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view mercurial/minifileset.py @ 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 | e79a69af1593 |
children | 57875cf423c9 |
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# 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)