Index: third_party/boto/boto/manage/task.py |
diff --git a/third_party/boto/boto/manage/task.py b/third_party/boto/boto/manage/task.py |
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+# Copyright (c) 2006-2009 Mitch Garnaat http://garnaat.org/ |
+# |
+# Permission is hereby granted, free of charge, to any person obtaining a |
+# copy of this software and associated documentation files (the |
+# "Software"), to deal in the Software without restriction, including |
+# without limitation the rights to use, copy, modify, merge, publish, dis- |
+# tribute, sublicense, and/or sell copies of the Software, and to permit |
+# persons to whom the Software is furnished to do so, subject to the fol- |
+# lowing conditions: |
+# |
+# The above copyright notice and this permission notice shall be included |
+# in all copies or substantial portions of the Software. |
+# |
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL- |
+# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT |
+# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
+# IN THE SOFTWARE. |
+# |
+ |
+import boto |
+from boto.sdb.db.property import StringProperty, DateTimeProperty, IntegerProperty |
+from boto.sdb.db.model import Model |
+import datetime, subprocess, StringIO, time |
+ |
+def check_hour(val): |
+ if val == '*': |
+ return |
+ if int(val) < 0 or int(val) > 23: |
+ raise ValueError |
+ |
+class Task(Model): |
+ |
+ """ |
+ A scheduled, repeating task that can be executed by any participating servers. |
+ The scheduling is similar to cron jobs. Each task has an hour attribute. |
+ The allowable values for hour are [0-23|*]. |
+ |
+ To keep the operation reasonably efficient and not cause excessive polling, |
+ the minimum granularity of a Task is hourly. Some examples: |
+ |
+ hour='*' - the task would be executed each hour |
+ hour='3' - the task would be executed at 3AM GMT each day. |
+ |
+ """ |
+ name = StringProperty() |
+ hour = StringProperty(required=True, validator=check_hour, default='*') |
+ command = StringProperty(required=True) |
+ last_executed = DateTimeProperty() |
+ last_status = IntegerProperty() |
+ last_output = StringProperty() |
+ message_id = StringProperty() |
+ |
+ @classmethod |
+ def start_all(cls, queue_name): |
+ for task in cls.all(): |
+ task.start(queue_name) |
+ |
+ def __init__(self, id=None, **kw): |
+ Model.__init__(self, id, **kw) |
+ self.hourly = self.hour == '*' |
+ self.daily = self.hour != '*' |
+ self.now = datetime.datetime.utcnow() |
+ |
+ def check(self): |
+ """ |
+ Determine how long until the next scheduled time for a Task. |
+ Returns the number of seconds until the next scheduled time or zero |
+ if the task needs to be run immediately. |
+ If it's an hourly task and it's never been run, run it now. |
+ If it's a daily task and it's never been run and the hour is right, run it now. |
+ """ |
+ boto.log.info('checking Task[%s]-now=%s, last=%s' % (self.name, self.now, self.last_executed)) |
+ |
+ if self.hourly and not self.last_executed: |
+ return 0 |
+ |
+ if self.daily and not self.last_executed: |
+ if int(self.hour) == self.now.hour: |
+ return 0 |
+ else: |
+ return max( (int(self.hour)-self.now.hour), (self.now.hour-int(self.hour)) )*60*60 |
+ |
+ delta = self.now - self.last_executed |
+ if self.hourly: |
+ if delta.seconds >= 60*60: |
+ return 0 |
+ else: |
+ return 60*60 - delta.seconds |
+ else: |
+ if int(self.hour) == self.now.hour: |
+ if delta.days >= 1: |
+ return 0 |
+ else: |
+ return 82800 # 23 hours, just to be safe |
+ else: |
+ return max( (int(self.hour)-self.now.hour), (self.now.hour-int(self.hour)) )*60*60 |
+ |
+ def _run(self, msg, vtimeout): |
+ boto.log.info('Task[%s] - running:%s' % (self.name, self.command)) |
+ log_fp = StringIO.StringIO() |
+ process = subprocess.Popen(self.command, shell=True, stdin=subprocess.PIPE, |
+ stdout=subprocess.PIPE, stderr=subprocess.PIPE) |
+ nsecs = 5 |
+ current_timeout = vtimeout |
+ while process.poll() == None: |
+ boto.log.info('nsecs=%s, timeout=%s' % (nsecs, current_timeout)) |
+ if nsecs >= current_timeout: |
+ current_timeout += vtimeout |
+ boto.log.info('Task[%s] - setting timeout to %d seconds' % (self.name, current_timeout)) |
+ if msg: |
+ msg.change_visibility(current_timeout) |
+ time.sleep(5) |
+ nsecs += 5 |
+ t = process.communicate() |
+ log_fp.write(t[0]) |
+ log_fp.write(t[1]) |
+ boto.log.info('Task[%s] - output: %s' % (self.name, log_fp.getvalue())) |
+ self.last_executed = self.now |
+ self.last_status = process.returncode |
+ self.last_output = log_fp.getvalue()[0:1023] |
+ |
+ def run(self, msg, vtimeout=60): |
+ delay = self.check() |
+ boto.log.info('Task[%s] - delay=%s seconds' % (self.name, delay)) |
+ if delay == 0: |
+ self._run(msg, vtimeout) |
+ queue = msg.queue |
+ new_msg = queue.new_message(self.id) |
+ new_msg = queue.write(new_msg) |
+ self.message_id = new_msg.id |
+ self.put() |
+ boto.log.info('Task[%s] - new message id=%s' % (self.name, new_msg.id)) |
+ msg.delete() |
+ boto.log.info('Task[%s] - deleted message %s' % (self.name, msg.id)) |
+ else: |
+ boto.log.info('new_vtimeout: %d' % delay) |
+ msg.change_visibility(delay) |
+ |
+ def start(self, queue_name): |
+ boto.log.info('Task[%s] - starting with queue: %s' % (self.name, queue_name)) |
+ queue = boto.lookup('sqs', queue_name) |
+ msg = queue.new_message(self.id) |
+ msg = queue.write(msg) |
+ self.message_id = msg.id |
+ self.put() |
+ boto.log.info('Task[%s] - start successful' % self.name) |
+ |
+class TaskPoller(object): |
+ |
+ def __init__(self, queue_name): |
+ self.sqs = boto.connect_sqs() |
+ self.queue = self.sqs.lookup(queue_name) |
+ |
+ def poll(self, wait=60, vtimeout=60): |
+ while True: |
+ m = self.queue.read(vtimeout) |
+ if m: |
+ task = Task.get_by_id(m.get_body()) |
+ if task: |
+ if not task.message_id or m.id == task.message_id: |
+ boto.log.info('Task[%s] - read message %s' % (task.name, m.id)) |
+ task.run(m, vtimeout) |
+ else: |
+ boto.log.info('Task[%s] - found extraneous message, ignoring' % task.name) |
+ else: |
+ time.sleep(wait) |
+ |
+ |
+ |
+ |
+ |
+ |