# Copyright 2020 Karlsruhe Institute of Technology
#
# 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.
from flask import current_app
from flask_login import current_user
import kadi.lib.constants as const
from kadi.ext.celery import celery
from kadi.ext.db import db
from kadi.lib.exceptions import KadiFilesizeMismatchError
from kadi.lib.tasks.core import launch_task
from kadi.lib.tasks.models import Task
from kadi.lib.tasks.models import TaskState
from .core import purge_record
from .models import Record
from .models import RecordState
from .models import Upload
from .models import UploadState
from .uploads import merge_chunk_data
@celery.task(name=const.TASK_MERGE_CHUNKS, soft_time_limit=const.ONE_HOUR, bind=True)
def _merge_chunks_task(self, upload_id, **kwargs):
task = Task.query.get(self.request.id)
upload = Upload.query.get(upload_id)
# Check if the upload is still ready to be processed at this point.
if upload is None or upload.state != UploadState.PROCESSING:
return None
file = None
try:
file = merge_chunk_data(upload)
if file is not None:
task.result = {"file": str(file.id)}
else:
task.state = TaskState.FAILURE
task.result = {"error": "Error creating or updating file."}
# Catches time limit exceeded exceptions as well.
except Exception as e:
db.session.rollback()
task.state = TaskState.FAILURE
if isinstance(e, KadiFilesizeMismatchError):
task.result = {"error": str(e)}
else:
current_app.logger.exception(e)
task.result = {"error": "Internal server error."}
db.session.commit()
return str(file.id) if file is not None else None
[docs]def start_merge_chunks_task(upload, user=None):
"""Merge the chunks of a local file upload in a background task.
Uses :func:`kadi.modules.records.uploads.merge_chunk_data`. The created task will be
kept in the database.
Note that this function issues one or more database commits.
:param upload: The upload that the chunks belong to.
:param user: (optional) The user who started the task. Defaults to the current user.
:return: The new task object if the task was started successfully, ``None``
otherwise.
"""
user = user if user is not None else current_user
return launch_task(
const.TASK_MERGE_CHUNKS, args=(str(upload.id),), user=user, keep=True
)
@celery.task(name=const.TASK_PURGE_RECORD, soft_time_limit=const.ONE_HOUR)
def _purge_record_task(record_id, **kwargs):
record = Record.query.get(record_id)
try:
purge_record(record)
# Catches time limit exceeded exceptions as well.
except Exception as e:
current_app.logger.exception(e)
db.session.rollback()
# In case the state of the record was already changed, we reset it so another
# attempt can be made to purge it (including the periodic cleanup task).
record.state = RecordState.DELETED
db.session.commit()
return False
return True
[docs]def start_purge_record_task(record):
"""Purge an existing record in a background task.
Uses :func:`kadi.modules.records.core.purge_record`.
:param record: The record to purge.
"""
return launch_task(const.TASK_PURGE_RECORD, args=(record.id,))