nodemap: introduce append-only incremental update of the persistent data
Rewriting the full nodemap for each transaction has a cost we would like to
avoid. We introduce a new way to write persistent nodemap data by adding new
information at the end for file. Any new and updated block as added at the end
of the file. The last block is the new root node.
With this method, some of the block already on disk get "dereferenced" and
become dead data. In later changesets, We'll start tracking the amount of dead
data to eventually re-generate a full nodemap.
Differential Revision: https://phab.mercurial-scm.org/D7886
#!/usr/bin/env python
from __future__ import absolute_import
"""
Small and dumb HTTP server for use in tests.
"""
import optparse
import os
import signal
import socket
import sys
from mercurial import (
encoding,
pycompat,
server,
util,
)
httpserver = util.httpserver
OptionParser = optparse.OptionParser
if os.environ.get('HGIPV6', '0') == '1':
class simplehttpserver(httpserver.httpserver):
address_family = socket.AF_INET6
else:
simplehttpserver = httpserver.httpserver
class _httprequesthandler(httpserver.simplehttprequesthandler):
def log_message(self, format, *args):
httpserver.simplehttprequesthandler.log_message(self, format, *args)
sys.stderr.flush()
class simplehttpservice(object):
def __init__(self, host, port):
self.address = (host, port)
def init(self):
self.httpd = simplehttpserver(self.address, _httprequesthandler)
def run(self):
self.httpd.serve_forever()
if __name__ == '__main__':
parser = OptionParser()
parser.add_option(
'-p',
'--port',
dest='port',
type='int',
default=8000,
help='TCP port to listen on',
metavar='PORT',
)
parser.add_option(
'-H',
'--host',
dest='host',
default='localhost',
help='hostname or IP to listen on',
metavar='HOST',
)
parser.add_option('--logfile', help='file name of access/error log')
parser.add_option(
'--pid',
dest='pid',
help='file name where the PID of the server is stored',
)
parser.add_option(
'-f',
'--foreground',
dest='foreground',
action='store_true',
help='do not start the HTTP server in the background',
)
parser.add_option('--daemon-postexec', action='append')
(options, args) = parser.parse_args()
signal.signal(signal.SIGTERM, lambda x, y: sys.exit(0))
if options.foreground and options.logfile:
parser.error(
"options --logfile and --foreground are mutually " "exclusive"
)
if options.foreground and options.pid:
parser.error("options --pid and --foreground are mutually exclusive")
opts = {
b'pid_file': options.pid,
b'daemon': not options.foreground,
b'daemon_postexec': pycompat.rapply(
encoding.strtolocal, options.daemon_postexec
),
}
service = simplehttpservice(options.host, options.port)
runargs = [sys.executable, __file__] + sys.argv[1:]
runargs = [pycompat.fsencode(a) for a in runargs]
server.runservice(
opts,
initfn=service.init,
runfn=service.run,
logfile=options.logfile,
runargs=runargs,
)