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.
# common patterns in test at can safely be replaced
import os
substitutions = [
# list of possible compressions
(br'(zstd,)?zlib,none,bzip2', br'$USUAL_COMPRESSIONS$'),
(br'=(zstd,)?zlib', br'=$BUNDLE2_COMPRESSIONS$'),
# capabilities sent through http
(
br'bundlecaps=HG20%2Cbundle2%3DHG20%250A'
br'bookmarks%250A'
br'changegroup%253D01%252C02%250A'
br'checkheads%253Drelated%250A'
br'digests%253Dmd5%252Csha1%252Csha512%250A'
br'error%253Dabort%252Cunsupportedcontent%252Cpushraced%252Cpushkey%250A'
br'hgtagsfnodes%250A'
br'listkeys%250A'
br'phases%253Dheads%250A'
br'pushkey%250A'
br'remote-changegroup%253Dhttp%252Chttps%250A'
br'stream%253Dv2',
# (the replacement patterns)
br'$USUAL_BUNDLE_CAPS$',
),
(
br'bundlecaps=HG20%2Cbundle2%3DHG20%250A'
br'bookmarks%250A'
br'changegroup%253D01%252C02%250A'
br'checkheads%3Drelated%0A'
br'digests%253Dmd5%252Csha1%252Csha512%250A'
br'error%253Dabort%252Cunsupportedcontent%252Cpushraced%252Cpushkey%250A'
br'hgtagsfnodes%250A'
br'listkeys%250A'
br'phases%253Dheads%250A'
br'pushkey%250A'
br'remote-changegroup%253Dhttp%252Chttps',
# (the replacement patterns)
br'$USUAL_BUNDLE_CAPS_SERVER$',
),
# bundle2 capabilities sent through ssh
(
br'bundle2=HG20%0A'
br'bookmarks%0A'
br'changegroup%3D01%2C02%0A'
br'checkheads%3Drelated%0A'
br'digests%3Dmd5%2Csha1%2Csha512%0A'
br'error%3Dabort%2Cunsupportedcontent%2Cpushraced%2Cpushkey%0A'
br'hgtagsfnodes%0A'
br'listkeys%0A'
br'phases%3Dheads%0A'
br'pushkey%0A'
br'remote-changegroup%3Dhttp%2Chttps%0A'
br'stream%3Dv2',
# (replacement patterns)
br'$USUAL_BUNDLE2_CAPS$',
),
# bundle2 capabilities advertised by the server
(
br'bundle2=HG20%0A'
br'bookmarks%0A'
br'changegroup%3D01%2C02%0A'
br'checkheads%3Drelated%0A'
br'digests%3Dmd5%2Csha1%2Csha512%0A'
br'error%3Dabort%2Cunsupportedcontent%2Cpushraced%2Cpushkey%0A'
br'hgtagsfnodes%0A'
br'listkeys%0A'
br'phases%3Dheads%0A'
br'pushkey%0A'
br'remote-changegroup%3Dhttp%2Chttps',
# (replacement patterns)
br'$USUAL_BUNDLE2_CAPS_SERVER$',
),
(
br'bundle2=HG20%0A'
br'bookmarks%0A'
br'changegroup%3D01%2C02%0A'
br'digests%3Dmd5%2Csha1%2Csha512%0A'
br'error%3Dabort%2Cunsupportedcontent%2Cpushraced%2Cpushkey%0A'
br'hgtagsfnodes%0A'
br'listkeys%0A'
br'pushkey%0A'
br'remote-changegroup%3Dhttp%2Chttps%0A'
br'stream%3Dv2',
# (replacement patterns)
br'$USUAL_BUNDLE2_CAPS_NO_PHASES$',
),
# HTTP access log dates
(
br' - - \[\d\d/.../2\d\d\d \d\d:\d\d:\d\d] "(GET|PUT|POST)',
lambda m: br' - - [$LOGDATE$] "' + m.group(1),
),
# HTTP error log dates
(
br' - - \[\d\d/.../2\d\d\d \d\d:\d\d:\d\d] (HG error:|Exception)',
lambda m: br' - - [$ERRDATE$] ' + m.group(1),
),
# HTTP header dates- RFC 1123
(
br'([Dd]ate): [A-Za-z]{3}, \d\d [A-Za-z]{3} \d{4} \d\d:\d\d:\d\d GMT',
lambda m: br'%s: $HTTP_DATE$' % m.group(1),
),
# LFS expiration value
(
br'"expires_at": "\d{4}-\d\d-\d\dT\d\d:\d\d:\d\dZ"',
br'"expires_at": "$ISO_8601_DATE_TIME$"',
),
