Mercurial > hg
view mercurial/filesetlang.py @ 38842:503f936489dd
lookup: add option to disambiguate prefix within revset
When resolving a nodeid prefix that is not unique within the repo and
the user has configured a revset that they want to disambiguate
within, we now try to look up within that revset before we fail. If
there is a unique match within the revset, we use that.
This is of course most effective at allowing a short prefix if the
revset contains few nodes. For most of our internal users at Google,
"not public()" is sufficiently small that a hex digit or two is
enough.
The implementation is currently pretty slow, but good enough for small
revsets (which is the expected use case). The scan in the revset is
linear. We may want to use a prefix tree if we want to allow users to
use a larger revset.
Credit for the idea goes to Kyle Lippincott.
Differential Revision: https://phab.mercurial-scm.org/D4037
author | Martin von Zweigbergk <martinvonz@google.com> |
---|---|
date | Wed, 28 Mar 2018 09:36:02 -0700 |
parents | ca4de8ba5b5f |
children | 61ab546b71c3 |
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# filesetlang.py - parser, tokenizer and utility for file set language # # Copyright 2010 Matt Mackall <mpm@selenic.com> # # 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, parser, pycompat, ) elements = { # token-type: binding-strength, primary, prefix, infix, suffix "(": (20, None, ("group", 1, ")"), ("func", 1, ")"), None), ":": (15, None, None, ("kindpat", 15), None), "-": (5, None, ("negate", 19), ("minus", 5), None), "not": (10, None, ("not", 10), None, None), "!": (10, None, ("not", 10), None, None), "and": (5, None, None, ("and", 5), None), "&": (5, None, None, ("and", 5), None), "or": (4, None, None, ("or", 4), None), "|": (4, None, None, ("or", 4), None), "+": (4, None, None, ("or", 4), None), ",": (2, None, None, ("list", 2), None), ")": (0, None, None, None, None), "symbol": (0, "symbol", None, None, None), "string": (0, "string", None, None, None), "end": (0, None, None, None, None), } keywords = {'and', 'or', 'not'} symbols = {} globchars = ".*{}[]?/\\_" def tokenize(program): pos, l = 0, len(program) program = pycompat.bytestr(program) while pos < l: c = program[pos] if c.isspace(): # skip inter-token whitespace pass elif c in "(),-:|&+!": # handle simple operators yield (c, None, pos) elif (c in '"\'' or c == 'r' and program[pos:pos + 2] in ("r'", 'r"')): # handle quoted strings if c == 'r': pos += 1 c = program[pos] decode = lambda x: x else: decode = parser.unescapestr pos += 1 s = pos while pos < l: # find closing quote d = program[pos] if d == '\\': # skip over escaped characters pos += 2 continue if d == c: yield ('string', decode(program[s:pos]), s) break pos += 1 else: raise error.ParseError(_("unterminated string"), s) elif c.isalnum() or c in globchars or ord(c) > 127: # gather up a symbol/keyword s = pos pos += 1 while pos < l: # find end of symbol d = program[pos] if not (d.isalnum() or d in globchars or ord(d) > 127): break pos += 1 sym = program[s:pos] if sym in keywords: # operator keywords yield (sym, None, s) else: yield ('symbol', sym, s) pos -= 1 else: raise error.ParseError(_("syntax error"), pos) pos += 1 yield ('end', None, pos) def parse(expr): p = parser.parser(elements) tree, pos = p.parse(tokenize(expr)) if pos != len(expr): raise error.ParseError(_("invalid token"), pos) return parser.simplifyinfixops(tree, {'list', 'or'}) def getsymbol(x): if x and x[0] == 'symbol': return x[1] raise error.ParseError(_('not a symbol')) def getstring(x, err): if x and (x[0] == 'string' or x[0] == 'symbol'): return x[1] raise error.ParseError(err) def getkindpat(x, y, allkinds, err): kind = getsymbol(x) pat = getstring(y, err) if kind not in allkinds: raise error.ParseError(_("invalid pattern kind: %s") % kind) return '%s:%s' % (kind, pat) def getpattern(x, allkinds, err): if x and x[0] == 'kindpat': return getkindpat(x[1], x[2], allkinds, err) return getstring(x, err) def getlist(x): if not x: return [] if x[0] == 'list': return list(x[1:]) return [x] def getargs(x, min, max, err): l = getlist(x) if len(l) < min or len(l) > max: raise error.ParseError(err) return l def _analyze(x): if x is None: return x op = x[0] if op in {'string', 'symbol'}: return x if op == 'kindpat': getsymbol(x[1]) # kind must be a symbol t = _analyze(x[2]) return (op, x[1], t) if op == 'group': return _analyze(x[1]) if op == 'negate': raise error.ParseError(_("can't use negate operator in this context")) if op == 'not': t = _analyze(x[1]) return (op, t) if op == 'and': ta = _analyze(x[1]) tb = _analyze(x[2]) return (op, ta, tb) if op == 'minus': return _analyze(('and', x[1], ('not', x[2]))) if op in {'list', 'or'}: ts = tuple(_analyze(y) for y in x[1:]) return (op,) + ts if op == 'func': getsymbol(x[1]) # function name must be a symbol ta = _analyze(x[2]) return (op, x[1], ta) raise error.ProgrammingError('invalid operator %r' % op) def analyze(x): """Transform raw parsed tree to evaluatable tree which can be fed to optimize() or getmatch() All pseudo operations should be mapped to real operations or functions defined in methods or symbols table respectively. """ return _analyze(x) def _optimizeandops(op, ta, tb): if tb is not None and tb[0] == 'not': return ('minus', ta, tb[1]) return (op, ta, tb) def _optimize(x): if x is None: return 0, x op = x[0] if op in {'string', 'symbol'}: return 0.5, x if op == 'kindpat': w, t = _optimize(x[2]) return w, (op, x[1], t) if op == 'not': w, t = _optimize(x[1]) return w, (op, t) if op == 'and': wa, ta = _optimize(x[1]) wb, tb = _optimize(x[2]) if wa <= wb: return wa, _optimizeandops(op, ta, tb) else: return wb, _optimizeandops(op, tb, ta) if op == 'or': ws, ts = zip(*(_optimize(y) for y in x[1:])) return max(ws), (op,) + ts if op == 'list': ws, ts = zip(*(_optimize(y) for y in x[1:])) return sum(ws), (op,) + ts if op == 'func': f = getsymbol(x[1]) w = getattr(symbols.get(f), '_weight', 1) wa, ta = _optimize(x[2]) return w + wa, (op, x[1], ta) raise error.ProgrammingError('invalid operator %r' % op) def optimize(x): """Reorder/rewrite evaluatable tree for optimization All pseudo operations should be transformed beforehand. """ _w, t = _optimize(x) return t def prettyformat(tree): return parser.prettyformat(tree, ('string', 'symbol'))