##// END OF EJS Templates
wireprotov2: implement commands as a generator of objects...
wireprotov2: implement commands as a generator of objects Previously, wire protocol version 2 inherited version 1's model of having separate types to represent the results of different wire protocol commands. As I implemented more powerful commands in future commits, I found I was using a common pattern of returning a special type to hold a generator. This meant the command function required a closure to do most of the work. That made logic flow more difficult to follow. I also noticed that many commands were effectively a sequence of objects to be CBOR encoded. I think it makes sense to define version 2 commands as generators. This way, commands can simply emit the data structures they wish to send to the client. This eliminates the need for a closure in command functions and removes encoding from the bodies of commands. As part of this commit, the handling of response objects has been moved into the serverreactor class. This puts the reactor in the driver's seat with regards to CBOR encoding and error handling. Having error handling in the function that emits frames is particularly important because exceptions in that function can lead to things getting in a bad state: I'm fairly certain that uncaught exceptions in the frame generator were causing deadlocks. I also introduced a dedicated error type for explicit error reporting in command handlers. This will be used in subsequent commits. There's still a bit of work to be done here, especially around formalizing the error handling "protocol." I've added yet another TODO to track this so we don't forget. Test output changed because we're using generators and no longer know we are at the end of the data until we hit the end of the generator. This means we can't emit the end-of-stream flag until we've exhausted the generator. Hence the introduction of 0-sized end-of-stream frames. Differential Revision: https://phab.mercurial-scm.org/D4472

File last commit:

r38915:e79a69af default
r39595:07b58266 default
Show More
minifileset.py
92 lines | 3.5 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,
filesetlang,
pycompat,
)
def _sizep(x):
# i18n: "size" is a keyword
expr = filesetlang.getstring(x, _("size requires an expression"))
return fileset.sizematcher(expr)
def _compile(tree):
if not tree:
raise error.ParseError(_("missing argument"))
op = tree[0]
if op == 'withstatus':
return _compile(tree[1])
elif op in {'symbol', 'string', 'kindpat'}:
name = filesetlang.getpattern(tree, {'path'}, _('invalid file pattern'))
if name.startswith('**'): # file extension test, ex. "**.tar.gz"
ext = name[2:]
for c in pycompat.bytestr(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:pl + 1] == '/')
return f
raise error.ParseError(_("unsupported file pattern: %s") % name,
hint=_('paths must be prefixed with "path:"'))
elif op in {'or', 'patterns'}:
funcs = [_compile(x) for x in tree[1:]]
return lambda n, s: any(f(n, s) for f in funcs)
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 == 'func':
symbols = {
'all': lambda n, s: True,
'none': lambda n, s: False,
'size': lambda n, s: _sizep(tree[2])(s),
}
name = filesetlang.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 == '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 = filesetlang.parse(text)
tree = filesetlang.analyze(tree)
tree = filesetlang.optimize(tree)
return _compile(tree)