cext: fix memory leak in phases computation
Without this a buffer whose size in bytes is the number of
changesets in the repository is leaked each time the repository is
opened and changeset phases are computed.
Impact: the current code in hgwebdir creates a new `localrepository`
instance for each HTTP request. Since any pull or push is made of several
requests, a team of 100 people can easily produce thousands of such
requests per day.
Being a low-level malloc, this leak can't be seen with the gc module and
tools relying on that, but was spotted by valgrind immediately.
Reproduction
------------
for i in range(cl_args.iterations):
repo = hg.repository(baseui, repo_path)
rev = repo.revs(rev).first()
ctx = repo[rev]
del ctx
del repo
# avoid any pollution by other type of leak
# (that should be fixed in 5.8)
repoview._filteredrepotypes.clear()
gc.collect()
Measurements
------------
Resident Set Size (RSS), taken on a clone of
mozilla-central for performance analysis (440 000
changesets).
before:
5.8+hg19.5ac0f2a8ba72 1000 iterations: 1606MB
5.8+hg19.5ac0f2a8ba72 10000 iterations: 5723MB
after:
5.8+hg20.e2084d39e145 1000 iterations: 555MB
5.8+hg20.e2084d39e145 10000 iterations: 555MB
(double checked, not a copy/paste error)
(e2084d39e14 is the present changeset, before amendment
of the message to add the measurements)
from __future__ import absolute_import
from __future__ import print_function
import unittest
from mercurial import (
mdiff,
pycompat,
)
from mercurial.dagop import (
annotateline,
_annotatedfile,
_annotatepair,
)
def tr(a):
return [
annotateline(fctx, lineno, skip)
for fctx, lineno, skip in zip(a.fctxs, a.linenos, a.skips)
]
class AnnotateTests(unittest.TestCase):
"""Unit tests for annotate code."""
def testannotatepair(self):
self.maxDiff = None # camelcase-required
oldfctx = b'old'
p1fctx, p2fctx, childfctx = b'p1', b'p2', b'c'
olddata = b'a\nb\n'
p1data = b'a\nb\nc\n'
p2data = b'a\nc\nd\n'
childdata = b'a\nb2\nc\nc2\nd\n'
diffopts = mdiff.diffopts()
def decorate(text, fctx):
n = text.count(b'\n')
linenos = pycompat.rangelist(1, n + 1)
return _annotatedfile([fctx] * n, linenos, [False] * n, text)
# Basic usage
oldann = decorate(olddata, oldfctx)
p1ann = decorate(p1data, p1fctx)
p1ann = _annotatepair([oldann], p1fctx, p1ann, False, diffopts)
self.assertEqual(
tr(p1ann),
[
annotateline(b'old', 1),
annotateline(b'old', 2),
annotateline(b'p1', 3),
],
)
p2ann = decorate(p2data, p2fctx)
p2ann = _annotatepair([oldann], p2fctx, p2ann, False, diffopts)
self.assertEqual(
tr(p2ann),
[
annotateline(b'old', 1),
annotateline(b'p2', 2),
annotateline(b'p2', 3),
],
)
# Test with multiple parents (note the difference caused by ordering)
childann = decorate(childdata, childfctx)
childann = _annotatepair(
[p1ann, p2ann], childfctx, childann, False, diffopts
)
self.assertEqual(
tr(childann),
[
annotateline(b'old', 1),
annotateline(b'c', 2),
annotateline(b'p2', 2),
annotateline(b'c', 4),
annotateline(b'p2', 3),
],
)
childann = decorate(childdata, childfctx)
childann = _annotatepair(
[p2ann, p1ann], childfctx, childann, False, diffopts
)
self.assertEqual(
tr(childann),
[
annotateline(b'old', 1),
annotateline(b'c', 2),
annotateline(b'p1', 3),
annotateline(b'c', 4),
annotateline(b'p2', 3),
],
)
# Test with skipchild (note the difference caused by ordering)
childann = decorate(childdata, childfctx)
childann = _annotatepair(
[p1ann, p2ann], childfctx, childann, True, diffopts
)
self.assertEqual(
tr(childann),
[
annotateline(b'old', 1),
annotateline(b'old', 2, True),
# note that this line was carried over from earlier so it is *not*
# marked skipped
annotateline(b'p2', 2),
annotateline(b'p2', 2, True),
annotateline(b'p2', 3),
],
)
childann = decorate(childdata, childfctx)
childann = _annotatepair(
[p2ann, p1ann], childfctx, childann, True, diffopts
)
self.assertEqual(
tr(childann),
[
annotateline(b'old', 1),
annotateline(b'old', 2, True),
annotateline(b'p1', 3),
annotateline(b'p1', 3, True),
annotateline(b'p2', 3),
],
)
if __name__ == '__main__':
import silenttestrunner
silenttestrunner.main(__name__)