tests/test-remotefilelog-cacheprocess.t

pycompat: use os.fsencode() to re-encode sys.argv

Historically, the previous code made sense, as Py_EncodeLocale() and
fs.fsencode() could possibly use different encodings. However, this is not the
case anymore for Python 3.2, which uses the locale encoding as the filesystem
encoding (this is not true for later Python versions, but see below). See
https://vstinner.github.io/painful-history-python-filesystem-encoding.html for
a source and more background information.

Using os.fsencode() is safer, as the documentation for sys.argv says that it can
be used to get the original bytes. When doing further changes, the Python
developers will take care that this continues to work.

One concrete case where os.fsencode() is more correct is when enabling Python's
UTF-8 mode. Py_DecodeLocale() will use UTF-8 in this case. Our previous code
would have encoded it using the locale encoding (which might be different),
whereas os.fsencode() will encode it with UTF-8.

Since we don’t claim to support the UTF-8 mode, this is not really a bug and the
patch can go to the default branch. It might be a good idea to not commit this
to the stable branch, as it could in theory introduce regressions.

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

  $ hg init repo
  $ cd repo
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
  $ echo x > x
  $ echo y > y
  $ echo z > z
  $ hg commit -qAm xy
  $ cd ..

  $ cat > cacheprocess-logger.py <<EOF
  > import os
  > import shutil
  > import sys
  > if sys.version_info[0] > 2:
  >     xrange = range
  > f = open('$TESTTMP/cachelog.log', 'w')
  > srccache = os.path.join('$TESTTMP', 'oldhgcache')
  > def log(message):
  >     f.write(message)
  >     f.flush()
  > destcache = sys.argv[-1]
  > try:
  >     while True:
  >         cmd = sys.stdin.readline().strip()
  >         log('got command %r\n' % cmd)
  >         if cmd == 'exit':
  >             sys.exit(0)
  >         elif cmd == 'get':
  >             count = int(sys.stdin.readline())
  >             log('client wants %r blobs\n' % count)
  >             wants = []
  >             for _ in xrange(count):
  >                 key = sys.stdin.readline()[:-1]
  >                 wants.append(key)
  >                 if '\0' in key:
  >                     _, key = key.split('\0')
  >                 srcpath = os.path.join(srccache, key)
  >                 if os.path.exists(srcpath):
  >                     dest = os.path.join(destcache, key)
  >                     destdir = os.path.dirname(dest)
  >                     if not os.path.exists(destdir):
  >                         os.makedirs(destdir)
  >                     shutil.copyfile(srcpath, dest)
  >                 else:
  >                     # report a cache miss
  >                     sys.stdout.write(key + '\n')
  >             sys.stdout.write('0\n')
  >             for key in sorted(wants):
  >                 log('requested %r\n' % key)
  >             sys.stdout.flush()
  >         elif cmd == 'set':
  >             raise Exception('todo writing')
  >         else:
  >             raise Exception('unknown command! %r' % cmd)
  > except Exception as e:
  >     log('Exception! %s\n' % e)
  >     raise
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [remotefilelog]
  > cacheprocess = python $TESTTMP/cacheprocess-logger.py
  > EOF

Test cache keys and cache misses.
  $ hgcloneshallow ssh://user@dummy/repo clone -q
  3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
  $ cat cachelog.log
  got command 'get'
  client wants 3 blobs
  requested 'master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
  requested 'master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'
  requested 'master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'
  got command 'set'
  Exception! todo writing

Test cache hits.
  $ mv hgcache oldhgcache
  $ rm cachelog.log
  $ hgcloneshallow ssh://user@dummy/repo clone-cachehit -q
  3 files fetched over 1 fetches - (0 misses, 100.00% hit ratio) over *s (glob)
  $ cat cachelog.log | grep -v exit
  got command 'get'
  client wants 3 blobs
  requested 'master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
  requested 'master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'
  requested 'master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'

  $ cat >> $HGRCPATH <<EOF
  > [remotefilelog]
  > cacheprocess.includepath = yes
  > EOF

Test cache keys and cache misses with includepath.
  $ rm -r hgcache oldhgcache
  $ rm cachelog.log
  $ hgcloneshallow ssh://user@dummy/repo clone-withpath -q
  3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
  $ cat cachelog.log
  got command 'get'
  client wants 3 blobs
  requested 'x\x00master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
  requested 'y\x00master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'
  requested 'z\x00master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'
  got command 'set'
  Exception! todo writing

Test cache hits with includepath.
  $ mv hgcache oldhgcache
  $ rm cachelog.log
  $ hgcloneshallow ssh://user@dummy/repo clone-withpath-cachehit -q
  3 files fetched over 1 fetches - (0 misses, 100.00% hit ratio) over *s (glob)
  $ cat cachelog.log | grep -v exit
  got command 'get'
  client wants 3 blobs
  requested 'x\x00master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
  requested 'y\x00master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'
  requested 'z\x00master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'