Mercurial > hg
view mercurial/filesetlang.py @ 47072:4c041c71ec01
revlog: introduce an explicit tracking of what the revlog is about
Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.
In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.
So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.
The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.
Differential Revision: https://phab.mercurial-scm.org/D10352
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 06 Apr 2021 05:20:24 +0200 |
parents | d4ba4d51f85f |
children | 6000f5b25c9b |
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# filesetlang.py - parser, tokenizer and utility for file set language # # Copyright 2010 Olivia Mackall <olivia@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 .pycompat import getattr from . import ( error, parser, pycompat, ) # common weight constants for static optimization # (see registrar.filesetpredicate for details) WEIGHT_CHECK_FILENAME = 0.5 WEIGHT_READ_CONTENTS = 30 WEIGHT_STATUS = 10 WEIGHT_STATUS_THOROUGH = 50 elements = { # token-type: binding-strength, primary, prefix, infix, suffix b"(": (20, None, (b"group", 1, b")"), (b"func", 1, b")"), None), b":": (15, None, None, (b"kindpat", 15), None), b"-": (5, None, (b"negate", 19), (b"minus", 5), None), b"not": (10, None, (b"not", 10), None, None), b"!": (10, None, (b"not", 10), None, None), b"and": (5, None, None, (b"and", 5), None), b"&": (5, None, None, (b"and", 5), None), b"or": (4, None, None, (b"or", 4), None), b"|": (4, None, None, (b"or", 4), None), b"+": (4, None, None, (b"or", 4), None), b",": (2, None, None, (b"list", 2), None), b")": (0, None, None, None, None), b"symbol": (0, b"symbol", None, None, None), b"string": (0, b"string", None, None, None), b"end": (0, None, None, None, None), } keywords = {b'and', b'or', b'not'} symbols = {} globchars = b".*{}[]?/\\_" 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 b"(),-:|&+!": # handle simple operators yield (c, None, pos) elif ( c in b'"\'' or c == b'r' and program[pos : pos + 2] in (b"r'", b'r"') ): # handle quoted strings if c == b'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 == b'\\': # skip over escaped characters pos += 2 continue if d == c: yield (b'string', decode(program[s:pos]), s) break pos += 1 else: raise error.ParseError(_(b"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 (b'symbol', sym, s) pos -= 1 else: raise error.ParseError(_(b"syntax error"), pos) pos += 1 yield (b'end', None, pos) def parse(expr): p = parser.parser(elements) tree, pos = p.parse(tokenize(expr)) if pos != len(expr): raise error.ParseError(_(b"invalid token"), pos) return parser.simplifyinfixops(tree, {b'list', b'or'}) def getsymbol(x): if x and x[0] == b'symbol': return x[1] raise error.ParseError(_(b'not a symbol')) def getstring(x, err): if x and (x[0] == b'string' or x[0] == b'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(_(b"invalid pattern kind: %s") % kind) return b'%s:%s' % (kind, pat) def getpattern(x, allkinds, err): if x and x[0] == b'kindpat': return getkindpat(x[1], x[2], allkinds, err) return getstring(x, err) def getlist(x): if not x: return [] if x[0] == b'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 {b'string', b'symbol'}: return x if op == b'kindpat': getsymbol(x[1]) # kind must be a symbol t = _analyze(x[2]) return (op, x[1], t) if op == b'group': return _analyze(x[1]) if op == b'negate': raise error.ParseError(_(b"can't use negate operator in this context")) if op == b'not': t = _analyze(x[1]) return (op, t) if op == b'and': ta = _analyze(x[1]) tb = _analyze(x[2]) return (op, ta, tb) if op == b'minus': return _analyze((b'and', x[1], (b'not', x[2]))) if op in {b'list', b'or'}: ts = tuple(_analyze(y) for y in x[1:]) return (op,) + ts if op == b'func': getsymbol(x[1]) # function name must be