debugrebuildfncache: add a cheaper option to rebuild the fncache
On my repository, debugrebuildfncache takes 5-10min with the lock.
With the flag added in this commit, it takes 10s. The tradeoff is that
it only recovers from certain kinds of corruptions. It is intended to
to recover faster from fncaches broken by a revlog split during a
transaction that ends up being rolled back.
Differential Revision: https://phab.mercurial-scm.org/D11265
#!/usr/bin/env python3
#
# Dumps output generated by Mercurial's command server in a formatted style to a
# given file or stderr if '-' is specified. Output is also written in its raw
# format to stdout.
#
# $ ./hg serve --cmds pipe | ./contrib/debugcmdserver.py -
# o, 52 -> 'capabilities: getencoding runcommand\nencoding: UTF-8'
from __future__ import absolute_import, print_function
import struct
import sys
if len(sys.argv) != 2:
print('usage: debugcmdserver.py FILE')
sys.exit(1)
outputfmt = '>cI'
outputfmtsize = struct.calcsize(outputfmt)
if sys.argv[1] == '-':
log = sys.stderr
else:
log = open(sys.argv[1], 'a')
def read(size):
data = sys.stdin.read(size)
if not data:
raise EOFError
sys.stdout.write(data)
sys.stdout.flush()
return data
try:
while True:
header = read(outputfmtsize)
channel, length = struct.unpack(outputfmt, header)
log.write('%s, %-4d' % (channel, length))
if channel in 'IL':
log.write(' -> waiting for input\n')
else:
data = read(length)
log.write(' -> %r\n' % data)
log.flush()
except EOFError:
pass
finally:
if log != sys.stderr:
log.close()