inhibit: add extension to warn evolve beta users

Summary: inhibit: add extension to warn evolve beta users

Test Plan:
Checked with and without cutoff date set in hgrc that the message
is displayed when it has to.

Reviewers: durham, pyd

Differential Revision: https://phabricator.fb.com/D2080693

Tasks: 6634899

inhibitwarn.py

@@ -0,0 +1,56 @@
+# inhibitwarn.py - Warn beta evolve users of the new inhibit extension
+#
+# Copyright 2015 Facebook, Inc.
+#
+# As we are rolling out inhibit, our evolve beta testers have to change their
+# config to keep using evolve unhinibitted as before. The goal of this extension
+# is to warn these users about inhibit and tell them how to deactivate it.
+#
+# To know who those users are we check the date of oldest obsolescence marker.
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+from mercurial import extensions
+from mercurial import localrepo
+import datetime
+msg = """
++------------------------------------------------------------------------------+
+|You seem to be an evolve beta user. We installed the inhibit extension        |
+|on your computer and it will inhibit the effect of evolve and disturb         |
+|your workflow. You need to disable inhibit in your .hgrc to keep working      |
+|with evolve. Use hg config --local to open your local config and add the next |
+|two lines:                                                                    |
+|[extensions]                                                                  |
+|inhibit=!                                                                     |
+|                                                                              |
+|If you are no longer an evolve beta user and you don't want to see this error |
+|with evolve ue hg config --local to open your local config and add the next   |
+|two lines:                                                                    |
+|[inhibit]                                                                     |
+|bypass-warning=True                                                           |
++------------------------------------------------------------------------------+
+"""
+
+def reposetup(ui, repo):
+    # No need to check anything if inhibit is not enabled
+    try:
+        if not extensions.find('inhibit'):
+            return
+    except KeyError:
+        return
+
+    bypass = repo.ui.configbool('inhibit', 'bypass-warning', False)
+    if bypass:
+        return
+    cutoffdate = repo.ui.config('inhibit', 'cutoff') or '18/05/2015'
+    cutofftime = int(datetime.datetime.strptime(cutoffdate,
+                    '%d/%m/%Y').strftime("%s"))
+    if repo.local():
+        for marker in repo.obsstore._all:
+            timestamp = marker[4][0]
+            if timestamp < cutofftime:
+                ui.write_err(msg)
+            # Only the first marker is checked as they are ordered chronologically
+            break
+

setup.py

@@ -22,6 +22,7 @@ setup(
         'githelp',
         'gitlookup',
         'gitrevset',
+        'inhibitwarn',
         'phabdiff',
         'phrevset',
         'pushvars',