deb-python-taskflow/taskflow/db/sqlalchemy/models.py

# -*- coding: utf-8 -*-

# vim: tabstop=4 shiftwidth=4 softtabstop=4

#    Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
#    Copyright (C) 2013 Rackspace Hosting 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.
"""
SQLAlchemy models for taskflow data.
"""

from oslo.config import cfg

from sqlalchemy import Column, Integer, String, Table, MetaData
from sqlalchemy.exc import IntegrityError
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import object_mapper, relationship, backref
from sqlalchemy import DateTime, ForeignKey
from sqlalchemy import types as types

from json import dumps, loads

from taskflow.db.sqlalchemy.session import get_session, get_engine
from taskflow.openstack.common import timeutils, uuidutils, exception

CONF = cfg.CONF
BASE = declarative_base()


class Json(types.TypeDecorator, types.MutableType):
    impl = types.Text

    def process_bind_param(self, value, dialect):
        return dumps(value)

    def process_result_value(self, value, dialect):
        return loads(value)


class TaskFlowBase(object):
    """Base class for TaskFlow Models."""
    __table_args__ = {'mysql_engine': 'InnoDB'}
    __table_initialized = False
    created_at = Column(DateTime, default=timeutils.utcnow)
    updated_at = Column(DateTime, default=timeutils.utcnow)

    def save(self, session=None):
        """Save this object."""
        if not session:
            session = get_session()
        session.add(self)
        try:
            session.flush()
        except IntegrityError, e:
            if str(e).endswith('is not unique'):
                raise exception.Duplicate(str(e))
            else:
                raise

    def delete(self, session=None):
        """Delete this object."""
        self.deleted = True
        self.deleted_at = timeutils.utcnow()
        if not session:
            session = get_session()
        session.delete(self)
        session.flush()

    def __setitem__(self, key, value):
        setattr(self, key, value)

    def __getitem__(self, key):
        return getattr(self, key)

    def get(self, key, default=None):
        return getattr(self, key, default)

    def __iter__(self):
        self._i = iter(object_mapper(self).columns)
        return self

    def next(self):
        n = self._i.next().name
        return n, getattr(self, n)

    def update(self, values):
        """Make the model object behave like a dict"""
        for k, v in values.iteritems():
            setattr(self, k, v)

    def iteritems(self):
        """Make the model object behave like a dict

           Includes attributes from joins."""
        local = dict(self)
        joined = dict([k, v] for k, v in self.__dict__.iteritems()
                      if not k[0] == '_')
        local.update(joined)
        return local.iteritems()


workflow_logbook_assoc = Table(
    'wf_lb_assoc', BASE.metadata,
    Column('workflow_id', Integer, ForeignKey('workflow.id')),
    Column('logbook_id', Integer, ForeignKey('logbook.id')),
    Column('id', Integer, primary_key=True)
)


workflow_job_assoc = Table(
    'wf_job_assoc', BASE.metadata,
    Column('workflow_id', Integer, ForeignKey('workflow.id')),
    Column('job_id', Integer, ForeignKey('job.id')),
    Column('id', Integer, primary_key=True)
)


class LogBook(BASE, TaskFlowBase):
    """Represents a logbook for a set of workflows"""

    __tablename__ = 'logbook'

    id = Column(Integer, primary_key=True)
    logbook_id = Column(String, default=uuidutils.generate_uuid,
                        unique=True)
    name = Column(String)
    workflows = relationship("Workflow",
                             secondary=workflow_logbook_assoc)
    job = relationship("Job", uselist=False, backref="logbook")


class Job(BASE, TaskFlowBase):
    """Represents a Job"""

    __tablename__ = 'job'

    id = Column(Integer, primary_key=True)
    job_id = Column(String, default=uuidutils.generate_uuid,
                    unique=True)
    name = Column(String)
    owner = Column(String)
    state = Column(String)
    workflows = relationship("Workflow",
                             secondary=workflow_job_assoc)
    logbook_id = Column(String, ForeignKey('logbook.logbook_id'))


class Workflow(BASE, TaskFlowBase):
    """Represents Workflow detail objects"""

    __tablename__ = 'workflow'

    id = Column(Integer, primary_key=True)
    name = Column(String, unique=True)
    tasks = relationship("Task", backref="workflow")


class Task(BASE, TaskFlowBase):
    """Represents Task detail objects"""

    __tablename__ = 'task'

    id = Column(Integer, primary_key=True)
    task_id = Column(String, default=uuidutils.generate_uuid)
    name = Column(String)
    results = Column(Json)
    exception = Column(String)
    stacktrace = Column(String)
    workflow_id = Column(String, ForeignKey('workflow.id'))


def create_tables():
    BASE.metadata.create_all(get_engine())