Several non-functional improvements to the code base.

Reduce the explicit use of the config.db global by introducing two new
helpers:
 - A new transaction() context manager which will commit the transaction on
   successful exit, otherwise it will abort the transaction
 - A new dbconnection decorator which calls the decorated method with the
   Storm store object as the first argument (after self).  This can be used
   instead of config.db.store.

By reducing the explicit use of this global, we have a better chance of
refactoring it away in the future.  Still TODO: runner.py and lmtp.py.

Be explicit about the `store` attribute on the IDatabase interface.

More consistent use of __future__ imports.

Remove an obsolete command line script.

1 files changed, 26 insertions, 20 deletions

diff --git a/src/mailman/model/roster.py b/src/mailman/model/roster.py
index 48d434ab1..84ed12930 100644
--- a/src/mailman/model/roster.py
+++ b/src/mailman/model/roster.py
@@ -22,7 +22,7 @@ the ones that fit a particular role.  These are used as the member, owner,
 moderator, and administrator roster filters.
 """
 
-from __future__ import absolute_import, unicode_literals
+from __future__ import absolute_import, print_function, unicode_literals
 
 __metaclass__ = type
 __all__ = [
@@ -40,7 +40,7 @@ __all__ = [
 from storm.expr import And, Or
 from zope.interface import implements
 
-from mailman.config import config
+from mailman.database.transaction import dbconnection
 from mailman.interfaces.member import DeliveryMode, MemberRole
 from mailman.interfaces.roster import IRoster
 from mailman.model.address import Address
@@ -64,8 +64,9 @@ class AbstractRoster:
     def __init__(self, mlist):
         self._mlist = mlist
 
-    def _query(self):
-        return config.db.store.find(
+    @dbconnection
+    def _query(self, store):
+        return store.find(
             Member,
             mailing_list=self._mlist.fqdn_listname,
             role=self.role)
@@ -101,9 +102,10 @@ class AbstractRoster:
         for member in self.members:
             yield member.address
 
-    def get_member(self, address):
+    @dbconnection
+    def get_member(self, store, address):
         """See `IRoster`."""
-        results = config.db.store.find(
+        results = store.find(
             Member,
             Member.mailing_list == self._mlist.fqdn_listname,
             Member.role == self.role,
@@ -157,16 +159,18 @@ class AdministratorRoster(AbstractRoster):
 
     name = 'administrator'
 
-    def _query(self):
-        return config.db.store.find(
+    @dbconnection
+    def _query(self, store):
+        return store.find(
             Member,
             Member.mailing_list == self._mlist.fqdn_listname,
             Or(Member.role == MemberRole.owner,
                Member.role == MemberRole.moderator))
 
-    def get_member(self, address):
+    @dbconnection
+    def get_member(self, store, address):
         """See `IRoster`."""
-        results = config.db.store.find(
+        results = store.find(
                 Member,
                 Member.mailing_list == self._mlist.fqdn_listname,
                 Or(Member.role == MemberRole.moderator,
@@ -194,7 +198,8 @@ class DeliveryMemberRoster(AbstractRoster):
         # checking the delivery mode to a query parameter.
         return len(tuple(self.members))
 
-    def _get_members(self, *delivery_modes):
+    @dbconnection
+    def _get_members(self, store, *delivery_modes):
         """The set of members for a mailing list, filter by delivery mode.
 
         :param delivery_modes: The modes to filter on.
@@ -202,7 +207,7 @@ class DeliveryMemberRoster(AbstractRoster):
         :return: A generator of members.
         :rtype: generator
         """
-        results = config.db.store.find(
+        results = store.find(
             Member,
             And(Member.mailing_list == self._mlist.fqdn_listname,
                 Member.role == MemberRole.member))
@@ -244,10 +249,9 @@ class Subscribers(AbstractRoster):
 
     name = 'subscribers'
 
-    def _query(self):
-        return config.db.store.find(
-            Member,
-            mailing_list=self._mlist.fqdn_listname)
+    @dbconnection
+    def _query(self, store):
+        return store.find(Member, mailing_list=self._mlist.fqdn_listname)
 
 
 
@@ -261,8 +265,9 @@ class Memberships:
     def __init__(self, user):
         self._user = user
 
-    def _query(self):
-        results = config.db.store.find(
+    @dbconnection
+    def _query(self, store):
+        results = store.find(
             Member,
             Or(Member.user_id == self._user.id,
                And(Address.user_id == self._user.id,
@@ -291,9 +296,10 @@ class Memberships:
         for address in self._user.addresses:
             yield address
 
-    def get_member(self, address):
+    @dbconnection
+    def get_member(self, store, address):
         """See `IRoster`."""
-        results = config.db.store.find(
+        results = store.find(
             Member,
             Member.address_id == Address.id,
             Address.user_id == self._user.id)