perf: clear vfs audit_cache before each run
When generating a stream clone, we spend a large amount of time auditing path.
Before this changes, the first run was warming the vfs cache for the other
runs, leading to a large runtime difference and a "faulty" reported timing for
the operation.
We now clear this important cache between run to get a more realistic timing.
Below are some example of median time change when clearing these cases. The
maximum time for a run did not changed significantly.
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# benchmark.name = hg.perf.exchange.stream.generate
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.version = latest
no-clearing: 17.289905
cache-clearing: 21.587965 (+24.86%, +4.30)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
no-clearing: 32.670748
cache-clearing: 40.467095 (+23.86%, +7.80)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
no-clearing: 37.838858
cache-clearing: 46.072749 (+21.76%, +8.23)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
no-clearing: 32.969395
cache-clearing: 39.646209 (+20.25%, +6.68)
In addition, this significantly reduce the timing difference between the
performance command, from the perf extensions and a `real `hg bundle` call
producing a stream bundle. Some significant differences remain especially on
the "mozilla-try" repositories, but they are now smaller.
Note that some of that difference will actually not be
attributable to the stream generation (like maybe phases or branch map
computation).
Below are some benchmarks done on a currently draft changeset fixing some
unrelated slowness in `hg bundle` (34a78972af409d1ff37c29e60f6ca811ad1a457d)
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
hg.perf.exchange.stream.generate: 21.587965
hg.command.bundle: 24.301799 (+12.57%, +2.71)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 40.467095
hg.command.bundle: 44.831317 (+10.78%, +4.36)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 39.646209
hg.command.bundle: 45.395258 (+14.50%, +5.75)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 46.072749
hg.command.bundle: 55.882608 (+21.29%, +9.81)
## data-env-vars.name = mozilla-try-2023-03-22-zlib-general-delta
hg.perf.exchange.stream.generate: 334.716708
hg.command.bundle: 377.856767 (+12.89%, +43.14)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 302.972301
hg.command.bundle: 326.098755 (+7.63%, +23.13)
#!/usr/bin/env python
import hashlib
import os
import random
import shutil
import stat
import struct
import sys
import tempfile
import unittest
import silenttestrunner
from mercurial.node import sha1nodeconstants
from mercurial import (
pycompat,
ui as uimod,
)
# Load the local remotefilelog, not the system one
sys.path[0:0] = [os.path.join(os.path.dirname(__file__), '..')]
from hgext.remotefilelog import (
basepack,
historypack,
)
class histpacktests(unittest.TestCase):
def setUp(self):
self.tempdirs = []
def tearDown(self):
for d in self.tempdirs:
shutil.rmtree(d)
def makeTempDir(self):
tempdir = tempfile.mkdtemp()
self.tempdirs.append(tempdir)
return pycompat.fsencode(tempdir)
def getHash(self, content):
return hashlib.sha1(content).digest()
def getFakeHash(self):
return b''.join(
pycompat.bytechr(random.randint(0, 255)) for _ in range(20)
)
def createPack(self, revisions=None):
"""Creates and returns a historypack containing the specified revisions.
`revisions` is a list of tuples, where each tuple contains a filanem,
node, p1node, p2node, and linknode.
"""
if revisions is None:
revisions = [
(
b"filename",
self.getFakeHash(),
sha1nodeconstants.nullid,
sha1nodeconstants.nullid,
self.getFakeHash(),
None,
)
]
packdir = pycompat.fsencode(self.makeTempDir())
packer = historypack.mutablehistorypack(uimod.ui(), packdir, version=2)
for filename, node, p1, p2, linknode, copyfrom in revisions:
packer.add(filename, node, p1, p2, linknode, copyfrom)
path = packer.close()
return historypack.historypack(path)
def testAddSingle(self):
"""Test putting a single entry into a pack and reading it out."""
filename = b"foo"
node = self.getFakeHash()
p1 = self.getFakeHash()
p2 = self.getFakeHash()
linknode = self.getFakeHash()
revisions = [(filename, node, p1, p2, linknode, None)]
pack = self.createPack(revisions)
actual = pack.getancestors(filename, node)[node]
self.assertEqual(p1, actual[0])
self.assertEqual(p2, actual[1])
self.assertEqual(linknode, actual[2])
def testAddMultiple(self):
"""Test putting multiple unrelated revisions into a pack and reading
them out.
"""
revisions = []
for i in range(10):
filename = b"foo-%d" % i
node = self.getFakeHash()
p1 = self.getFakeHash()
p2 = self.getFakeHash()
linknode = self.getFakeHash()
revisions.append((filename, node, p1, p2, linknode, None))
pack = self.createPack(revisions)
for filename, node, p1, p2, linknode, copyfrom in revisions:
actual = pack.getancestors(filename, node)[node]
self.assertEqual(p1, actual[0])
self.assertEqual(p2, actual[1])
self.assertEqual(linknode, actual[2])
self.assertEqual(copyfrom, actual[3])
def testAddAncestorChain(self):
"""Test putting multiple revisions in into a pack and read the ancestor
chain.
