revisionbranchcache: fall back to slow path if starting readonly (issue4531)
Transitioning to Mercurial versions with revision branch cache could be slow as
long as all operations were readonly (revset queries) and the cache would be
populated but not written back.
Instead, fall back to using the consistently slow path when readonly and the
cache doesn't exist yet. That avoids the overhead of populating the cache
without writing it back.
If not readonly, it will still populate all missing entries initially. That
avoids repeated writing of the cache file with small updates, and it also makes
sure a fully populated cache available for the readonly operations.
#!/usr/bin/env python
"""
Small and dumb HTTP server for use in tests.
"""
from optparse import OptionParser
import BaseHTTPServer, SimpleHTTPServer, signal, sys
from mercurial import cmdutil
class simplehttpservice(object):
def __init__(self, host, port):
self.address = (host, port)
def init(self):
self.httpd = BaseHTTPServer.HTTPServer(
self.address, SimpleHTTPServer.SimpleHTTPRequestHandler)
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('--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-pipefds')
(options, args) = parser.parse_args()
signal.signal(signal.SIGTERM, lambda x, y: sys.exit(0))
if options.foreground and options.pid:
parser.error("options --pid and --foreground are mutually exclusive")
opts = {'pid_file': options.pid,
'daemon': not options.foreground,
'daemon_pipefds': options.daemon_pipefds}
service = simplehttpservice(options.host, options.port)
cmdutil.service(opts, initfn=service.init, runfn=service.run,
runargs=[sys.executable, __file__] + sys.argv[1:])