Added boto/ to depot_tools/third_party

third_party/boto/manage/task.py

+# 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)
+
+
+
+    
+
+