remove remaining == None

sa does not allow is None in the whereclauses,
we create a simple null constant for usage inside the db apis

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>

master/buildbot/db/__init__.py

@@ -12,3 +12,6 @@
 # Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 # Copyright Buildbot Team Members
+
+# a null constant to use in sqlalchemy whereclauses e.g. (tbl.c.results == null)
+null = None

master/buildbot/db/buildrequests.py

@@ -17,6 +17,7 @@
 import sqlalchemy as sa
 
 from buildbot.db import base
+from buildbot.db import null
 from buildbot.util import datetime2epoch
 from buildbot.util import epoch2datetime
 from twisted.internet import reactor
@@ -82,11 +83,11 @@ def thd(conn):
                 if isinstance(claimed, bool):
                     if not claimed:
                         q = q.where(
-                            (claims_tbl.c.claimed_at == None) &
+                            (claims_tbl.c.claimed_at == null) &
                             (reqs_tbl.c.complete == 0))
                     else:
                         q = q.where(
-                            (claims_tbl.c.claimed_at != None))
+                            (claims_tbl.c.claimed_at != null))
                 else:
                     q = q.where(
                         (claims_tbl.c.masterid == claimed))

master/buildbot/db/builds.py

@@ -16,6 +16,7 @@
 import sqlalchemy as sa
 
 from buildbot.db import base
+from buildbot.db import null
 from buildbot.util import epoch2datetime
 from buildbot.util import json
 from twisted.internet import reactor

master/buildbot/db/buildsets.py

@@ -20,6 +20,7 @@
 import sqlalchemy as sa
 
 from buildbot.db import base
+from buildbot.db import null
 from buildbot.util import datetime2epoch
 from buildbot.util import epoch2datetime
 from buildbot.util import json
@@ -127,7 +128,7 @@ def thd(conn):
 
             q = tbl.update(whereclause=(
                 (tbl.c.id == bsid) &
-                ((tbl.c.complete == None) | (tbl.c.complete != 1))))
+                ((tbl.c.complete == null) | (tbl.c.complete != 1))))
             res = conn.execute(q,
                                complete=1,
                                results=results,
@@ -157,7 +158,7 @@ def thd(conn):
                     q = q.where(bs_tbl.c.complete != 0)
                 else:
                     q = q.where((bs_tbl.c.complete == 0) |
-                                (bs_tbl.c.complete == None))
+                                (bs_tbl.c.complete == null))
             res = conn.execute(q)
             return [self._thd_row2dict(conn, row) for row in res.fetchall()]
         return self.db.pool.do(thd)
@@ -180,7 +181,7 @@ def thd(conn):
                     q = q.where(bs_tbl.c.complete != 0)
                 else:
                     q = q.where((bs_tbl.c.complete == 0) |
-                                (bs_tbl.c.complete == None))
+                                (bs_tbl.c.complete == null))
             if branch:
                 q = q.where(ss_tbl.c.branch == branch)
             if repository:

master/buildbot/db/changesources.py

@@ -16,6 +16,7 @@
 import sqlalchemy as sa
 
 from buildbot.db import base
+from buildbot.db import null
 from twisted.internet import defer
 
 
@@ -86,9 +87,9 @@ def thd(conn):
                 if masterid is not None:
                     wc = (cs_mst_tbl.c.masterid == masterid)
                 elif active:
-                    wc = (cs_mst_tbl.c.masterid != None)
+                    wc = (cs_mst_tbl.c.masterid != null)
                 elif active is not None:
-                    wc = (cs_mst_tbl.c.masterid == None)
+                    wc = (cs_mst_tbl.c.masterid == null)
 
             q = sa.select([cs_tbl.c.id, cs_tbl.c.name,
                            cs_mst_tbl.c.masterid],

master/buildbot/db/migrate/versions/011_add_buildrequest_claims.py

@@ -16,6 +16,7 @@
 import migrate
 import sqlalchemy as sa
 
+from buildbot.db import null
 from buildbot.util import sautils
 
 
@@ -32,7 +33,7 @@ def migrate_claims(migrate_engine, metadata, buildrequests, objects,
         buildrequests.c.claimed_by_name.label("name"),
         sa.literal_column("'BuildMaster'").label("class_name"),
     ],
-        whereclause=buildrequests.c.claimed_by_name != None,
+        whereclause=buildrequests.c.claimed_by_name != null,
         distinct=True)
 
     # this doesn't seem to work without str() -- verified in sqla 0.6.0 - 0.7.1
@@ -50,7 +51,7 @@ def migrate_claims(migrate_engine, metadata, buildrequests, objects,
         objects.c.id.label('objectid'),
         buildrequests.c.claimed_at,
     ], from_obj=[join],
-        whereclause=buildrequests.c.claimed_by_name != None)
+        whereclause=buildrequests.c.claimed_by_name != null)
     migrate_engine.execute(
         str(sautils.InsertFromSelect(buildrequest_claims, claims)))
 

master/buildbot/db/schedulers.py

@@ -17,6 +17,7 @@
 import sqlalchemy.exc
 
 from buildbot.db import base
+from buildbot.db import null
 from twisted.internet import defer
 
 
@@ -160,9 +161,9 @@ def thd(conn):
                 if masterid is not None:
                     wc = (sch_mst_tbl.c.masterid == masterid)
                 elif active:
-                    wc = (sch_mst_tbl.c.masterid != None)
+                    wc = (sch_mst_tbl.c.masterid != null)
                 elif active is not None:
-                    wc = (sch_mst_tbl.c.masterid == None)
+                    wc = (sch_mst_tbl.c.masterid == null)
 
             q = sa.select([sch_tbl.c.id, sch_tbl.c.name,
                            sch_mst_tbl.c.masterid],

master/docs/developer/database.rst

@@ -8,11 +8,6 @@ backend.  This section describes the database connector classes, which allow
 other parts of Buildbot to access the database.  It also describes how to
 modify the database schema and the connector classes themselves.
 
-.. note::
-
-    Buildbot is only half-migrated to a database backend.  Build and builder
-    status information is still stored on disk in pickle files.  This is
-    difficult to fix, although work is underway.
 
 Database Overview
 -----------------
@@ -1510,6 +1505,18 @@ Queries can be constructed using any of the SQLAlchemy core methods, using
 tables from :class:`~buildbot.db.model.Model`, and executed with the connection
 object, ``conn``.
 
+.. note::
+
+    SQLAlchemy requires the use of a syntax that is forbidden by pep8.
+    If in where clauses you need to select rows where a value is null,
+    you need to write (`tbl.c.value == None`). This form is forbidden by pep8
+    which requires the use of `is None` instead of `== None`. As sqlalchemy is using operator
+    overloading to implement pythonic SQL statements, and `is` operator is not overloadable,
+    we need to keep the `==` operators. In order to solve this issue, buildbot
+    uses `buildbot.db.null` constant, which is `None`.
+    So instead of writting `tbl.c.value == None`, please write `tbl.c.value == null`)
+
+
 .. py:class:: DBThreadPool
 
     .. py:method:: do(callable, ...)

master/docs/manual/cfg-schedulers.rst

@@ -1226,7 +1226,7 @@ the new build.  The new parameter is:
 Example::
 
     def get_compatible_builds(status, builder):
-        if builder == None: # this is the case for force_build_all
+        if builder is None: # this is the case for force_build_all
             return ["cannot generate build list here"]
         # find all successful builds in builder1 and builder2
         builds = []