Merge pull request #2018 from matthewrmshin/6.11.x-fix-command-polling

Restore command polling simple print/write

bin/cylc-stop

@@ -51,10 +51,10 @@ from cylc.task_id import TaskID
 from cylc.network.suite_command import SuiteCommandClient
 from cylc.network.suite_info import SuiteInfoClient
 from cylc.option_parsers import CylcOptionParser as COP
-from cylc.command_polling import poller
+from cylc.command_polling import Poller
 
 
-class stop_poller(poller):
+class StopPoller(Poller):
     """A polling object that checks if a suite has stopped yet."""
 
     def load(self):
@@ -102,7 +102,7 @@ def main():
         help="Shut down after time STOP (ISO 8601 formatted)",
         action="store", dest="wall_clock")
 
-    stop_poller.add_to_cmd_options(parser, d_max_polls=0)
+    StopPoller.add_to_cmd_options(parser, d_max_polls=0)
     (options, args) = parser.parse_args()
     suite = args[0]
 
@@ -123,7 +123,7 @@ def main():
 
     if int(options.max_polls) > 0:
         # (test to avoid the "nothing to do" warning for # --max-polls=0)
-        spoller = stop_poller(
+        spoller = StopPoller(
             "suite stopped", options.interval, options.max_polls,
             args={
                 'suite': suite,

bin/cylc-suite-state

@@ -61,13 +61,13 @@ from cylc.option_parsers import CylcOptionParser as COP
 from cylc.dbstatecheck import (
     CylcSuiteDBChecker, DBNotFoundError, DBOperationError)
 from cylc.cfgspec.globalcfg import GLOBAL_CFG
-from cylc.command_polling import poller
+from cylc.command_polling import Poller
 from cylc.task_state import TASK_STATUSES_ORDERED
 
 from isodatetime.parsers import TimePointParser, DurationParser
 
 
-class suite_poller(poller):
+class SuitePoller(Poller):
     """A polling object that checks suite state."""
 
     def connect(self):
@@ -174,7 +174,7 @@ def main():
              "check for. " + conds + states,
         action="store", dest="status", default=None)
 
-    suite_poller.add_to_cmd_options(parser)
+    SuitePoller.add_to_cmd_options(parser)
     (options, args) = parser.parse_args(remove_opts=["--db", "--debug"])
 
     suite = args[0]
@@ -232,7 +232,7 @@ def main():
         os.path.expanduser(
             options.run_dir or GLOBAL_CFG.get_host_item('run directory')))
 
-    spoller = suite_poller(
+    spoller = SuitePoller(
         "requested state",
         options.interval, options.max_polls,
         args={'suite': suite,

lib/cylc/command_polling.py

@@ -15,20 +15,19 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+"""Encapsulates polling activity for CLI commands."""
 
 import sys
-from time import sleep, time
+from time import sleep
 
-from cylc.suite_logging import OUT, ERR
 
-
-class poller(object):
+class Poller(object):
     """Encapsulates polling activity for cylc commands. Derived classes
     must override the check() method to test the polling condition."""
 
     @classmethod
     def add_to_cmd_options(cls, parser, d_interval=60, d_max_polls=10):
-        # add command line options for polling
+        """Add command line options for commands that can do polling"""
         parser.add_option(
             "--max-polls",
             help="Maximum number of polls (default " + str(d_max_polls) + ").",
@@ -47,27 +46,29 @@ def add_to_cmd_options(cls, parser, d_interval=60, d_max_polls=10):
             dest="interval",
             default=d_interval)
 
-    def __init__(self, condition, interval, max_polls, args={}):
+    def __init__(self, condition, interval, max_polls, args):
 
         self.condition = condition  # e.g. "suite stopped"
 
-        """check max_polls is an int"""
+        # check max_polls is an int
         try:
             self.max_polls = int(max_polls)
-        except:
-            ERR.error("max_polls must be an int")
-            sys.exit(1)
+        except ValueError:
+            sys.exit("max_polls must be an int")
 
-        """check interval is an int"""
+        # check interval is an int
         try:
             self.interval = int(interval)
-        except:
-            ERR.error("interval must be an integer")
-            sys.exit(1)
+        except ValueError:
+            sys.exit("interval must be an integer")
 
         self.n_polls = 0
         self.args = args  # any extra parameters needed by check()
 
+    def check(self):
+        """Abstract method. Test polling condition."""
+        raise NotImplementedError()
+
     def poll(self):
         """Poll for the condition embodied by self.check().
         Return True if condition met, or False if polling exhausted."""
@@ -76,27 +77,23 @@ def poll(self):
             # exit 1 as we can't know if the condition is satisfied
             sys.exit("WARNING: nothing to do (--max-polls=0)")
         elif self.max_polls == 1:
-            log_msg = "checking"
+            sys.stdout.write("checking for '%s'" % self.condition)
         else:
-            log_msg = "polling"
-        log_msg += " for '" + self.condition + "'"
+            sys.stdout.write("polling for '%s'" % self.condition)
 
-        done = False
-        while (not done and self.n_polls < self.max_polls):
+        while self.n_polls < self.max_polls:
             self.n_polls += 1
             if self.check():
-                done = True
-            else:
-                if self.max_polls > 1:
-                    log_msg += '.'
-                    sleep(self.interval)
-        if done:
-            OUT.info(log_msg + ": satisfied")
-            return True
-        else:
-            OUT.info(log_msg)
-            err_msg = "condition not satisfied",
+                sys.stdout.write(": satisfied\n")
+                return True
             if self.max_polls > 1:
-                err_msg += "\nafter " + str(self.max_polls) + " polls"
-            ERR.error(err_msg)
-            return False
+                sys.stdout.write(".")
+                sleep(self.interval)
+        sys.stdout.write("\n")
+        if self.max_polls > 1:
+            sys.stderr.write(
+                "ERROR: condition not satisfied after %d polls\n" %
+                self.max_polls)
+        else:
+            sys.stderr.write("ERROR: condition not satisfied\n")
+        return False