Mercurial > hg
view tests/test-parseindex.t @ 25881:9de443515f1d stable
help: scripting help topic
There are a lot of non-human consumers of Mercurial. And the challenges
and considerations for machines consuming Mercurial is significantly
different from what humans face.
I think there are enough special considerations around how machines
consume Mercurial that a dedicated help topic is warranted. I concede
the audience for this topic is probably small compared to the general
audience. However, lots of normal Mercurial users do things like create
one-off shell scripts for common workflows that I think this is useful
enough to be in the install (as opposed to, say, a wiki page - which
most users will likely never find).
This text is by no means perfect. But you have to start somewhere. I
think I did cover the important parts, though.
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Sat, 18 Jul 2015 17:10:28 -0700 |
parents | 1619563959b3 |
children | c8d41c9c23c7 |
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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 mercurial import changelog, scmutil > from mercurial.node import * > > 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 opener(*args): > o = scmutil.opener(*args) > def wrapper(*a): > f = o(*a) > return singlebyteread(f) > return wrapper > > cl = changelog.changelog(opener('.hg/store')) > print len(cl), 'revisions:' > for r in cl: > print short(cl.node(r)) > EOF $ python test.py 2 revisions: 7c31755bf9b5 26333235a41c $ cd .. Test corrupted p1/p2 fields that could cause SEGV at parsers.c: #if no-pure $ mkdir invalidparent $ cd invalidparent $ hg clone --pull -q --config phases.publish=False ../a limit $ hg clone --pull -q --config phases.publish=False ../a segv $ rm -R limit/.hg/cache segv/.hg/cache $ python <<EOF > data = open("limit/.hg/store/00changelog.i", "rb").read() > for n, p in [('limit', '\0\0\0\x02'), ('segv', '\0\x01\0\0')]: > # corrupt p1 at rev0 and p2 at rev1 > d = data[:24] + p + data[28:127 + 28] + p + data[127 + 32:] > open(n + "/.hg/store/00changelog.i", "wb").write(d) > EOF $ hg debugindex -f1 limit/.hg/store/00changelog.i rev flag offset length size base link p1 p2 nodeid 0 0000 0 63 62 0 0 2 -1 7c31755bf9b5 1 0000 63 66 65 1 1 0 2 26333235a41c $ hg debugindex -f1 segv/.hg/store/00changelog.i rev flag offset length size base link p1 p2 nodeid 0 0000 0 63 62 0 0 65536 -1 7c31755bf9b5 1 0000 63 66 65 1 1 0 65536 26333235a41c $ cat <<EOF > test.py > import sys > from mercurial import changelog, scmutil > cl = changelog.changelog(scmutil.vfs(sys.argv[1])) > n0, n1 = cl.node(0), cl.node(1) > ops = [ > ('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 + ':', > try: > f() > print 'uncaught buffer overflow?' > except ValueError, inst: > print inst > EOF $ python test.py limit/.hg/store 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 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