From 9f32a0db0b77fe46b6e44573c3f989ee96626fb7 2013-02-25 15:28:37
From: Lance Edgar <lance@edbob.org>
Date: 2013-02-25 15:28:37
Subject: [PATCH] Added `purge-batches` command.

This command will delete forever all batches whose purge date has
passed.  It is meant to be run on a scheduled basis, e.g. nightly.

---

diff --git a/rattail/commands.py b/rattail/commands.py
index a69ced2458724866251272365d410ceb32895fdf..4039b1df3178acec75d9bbc989ec31ba1fea1554 100644
--- a/rattail/commands.py
+++ b/rattail/commands.py
@@ -163,7 +163,35 @@ class PalmCommand(commands.Subcommand):
             # Unregister conduit's COM server.
             from win32com.server.register import UnregisterClasses
             UnregisterClasses(palm.PalmConduit)
+
             
+class PurgeBatchesCommand(commands.Subcommand):
+    """
+    .. highlight:: sh
+
+    Purges stale batches from the database; called as::
+
+      rattail purge-batches
+    """
+
+    name = 'purge-batches'
+    description = "Purge stale batches from the database"
+
+    def run(self, args):
+        from rattail.db.batches.util import purge_batches
+
+        edbob.init_modules(['edbob.db', 'rattail.db'])
+
+        print "Purging batches from database:"
+        print "    %s" % edbob.engine.url
+
+        session = edbob.Session()
+        purged = purge_batches(session)
+        session.commit()
+        session.close()
+
+        print "\nPurged %d batches" % purged
+
 
 def main(*args):
     """
diff --git a/rattail/db/batches/util.py b/rattail/db/batches/util.py
new file mode 100644
index 0000000000000000000000000000000000000000..bd3344b7c0213c701fc448b7cce4ca84f5c68eb0
--- /dev/null
+++ b/rattail/db/batches/util.py
@@ -0,0 +1,93 @@
+#!/usr/bin/env python
+# -*- coding: utf-8  -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2012 Lance Edgar
+#
+#  This file is part of Rattail.
+#
+#  Rattail is free software: you can redistribute it and/or modify it under the
+#  terms of the GNU Affero General Public License as published by the Free
+#  Software Foundation, either version 3 of the License, or (at your option)
+#  any later version.
+#
+#  Rattail is distributed in the hope that it will be useful, but WITHOUT ANY
+#  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#  FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#  more details.
+#
+#  You should have received a copy of the GNU Affero General Public License
+#  along with Rattail.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+
+"""
+``rattail.db.batches.util`` -- Batch Utilities
+"""
+
+import re
+
+from sqlalchemy import MetaData
+
+import edbob
+from edbob.time import local_time
+
+import rattail
+from rattail.db.extension.model import Batch
+
+
+def purge_batches(session, effective_date=None):
+    """
+    Purge batches from the database which are considered old.
+
+    :param session: Active database session.
+    :type session: ``sqlalchemy.orm.Session`` instance
+
+    :param effective_date: Date against which comparisons should be made when
+       determining if a batch is "old" (based on its
+       :attr:`rattail.db.model.Batch.purge` attribute).  If no value is
+       provided, then :func:`rattail.time.local_time()` is called to determine
+       the current date.
+    :type effective_date: ``datetime.date`` instance, or ``None``
+
+    :returns: ``None``
+    """
+
+    if effective_date is None:
+        edbob.init_modules(['edbob.time'])
+        effective_date = local_time().date()
+
+    purged = 0
+
+    q = session.query(Batch)
+    q = q.filter(Batch.purge != None)
+    q = q.filter(Batch.purge < effective_date)
+    for batch in q:
+        batch.drop_table()
+        session.delete(batch)
+        session.flush()
+        purged += 1
+
+    # This should theoretically not be necessary, if/when the batch processing
+    # is cleaning up after itself properly.  For now though, it seems that
+    # orphaned data tables are sometimes being left behind.
+
+    batch_pattern = re.compile(r'^batch\.[0-9a-f]{32}$')
+
+    current_batches = []
+    for batch in session.query(Batch):
+        current_batches.append('batch.%s' % batch.uuid)
+
+    def orphaned_batches(name, metadata):
+        if batch_pattern.match(name):
+            if name not in current_batches:
+                return True
+        return False
+
+    metadata = MetaData(session.bind)
+    metadata.reflect(only=orphaned_batches)
+    for table in reversed(metadata.sorted_tables):
+        table.drop()
+
+    return purged
diff --git a/setup.py b/setup.py
index e5591eb82d3637df48bd705493bab9577a74ef72..3f9d53772f2f5dfa03781ee1888175b13c11c219 100644
--- a/setup.py
+++ b/setup.py
@@ -116,6 +116,7 @@ dbsync = rattail.commands:DatabaseSyncCommand
 filemon = rattail.commands:FileMonitorCommand
 load-host-data = rattail.commands:LoadHostDataCommand
 palm = rattail.commands:PalmCommand
+purge-batches = rattail.commands:PurgeBatchesCommand
 
 [rattail.batches.providers]
 print_labels = rattail.batches.providers.labels:PrintLabels