# Windows has an extra '/' in the following lines that get globbed away:
# pushing to file:/*/$TESTTMP/r2 (glob)
# comparing with file:/*/$TESTTMP/r2 (glob)
# sub/maybelarge.dat: largefile 34..9c not available from
# file:/*/$TESTTMP/largefiles-repo (glob)
(
br'(.*file:/)/?(/\$TESTTMP.*)',
lambda m: m.group(1) + b'*' + m.group(2) + b' (glob)',
),
# `hg clone --stream` output
(
br'transferred (\S+?) KB in \S+? seconds \(.+?/sec\)(?: \(glob\))?(.*)',
lambda m: (
br'transferred %s KB in * seconds (* */sec) (glob)%s'
% (m.group(1), m.group(2))
),
),
]
# Various platform error strings, keyed on a common replacement string
_errors = {
br'$ENOENT$': (
# IOError in Python does not have the same error message
# than in Rust, and automatic conversion is not possible
# because of module member privacy.
br'No such file or directory \(os error 2\)',
# strerror()
br'No such file or directory',
# FormatMessage(ERROR_FILE_NOT_FOUND)
br'The system cannot find the file specified',
),
br'$ENOTDIR$': (
# strerror()
br'Not a directory',
# FormatMessage(ERROR_PATH_NOT_FOUND)
br'The system cannot find the path specified',
),
br'$ECONNRESET$': (
# strerror()
br'Connection reset by peer',
# FormatMessage(WSAECONNRESET)
br'An existing connection was forcibly closed by the remote host',
),
br'$EADDRINUSE$': (
# strerror()
br'Address already in use',
# FormatMessage(WSAEADDRINUSE)
br'Only one usage of each socket address'
br' \(protocol/network address/port\) is normally permitted',
),
br'$EADDRNOTAVAIL$': (
# strerror()
br'Cannot assign requested address',
# FormatMessage(WSAEADDRNOTAVAIL)
),
}
for replace, msgs in _errors.items():
substitutions.extend((m, replace) for m in msgs)
# Output lines on Windows that can be autocorrected for '\' vs '/' path
# differences.
_winpathfixes = [
# cloning subrepo s\ss from $TESTTMP/t/s/ss
# cloning subrepo foo\bar from http://localhost:$HGPORT/foo/bar
br'(?m)^cloning subrepo \S+\\.*',
# pulling from $TESTTMP\issue1852a
br'(?m)^pulling from \$TESTTMP\\.*',
# pushing to $TESTTMP\a
br'(?m)^pushing to \$TESTTMP\\.*',
# pushing subrepo s\ss to $TESTTMP/t/s/ss
br'(?m)^pushing subrepo \S+\\\S+ to.*',
# moving d1\d11\a1 to d3/d11/a1
br'(?m)^moving \S+\\.*',
# d1\a: not recording move - dummy does not exist
br'\S+\\\S+: not recording move .+',
# reverting s\a
br'(?m)^reverting (?!subrepo ).*\\.*',
# saved backup bundle to
# $TESTTMP\test\.hg\strip-backup/443431ffac4f-2fc5398a-backup.hg
br'(?m)^saved backup bundle to \$TESTTMP.*\.hg',
# no changes made to subrepo s\ss since last push to ../tcc/s/ss
br'(?m)^no changes made to subrepo \S+\\\S+ since.*',
# changeset 5:9cc5aa7204f0: stuff/maybelarge.dat references missing
# $TESTTMP\largefiles-repo-hg\.hg\largefiles\76..38
br'(?m)^changeset .* references (corrupted|missing) \$TESTTMP\\.*',
# stuff/maybelarge.dat: largefile 76..38 not available from
# file:/*/$TESTTMP\largefiles-repo (glob)
br'.*: largefile \S+ not available from file:/\*/.+',
]
if os.name == 'nt':
substitutions.extend(
[
(s, lambda match: match.group().replace(b'\\', b'/'))
for s in _winpathfixes
]
)