procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
# 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 .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'))