import sys
import time
import traceback
import logging
from datetime import datetime
import pymongo
from pylons import c, g
import ming
from ming.utils import LazyProperty
from ming import schema as S
from ming.orm import session, FieldProperty
from ming.orm.declarative import MappedClass
from .session import main_orm_session
log = logging.getLogger(__name__)
class MonQTask(MappedClass):
'''Task to be executed by the taskd daemon.
Properties
- _id - bson.ObjectId() for this task
- state - 'ready', 'busy', 'error', or 'complete' task status
- priority - integer priority, higher is more priority
- result_type - either 'keep' or 'forget', what to do with the task when
it's done
- time_queue - time the task was queued
- time_start - time taskd began working on the task
- time_stop - time taskd stopped working on the task
- task_name - full dotted name of the task function to run
- process - identifier for which taskd process is working on the task
- context - values used to set c.project, c.app, c.user for the task
- args - *args to be sent to the task function
- kwargs - **kwargs to be sent to the task function
- result - if the task is complete, the return value. If in error, the traceback.
'''
states = ('ready', 'busy', 'error', 'complete')
result_types = ('keep', 'forget')
class __mongometa__:
session = main_orm_session
name = 'monq_task'
indexes = [
[
# used in MonQTask.get() method
# also 'state' queries exist in several other methods
('state', ming.ASCENDING),
('priority', ming.DESCENDING),
('time_queue', ming.ASCENDING)
],
[
# used by SF internal tool, but could be generally useful to
# have an index on task_name
'state', 'task_name', 'time_queue'
],
]
_id = FieldProperty(S.ObjectId)
state = FieldProperty(S.OneOf(*states))
priority = FieldProperty(int)
result_type = FieldProperty(S.OneOf(*result_types))
time_queue = FieldProperty(datetime, if_missing=datetime.utcnow)
time_start = FieldProperty(datetime, if_missing=None)
time_stop = FieldProperty(datetime, if_missing=None)
task_name = FieldProperty(str)
process = FieldProperty(str)
context = FieldProperty(dict(
project_id=S.ObjectId,
app_config_id=S.ObjectId,
user_id=S.ObjectId))
args = FieldProperty([])
kwargs = FieldProperty({None:None})
result = FieldProperty(None, if_missing=None)
def __repr__(self):
from allura import model as M
project = M.Project.query.get(_id=self.context.project_id)
app = None
if project:
app_config = M.AppConfig.query.get(_id=self.context.app_config_id)
if app_config:
app = project.app_instance(app_config)
user = M.User.query.get(_id=self.context.user_id)
project_url = project and project.url() or None
app_mount = app and app.config.options.mount_point or None
username = user and user.username or None
return '<%s %s (%s) P:%d %s %s project:%s app:%s user:%s>' % (
self.__class__.__name__,
self._id,
self.state,
self.priority,
self.task_name,
self.process,
project_url,
app_mount,
username)
@LazyProperty
def function(self):
'''The function that is called by this task'''
smod, sfunc = self.task_name.rsplit('.', 1)
cur = __import__(smod, fromlist=[sfunc])
return getattr(cur, sfunc)
@classmethod
def post(cls,
function,
args=None,
kwargs=None,
result_type='forget',
priority=10):
'''Create a new task object based on the current context.'''
if args is None: args = ()
if kwargs is None: kwargs = {}
task_name = '%s.%s' % (
function.__module__,
function.__name__)
context = dict(
project_id=None,
app_config_id=None,
user_id=None)
if getattr(c, 'project', None):
context['project_id']=c.project._id
if getattr(c, 'app', None):
context['app_config_id']=c.app.config._id
if getattr(c, 'user', None):
context['user_id']=c.user._id
obj = cls(
state='ready',
priority=priority,
result_type=result_type,
task_name=task_name,
args=args,
kwargs=kwargs,
process=None,
result=None,
context=context)
session(obj).flush(obj)
try:
if g.amq_conn:
g.amq_conn.queue.put('')
except:
log.warning('Error putting to amq_conn', exc_info=True)
return obj
@classmethod
def get(cls, process='worker', state='ready', waitfunc=None):
'''Get the highest-priority, oldest, ready task and lock it to the
current process. If no task is available and waitfunc is supplied, call
the waitfunc before trying to get the task again. If waitfunc is None
and no tasks are available, return None.
'''
sort = [
('priority', ming.DESCENDING),
('time_queue', ming.ASCENDING)]
while True:
try:
obj = cls.query.find_and_modify(
query=dict(state=state),
update={
'$set': dict(
state='busy',
process=process)
},
new=True,
sort=sort)
if obj is not None: return obj
except pymongo.errors.OperationFailure, exc:
if 'No matching object found' not in exc.args[0]:
raise
if waitfunc is None:
return None
waitfunc()
@classmethod
def timeout_tasks(cls, older_than):
'''Mark all busy tasks older than a certain datetime as 'ready' again.
Used to retry 'stuck' tasks.'''
spec = dict(state='busy')
spec['time_start'] = {'$lt':older_than}
cls.query.update(spec, {'$set': dict(state='ready')}, multi=True)
@classmethod
def clear_complete(cls):
'''Delete the task objects for complete tasks'''
spec = dict(state='complete')
cls.query.remove(spec)
@classmethod
def run_ready(cls, worker=None):
'''Run all the tasks that are currently ready'''
i=0
for i, task in enumerate(cls.query.find(dict(state='ready')).all()):
task.process = worker
task()
return i
def __call__(self, restore_context=True):
'''Call the task function with its context. If restore_context is True,
c.project/app/user will be restored to the values they had before this
function was called.
'''
from allura import model as M
self.time_start = datetime.utcnow()
session(self).flush(self)
log.info('%r', self)
old_cproject = getattr(c, 'project', None)
old_capp = getattr(c, 'app', None)
old_cuser = getattr(c, 'user', None)
try:
func = self.function
c.project = M.Project.query.get(_id=self.context.project_id)
c.app = None
if c.project:
app_config = M.AppConfig.query.get(_id=self.context.app_config_id)
if app_config:
c.app = c.project.app_instance(app_config)
c.user = M.User.query.get(_id=self.context.user_id)
self.result = func(*self.args, **self.kwargs)
self.state = 'complete'
return self.result
except Exception, exc:
log.exception('%r', self)
self.state = 'error'
if hasattr(exc, 'format_error'):
self.result = exc.format_error()
log.error(self.result)
else:
self.result = traceback.format_exc()
raise
finally:
self.time_stop = datetime.utcnow()
main_orm_session.flush(self)
if restore_context:
c.project = old_cproject
c.app = old_capp
c.user = old_cuser
def join(self, poll_interval=0.1):
'''Wait until this task is either complete or errors out, then return the result.'''
while self.state not in ('complete', 'error'):
time.sleep(poll_interval)
self.query.find(dict(_id=self._id), refresh=True).first()
return self.result
@classmethod
def list(cls, state='ready'):
'''Print all tasks of a certain status to sys.stdout. Used for debugging.'''
for t in cls.query.find(dict(state=state)):
sys.stdout.write('%r\n' % t)