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.
# grep.py - logic for history walk and grep
#
# Copyright 2005-2007 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.
import difflib
from .i18n import _
from . import (
error,
match as matchmod,
pycompat,
scmutil,
util,
)
def matchlines(body, regexp):
begin = 0
linenum = 0
while begin < len(body):
match = regexp.search(body, begin)
if not match:
break
mstart, mend = match.span()
linenum += body.count(b'\n', begin, mstart) + 1
lstart = body.rfind(b'\n', begin, mstart) + 1 or begin
begin = body.find(b'\n', mend) + 1 or len(body) + 1
lend = begin - 1
yield linenum, mstart - lstart, mend - lstart, body[lstart:lend]
class linestate:
def __init__(self, line, linenum, colstart, colend):
self.line = line
self.linenum = linenum
self.colstart = colstart
self.colend = colend
def __hash__(self):
return hash(self.line)
def __eq__(self, other):
return self.line == other.line
def findpos(self, regexp):
"""Iterate all (start, end) indices of matches"""
yield self.colstart, self.colend
p = self.colend
while p < len(self.line):
m = regexp.search(self.line, p)
if not m:
break
if m.end() == p:
p += 1
else:
yield m.span()
p = m.end()
def difflinestates(a, b):
sm = difflib.SequenceMatcher(None, a, b)
for tag, alo, ahi, blo, bhi in sm.get_opcodes():
if tag == 'insert':
for i in range(blo, bhi):
yield (b'+', b[i])
elif tag == 'delete':
for i in range(alo, ahi):
yield (b'-', a[i])
elif tag == 'replace':
for i in range(alo, ahi):
yield (b'-', a[i])
for i in range(blo, bhi):
yield (b'+', b[i])
class grepsearcher:
"""Search files and revisions for lines matching the given pattern
Options:
- all_files to search unchanged files at that revision.
- diff to search files in the parent revision so diffs can be generated.
- follow to skip files across copies and renames.
"""
def __init__(
self, ui, repo, regexp, all_files=False, diff=False, follow=False
):
self._ui = ui
self._repo = repo
self._regexp = regexp
self._all_files = all_files
self._diff = diff
self._follow = follow
self._getfile = util.lrucachefunc(repo.file)
self._getrenamed = scmutil.getrenamedfn(repo)
self._matches = {}
self._copies = {}
self._skip = set()
self._revfiles = {}
def skipfile(self, fn, rev):
"""Exclude the given file (and the copy at the specified revision)
from future search"""
copy = self._copies.get(rev, {}).get(fn)
self._skip.add(fn)
if copy:
self._skip.add(copy)
def searchfiles(self, revs, makefilematcher):
"""Walk files and revisions to yield (fn, ctx, pstates, states)
matches
states is a list of linestate objects. pstates may be empty unless
diff is True.
"""
for ctx in scmutil.walkchangerevs(
self._repo, revs, makefilematcher, self._prep
):
rev = ctx.rev()
parent = ctx.p1().rev()
for fn in sorted(self._revfiles.get(rev, [])):
states = self._matches[rev][fn]
copy = self._copies.get(rev, {}).get(fn)
if fn in self._skip:
if copy:
self._skip.add(copy)
continue
pstates = self._matches.get(parent, {}).get(copy or fn, [])
if pstates or states:
yield fn, ctx, pstates, states
del self._revfiles[rev]
# We will keep the matches dict for the duration of the window
# clear the matches dict once the window is over
if not self._revfiles:
self._matches.clear()
def _grepbody(self, fn, rev, body):
self._matches[rev].setdefault(fn, [])
m = self._matches[rev][fn]
if body is None:
return
for lnum, cstart, cend, line in matchlines(body, self._regexp):
s = linestate(line, lnum, cstart, cend)
m.append(s)
def _readfile(self, ctx, fn):
rev = ctx.rev()
if rev is None:
fctx = ctx[fn]
try:
return fctx.data()
except FileNotFoundError:
pass
else:
flog = self._getfile(fn)
fnode = ctx.filenode(fn)
try:
return flog.read(fnode)
except error.CensoredNodeError:
self._ui.warn(
_(
b'cannot search in censored file: '
b'%(filename)s:%(revnum)s\n'
)
% {b'filename': fn, b'revnum': pycompat.bytestr(rev)}
)
def _prep(self, ctx, fmatch):
rev = ctx.rev()
pctx = ctx.p1()
self._matches.setdefault(rev, {})
if self._diff:
parent = pctx.rev()
self._matches.setdefault(parent, {})
files = self._revfiles.setdefault(rev, [])
if rev is None:
# in `hg grep pattern`, 2/3 of the time is spent is spent in
# pathauditor checks without this in mozilla-central
contextmanager = self._repo.wvfs.audit.cached
else:
contextmanager = util.nullcontextmanager
with contextmanager():
# TODO: maybe better to warn missing files?
if self._all_files:
fmatch = matchmod.badmatch(fmatch, lambda f, msg: None)
filenames = ctx.matches(fmatch)
else:
filenames = (f for f in ctx.files() if fmatch(f))
for fn in filenames:
# fn might not exist in the revision (could be a file removed by
# the revision). We could check `fn not in ctx` even when rev is
# None, but it's less racy to protect againt that in readfile.
if rev is not None and fn not in ctx:
continue
copy = None
if self._follow:
copy = self._getrenamed(fn, rev)
if copy:
self._copies.setdefault(rev, {})[fn] = copy
if fn in self._skip:
self._skip.add(copy)
if fn in self._skip:
continue
files.append(fn)
if fn not in self._matches[rev]:
self._grepbody(fn, rev, self._readfile(ctx, fn))
if self._diff:
pfn = copy or fn
if pfn not in self._matches[parent] and pfn in pctx:
self._grepbody(pfn, parent, self._readfile(pctx, pfn))