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
$ echo z > z
$ hg commit -qAm x
$ echo x2 > x
$ echo y > y
$ hg commit -qAm y
$ hg bookmark foo
$ cd ..
# prefetch a revision
$ hgcloneshallow ssh://user@dummy/master shallow --noupdate
streaming all changes
2 files to transfer, 528 bytes of data (no-zstd !)
transferred 528 bytes in * seconds (* */sec) (glob) (no-zstd !)
2 files to transfer, 532 bytes of data (zstd !)
transferred 532 bytes in * seconds (* */sec) (glob) (zstd !)
searching for changes
no changes found
$ cd shallow
$ hg prefetch -r 0
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 0 x
x
# prefetch with base
$ clearcache
$ hg prefetch -r 0::1 -b 0
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 1 x
x2
$ hg cat -r 1 y
y
$ hg cat -r 0 x
x
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 0 z
z
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ hg prefetch -r 0::1 --base 0
$ hg prefetch -r 0::1 -b 1
$ hg prefetch -r 0::1
# prefetch a range of revisions
$ clearcache
$ hg prefetch -r 0::1
4 files fetched over 1 fetches - (4 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 0 x
x
$ hg cat -r 1 x
x2
# prefetch certain files
$ clearcache
$ hg prefetch -r 1 x
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 1 x
x2
$ hg cat -r 1 y
y
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
# prefetch on pull when configured
$ printf "[remotefilelog]\npullprefetch=bookmark()\n" >> .hg/hgrc
$ hg strip tip
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/109c3a557a73-3f43405e-backup.hg (glob)
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ clearcache
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 109c3a557a73
(run 'hg update' to get a working copy)
prefetching file contents
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
$ hg up tip
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
# prefetch only fetches changes not in working copy
$ hg strip tip
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/109c3a557a73-3f43405e-backup.hg (glob)
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ clearcache
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 109c3a557a73
(run 'hg update' to get a working copy)
prefetching file contents
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
# Make some local commits that produce the same file versions as are on the
# server. To simulate a situation where we have local commits that were somehow
# pushed, and we will soon pull.
$ hg prefetch -r 'all()'
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ hg strip -q -r 0
$ echo x > x
$ echo z > z
$ hg commit -qAm x
$ echo x2 > x
$ echo y > y
$ hg commit -qAm y
# prefetch server versions, even if local versions are available
$ clearcache
$ hg strip -q tip
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 109c3a557a73
1 local changesets published (?)
(run 'hg update' to get a working copy)
prefetching file contents
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ cd ..
# Prefetch unknown files during checkout
$ hgcloneshallow ssh://user@dummy/master shallow2
streaming all changes
2 files to transfer, 528 bytes of data (no-zstd !)
transferred 528 bytes in * seconds * (glob) (no-zstd !)
2 files to transfer, 532 bytes of data (zstd !)
transferred 532 bytes in * seconds (* */sec) (glob) (zstd !)
searching for changes
no changes found
updating to branch default
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over * (glob)
$ cd shallow2
$ hg up -q null
$ echo x > x
$ echo y > y
$ echo z > z
$ clearcache
$ hg up tip
x: untracked file differs
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over * (glob)
abort: untracked files in working directory differ from files in requested revision
[20]
$ hg revert --all
# Test batch fetching of lookup files during hg status
$ hg up --clean tip
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg debugrebuilddirstate
$ clearcache
$ hg status
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over * (glob)
# Prefetch during addrename detection
$ hg up -q --clean tip
$ hg revert --all
$ mv x x2
$ mv y y2
$ mv z z2
$ echo a > a
$ hg add a
$ rm a
$ clearcache
$ hg addremove -s 50 > /dev/null
3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over * (glob)
$ hg revert --all
forgetting x2
forgetting y2
forgetting z2
undeleting x
undeleting y
undeleting z
# Revert across double renames. Note: the scary "abort", error is because
# https://bz.mercurial-scm.org/5419 .
$ cd ../master
$ hg mv z z2
$ hg commit -m 'move z -> z2'
$ cd ../shallow2
$ hg pull -q
$ clearcache
$ hg mv y y2
y2: not overwriting - file exists
('hg rename --after' to record the rename)
[1]
$ hg mv x x2
x2: not overwriting - file exists
('hg rename --after' to record the rename)
[1]
$ hg mv z2 z3
z2: not copying - file is not managed
abort: no files to copy
(maybe you meant to use --after --at-rev=.)
[10]
$ find $CACHEDIR -type f | sort
.. The following output line about files fetches is globed because it is
.. flaky, the core the test is checked when checking the cache dir, so
.. hopefully this flakyness is not hiding any actual bug.
$ hg revert -a -r 1 || true
? files fetched over 1 fetches - (? misses, 0.00% hit ratio) over * (glob)
abort: z2@109c3a557a73: not found in manifest (?)
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/ef95c5376f34698742fe34f315fd82136f8f68c0
$TESTTMP/hgcache/master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a
$TESTTMP/hgcache/master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
$TESTTMP/hgcache/repos
# warning when we have excess remotefilelog fetching
$ cat > repeated_fetch.py << EOF
> import binascii
> from mercurial import extensions, registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command(b'repeated-fetch', [], b'', inferrepo=True)
> def repeated_fetch(ui, repo, *args, **opts):
> for i in range(20):
> try:
> hexid = (b'%02x' % (i + 1)) * 20
> repo.fileservice.prefetch([(b'somefile.txt', hexid)])
> except Exception:
> pass
> EOF
We should only output to the user once. We're ignoring most of the output
because we're not actually fetching anything real here, all the hashes are
bogus, so it's just going to be errors and a final summary of all the misses.
$ hg --config extensions.repeated_fetch=repeated_fetch.py \
> --config remotefilelog.fetchwarning="fetch warning!" \
> --config extensions.blackbox= \
> repeated-fetch 2>&1 | grep 'fetch warning'
fetch warning!
We should output to blackbox three times, with a stack trace on each (though
that isn't tested here).
$ grep 'excess remotefilelog fetching' .hg/blackbox.log
.* excess remotefilelog fetching: (re)
.* excess remotefilelog fetching: (re)
.* excess remotefilelog fetching: (re)