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view tests/test-parseindex.t @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | 07ade2dc41db |
children | 3518da504303 |
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revlog.parseindex must be able to parse the index file even if an index entry is split between two 64k blocks. The ideal test would be to create an index file with inline data where 64k < size < 64k + 64 (64k is the size of the read buffer, 64 is the size of an index entry) and with an index entry starting right before the 64k block boundary, and try to read it. We approximate that by reducing the read buffer to 1 byte. $ hg init a $ cd a $ echo abc > foo $ hg add foo $ hg commit -m 'add foo' $ echo >> foo $ hg commit -m 'change foo' $ hg log -r 0: changeset: 0:7c31755bf9b5 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: add foo changeset: 1:26333235a41c tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: change foo $ cat >> test.py << EOF > from __future__ import print_function > from mercurial import changelog, node, pycompat, vfs > > class singlebyteread(object): > def __init__(self, real): > self.real = real > > def read(self, size=-1): > if size == 65536: > size = 1 > return self.real.read(size) > > def __getattr__(self, key): > return getattr(self.real, key) > > def __enter__(self): > self.real.__enter__() > return self > > def __exit__(self, *args, **kwargs): > return self.real.__exit__(*args, **kwargs) > > def opener(*args): > o = vfs.vfs(*args) > def wrapper(*a, **kwargs): > f = o(*a, **kwargs) > return singlebyteread(f) > return wrapper > > cl = changelog.changelog(opener(b'.hg/store')) > print(len(cl), 'revisions:') > for r in cl: > print(pycompat.sysstr(node.short(cl.node(r)))) > EOF $ "$PYTHON" test.py 2 revisions: 7c31755bf9b5 26333235a41c $ cd .. #if no-pure Test SEGV caused by bad revision passed to reachableroots() (issue4775): $ cd a $ "$PYTHON" <<EOF > from __future__ import print_function > from mercurial import changelog, vfs > cl = changelog.changelog(vfs.vfs(b'.hg/store')) > print('good heads:') > for head in [0, len(cl) - 1, -1]: > print('%s: %r' % (head, cl.reachableroots(0, [head], [0]))) > print('bad heads:') > for head in [len(cl), 10000, -2, -10000, None]: > print('%s:' % head, end=' ') > try: > cl.reachableroots(0, [head], [0]) > print('uncaught buffer overflow?') > except (IndexError, TypeError) as inst: > print(inst) > print('good roots:') > for root in [0, len(cl) - 1, -1]: > print('%s: %r' % (root, cl.reachableroots(root, [len(cl) - 1], [root]))) > print('out-of-range roots are ignored:') > for root in [len(cl), 10000, -2, -10000]: > print('%s: %r' % (root, cl.reachableroots(root, [len(cl) - 1], [root]))) > print('bad roots:') > for root in [None]: > print('%s:' % root, end=' ') > try: > cl.reachableroots(root, [len(cl) - 1], [root]) > print('uncaught error?') > except TypeError as inst: > print(inst) > EOF good heads: 0: [0] 1: [0] -1: [] bad heads: 2: head out of range 10000: head out of range -2: head out of range -10000: head out of range None: an integer is required( .got type NoneType.)? (re) good roots: 0: [0] 1: [1] -1: [-1] out-of-range roots are ignored: 2: [] 10000: [] -2: [] -10000: [] bad roots: None: an integer is required( .got type NoneType.)? (re) $ cd .. Test corrupted p1/p2 fields that could cause SEGV at parsers.c: $ mkdir invalidparent $ cd invalidparent $ hg clone --pull -q --config phases.publish=False ../a limit --config format.sparse-revlog=no $ hg clone --pull -q --config phases.publish=False ../a neglimit --config format.sparse-revlog=no $ hg clone --pull -q --config phases.publish=False ../a segv --config format.sparse-revlog=no $ rm -R limit/.hg/cache neglimit/.hg/cache segv/.hg/cache $ "$PYTHON" <<EOF > data = open("limit/.hg/store/00changelog.i", "rb").read() > poisons = [ > (b'limit', b'\0\0\0\x02'), > (b'neglimit', b'\xff\xff\xff\xfe'), > (b'segv', b'\0\x01\0\0'), > ] > for n, p in poisons: > # corrupt p1 at rev0 and p2 at rev1 > d = data[:24] + p + data[28:127 + 28] + p + data[127 + 32:] > open(n + b"/.hg/store/00changelog.i", "wb").write(d) > EOF $ hg -R limit debugrevlogindex -f1 -c rev flag size link p1 p2 nodeid 0 0000 62 0 2 -1 7c31755bf9b5 1 0000 65 1 0 2 26333235a41c $ hg -R limit debugdeltachain -c rev chain# chainlen prev delta size rawsize chainsize ratio lindist extradist extraratio 0 1 1 -1 base 63 62 63 1.01613 63 0 0.00000 1 2 1 -1 base 66 65 66 1.01538 66 0 0.00000 $ hg -R neglimit debugrevlogindex -f1 -c rev flag size link p1 p2 nodeid 0 0000 62 0 -2 -1 7c31755bf9b5 1 0000 65 1 0 -2 26333235a41c $ hg -R segv debugrevlogindex -f1 -c rev flag size link p1 p2 nodeid 0 0000 62 0 65536 -1 7c31755bf9b5 1 0000 65 1 0 65536 26333235a41c $ hg -R segv debugdeltachain -c rev chain# chainlen prev delta size rawsize chainsize ratio lindist extradist extraratio 0 1 1 -1 base 63 62 63 1.01613 63 0 0.00000 1 2 1 -1 base 66 65 66 1.01538 66 0 0.00000 $ cat <<EOF > test.py > from __future__ import print_function > import sys > from mercurial import changelog, pycompat, vfs > cl = changelog.changelog(vfs.vfs(pycompat.fsencode(sys.argv[1]))) > n0, n1 = cl.node(0), cl.node(1) > ops = [ > ('reachableroots', > lambda: cl.index.reachableroots2(0, [1], [0], False)), > ('compute_phases_map_sets', lambda: cl.computephases([[0], []])), > ('index_headrevs', lambda: cl.headrevs()), > ('find_gca_candidates', lambda: cl.commonancestorsheads(n0, n1)), > ('find_deepest', lambda: cl.ancestor(n0, n1)), > ] > for l, f in ops: > print(l + ':', end=' ') > try: > f() > print('uncaught buffer overflow?') > except ValueError as inst: > print(inst) > EOF $ "$PYTHON" test.py limit/.hg/store reachableroots: parent out of range compute_phases_map_sets: parent out of range index_headrevs: parent out of range find_gca_candidates: parent out of range find_deepest: parent out of range $ "$PYTHON" test.py neglimit/.hg/store reachableroots: parent out of range compute_phases_map_sets: parent out of range index_headrevs: parent out of range find_gca_candidates: parent out of range find_deepest: parent out of range $ "$PYTHON" test.py segv/.hg/store reachableroots: parent out of range compute_phases_map_sets: parent out of range index_headrevs: parent out of range find_gca_candidates: parent out of range find_deepest: parent out of range $ cd .. #endif