Mercurial > hg
view mercurial/filesetlang.py @ 42377:0546ead39a7e stable
manifest: avoid corruption by dropping removed files with pure (issue5801)
Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`. But no effort was made to
ignore them when compacting the dictionary into text form. This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible. As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry. This typically resulted in
a ValueError complaining about unsorted manifest entries.
Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot. A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.
In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes. However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.
[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511
author | Matt Harbison <matt_harbison@yahoo.com> |
---|---|
date | Thu, 23 May 2019 21:54:24 -0400 |
parents | e79a69af1593 |
children | 2372284d9457 |
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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, ) # 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 "(": (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 _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 {'string', 'symbol', 'kindpat'}: return (), x if op == 'not': h, t = _insertstatushints(x[1]) return h, (op, t) if op == 'and': ha, ta = _insertstatushints(x[1]) hb, tb = _insertstatushints(x[2]) hr = ha + hb if ha and hb: return hr, ('withstatus', (op, ta, tb), ('string', ' '.join(hr))) return hr, (op, ta, tb) if op == '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, ('withstatus', (op,) + ts, ('string', ' '.join(hr))) return hr, (op,) + ts if op == 'list': hs, ts = zip(*(_insertstatushints(y) for y in x[1:])) return sum(hs, ()), (op,) + ts if op == '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,), ('withstatus', (op, x[1], ta), ('string', f)) return (), (op, x[1], ta) raise error.ProgrammingError('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 == '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 {'string', 'symbol', 'kindpat'}: return x if op == 'not': t = _mergestatushints(x[1], instatus) return (op, t) if op == 'and': ta = _mergestatushints(x[1], instatus) tb = _mergestatushints(x[2], instatus) return (op, ta, tb) if op in {'list', 'or'}: ts = tuple(_mergestatushints(y, instatus) for y in x[1:]) return (op,) + ts if op == 'func': # don't propagate 'instatus' crossing a function boundary ta = _mergestatushints(x[2], instatus=False) 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. """ 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] == 'not': return ('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 {'string', 'symbol', 'kindpat'}: ss.append(t) continue ws.append(w) ts.append(t) if ss: ws.append(WEIGHT_CHECK_FILENAME) ts.append(('patterns',) + tuple(ss)) return ws, ts def _optimize(x): if x is None: return 0, x op = x[0] if op == 'withstatus': w, t = _optimize(x[1]) return w, (op, t, x[2]) if op in {'string', 'symbol'}: return WEIGHT_CHECK_FILENAME, 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 = _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 == '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'))