revlog: use existing file handle when reading during _addrevision
_addrevision() may need to read from revlogs as part of computing
deltas. Previously, we would flush existing file handles and open
a new, short-lived file handle to perform the reading.
If we have an existing file handle, it seems logical to reuse it
for reading instead of opening a new file handle. This patch
makes that the new behavior.
After this patch, revlog files are only reopened when adding
revisions if the revlog is switched from inline to non-inline.
On Linux when unbundling a bundle of the mozilla-central repo, this
patch has the following impact on system call counts:
Call Before After Delta
write 827,639 673,390 -154,249
open 700,103 684,089 -16,014
read 74,489 74,489 0
fstat 493,924 461,896 -32,028
close 249,131 233,117 -16,014
stat 242,001 242,001 0
lstat 18,676 18,676 0
lseek 20,268 20,268 0
ioctl 14,652 13,173 -1,479
TOTAL 3,180,758 2,930,679 -250,079
It's worth noting that many of the open() calls fail due to missing
files. That's why there are many more open() calls than close().
Despite the significant system call reduction, this change does not
seem to have a significant performance impact on Linux.
On Windows 10 (not a VM, on a SSD), this patch appears to reduce
unbundle time for mozilla-central from ~960s to ~920s. This isn't
as significant as I was hoping. But a decrease it is nonetheless.
Still, Windows unbundle performance is still >2x slower than Linux.
Despite the lack of significant gains, fewer system calls is fewer
system calls. If nothing else, this will narrow the focus of potential
areas to optimize in the future.
import os
def check(a, b):
if a != b:
print (a, b)
def cert(cn):
return {'subject': ((('commonName', cn),),)}
from mercurial.sslutil import _verifycert
# Test non-wildcard certificates
check(_verifycert(cert('example.com'), 'example.com'),
None)
check(_verifycert(cert('example.com'), 'www.example.com'),
'certificate is for example.com')
check(_verifycert(cert('www.example.com'), 'example.com'),
'certificate is for www.example.com')
# Test wildcard certificates
check(_verifycert(cert('*.example.com'), 'www.example.com'),
None)
check(_verifycert(cert('*.example.com'), 'example.com'),
'certificate is for *.example.com')
check(_verifycert(cert('*.example.com'), 'w.w.example.com'),
'certificate is for *.example.com')
# Test subjectAltName
san_cert = {'subject': ((('commonName', 'example.com'),),),
'subjectAltName': (('DNS', '*.example.net'),
('DNS', 'example.net'))}
check(_verifycert(san_cert, 'example.net'),
None)
check(_verifycert(san_cert, 'foo.example.net'),
None)
# no fallback to subject commonName when subjectAltName has DNS
check(_verifycert(san_cert, 'example.com'),
'certificate is for *.example.net, example.net')
# fallback to subject commonName when no DNS in subjectAltName
san_cert = {'subject': ((('commonName', 'example.com'),),),
'subjectAltName': (('IP Address', '8.8.8.8'),)}
check(_verifycert(san_cert, 'example.com'), None)
# Avoid some pitfalls
check(_verifycert(cert('*.foo'), 'foo'),
'certificate is for *.foo')
check(_verifycert(cert('*o'), 'foo'),
'certificate is for *o')
check(_verifycert({'subject': ()},
'example.com'),
'no commonName or subjectAltName found in certificate')
check(_verifycert(None, 'example.com'),
'no certificate received')
# Unicode (IDN) certname isn't supported
check(_verifycert(cert(u'\u4f8b.jp'), 'example.jp'),
'IDN in certificate not supported')
import doctest
def test_url():
"""
>>> from mercurial.util import url
This tests for edge cases in url.URL's parsing algorithm. Most of
these aren't useful for documentation purposes, so they aren't
part of the class's doc tests.
Query strings and fragments:
>>> url('http://host/a?b#c')
<url scheme: 'http', host: 'host', path: 'a', query: 'b', fragment: 'c'>
>>> url('http://host/a?')
