Use the sqlalchemy-utils json type instead of our own

Change-Id: Ie01ea85e74f1daed6bfa5158c0faa476d06873ba

2 files changed, 66 insertions, 23 deletions

diff --git a/taskflow/persistence/backends/sqlalchemy/alembic/versions/2ad4984f2864_switch_postgres_to_json_native.py b/taskflow/persistence/backends/sqlalchemy/alembic/versions/2ad4984f2864_switch_postgres_to_json_native.py
new file mode 100644
index 0000000..e795dfc
--- /dev/null
+++ b/taskflow/persistence/backends/sqlalchemy/alembic/versions/2ad4984f2864_switch_postgres_to_json_native.py
@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+
+#    Copyright (C) 2012-2013 Yahoo! Inc. All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""Switch postgres to json native type.
+
+Revision ID: 2ad4984f2864
+Revises: 589dccdf2b6e
+Create Date: 2015-06-04 13:08:36.667948
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '2ad4984f2864'
+down_revision = '589dccdf2b6e'
+
+from alembic import op
+
+
+_ALTER_TO_JSON_TPL = 'ALTER TABLE %s ALTER COLUMN %s TYPE JSON USING %s::JSON'
+_TABLES_COLS = tuple([
+    ('logbooks', 'meta'),
+    ('flowdetails', 'meta'),
+    ('atomdetails', 'meta'),
+    ('atomdetails', 'failure'),
+    ('atomdetails', 'revert_failure'),
+    ('atomdetails', 'results'),
+    ('atomdetails', 'revert_results'),
+])
+_ALTER_TO_TEXT_TPL = 'ALTER TABLE %s ALTER COLUMN %s TYPE TEXT'
+
+
+def upgrade():
+    b = op.get_bind()
+    if b.dialect.name.startswith('postgresql'):
+        for (table_name, col_name) in _TABLES_COLS:
+            q = _ALTER_TO_JSON_TPL % (table_name, col_name, col_name)
+            op.execute(q)
+
+
+def downgrade():
+    b = op.get_bind()
+    if b.dialect.name.startswith('postgresql'):
+        for (table_name, col_name) in _TABLES_COLS:
+            q = _ALTER_TO_TEXT_TPL % (table_name, col_name)
+            op.execute(q)
diff --git a/taskflow/persistence/backends/sqlalchemy/tables.py b/taskflow/persistence/backends/sqlalchemy/tables.py
index 65969fb..b9b065e 100644
--- a/taskflow/persistence/backends/sqlalchemy/tables.py
+++ b/taskflow/persistence/backends/sqlalchemy/tables.py
@@ -16,11 +16,10 @@
 
 import collections
 
-from oslo_serialization import jsonutils
 from oslo_utils import timeutils
 from oslo_utils import uuidutils
 from sqlalchemy import Table, Column, String, ForeignKey, DateTime, Enum
-from sqlalchemy import types
+import sqlalchemy_utils as su
 
 from taskflow.persistence import models
 from taskflow import states
@@ -35,20 +34,6 @@ STATE_LENGTH = 255
 VERSION_LENGTH = 64
 
 
-class Json(types.TypeDecorator):
-    impl = types.Text
-
-    def process_bind_param(self, value, dialect):
-        if not value:
-            return None
-        return jsonutils.dumps(value)
-
-    def process_result_value(self, value, dialect):
-        if not value:
-            return None
-        return jsonutils.loads(value)
-
-
 def fetch(metadata):
     """Returns the master set of table objects (which is also there schema)."""
     logbooks = Table('logbooks', metadata,
@@ -56,7 +41,7 @@ def fetch(metadata):
                             default=timeutils.utcnow),
                      Column('updated_at', DateTime,
                             onupdate=timeutils.utcnow),
-                     Column('meta', Json),
+                     Column('meta', su.JSONType),
                      Column('name', String(length=NAME_LENGTH)),
                      Column('uuid', String(length=UUID_LENGTH),
                             primary_key=True, nullable=False, unique=True,
@@ -69,7 +54,7 @@ def fetch(metadata):
                         Column('parent_uuid', String(length=UUID_LENGTH),
                                ForeignKey('logbooks.uuid',
                                           ondelete='CASCADE')),
-                        Column('meta', Json),
+                        Column('meta', su.JSONType),
                         Column('name', String(length=NAME_LENGTH)),
                         Column('state', String(length=STATE_LENGTH)),
                         Column('uuid', String(length=UUID_LENGTH),
@@ -80,7 +65,7 @@ def fetch(metadata):
                                default=timeutils.utcnow),
                         Column('updated_at', DateTime,
                                onupdate=timeutils.utcnow),
-                        Column('meta', Json),
+                        Column('meta', su.JSONType),
                         Column('parent_uuid', String(length=UUID_LENGTH),
                                ForeignKey('flowdetails.uuid',
                                           ondelete='CASCADE')),
@@ -90,10 +75,10 @@ def fetch(metadata):
                         Column('uuid', String(length=UUID_LENGTH),
                                primary_key=True, nullable=False, unique=True,
                                default=uuidutils.generate_uuid),
-                        Column('failure', Json),
-                        Column('results', Json),
-                        Column('revert_results', Json),
-                        Column('revert_failure', Json),
+                        Column('failure', su.JSONType),
+                        Column('results', su.JSONType),
+                        Column('revert_results', su.JSONType),
+                        Column('revert_failure', su.JSONType),
                         Column('atom_type', Enum(*models.ATOM_TYPES,
                                                  name='atom_types')),
                         Column('intention', Enum(*states.INTENTIONS,