warn(_('copy of old repository backed up at %s\n') %
-                            backuppath)
-                    ui.warn(_('the old repository will not be deleted; remove '
-                              'it to free up disk space once the upgraded '
-                              'repository is verified\n'))
+            if backuppath:
+                ui.warn(_('copy of old repository backed up at %s\n') %
+                        backuppath)
+                ui.warn(_('the old repository will not be deleted; remove '
+                          'it to free up disk space once the upgraded '
+                          'repository is verified\n'))