infinitepush: add background backup

Summary:
`hg backup --background` will be used as a `txnclose` hook to backup all of the
local commits to infinitepush.

Test Plan: Run `test-infinitepush-*`

Reviewers: rmcelroy, mitrandir, durham

Reviewed By: durham

Subscribers: mjpieters, #sourcecontrol

Differential Revision: https://phabricator.intern.facebook.com/D4175953

Tasks: 12479677

Signature: t1:4175953:1479145307:e698903b519361b376f6e182db7c49869c992617

infinitepush/__init__.py

@@ -60,6 +60,7 @@ import resource
 import tempfile
 
 from collections import defaultdict
+from hgext3rd.extutil import runshellcommand
 from mercurial import (
     bundle2,
     changegroup,
@@ -621,13 +622,16 @@ def _push(orig, ui, repo, dest=None, *args, **opts):
             exchange._localphasemove = oldphasemove
     return result
 
-@command('debugbackup')
-def backup(ui, repo, dest=None):
+@command('debugbackup', [('', 'background', None, 'run backup in background')])
+def backup(ui, repo, dest=None, **opts):
     """
     Saves new non-extinct commits since the last `hg backup` or from 0 revision
     if this backup is the first.
     """
 
+    if opts.get('background'):
+        runshellcommand('hg backup', os.environ)
+        return 0
     backuptipfile = 'infinitepushbackuptip'
     backuptip = repo.svfs.tryread(backuptipfile)
     try:

setup.py

@@ -181,6 +181,7 @@ if not components:
 dependencies = {
     'absorb' : ['linelog'],
     'fastannotate' : ['linelog'],
+    'infinitepush' : ['extutil'],
     'remotefilelog' : ['cdatapack', 'extutil'],
     'treemanifest' : ['ctreemanifest', 'cdatapack', 'fastmanifest'],
 }

tests/test-infinitepush-backup.t

@@ -126,3 +126,18 @@ Create two more heads and backup them
   remote: pushing 2 commits:
   remote:     f79c5017def3  newhead1
   remote:     667453c0787e  newhead2
+
+Backup in background
+  $ cat .hg/store/infinitepushbackuptip
+  6 (no-eol)
+  $ mkcommit newcommit
+  $ tip=`hg log -r tip -T '{rev}'`
+  $ hg backup --background
+  >>> from time import sleep
+  >>> for i in range(5):
+  ...   sleep(0.1)
+  ...   backuptip = int(open('.hg/store/infinitepushbackuptip').read())
+  ...   if backuptip == 7:
+  ...     break
+  $ cat .hg/store/infinitepushbackuptip
+  7 (no-eol)