a symbol ta = _analyze(x[2]) return (op, x[1], ta) raise error.ProgrammingError(b'invalid operator %r' % op) def _insertstatushints(x): """Insert hint nodes where status should be calculated (first path) This works in bottom-up way, summing up status names and inserting hint nodes at 'and' and 'or' as needed. Thus redundant hint nodes may be left. Returns (status-names, new-tree) at the given subtree, where status-names is a sum of status names referenced in the given subtree. """ if x is None: return (), x op = x[0] if op in {b'string', b'symbol', b'kindpat'}: return (), x if op == b'not': h, t = _insertstatushints(x[1]) return h, (op, t) if op == b'and': ha, ta = _insertstatushints(x[1]) hb, tb = _insertstatushints(x[2]) hr = ha + hb if ha and hb: return hr, (b'withstatus', (op, ta, tb), (b'string', b' '.join(hr))) return hr, (op, ta, tb) if op == b'or': hs, ts = zip(*(_insertstatushints(y) for y in x[1:])) hr = sum(hs, ()) if sum(bool(h) for h in hs) > 1: return hr, (b'withstatus', (op,) + ts, (b'string', b' '.join(hr))) return hr, (op,) + ts if op == b'list': hs, ts = zip(*(_insertstatushints(y) for y in x[1:])) return sum(hs, ()), (op,) + ts if op == b'func': f = getsymbol(x[1]) # don't propagate 'ha' crossing a function boundary ha, ta = _insertstatushints(x[2]) if getattr(symbols.get(f), '_callstatus', False): return (f,), (b'withstatus', (op, x[1], ta), (b'string', f)) return (), (op, x[1], ta) raise error.ProgrammingError(b'invalid operator %r' % op) def _mergestatushints(x, instatus): """Remove redundant status hint nodes (second path) This is the top-down path to eliminate inner hint nodes. """ if x is None: return x op = x[0] if op == b'withstatus': if instatus: # drop redundant hint node return _mergestatushints(x[1], instatus) t = _mergestatushints(x[1], instatus=True) return (op, t, x[2]) if op in {b'string', b'symbol', b'kindpat'}: return x if op == b'not': t = _mergestatushints(x[1], instatus) return (op, t) if op == b'and': ta = _mergestatushints(x[1], instatus) tb = _mergestatushints(x[2], instatus) return (op, ta, tb) if op in {b'list', b'or'}: ts = tuple(_mergestatushints(y, instatus) for y in x[1:]) return (op,) + ts if op == b'func': # don't propagate 'instatus' crossing a function boundary ta = _mergestatushints(x[2], instatus=False) return (op, x[1], ta) raise error.ProgrammingError(b'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. """ t = _analyze(x) _h, t = _insertstatushints(t) return _mergestatushints(t, instatus=False) def _optimizeandops(op, ta, tb): if tb is not None and tb[0] == b'not': return (b'minus', ta, tb[1]) return (op, ta, tb) def _optimizeunion(xs): # collect string patterns so they can be compiled into a single regexp ws, ts, ss = [], [], [] for x in xs: w, t = _optimize(x) if t is not None and t[0] in {b'string', b'symbol', b'kindpat'}: ss.append(t) continue ws.append(w) ts.append(t) if ss: ws.append(WEIGHT_CHECK_FILENAME) ts.append((b'patterns',) + tuple(ss)) return ws, ts def _optimize(x): if x is None: return 0, x op = x[0] if op == b'withstatus': w, t = _optimize(x[1]) return w, (op, t, x[2]) if op in {b'string', b'symbol'}: return WEIGHT_CHECK_FILENAME, x if op == b'kindpat': w, t = _optimize(x[2]) return w, (op, x[1], t) if op == b'not': w, t = _optimize(x[1]) return w, (op, t) if op == b'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 == b'or': ws, ts = _optimizeunion(x[1:]) if len(ts) == 1: return ws[0], ts[0] # 'or' operation is fully optimized out ts = tuple( it[1] for it in sorted(enumerate(ts), key=lambda it: ws[it[0]]) ) return max(ws), (op,) + ts if op == b'list': ws, ts = zip(*(_optimize(y) for y in x[1:])) return sum(ws), (op,) + ts if op == b'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(b'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, (b'string', b'symbol'))