<url scheme: 'http', host: 'host', path: 'a'>
>>> url('http://host/a#b#c')
<url scheme: 'http', host: 'host', path: 'a', fragment: 'b#c'>
>>> url('http://host/a#b?c')
<url scheme: 'http', host: 'host', path: 'a', fragment: 'b?c'>
>>> url('http://host/?a#b')
<url scheme: 'http', host: 'host', path: '', query: 'a', fragment: 'b'>
>>> url('http://host/?a#b', parsequery=False)
<url scheme: 'http', host: 'host', path: '?a', fragment: 'b'>
>>> url('http://host/?a#b', parsefragment=False)
<url scheme: 'http', host: 'host', path: '', query: 'a#b'>
>>> url('http://host/?a#b', parsequery=False, parsefragment=False)
<url scheme: 'http', host: 'host', path: '?a#b'>
IPv6 addresses:
>>> url('ldap://[2001:db8::7]/c=GB?objectClass?one')
<url scheme: 'ldap', host: '[2001:db8::7]', path: 'c=GB',
query: 'objectClass?one'>
>>> url('ldap://joe:xxx@[2001:db8::7]:80/c=GB?objectClass?one')
<url scheme: 'ldap', user: 'joe', passwd: 'xxx', host: '[2001:db8::7]',
port: '80', path: 'c=GB', query: 'objectClass?one'>
Missing scheme, host, etc.:
>>> url('://192.0.2.16:80/')
<url path: '://192.0.2.16:80/'>
>>> url('http://mercurial.selenic.com')
<url scheme: 'http', host: 'mercurial.selenic.com'>
>>> url('/foo')
<url path: '/foo'>
>>> url('bundle:/foo')
<url scheme: 'bundle', path: '/foo'>
>>> url('a?b#c')
<url path: 'a?b', fragment: 'c'>
>>> url('http://x.com?arg=/foo')
<url scheme: 'http', host: 'x.com', query: 'arg=/foo'>
>>> url('http://joe:xxx@/foo')
<url scheme: 'http', user: 'joe', passwd: 'xxx', path: 'foo'>
Just a scheme and a path:
>>> url('mailto:John.Doe@example.com')
<url scheme: 'mailto', path: 'John.Doe@example.com'>
>>> url('a:b:c:d')
<url path: 'a:b:c:d'>
>>> url('aa:bb:cc:dd')
<url scheme: 'aa', path: 'bb:cc:dd'>
SSH examples:
>>> url('ssh://joe@host//home/joe')
<url scheme: 'ssh', user: 'joe', host: 'host', path: '/home/joe'>
>>> url('ssh://joe:xxx@host/src')
<url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host', path: 'src'>
>>> url('ssh://joe:xxx@host')
<url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host'>
>>> url('ssh://joe@host')
<url scheme: 'ssh', user: 'joe', host: 'host'>
>>> url('ssh://host')
<url scheme: 'ssh', host: 'host'>
>>> url('ssh://')
<url scheme: 'ssh'>
>>> url('ssh:')
<url scheme: 'ssh'>
Non-numeric port:
>>> url('http://example.com:dd')
<url scheme: 'http', host: 'example.com', port: 'dd'>
>>> url('ssh://joe:xxx@host:ssh/foo')
<url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host', port: 'ssh',
path: 'foo'>
Bad authentication credentials:
>>> url('http://joe@joeville:123@4:@host/a?b#c')
<url scheme: 'http', user: 'joe@joeville', passwd: '123@4:',
host: 'host', path: 'a', query: 'b', fragment: 'c'>
>>> url('http://!*#?/@!*#?/:@host/a?b#c')
<url scheme: 'http', host: '!*', fragment: '?/@!*#?/:@host/a?b#c'>
>>> url('http://!*#?@!*#?:@host/a?b#c')
<url scheme: 'http', host: '!*', fragment: '?@!*#?:@host/a?b#c'>
>>> url('http://!*@:!*@@host/a?b#c')
<url scheme: 'http', user: '!*@', passwd: '!*@', host: 'host',
path: 'a', query: 'b', fragment: 'c'>
File paths:
>>> url('a/b/c/d.g.f')
<url path: 'a/b/c/d.g.f'>
>>> url('/x///z/y/')
<url path: '/x///z/y/'>
>>> url('/foo:bar')
<url path: '/foo:bar'>
>>> url('\\\\foo:bar')
<url path: '\\\\foo:bar'>
>>> url('./foo:bar')
<url path: './foo:bar'>
Non-localhost file URL:
>>> u = url('file://mercurial.selenic.com/foo')
Traceback (most recent call last):
File "<stdin>", line 1, in ?
Abort: file:// URLs can only refer to localhost
Empty URL:
>>> u = url('')
>>> u
<url path: ''>
>>> str(u)
''
Empty path with query string:
>>> str(url('http://foo/?bar'))
'http://foo/?bar'
Invalid path:
>>> u = url('http://foo/bar')
>>> u.path = 'bar'
>>> str(u)
'http://foo/bar'
>>> u = url('file:/foo/bar/baz')
>>> u
<url scheme: 'file', path: '/foo/bar/baz'>
>>> str(u)
'file:///foo/bar/baz'
>>> u.localpath()
'/foo/bar/baz'
>>> u = url('file:///foo/bar/baz')
>>> u
<url scheme: 'file', path: '/foo/bar/baz'>
>>> str(u)
'file:///foo/bar/baz'
>>> u.localpath()
'/foo/bar/baz'
>>> u = url('file:///f:oo/bar/baz')
>>> u
<url scheme: 'file', path: 'f:oo/bar/baz'>
>>> str(u)
'file:///f:oo/bar/baz'
>>> u.localpath()
'f:oo/bar/baz'
>>> u = url('file://localhost/f:oo/bar/baz')
>>> u
<url scheme: 'file', host: 'localhost', path: 'f:oo/bar/baz'>
>>> str(u)
'file://localhost/f:oo/bar/baz'
>>> u.localpath()
'f:oo/bar/baz'
>>> u = url('file:foo/bar/baz')
>>> u
<url scheme: 'file', path: 'foo/bar/baz'>
>>> str(u)
'file:foo/bar/baz'
>>> u.localpath()
'foo/bar/baz'
"""
if 'TERM' in os.environ:
del os.environ['TERM']
doctest.testmod(optionflags=doctest.NORMALIZE_WHITESPACE)