bdiff: give slight preference to longest matches in the middle of the B side
We already have a slight preference for matches close to the middle on the A
side. Now, do the same on the B side.
j is iterating the b range backwards and we thus accept a new j if the previous
match was in the upper half.
This makes the test-bhalf diff "correct". It obviously also gives more
preference to balanced recursion than to appending to sequences. That is kind
of correct, but will also unfortunately make some bundles bigger. No doubt, we
can also create examples where it will make them smaller ...
The bundle size for 4.0 (hg bundle --base null -r 4.0 x.hg) happens to go from
22803824 to 22806817 bytes - an 0.01% increase.
#!/usr/bin/env python
# Undump a dump from dumprevlog
# $ hg init
# $ undumprevlog < repo.dump
from __future__ import absolute_import
import sys
from mercurial import (
node,
revlog,
scmutil,
transaction,
util,
)
for fp in (sys.stdin, sys.stdout, sys.stderr):
util.setbinary(fp)
opener = scmutil.opener('.', False)
tr = transaction.transaction(sys.stderr.write, opener, {'store': opener},
"undump.journal")
while True:
l = sys.stdin.readline()
if not l:
break
if l.startswith("file:"):
f = l[6:-1]
r = revlog.revlog(opener, f)
print f
elif l.startswith("node:"):
n = node.bin(l[6:-1])
elif l.startswith("linkrev:"):
lr = int(l[9:-1])
elif l.startswith("parents:"):
p = l[9:-1].split()
p1 = node.bin(p[0])
p2 = node.bin(p[1])
elif l.startswith("length:"):
length = int(l[8:-1])
sys.stdin.readline() # start marker
d = sys.stdin.read(length)
sys.stdin.readline() # end marker
r.addrevision(d, tr, lr, p1, p2)
tr.close()