branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
#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
> 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 range(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'