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
# Tests for the complicated linknode logic in remotefilelog.py::ancestormap()
$ . "$TESTDIR/remotefilelog-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> serverexpiration=-1
> EOF
$ echo x > x
$ hg commit -qAm x
$ cd ..
$ hgcloneshallow ssh://user@dummy/master shallow -q
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
# Rebase produces correct log -f linknodes
$ cd shallow
$ echo y > y
$ hg commit -qAm y
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo x >> x
$ hg commit -qAm xx
$ hg log -f x --template "{node|short}\n"
0632994590a8
b292c1e3311f
$ hg rebase -d 1
rebasing 2:0632994590a8 tip "xx"
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/0632994590a8-0bc786d8-rebase.hg (glob)
$ hg log -f x --template "{node|short}\n"
81deab2073bc
b292c1e3311f
# Rebase back, log -f still works
$ hg rebase -d 0 -r 2
rebasing 2:81deab2073bc tip "xx"
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/81deab2073bc-80cb4fda-rebase.hg (glob)
$ hg log -f x --template "{node|short}\n"
b3fca10fb42d
b292c1e3311f
$ hg rebase -d 1 -r 2
rebasing 2:b3fca10fb42d tip "xx"
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/b3fca10fb42d-da73a0c7-rebase.hg (glob)
$ cd ..
# Reset repos
$ clearcache
$ rm -rf master
$ rm -rf shallow
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> serverexpiration=-1
> EOF
$ echo x > x
$ hg commit -qAm x
$ cd ..
$ hgcloneshallow ssh://user@dummy/master shallow -q
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
# Rebase stack onto landed commit
$ cd master
$ echo x >> x
$ hg commit -Aqm xx
$ cd ../shallow
$ echo x >> x
$ hg commit -Aqm xx2
$ echo y >> x
$ hg commit -Aqm xxy
$ hg pull -q
$ hg rebase -d tip
rebasing 1:4549721d828f "xx2"
note: not rebasing 1:4549721d828f "xx2", its destination already has all its changes
rebasing 2:5ef6d97e851c "xxy"
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/4549721d828f-b084e33c-rebase.hg (glob)
$ hg log -f x --template '{node|short}\n'
4ae8e31c85ef
0632994590a8
b292c1e3311f
$ cd ..
# system cache has invalid linknode, but .hg/store/data has valid
$ cd shallow
$ hg strip -r 1 -q
$ rm -rf .hg/store/data/*
$ echo x >> x
$ hg commit -Aqm xx_local
$ hg log -f x --template '{rev}:{node|short}\n'
1:21847713771d
0:b292c1e3311f
$ cd ..
$ rm -rf shallow
/* Local linknode is invalid; remote linknode is valid (formerly slow case) */
$ hgcloneshallow ssh://user@dummy/master shallow -q
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over * (glob)
$ cd shallow
$ echo x >> x
$ hg commit -Aqm xx2
$ cd ../master
$ echo y >> y
$ hg commit -Aqm yy2
$ echo x >> x
$ hg commit -Aqm xx2-fake-rebased
$ echo y >> y
$ hg commit -Aqm yy3
$ cd ../shallow
$ hg pull --config remotefilelog.debug=True
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 0 changes to 0 files (+1 heads)
new changesets 01979f9404f8:7200df4e0aca
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg update tip -q
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ echo x > x
$ hg commit -qAm xx3
# At this point, the linknode points to c1254e70bad1 instead of 32e6611f6149
$ hg log -G -T '{node|short} {desc} {phase} {files}\n'
@ a5957b6bf0bd xx3 draft x
|
o 7200df4e0aca yy3 public y
|
o 32e6611f6149 xx2-fake-rebased public x
|
o 01979f9404f8 yy2 public y
|
| o c1254e70bad1 xx2 draft x
|/
o 0632994590a8 xx public x
|
o b292c1e3311f x public x
# Check the contents of the local blob for incorrect linknode
$ hg debugremotefilelog .hg/store/data/11f6ad8ec52a2984abaafd7c3b516503785c2072/d4a3ed9310e5bd9887e3bf779da5077efab28216
size: 6 bytes
path: .hg/store/data/11f6ad8ec52a2984abaafd7c3b516503785c2072/d4a3ed9310e5bd9887e3bf779da5077efab28216
key: d4a3ed9310e5
node => p1 p2 linknode copyfrom
d4a3ed9310e5 => aee31534993a 000000000000 c1254e70bad1
aee31534993a => 1406e7411862 000000000000 0632994590a8
1406e7411862 => 000000000000 000000000000 b292c1e3311f
# Verify that we do a fetch on the first log (remote blob fetch for linkrev fix)
$ hg log -f x -T '{node|short} {desc} {phase} {files}\n'
a5957b6bf0bd xx3 draft x
32e6611f6149 xx2-fake-rebased public x
0632994590a8 xx public x
b292c1e3311f x public x
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
# But not after that
$ hg log -f x -T '{node|short} {desc} {phase} {files}\n'
a5957b6bf0bd xx3 draft x
32e6611f6149 xx2-fake-rebased public x
0632994590a8 xx public x
b292c1e3311f x public x
# Check the contents of the remote blob for correct linknode
$ hg debugremotefilelog $CACHEDIR/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/d4a3ed9310e5bd9887e3bf779da5077efab28216
size: 6 bytes
path: $TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/d4a3ed9310e5bd9887e3bf779da5077efab28216
key: d4a3ed9310e5
node => p1 p2 linknode copyfrom
d4a3ed9310e5 => aee31534993a 000000000000 32e6611f6149
aee31534993a => 1406e7411862 000000000000 0632994590a8
1406e7411862 => 000000000000 000000000000 b292c1e3311f