revlog: implement changelogv2 packing and unpacking in C
This introduces a C implementation of changelogv2 records packing and unpacking
operations matching the pure Python counterpart, similarly to what we already
have for revlogv1 and revlogv2.
This is also necessary to access changelogv2 record fields from future Rust
code without going through the Python part, which would annihilate any
performance benefit.
Differential Revision: https://phab.mercurial-scm.org/D12178
#!/usr/bin/env python3
# Undump a dump from dumprevlog
# $ hg init
# $ undumprevlog < repo.dump
from __future__ import absolute_import, print_function
import sys
from mercurial.node import bin
from mercurial import (
encoding,
revlog,
transaction,
vfs as vfsmod,
)
from mercurial.utils import procutil
from mercurial.revlogutils import (
constants as revlog_constants,
)
for fp in (sys.stdin, sys.stdout, sys.stderr):
procutil.setbinary(fp)
opener = vfsmod.vfs(b'.', False)
tr = transaction.transaction(
sys.stderr.write, opener, {b'store': opener}, b"undump.journal"
)
while True:
l = sys.stdin.readline()
if not l:
break
if l.startswith("file:"):
f = encoding.strtolocal(l[6:-1])
assert f.endswith(b'.i')
r = revlog.revlog(
opener,
target=(revlog_constants.KIND_OTHER, b'undump-revlog'),
radix=f[:-2],
)
procutil.stdout.write(b'%s\n' % f)
elif l.startswith("node:"):
n = bin(l[6:-1])
elif l.startswith("linkrev:"):
lr = int(l[9:-1])
elif l.startswith("parents:"):
p = l[9:-1].split()
p1 = bin(p[0])
p2 = bin(p[1])
elif l.startswith("length:"):
length = int(l[8:-1])
sys.stdin.readline() # start marker
d = encoding.strtolocal(sys.stdin.read(length))
sys.stdin.readline() # end marker
r.addrevision(d, tr, lr, p1, p2)
tr.close()