Add ability to purge streams on completion.

default to deleting streams once finished with them (if no error)

ChangeLog

@@ -1,3 +1,9 @@
+commit 2d47fa6f6e0de0a54975ff92fc87785a052d4371
+Author: Monsyne Dragon <mdragon@rackspace.com>
+Date:   Mon Sep 8 23:02:52 2014 +0000
+
+    Add reset stream method.
+
 commit ca0d09f7bc017ef9e372ae29a0c19bf20b68aca5
 Author: Monsyne Dragon <mdragon@rackspace.com>
 Date:   Mon Sep 8 19:57:24 2014 +0000

tests/test_db.py

@@ -439,3 +439,11 @@ class TestDB(unittest.TestCase):
         stream = self.db.get_stream_by_id(6)
         stream = self.db.reset_stream(stream)
         self.assertEqual(stream.state, models.StreamState.retry_expire)
+
+    def test_purge_stream(self):
+        stream = self.db.get_stream_by_id(1)
+        self.db.purge_stream(stream)
+        with self.assertRaises(db.NoSuchStreamError):
+            self.db.get_stream_by_id(1)
+
+

tests/test_pipeline_manager.py

@@ -201,13 +201,23 @@ class TestPipelineManager(unittest.TestCase):
         super(TestPipelineManager, self).setUp()
 
     @mock.patch.object(pipeline_manager.ConfigManager, 'wrap')
-    def test_complete_stream(self, mock_config_wrap):
+    def test_complete_stream_nopurge(self, mock_config_wrap):
         pm = pipeline_manager.PipelineManager('test')
         pm.db = mock.MagicMock(spec=pm.db)
+        pm.purge_completed_streams = False
         stream = "test stream"
         pm._complete_stream(stream)
         pm.db.set_stream_state.assert_called_once_with(stream, StreamState.completed)
 
+    @mock.patch.object(pipeline_manager.ConfigManager, 'wrap')
+    def test_complete_stream_purge(self, mock_config_wrap):
+        pm = pipeline_manager.PipelineManager('test')
+        pm.db = mock.MagicMock(spec=pm.db)
+        pm.purge_completed_streams = True
+        stream = "test stream"
+        pm._complete_stream(stream)
+        pm.db.purge_stream.assert_called_once_with(stream)
+
     @mock.patch.object(pipeline_manager.ConfigManager, 'wrap')
     def test_error_stream(self, mock_config_wrap):
         pm = pipeline_manager.PipelineManager('test')

winchester/db/__init__.py

@@ -1,4 +1,5 @@
 from winchester.db.interface import DuplicateError, LockError
+from winchester.db.interface import NoSuchEventError, NoSuchStreamError
 from winchester.db.interface import DBInterface
 
 

winchester/db/interface.py

@@ -4,6 +4,8 @@ import sqlalchemy
 from sqlalchemy import and_, or_
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm.exc import NoResultFound
+from sqlalchemy.orm.exc import MultipleResultsFound
 
 from winchester import models
 from winchester.config import ConfigManager, ConfigSection, ConfigItem
@@ -23,6 +25,14 @@ class LockError(models.DBException):
     pass
 
 
+class NoSuchEventError(models.DBException):
+    pass
+
+
+class NoSuchStreamError(models.DBException):
+    pass
+
+
 def sessioned(func):
     def with_session(self, *args, **kw):
         if 'session' in kw:
@@ -108,14 +118,20 @@ class DBInterface(object):
 
     @sessioned
     def get_event_by_message_id(self, message_id, session=None):
-        e = session.query(models.Event).\
-            filter(models.Event.message_id == message_id).one()
+        try:
+            e = session.query(models.Event).\
+                filter(models.Event.message_id == message_id).one()
+        except NoResultFound:
+            raise NoSuchEventError("No event found with message_id %s!" % message_id)
         return e.as_dict
 
     @sessioned
     def get_stream_by_id(self, stream_id, session=None):
-        s = session.query(models.Stream).\
-            filter(models.Stream.id == stream_id).one()
+        try:
+            s = session.query(models.Stream).\
+                filter(models.Stream.id == stream_id).one()
+        except NoResultFound:
+            raise NoSuchStreamError("No stream found with id %s!" % stream_id)
         return s
 
     @sessioned
@@ -217,3 +233,10 @@ class DBInterface(object):
         if stream.state == models.StreamState.expire_error:
             return self.set_stream_state(stream, models.StreamState.retry_expire)
         return stream
+
+    @sessioned
+    def purge_stream(self, stream, session=None):
+        if stream not in session:
+            session.add(stream)
+        session.delete(stream)
+

winchester/models.py

@@ -342,6 +342,7 @@ class Stream(ProxiedDictMixin, Base):
     state_serial_no = Column(Integer, default=0, nullable=False)
 
     distinguished_by = relationship("DistinguishingTrait",
+                    cascade="save-update, merge, delete, delete-orphan",
                     collection_class=attribute_mapped_collection('name'))
     _proxied = association_proxy("distinguished_by", "value",
                     creator=lambda name, value: DistinguishingTrait(name=name, value=value))

winchester/pipeline_manager.py

@@ -112,6 +112,8 @@ class PipelineManager(object):
                     pipeline_config=ConfigItem(required=True,
                                        help="Name of pipeline config file "
                                             "defining the handlers for each pipeline."),
+                    purge_completed_streams=ConfigItem(help="Delete successfully proccessed "
+                                                       "streams when finished?", default=True),
                    )
 
     def __init__(self, config, db=None, pipeline_handlers=None, pipeline_config=None, trigger_defs=None):
@@ -156,6 +158,7 @@ class PipelineManager(object):
         self.pipeline_worker_batch_size = config['pipeline_worker_batch_size']
         self.pipeline_worker_delay = config['pipeline_worker_delay']
         self.statistics_period = config['statistics_period']
+        self.purge_completed_streams = config['purge_completed_streams']
         self.streams_fired = 0
         self.streams_expired = 0
         self.streams_loaded = 0
@@ -209,13 +212,28 @@ class PipelineManager(object):
         return True
 
     def _complete_stream(self, stream):
-        self.db.set_stream_state(stream, StreamState.completed)
+        if self.purge_completed_streams:
+            self.db.purge_stream(stream)
+        else:
+            try:
+                self.db.set_stream_state(stream, StreamState.completed)
+            except LockError:
+                logger.error("Stream %s locked while trying to set 'complete' state! "
+                             "This should not happen." % stream.id)
 
     def _error_stream(self, stream):
-        self.db.set_stream_state(stream, StreamState.error)
+        try:
+            self.db.set_stream_state(stream, StreamState.error)
+        except LockError:
+            logger.error("Stream %s locked while trying to set 'error' state! "
+                         "This should not happen." % stream.id)
 
     def _expire_error_stream(self, stream):
-        self.db.set_stream_state(stream, StreamState.expire_error)
+        try:
+            self.db.set_stream_state(stream, StreamState.expire_error)
+        except LockError:
+            logger.error("Stream %s locked while trying to set 'expire_error' state! "
+                         "This should not happen." % stream.id)
 
     def fire_stream(self, stream):
         try: