push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
import unittest
from mercurial import policy
from mercurial.testing import revlog as revlogtesting
PartialDiscovery = policy.importrust('discovery', member='PartialDiscovery')
try:
from mercurial.cext import parsers as cparsers
except ImportError:
cparsers = None
# picked from test-parse-index2, copied rather than imported
# so that it stays stable even if test-parse-index2 changes or disappears.
data_non_inlined = (
b'\x00\x00\x00\x01\x00\x00\x00\x00\x00\x01D\x19'
b'\x00\x07e\x12\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff'
b'\xff\xff\xff\xff\xd1\xf4\xbb\xb0\xbe\xfc\x13\xbd\x8c\xd3\x9d'
b'\x0f\xcd\xd9;\x8c\x07\x8cJ/\x00\x00\x00\x00\x00\x00\x00\x00\x00'
b'\x00\x00\x00\x00\x00\x00\x01D\x19\x00\x00\x00\x00\x00\xdf\x00'
b'\x00\x01q\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x00\xff'
b'\xff\xff\xff\xc1\x12\xb9\x04\x96\xa4Z1t\x91\xdfsJ\x90\xf0\x9bh'
b'\x07l&\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
b'\x00\x01D\xf8\x00\x00\x00\x00\x01\x1b\x00\x00\x01\xb8\x00\x00'
b'\x00\x01\x00\x00\x00\x02\x00\x00\x00\x01\xff\xff\xff\xff\x02\n'
b'\x0e\xc6&\xa1\x92\xae6\x0b\x02i\xfe-\xe5\xbao\x05\xd1\xe7\x00'
b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01F'
b'\x13\x00\x00\x00\x00\x01\xec\x00\x00\x03\x06\x00\x00\x00\x01'
b'\x00\x00\x00\x03\x00\x00\x00\x02\xff\xff\xff\xff\x12\xcb\xeby1'
b'\xb6\r\x98B\xcb\x07\xbd`\x8f\x92\xd9\xc4\x84\xbdK\x00\x00\x00'
b'\x00\x00\x00\x00\x00\x00\x00\x00\x00'
)
class fakechangelog:
def __init__(self, idx):
self.index = idx
class fakerepo:
def __init__(self, idx):
"""Just make so that self.changelog.index is the given idx."""
self.changelog = fakechangelog(idx)
@unittest.skipIf(
PartialDiscovery is None or cparsers is None,
"rustext or the C Extension parsers module "
"discovery relies on is not available",
)
class rustdiscoverytest(revlogtesting.RustRevlogBasedTestBase):
"""Test the correctness of binding to Rust code.
This test is merely for the binding to Rust itself: extraction of
Python variable, giving back the results etc.
It is not meant to test the algorithmic correctness of the provided
methods. Hence the very simple embedded index data is good enough.
Algorithmic correctness is asserted by the Rust unit tests.
"""
def parseindex(self):
return self.parserustindex(data=data_non_inlined)
def repo(self):
return fakerepo(self.parseindex())
def testindex(self):
idx = self.parseindex()
# checking our assumptions about the index binary data:
self.assertEqual(
{i: (r[5], r[6]) for i, r in enumerate(idx)},
{0: (-1, -1), 1: (0, -1), 2: (1, -1), 3: (2, -1)},
)
def testaddcommonsmissings(self):
disco = PartialDiscovery(self.repo(), [3], True)
self.assertFalse(disco.hasinfo())
self.assertFalse(disco.iscomplete())
disco.addcommons([1])
self.assertTrue(disco.hasinfo())
self.assertFalse(disco.iscomplete())
disco.addmissings([2])
self.assertTrue(disco.hasinfo())
self.assertTrue(disco.iscomplete())
self.assertEqual(disco.commonheads(), {1})
def testaddmissingsstats(self):
disco = PartialDiscovery(self.repo(), [3], True)
self.assertIsNone(disco.stats()['undecided'], None)
disco.addmissings([2])
self.assertEqual(disco.stats()['undecided'], 2)
def testaddinfocommonfirst(self):
disco = PartialDiscovery(self.repo(), [3], True)
disco.addinfo([(1, True), (2, False)])
self.assertTrue(disco.hasinfo())
self.assertTrue(disco.iscomplete())
self.assertEqual(disco.commonheads(), {1})
def testaddinfomissingfirst(self):
disco = PartialDiscovery(self.repo(), [3], True)
disco.addinfo([(2, False), (1, True)])
self.assertTrue(disco.hasinfo())
self.assertTrue(disco.iscomplete())
self.assertEqual(disco.commonheads(), {1})
def testinitnorandom(self):
PartialDiscovery(self.repo(), [3], True, randomize=False)
if __name__ == '__main__':
import silenttestrunner
silenttestrunner.main(__name__)