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.
A new repository uses zlib storage, which doesn't need a requirement
$ cat << EOF >> $HGRCPATH
> [format]
> # stabilize test accross variant
> revlog-compression=zlib
> EOF
$ hg init default
$ cd default
$ hg debugrequires | grep compression
[1]
$ touch foo
$ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text to trigger compression'
$ hg debugrevlog -c | grep 0x78
0x78 (x) : 1 (100.00%)
0x78 (x) : 110 (100.00%)
$ cd ..
Unknown compression engine to format.compression aborts
$ hg --config format.revlog-compression=unknown init unknown
abort: compression engines "unknown" defined by format.revlog-compression not available
(run "hg debuginstall" to list available compression engines)
[255]
unknown compression engine in a list with known one works fine
$ hg --config format.revlog-compression=zlib,unknown init zlib-before-unknow
$ hg --config format.revlog-compression=unknown,zlib init unknown-before-zlib
A requirement specifying an unknown compression engine results in bail
$ hg init unknownrequirement
$ cd unknownrequirement
$ echo exp-compression-unknown >> .hg/requires
$ hg log
abort: repository requires features unknown to this Mercurial: exp-compression-unknown
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ cd ..
Specifying a new format.compression on an existing repo won't introduce data
with that engine or a requirement
$ cd default
$ touch bar
$ hg --config format.revlog-compression=none -q commit -A -m 'add bar with a lot of repeated repeated repeated text'
$ hg debugrequires | grep compression
[1]
$ hg debugrevlog -c | grep 0x78
0x78 (x) : 2 (100.00%)
0x78 (x) : 199 (100.00%)
$ cd ..
#if zstd
$ hg --config format.revlog-compression=zstd init zstd
$ cd zstd
$ hg debugrequires | grep compression
revlog-compression-zstd
$ touch foo
$ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text'
$ hg debugrevlog -c | grep 0x28
0x28 : 1 (100.00%)
0x28 : 98 (100.00%)
$ cd ..
#endif
checking zlib options
=====================
$ hg init zlib-level-default
$ hg init zlib-level-1
$ cat << EOF >> zlib-level-1/.hg/hgrc
> [storage]
> revlog.zlib.level=1
> EOF
$ hg init zlib-level-9
$ cat << EOF >> zlib-level-9/.hg/hgrc
> [storage]
> revlog.zlib.level=9
> EOF
$ commitone() {
> repo=$1
> cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
> hg -R $repo add $repo/a
> hg -R $repo commit -m some-commit
> }
$ for repo in zlib-level-default zlib-level-1 zlib-level-9; do
> commitone $repo
> done
$ $RUNTESTDIR/f -s */.hg/store/data/*
default/.hg/store/data/bar.i: size=64
default/.hg/store/data/foo.i: size=64
zlib-level-1/.hg/store/data/a.i: size=4146
zlib-level-9/.hg/store/data/a.i: size=4138
zlib-level-default/.hg/store/data/a.i: size=4138
zstd/.hg/store/data/foo.i: size=64 (zstd !)
Test error cases
$ hg init zlib-level-invalid
$ cat << EOF >> zlib-level-invalid/.hg/hgrc
> [storage]
> revlog.zlib.level=foobar
> EOF
$ commitone zlib-level-invalid
config error: storage.revlog.zlib.level is not a valid integer ('foobar')
config error: storage.revlog.zlib.level is not a valid integer ('foobar')
[30]
$ hg init zlib-level-out-of-range
$ cat << EOF >> zlib-level-out-of-range/.hg/hgrc
> [storage]
> revlog.zlib.level=42
> EOF
$ commitone zlib-level-out-of-range
abort: invalid value for `storage.revlog.zlib.level` config: 42
abort: invalid value for `storage.revlog.zlib.level` config: 42
[255]
checking details of none compression
====================================
$ hg init none-compression --config format.revlog-compression=none
$ commitone() {
> repo=$1
> cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
> hg -R $repo add $repo/a
> hg -R $repo commit -m some-commit
> }
$ commitone none-compression
$ hg log -R none-compression
changeset: 0:68b53da39cd8
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: some-commit
$ hg debugrequires -R none-compression/ | grep compression
exp-compression-none
$ $RUNTESTDIR/f -s none-compression/.hg/store/data/*
none-compression/.hg/store/data/a.i: size=4216
#if zstd
checking zstd options
=====================
$ hg init zstd-level-default --config format.revlog-compression=zstd
$ hg init zstd-level-1 --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-1/.hg/hgrc
> [storage]
> revlog.zstd.level=1
> EOF
$ hg init zstd-level-22 --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-22/.hg/hgrc
> [storage]
> revlog.zstd.level=22
> EOF
$ commitone() {
> repo=$1
> cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
> hg -R $repo add $repo/a
> hg -R $repo commit -m some-commit
> }
$ for repo in zstd-level-default zstd-level-1 zstd-level-22; do
> commitone $repo
> done
$ $RUNTESTDIR/f -s zstd-*/.hg/store/data/*
zstd-level-1/.hg/store/data/a.i: size=4114
zstd-level-22/.hg/store/data/a.i: size=4091
zstd-level-default/\.hg/store/data/a\.i: size=(4094|4102) (re)
Test error cases
$ hg init zstd-level-invalid --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-invalid/.hg/hgrc
> [storage]
> revlog.zstd.level=foobar
> EOF
$ commitone zstd-level-invalid
config error: storage.revlog.zstd.level is not a valid integer ('foobar')
config error: storage.revlog.zstd.level is not a valid integer ('foobar')
[30]
$ hg init zstd-level-out-of-range --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-out-of-range/.hg/hgrc
> [storage]
> revlog.zstd.level=42
> EOF
$ commitone zstd-level-out-of-range
abort: invalid value for `storage.revlog.zstd.level` config: 42
abort: invalid value for `storage.revlog.zstd.level` config: 42
[255]
#endif