#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
OpenERP cron jobs worker

This script executes OpenERP cron jobs. Normally, cron jobs are handled by the
OpenERP server but depending on deployment needs, independent worker processes
can be used. This is especially the case when the server is run via Gunicorn.

OpenERP cron jobs worker re-uses openerp-server command-line options but does
not honor all of them.

Meaningful options include:

  -d, --database  comma-separated list of databases to monitor for cron jobs
                  processing. If left empty, the worker monitors all databases
                  (given by `psql -ls`).

  --addons-path   as ususal.

  --cpu-time-limit
  --virtual-memory-limit
  --virtual-memory-reset  Those three options have the same meaning the for
                          the server with Gunicorn. The only catch is: To
                          not enable rlimits by default, those options are
                          honored only when --cpu-time-limte is different than
                          60 (its default value).
"""

import logging
import os
import signal
import sys

import openerp

# Also use the `openerp` logger for the main script.
_logger = logging.getLogger('openerp')

# Variable keeping track of the number of calls to the signal handler defined
# below. This variable is monitored by ``quit_on_signals()``.
quit_signals_received = 0

# TODO copy/pasted from openerp-server
def signal_handler(sig, frame):
    """ Signal handler: exit ungracefully on the second handled signal.

    :param sig: the signal number
    :param frame: the interrupted stack frame or None
    """
    global quit_signals_received
    quit_signals_received += 1
    import openerp.addons.base
    openerp.addons.base.ir.ir_cron.quit_signal_received = True
    if quit_signals_received == 1 and openerp.addons.base.ir.ir_cron.job_in_progress:
        _logger.info("Waiting for the current job to complete.")
        print "Waiting for the current job to complete."
        print "Hit Ctrl-C again to force shutdown."
    if quit_signals_received > 1:
        # logging.shutdown was already called at this point.
        sys.stderr.write("Forced shutdown.\n")
        os._exit(0)

# TODO copy/pasted from openerp-server
def setup_signal_handlers():
    """ Register the signal handler defined above. """
    SIGNALS = map(lambda x: getattr(signal, "SIG%s" % x), "INT TERM".split())
    if os.name == 'posix':
        map(lambda sig: signal.signal(sig, signal_handler), SIGNALS)
    elif os.name == 'nt':
        import win32api
        win32api.SetConsoleCtrlHandler(lambda sig: signal_handler(sig, None), 1)

def list_databases():
    import subprocess
    p1 = subprocess.Popen(["psql", "-lAt"], stdout=subprocess.PIPE)
    p2 = subprocess.Popen(["cut", "-f", "1", "-d", "|"], stdin=p1.stdout, stdout=subprocess.PIPE)
    p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
    output = p2.communicate()[0]
    databases = output.splitlines()
    # TODO filter out non-OpenERP databases
    databases = [d for d in databases if d not in ['template0', 'template1', 'postgres']]
    databases = [d for d in databases if not d.startswith('postgres')]
    return databases

if __name__ == '__main__':
    os.environ['TZ'] = 'UTC'
    openerp.tools.config.parse_config(sys.argv[1:])
    config = openerp.tools.config
    if config['log_handler'] == [':INFO']:
        # Replace the default value, which is suitable for openerp-server.
        config['log_handler'].append('openerp.addons.base.ir.ir_cron:DEBUG')
    setup_signal_handlers()
    openerp.modules.module.initialize_sys_path()
    openerp.modules.loading.open_openerp_namespace()
    openerp.netsvc.init_logger()
    openerp.cron.enable_schedule_wakeup = False
    openerp.multi_process = True # enable multi-process signaling
    import openerp.addons.base
    print "OpenERP cron jobs worker. Hit Ctrl-C to exit."
    print "Documentation is available at the top of the `opener-cron-worker` file."
    if config['db_name']:
        db_names = config['db_name'].split(',')
        print "Monitoring %s databases." % len(db_names)
    else:
        db_names = list_databases
        print "Monitored databases are auto-discovered."
    openerp.addons.base.ir.ir_cron.ir_cron._run(db_names)

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