"""
revisions = []
filename = b"foo"
lastnode = sha1nodeconstants.nullid
for i in range(10):
node = self.getFakeHash()
revisions.append(
(
filename,
node,
lastnode,
sha1nodeconstants.nullid,
sha1nodeconstants.nullid,
None,
)
)
lastnode = node
# revisions must be added in topological order, newest first
revisions = list(reversed(revisions))
pack = self.createPack(revisions)
# Test that the chain has all the entries
ancestors = pack.getancestors(revisions[0][0], revisions[0][1])
for filename, node, p1, p2, linknode, copyfrom in revisions:
ap1, ap2, alinknode, acopyfrom = ancestors[node]
self.assertEqual(ap1, p1)
self.assertEqual(ap2, p2)
self.assertEqual(alinknode, linknode)
self.assertEqual(acopyfrom, copyfrom)
def testPackMany(self):
"""Pack many related and unrelated ancestors."""
# Build a random pack file
allentries = {}
ancestorcounts = {}
revisions = []
random.seed(0)
for i in range(100):
filename = b"filename-%d" % i
entries = []
p2 = sha1nodeconstants.nullid
linknode = sha1nodeconstants.nullid
for j in range(random.randint(1, 100)):
node = self.getFakeHash()
p1 = sha1nodeconstants.nullid
if len(entries) > 0:
p1 = entries[random.randint(0, len(entries) - 1)]
entries.append(node)
revisions.append((filename, node, p1, p2, linknode, None))
allentries[(filename, node)] = (p1, p2, linknode)
if p1 == sha1nodeconstants.nullid:
ancestorcounts[(filename, node)] = 1
else:
newcount = ancestorcounts[(filename, p1)] + 1
ancestorcounts[(filename, node)] = newcount
# Must add file entries in reverse topological order
revisions = list(reversed(revisions))
pack = self.createPack(revisions)
# Verify the pack contents
for (filename, node) in allentries:
ancestors = pack.getancestors(filename, node)
self.assertEqual(ancestorcounts[(filename, node)], len(ancestors))
for anode, (ap1, ap2, alinknode, copyfrom) in ancestors.items():
ep1, ep2, elinknode = allentries[(filename, anode)]
self.assertEqual(ap1, ep1)
self.assertEqual(ap2, ep2)
self.assertEqual(alinknode, elinknode)
self.assertEqual(copyfrom, None)
def testGetNodeInfo(self):
revisions = []
filename = b"foo"
lastnode = sha1nodeconstants.nullid
for i in range(10):
node = self.getFakeHash()
revisions.append(
(
filename,
node,
lastnode,
sha1nodeconstants.nullid,
sha1nodeconstants.nullid,
None,
)
)
lastnode = node
pack = self.createPack(revisions)
# Test that getnodeinfo returns the expected results
for filename, node, p1, p2, linknode, copyfrom in revisions:
ap1, ap2, alinknode, acopyfrom = pack.getnodeinfo(filename, node)
self.assertEqual(ap1, p1)
self.assertEqual(ap2, p2)
self.assertEqual(alinknode, linknode)
self.assertEqual(acopyfrom, copyfrom)
def testGetMissing(self):
"""Test the getmissing() api."""
revisions = []
filename = b"foo"
for i in range(10):
node = self.getFakeHash()
p1 = self.getFakeHash()
p2 = self.getFakeHash()
linknode = self.getFakeHash()
revisions.append((filename, node, p1, p2, linknode, None))
pack = self.createPack(revisions)
missing = pack.getmissing([(filename, revisions[0][1])])
self.assertFalse(missing)
missing = pack.getmissing(
[(filename, revisions[0][1]), (filename, revisions[1][1])]
)
self.assertFalse(missing)
fakenode = self.getFakeHash()
missing = pack.getmissing(
[(filename, revisions[0][1]), (filename, fakenode)]
)
self.assertEqual(missing, [(filename, fakenode)])
# Test getmissing on a non-existant filename
missing = pack.getmissing([(b"bar", fakenode)])
self.assertEqual(missing, [(b"bar", fakenode)])
def testAddThrows(self):
pack = self.createPack()
try:
pack.add(
b'filename',
sha1nodeconstants.nullid,
sha1nodeconstants.nullid,
sha1nodeconstants.nullid,
sha1nodeconstants.nullid,
None,
)
self.assertTrue(False, "historypack.add should throw")
except RuntimeError:
pass
def testBadVersionThrows(self):
pack = self.createPack()
path = pack.path + b'.histpack'
with open(path, 'rb') as f:
raw = f.read()
raw = struct.pack('!B', 255) + raw[1:]
os.chmod(path, os.stat(path).st_mode | stat.S_IWRITE)
with open(path, 'wb+') as f:
f.write(raw)
try:
historypack.historypack(pack.path)
self.assertTrue(False, "bad version number should have thrown")
except RuntimeError:
pass
def testLargePack(self):
"""Test creating and reading from a large pack with over X entries.
This causes it to use a 2^16 fanout table instead."""
total = basepack.SMALLFANOUTCUTOFF + 1
revisions = []
for i in range(total):
filename = b"foo-%d" % i
node = self.getFakeHash()
p1 = self.getFakeHash()
p2 = self.getFakeHash()
linknode = self.getFakeHash()
revisions.append((filename, node, p1, p2, linknode, None))
pack = self.createPack(revisions)
self.assertEqual(pack.params.fanoutprefix, basepack.LARGEFANOUTPREFIX)
for filename, node, p1, p2, linknode, copyfrom in revisions:
actual = pack.getancestors(filename, node)[node]
self.assertEqual(p1, actual[0])
self.assertEqual(p2, actual[1])
self.assertEqual(linknode, actual[2])
self.assertEqual(copyfrom, actual[3])
# TODO:
# histpack store:
# - repack two packs into one
if __name__ == '__main__':
if pycompat.iswindows:
sys.exit(80) # Skip on Windows
silenttestrunner.main(__name__)