Unify Query and select() , move all processing to compile phase

Convert Query to do virtually all compile state computation
in the _compile_context() phase, and organize it all
such that a plain select() construct may also be used as the
source of information in order to generate ORM query state.
This makes it such that Query is not needed except for
its additional methods like from_self() which are all to
be deprecated.

The construction of ORM state will occur beyond the
caching boundary when the new execution model is integrated.

future select() gains a working join() and filter_by() method.
as we continue to rebase and merge each commit in the steps,
callcounts continue to bump around.  will have to look at
the final result when it's all in.

References: #5159
References: #4705
References: #4639
References: #4871
References: #5010

Change-Id: I19e05b3424b07114cce6c439b05198ac47f7ac10

1 files changed, 12 insertions, 8 deletions

diff --git a/lib/sqlalchemy/ext/serializer.py b/lib/sqlalchemy/ext/serializer.py
index ec5e8985c..afd44ca3d 100644
--- a/lib/sqlalchemy/ext/serializer.py
+++ b/lib/sqlalchemy/ext/serializer.py
@@ -59,7 +59,6 @@ from .. import Column
 from .. import Table
 from ..engine import Engine
 from ..orm import class_mapper
-from ..orm.attributes import QueryableAttribute
 from ..orm.interfaces import MapperProperty
 from ..orm.mapper import Mapper
 from ..orm.session import Session
@@ -78,11 +77,7 @@ def Serializer(*args, **kw):
 
     def persistent_id(obj):
         # print "serializing:", repr(obj)
-        if isinstance(obj, QueryableAttribute):
-            cls = obj.impl.class_
-            key = obj.impl.key
-            id_ = "attribute:" + key + ":" + b64encode(pickle.dumps(cls))
-        elif isinstance(obj, Mapper) and not obj.non_primary:
+        if isinstance(obj, Mapper) and not obj.non_primary:
             id_ = "mapper:" + b64encode(pickle.dumps(obj.class_))
         elif isinstance(obj, MapperProperty) and not obj.parent.non_primary:
             id_ = (
@@ -92,7 +87,12 @@ def Serializer(*args, **kw):
                 + obj.key
             )
         elif isinstance(obj, Table):
-            id_ = "table:" + text_type(obj.key)
+            if "parententity" in obj._annotations:
+                id_ = "mapper_selectable:" + b64encode(
+                    pickle.dumps(obj._annotations["parententity"].class_)
+                )
+            else:
+                id_ = "table:" + text_type(obj.key)
         elif isinstance(obj, Column) and isinstance(obj.table, Table):
             id_ = (
                 "column:" + text_type(obj.table.key) + ":" + text_type(obj.key)
@@ -110,7 +110,8 @@ def Serializer(*args, **kw):
 
 
 our_ids = re.compile(
-    r"(mapperprop|mapper|table|column|session|attribute|engine):(.*)"
+    r"(mapperprop|mapper|mapper_selectable|table|column|"
+    r"session|attribute|engine):(.*)"
 )
 
 
@@ -140,6 +141,9 @@ def Deserializer(file, metadata=None, scoped_session=None, engine=None):
             elif type_ == "mapper":
                 cls = pickle.loads(b64decode(args))
                 return class_mapper(cls)
+            elif type_ == "mapper_selectable":
+                cls = pickle.loads(b64decode(args))
+                return class_mapper(cls).__clause_element__()
             elif type_ == "mapperprop":
                 mapper, keyname = args.split(":")
                 cls = pickle.loads(b64decode(mapper))