nodemap: code to parse the persistent binary nodemap data
We now have code to read back what we persisted. This will be put to use in
later changesets.
Differential Revision: https://phab.mercurial-scm.org/D7844
# 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 .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'))