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.
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> EOF
$ echo x > x
$ hg commit -qAm x
$ mkdir dir
$ echo y > dir/y
$ hg commit -qAm y
$ cd ..
Shallow clone from full
$ hgcloneshallow ssh://user@dummy/master shallow --noupdate
streaming all changes
2 files to transfer, 473 bytes of data
transferred 473 bytes in * seconds (*/sec) (glob)
searching for changes
no changes found
$ cd shallow
$ hg debugrequires
dotencode
dirstate-v2 (dirstate-v2 !)
exp-remotefilelog-repo-req-1
fncache
generaldelta
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
$ hg update
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
Log on a file without -f
$ hg log dir/y
warning: file log can be slow on large repos - use -f to speed it up
changeset: 1:2e73264fab97
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: y
Log on a file with -f
$ hg log -f dir/y
changeset: 1:2e73264fab97
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: y
Log on a file with kind in path
$ hg log -r "filelog('path:dir/y')"
changeset: 1:2e73264fab97
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: y
Log on multiple files with -f
$ hg log -f dir/y x
changeset: 1:2e73264fab97
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: y
changeset: 0:b292c1e3311f
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: x
Log on a directory
$ hg log dir
changeset: 1:2e73264fab97
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: y
Log on a file from inside a directory
$ cd dir
$ hg log y
warning: file log can be slow on large repos - use -f to speed it up
changeset: 1:2e73264fab97
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: y
Log on a file via -fr
$ cd ..
$ hg log -fr tip dir/ --template '{rev}\n'
1
Trace renames
$ hg mv x z
$ hg commit -m move
$ hg log -f z -T '{desc} {file_copies}\n' -G
@ move z (x)
:
o x
Verify remotefilelog handles rename metadata stripping when comparing file sizes
$ hg debugrebuilddirstate
$ hg status