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)

import struct
import unittest

from mercurial.node import hex

try:
    from mercurial import rustext

    rustext.__name__  # trigger immediate actual import
except ImportError:
    rustext = None
else:
    from mercurial.rustext import revlog

    # this would fail already without appropriate ancestor.__package__
    from mercurial.rustext.ancestor import LazyAncestors

from mercurial.testing import revlog as revlogtesting

header = struct.unpack(">I", revlogtesting.data_non_inlined[:4])[0]


@unittest.skipIf(
    rustext is None,
    "rustext module revlog relies on is not available",
)
class RustRevlogIndexTest(revlogtesting.RevlogBasedTestBase):
    def test_heads(self):
        idx = self.parseindex()
        rustidx = revlog.Index(revlogtesting.data_non_inlined, header)
        self.assertEqual(rustidx.headrevs(), idx.headrevs())

    def test_len(self):
        idx = self.parseindex()
        rustidx = revlog.Index(revlogtesting.data_non_inlined, header)
        self.assertEqual(len(rustidx), len(idx))

    def test_ancestors(self):
        rustidx = revlog.Index(revlogtesting.data_non_inlined, header)
        lazy = LazyAncestors(rustidx, [3], 0, True)
        # we have two more references to the index:
        # - in its inner iterator for __contains__ and __bool__
        # - in the LazyAncestors instance itself (to spawn new iterators)
        self.assertTrue(2 in lazy)
        self.assertTrue(bool(lazy))
        self.assertEqual(list(lazy), [3, 2, 1, 0])
        # a second time to validate that we spawn new iterators
        self.assertEqual(list(lazy), [3, 2, 1, 0])

        # let's check bool for an empty one
        self.assertFalse(LazyAncestors(rustidx, [0], 0, False))


@unittest.skipIf(
    rustext is None,
    "rustext module revlog relies on is not available",
)
class RustRevlogNodeTreeClassTest(revlogtesting.RustRevlogBasedTestBase):
    def test_standalone_nodetree(self):
        idx = self.parserustindex()
        nt = revlog.NodeTree(idx)
        for i in range(4):
            nt.insert(i)

        bin_nodes = [entry[7] for entry in idx]
        hex_nodes = [hex(n) for n in bin_nodes]

        for i, node in enumerate(hex_nodes):
            self.assertEqual(nt.prefix_rev_lookup(node), i)
            self.assertEqual(nt.prefix_rev_lookup(node[:5]), i)

        # all 4 revisions in idx (standard data set) have different
        # first nybbles in their Node IDs,
        # hence `nt.shortest()` should return 1 for them, except when
        # the leading nybble is 0 (ambiguity with NULL_NODE)
        for i, (bin_node, hex_node) in enumerate(zip(bin_nodes, hex_nodes)):
            shortest = nt.shortest(bin_node)
            expected = 2 if hex_node[0] == ord('0') else 1
            self.assertEqual(shortest, expected)
            self.assertEqual(nt.prefix_rev_lookup(hex_node[:shortest]), i)

        # test invalidation (generation poisoning) detection
        del idx[3]
        self.assertTrue(nt.is_invalidated())


if __name__ == '__main__':
    import silenttestrunner

    silenttestrunner.main(__name__)