##// END OF EJS Templates
httppeer: remove support for connecting to <0.9.1 servers (BC)...
httppeer: remove support for connecting to <0.9.1 servers (BC) Previously, HTTP wire protocol clients would attempt a "capabilities" wire protocol command. If that failed, they would fall back to issuing a "between" command. The "capabilities" command was added in Mercurial 0.9.1 (released July 2006). The "between" command has been present for as long as the wire protocol has existed. So if the "between" command failed, it was safe to assume that the remote could not speak any version of the Mercurial wire protocol. The "between" fallback was added in 395a84f78736 in 2011. Before that changeset, Mercurial would *always* issue the "between" command and would issue "capabilities" if capabilities were requested. At that time, many connections would issue "capabilities" eventually, so it was decided to issue "capabilities" by default and fall back to "between" if that failed. This saved a round trip when connecting to modern servers while still preserving compatibility with legacy servers. Fast forward ~7 years. Mercurial servers supporting "capabilities" have been around for over a decade. If modern clients are connecting to <0.9.1 servers, they are getting a bad experience. They may even be getting bad data (an old server is vulnerable to numerous security issues and could have been p0wned, leading to a Mercurial repository serving backdoors or other badness). In addition, the fallback can harm experience for modern servers. If a client experiences an intermittent HTTP request failure (due to bad network, etc) and falls back to a "between" that works, it would assume an empty capability set and would attempt to communicate with the repository using a very ancient wire protocol. Auditing HTTP logs for hg.mozilla.org, I did find a handful of requests for the null range of the "between" command. However, requests can be days apart. And when I do see requests, they come in batches. Those batches seem to correlate to spikes of HTTP 500 or other server/network events. So I think these requests are fallbacks from failed "capabilities" requests and not from old clients. If you need even more evidence to discontinue support, apparently we have no test coverage for communicating with servers not supporting "capabilities." I know this because all tests pass with the "between" fallback removed. Finally, server-side support for <0.9.1 pushing (the "addchangegroup" wire protocol command along with locking-related commands) was dropped from the HTTP client in fda0867cfe03 in 2017 and the SSH client in 9f6e0e7ef828 in 2015. I think this all adds up to enough justification for removing client support for communicating with servers not supporting "capabilities." So this commit removes that fallback. Differential Revision: https://phab.mercurial-scm.org/D2001

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minifileset.py
85 lines | 3.3 KiB | text/x-python | PythonLexer
# minifileset.py - a simple language to select files
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
from .i18n import _
from . import (
error,
fileset,
)
def _compile(tree):
if not tree:
raise error.ParseError(_("missing argument"))
op = tree[0]
if op in {'symbol', 'string', 'kindpat'}:
name = fileset.getpattern(tree, {'path'}, _('invalid file pattern'))
if name.startswith('**'): # file extension test, ex. "**.tar.gz"
ext = name[2:]
for c in ext:
if c in '*{}[]?/\\':
raise error.ParseError(_('reserved character: %s') % c)
return lambda n, s: n.endswith(ext)
elif name.startswith('path:'): # directory or full path test
p = name[5:] # prefix
pl = len(p)
f = lambda n, s: n.startswith(p) and (len(n) == pl or n[pl] == '/')
return f
raise error.ParseError(_("unsupported file pattern: %s") % name,
hint=_('paths must be prefixed with "path:"'))
elif op == 'or':
func1 = _compile(tree[1])
func2 = _compile(tree[2])
return lambda n, s: func1(n, s) or func2(n, s)
elif op == 'and':
func1 = _compile(tree[1])
func2 = _compile(tree[2])
return lambda n, s: func1(n, s) and func2(n, s)
elif op == 'not':
return lambda n, s: not _compile(tree[1])(n, s)
elif op == 'group':
return _compile(tree[1])
elif op == 'func':
symbols = {
'all': lambda n, s: True,
'none': lambda n, s: False,
'size': lambda n, s: fileset.sizematcher(tree[2])(s),
}
name = fileset.getsymbol(tree[1])
if name in symbols:
return symbols[name]
raise error.UnknownIdentifier(name, symbols.keys())
elif op == 'minus': # equivalent to 'x and not y'
func1 = _compile(tree[1])
func2 = _compile(tree[2])
return lambda n, s: func1(n, s) and not func2(n, s)
elif op == 'negate':
raise error.ParseError(_("can't use negate operator in this context"))
elif op == 'list':
raise error.ParseError(_("can't use a list in this context"),
hint=_('see hg help "filesets.x or y"'))
raise error.ProgrammingError('illegal tree: %r' % (tree,))
def compile(text):
"""generate a function (path, size) -> bool from filter specification.
"text" could contain the operators defined by the fileset language for
common logic operations, and parenthesis for grouping. The supported path
tests are '**.extname' for file extension test, and '"path:dir/subdir"'
for prefix test. The ``size()`` predicate is borrowed from filesets to test
file size. The predicates ``all()`` and ``none()`` are also supported.
'(**.php & size(">10MB")) | **.zip | (path:bin & !path:bin/README)' for
example, will catch all php files whose size is greater than 10 MB, all
files whose name ends with ".zip", and all files under "bin" in the repo
root except for "bin/README".
"""
tree = fileset.parse(text)
return _compile(tree)