1 import threading

     2 import time

     3 

     4 

     5 class DelayedQueryThread(threading.Thread):

     6     def __init__(self, targetdbm, targetname, delay, query, args):

     7         threading.Thread.__init__(self)

     8         self.targetdbm = targetdbm

     9         self.targetname = targetname

    10         self.delay = delay

    11         self.query = query

    12         self.args = args

    13         

    14     def run(self):

    15         time.sleep(self.delay)

    16         with self.targetdbm.cursor(self.targetname) as curs:

    17             curs.execute(self.query, self.args)

    18 

    19 

    20 class DelayedQuery:

    21     def __init__(self, targetdbm):

    22         '''Initialize DelayedQuery.

    23         

    24         targetdbm -- PgManager-like object

    25         

    26         '''

    27         self.targetdbm = targetdbm

    28         self.queryids = set()

    29 

    30     def add(self, delay, query, args, targetname='default', queryid=None):

    31         '''Add query to schedule.

    32         

    33         delay -- how long to wait, in seconds

    34         query, args -- query to be run after delay

    35         targetname -- name of connection in PgManager

    36         queryid -- discard if query with same id is already scheduled

    37         

    38         '''

    39         if queryid is not None:

    40             if queryid in self.queryids:

    41                 return

    42             self.queryids.add(queryid)

    43         

    44         t = DelayedQueryThread(self.targetdbm, targetname, delay, query, args)

    45         t.start()

    46