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.
# Base Revsets to be used with revsetbenchmarks.py script
#
# The goal of this file is to gather a limited amount of revsets that allow a
# good coverage of the internal revsets mechanisms. Revsets included should not
# be selected for their individual implementation, but for what they reveal of
# the internal implementation of smartsets classes (and their interactions).
#
# Use and update this file when you change internal implementation of these
# smartsets classes. Please include a comment explaining what each of your
# addition is testing. Also check if your changes to the smartset class makes
# some of the tests inadequate and replace them with a new one testing the same
# behavior.
#
# If you want to benchmark revsets predicate itself, check 'all-revsets.txt'.
#
# The current content of this file is currently likely not reaching this goal
# entirely, feel free, to audit its content and comment on each revset to
# highlight what internal mechanisms they test.
all()
draft()
::tip
draft() and ::tip
::tip and draft()
0::tip
roots(0::tip)
author(lmoscovicz)
author(olivia)
author(lmoscovicz) or author(olivia)
author(olivia) or author(lmoscovicz)
tip:0
0::
# those two `roots(...)` inputs are close to what phase movement use.
roots((tip~100::) - (tip~100::tip))
roots((0::) - (0::tip))
42:68 and roots(42:tip)
::p1(p1(tip))::
public()
:10000 and public()
draft()
:10000 and draft()
roots((0:tip)::)
(not public() - obsolete())
(_intlist('20000\x0020001')) and merge()
parents(20000)
(20000::) - (20000)
# The one below is used by rebase
(children(ancestor(tip~5, tip)) and ::(tip~5))::
heads(commonancestors(last(head(), 2)))
heads(-10000:-1)
roots(-10000:-1)
only(max(head()), min(head()))