view tests/test-remotefilelog-cacheprocess.t @ 42943:5fadf6103790

remotefilelog: replace repack lock to solve race condition

2c74337e6483 reduced the probability of race-conditions when starting
background repack and prefetch and we saw the difference in our CI instance
with all failures disappearing except one where one call to waitonrepack seems
to returns too early.

I'm not sure what exactly goes wrong but I realized that while the prefetch
operation uses a standard Mercurial lock, the repack operation is using a
custom lock based on `fcntl.flock` on available platforms. As `extutil.flock`
fallback on traditional Mercurial locks on other platforms and the tests are
stable on my laptop, our CI environment and GCC112, I'm sending this patch to
standardize the behavior across environments.

Differential Revision: https://phab.mercurial-scm.org/D6844

#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'