--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pgtoolkit/tools/loopquery.py	Tue May 06 18:37:43 2014 +0200
@@ -0,0 +1,101 @@
+from pgtoolkit.toolbase import ToolBase
+
+import logging.handlers
+import time
+from datetime import datetime, timedelta
+
+
+class LoopQueryTool(ToolBase):
+
+    """
+    Execute queries in loop, with configurable interval.
+
+    """
+
+    def __init__(self):
+        ToolBase.__init__(self, name='loopquery')
+        self.target_isolation_level = 'autocommit'
+
+    def specify_args(self):
+        ToolBase.specify_args(self)
+        self.parser.add_argument('target', nargs='?', metavar='target', type=str, help='Target database')
+        self.parser.add_argument('-c', dest='config', type=str, help='Additional config file (besides pgtoolkit.conf).')
+        self.parser.add_argument('-q', dest='queries', metavar='QUERY', nargs='*', help='Queries to run.')
+        self.parser.add_argument('--mins', dest='delay_mins', type=int, help='Delay between queries in minutes.')
+        self.parser.add_argument('--secs', dest='delay_secs', type=int, help='Delay between queries in seconds.')
+
+        self.config.add_option('target', type=str, default=None)
+        self.config.add_option('queries', type=list, default=[])
+        self.config.add_option('delay_mins', type=int, default=0)
+        self.config.add_option('delay_secs', type=int, default=0)
+        self.config.add_option('log_path', type=str)
+
+    def load_args(self, args=None, config_file=None):
+        ToolBase.load_args(self, args, config_file)
+        if self.args.config:
+            self.config.load(self.args.config)
+        self.queries = self.args.queries or self.config.queries
+        self.delay_mins = self.args.delay_mins or self.config.delay_mins
+        self.delay_secs = self.args.delay_secs or self.config.delay_secs
+
+    def init_logging(self):
+        ToolBase.init_logging(self)
+        if self.config.log_path:
+            self.init_file_logs(self.config.log_path)
+
+    def setup(self, args=None):
+        ToolBase.setup(self, args)
+        self.prepare_conns(target=self.args.target or self.config.target)
+
+    def init_file_logs(self, path):
+        format = logging.Formatter('%(asctime)s %(levelname)-5s %(message)s', '%y-%m-%d %H:%M:%S')
+        handler = logging.handlers.TimedRotatingFileHandler(path+'/main.log', when='midnight', backupCount=5)
+        handler.setFormatter(format)
+        handler.setLevel(logging.DEBUG)
+        logging.getLogger('main').addHandler(handler)
+
+        format = logging.Formatter('%(asctime)s %(message)s', '%y-%m-%d %H:%M:%S')
+        handler = logging.handlers.TimedRotatingFileHandler(path+'/pgnotices.log', when='midnight', backupCount=5)
+        handler.setFormatter(format)
+        handler.setLevel(logging.DEBUG)
+        logging.getLogger('pgmanager_notices').addHandler(handler)
+
+    def main(self):
+        self.reset()
+        while True:
+            self.wait()
+            self.action()
+
+    def reset(self):
+        """Check current time, set next action time."""
+        dt = datetime.today()
+        dt = dt.replace(microsecond = 0)
+        self.next_action_time = dt + timedelta(minutes = self.delay_mins,
+                                               seconds = self.delay_secs)
+
+    def wait(self):
+        """Wait for action time, compute next action time."""
+        now = datetime.today()
+        self.log.debug('Next run %s', self.next_action_time)
+        if self.next_action_time > now:
+            td = self.next_action_time - now
+            self.log.debug('Sleep %ds', td.seconds + td.microseconds/1e6)
+            time.sleep(td.seconds + td.microseconds/1e6)
+        self.next_action_time += timedelta(minutes = self.delay_mins,
+                                           seconds = self.delay_secs)
+        # in case that action took too long and next planned time would
+        # be in past -> reset planner
+        if self.next_action_time < now:
+            self.reset()
+
+    def action(self):
+        """Execute the queries."""
+        for q in self.queries:
+            self.log.info('%s', q)
+            with self.pgm.cursor('target') as curs:
+                curs.execute(q)
+        self.log.info('Done')
+
+
+cls = LoopQueryTool
+