from __future__ import absolute_import from apscheduler.jobstores.base import BaseJobStore, JobLookupError, ConflictingIdError from apscheduler.util import maybe_ref, datetime_to_utc_timestamp, utc_timestamp_to_datetime from apscheduler.job import Job try: import cPickle as pickle except ImportError: # pragma: nocover import pickle try: from sqlalchemy import ( create_engine, Table, Column, MetaData, Unicode, Float, LargeBinary, select) from sqlalchemy.exc import IntegrityError from sqlalchemy.sql.expression import null except ImportError: # pragma: nocover raise ImportError('SQLAlchemyJobStore requires SQLAlchemy installed') class SQLAlchemyJobStore(BaseJobStore): """ Stores jobs in a database table using SQLAlchemy. The table will be created if it doesn't exist in the database. Plugin alias: ``sqlalchemy`` :param str url: connection string (see :ref:`SQLAlchemy documentation ` on this) :param engine: an SQLAlchemy :class:`~sqlalchemy.engine.Engine` to use instead of creating a new one based on ``url`` :param str tablename: name of the table to store jobs in :param metadata: a :class:`~sqlalchemy.schema.MetaData` instance to use instead of creating a new one :param int pickle_protocol: pickle protocol level to use (for serialization), defaults to the highest available :param str tableschema: name of the (existing) schema in the target database where the table should be :param dict engine_options: keyword arguments to :func:`~sqlalchemy.create_engine` (ignored if ``engine`` is given) """ def __init__(self, url=None, engine=None, tablename='apscheduler_jobs', metadata=None, pickle_protocol=pickle.HIGHEST_PROTOCOL, tableschema=None, engine_options=None): super(SQLAlchemyJobStore, self).__init__() self.pickle_protocol = pickle_protocol metadata = maybe_ref(metadata) or MetaData() if engine: self.engine = maybe_ref(engine) elif url: self.engine = create_engine(url, **(engine_options or {})) else: raise ValueError('Need either "engine" or "url" defined') # 191 = max key length in MySQL for InnoDB/utf8mb4 tables, # 25 = precision that translates to an 8-byte float self.jobs_t = Table( tablename, metadata, Column('id', Unicode(191, _warn_on_bytestring=False), primary_key=True), Column('next_run_time', Float(25), index=True), Column('job_state', LargeBinary, nullable=False), schema=tableschema ) def start(self, scheduler, alias): super(SQLAlchemyJobStore, self).start(scheduler, alias) self.jobs_t.create(self.engine, True) def lookup_job(self, job_id): selectable = select([self.jobs_t.c.job_state]).where(self.jobs_t.c.id == job_id) job_state = self.engine.execute(selectable).scalar() return self._reconstitute_job(job_state) if job_state else None def get_due_jobs(self, now): timestamp = datetime_to_utc_timestamp(now) return self._get_jobs(self.jobs_t.c.next_run_time <= timestamp) def get_next_run_time(self): selectable = select([self.jobs_t.c.next_run_time]).\ where(self.jobs_t.c.next_run_time != null()).\ order_by(self.jobs_t.c.next_run_time).limit(1) next_run_time = self.engine.execute(selectable).scalar() return utc_timestamp_to_datetime(next_run_time) def get_all_jobs(self): jobs = self._get_jobs() self._fix_paused_jobs_sorting(jobs) return jobs def add_job(self, job): insert = self.jobs_t.insert().values(**{ 'id': job.id, 'next_run_time': datetime_to_utc_timestamp(job.next_run_time), 'job_state': pickle.dumps(job.__getstate__(), self.pickle_protocol) }) try: self.engine.execute(insert) except IntegrityError: raise ConflictingIdError(job.id) def update_job(self, job): update = self.jobs_t.update().values(**{ 'next_run_time': datetime_to_utc_timestamp(job.next_run_time), 'job_state': pickle.dumps(job.__getstate__(), self.pickle_protocol) }).where(self.jobs_t.c.id == job.id) result = self.engine.execute(update) if result.rowcount == 0: raise JobLookupError(job.id) def remove_job(self, job_id): delete = self.jobs_t.delete().where(self.jobs_t.c.id == job_id) result = self.engine.execute(delete) if result.rowcount == 0: raise JobLookupError(job_id) def remove_all_jobs(self): delete = self.jobs_t.delete() self.engine.execute(delete) def shutdown(self): self.engine.dispose() def _reconstitute_job(self, job_state): job_state = pickle.loads(job_state) job_state['jobstore'] = self job = Job.__new__(Job) job.__setstate__(job_state) job._scheduler = self._scheduler job._jobstore_alias = self._alias return job def _get_jobs(self, *conditions): jobs = [] selectable = select([self.jobs_t.c.id, self.jobs_t.c.job_state]).\ order_by(self.jobs_t.c.next_run_time) selectable = selectable.where(*conditions) if conditions else selectable failed_job_ids = set() for row in self.engine.execute(selectable): try: jobs.append(self._reconstitute_job(row.job_state)) except BaseException: self._logger.exception('Unable to restore job "%s" -- removing it', row.id) failed_job_ids.add(row.id) # Remove all the jobs we failed to restore if failed_job_ids: delete = self.jobs_t.delete().where(self.jobs_t.c.id.in_(failed_job_ids)) self.engine.execute(delete) return jobs def __repr__(self): return '<%s (url=%s)>' % (self.__class__.__name__, self.engine.url)