Files
superset2/superset/tasks/ambient_context.py
2026-02-09 10:45:56 -08:00

88 lines
3.0 KiB
Python

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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.
"""Ambient context management for the Global Task Framework (GTF)"""
from contextlib import contextmanager
from contextvars import ContextVar
from typing import Iterator
from superset.tasks.context import TaskContext
# Global context variable for ambient context pattern
# This is thread-safe and async-safe via Python's contextvars
_current_context: ContextVar[TaskContext | None] = ContextVar(
"task_context", default=None
)
def get_context() -> TaskContext:
"""
Get the current task context from contextvars.
This function provides ambient access to the task context without
requiring it to be passed as a parameter. It can only be called
from within a task execution.
:returns: The current TaskContext
:raises RuntimeError: If called outside a task execution context
Example:
>>> @task()
>>> def my_task(chart_id: int) -> None:
>>> ctx = get_context() # Access ambient context
>>>
>>> # Update progress and payload atomically
>>> ctx.update_task(
>>> progress=0.5,
>>> payload={"chart_id": chart_id}
>>> )
"""
ctx = _current_context.get()
if ctx is None:
raise RuntimeError(
"get_context() called outside task execution context. "
"This function can only be called from within a @task "
"decorated function."
)
return ctx
@contextmanager
def use_context(ctx: TaskContext) -> Iterator[None]:
"""
Context manager to set ambient context for task execution.
This is used internally by the framework to establish the ambient context
before executing a task function. The context is automatically cleaned up
after execution, even if the task raises an exception.
:param ctx: TaskContext to set as the current context
:yields: None
Example (internal framework use):
>>> ctx = TaskContext(task_uuid=task.uuid)
>>> with use_context(ctx):
>>> # Task function can now call get_context()
>>> task_function(*args, **kwargs)
>>> # Context automatically reset after execution
"""
token = _current_context.set(ctx)
try:
yield
finally:
_current_context.reset(token)