rhodecode/lib/celerylib/__init__.py

# -*- coding: utf-8 -*-
"""
    rhodecode.lib.celerylib.__init__
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    celery libs for RhodeCode

    :created_on: Nov 27, 2010
    :author: marcink
    :copyright: (C) 2009-2011 Marcin Kuzminski <[e-mail]>
    :license: GPLv3, see COPYING for more details.
"""
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import sys
import socket
import traceback
import logging
from os.path import dirname as dn, join as jn

from hashlib import md5
from decorator import decorator
from pylons import  config

from vcs.utils.lazy import LazyProperty

from rhodecode.lib import str2bool, safe_str
from rhodecode.lib.pidlock import DaemonLock, LockHeld

from celery.messaging import establish_connection


log = logging.getLogger(__name__)

try:
    CELERY_ON = str2bool(config['app_conf'].get('use_celery'))
except KeyError:
    CELERY_ON = False


class ResultWrapper(object):
    def __init__(self, task):
        self.task = task

    @LazyProperty
    def result(self):
        return self.task


def run_task(task, *args, **kwargs):
    if CELERY_ON:
        try:
            t = task.apply_async(args=args, kwargs=kwargs)
            log.info('running task %s:%s', t.task_id, task)
            return t

        except socket.error, e:
            if isinstance(e, IOError) and e.errno == 111:
                log.debug('Unable to connect to celeryd. Sync execution')
            else:
                log.error(traceback.format_exc())
        except KeyError, e:
                log.debug('Unable to connect to celeryd. Sync execution')
        except Exception, e:
            log.error(traceback.format_exc())

    log.debug('executing task %s in sync mode', task)
    return ResultWrapper(task(*args, **kwargs))


def __get_lockkey(func, *fargs, **fkwargs):
    params = list(fargs)
    params.extend(['%s-%s' % ar for ar in fkwargs.items()])

    func_name = str(func.__name__) if hasattr(func, '__name__') else str(func)

    lockkey = 'task_%s.lock' % \
        md5(func_name + '-' + '-'.join(map(safe_str, params))).hexdigest()
    return lockkey


def locked_task(func):
    def __wrapper(func, *fargs, **fkwargs):
        lockkey = __get_lockkey(func, *fargs, **fkwargs)
        lockkey_path = config['here']

        log.info('running task with lockkey %s', lockkey)
        try:
            l = DaemonLock(file_=jn(lockkey_path, lockkey))
            ret = func(*fargs, **fkwargs)
            l.release()
            return ret
        except LockHeld:
            log.info('LockHeld')
            return 'Task with key %s already running' % lockkey

    return decorator(__wrapper, func)