mirror of
https://github.com/apache/superset.git
synced 2026-04-08 02:45:22 +00:00
126 lines
5.0 KiB
Python
126 lines
5.0 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.
|
|
import logging
|
|
from datetime import datetime, timedelta
|
|
from functools import wraps
|
|
from typing import Any, Callable, Iterator
|
|
|
|
from contextlib2 import contextmanager
|
|
from flask import request
|
|
from werkzeug.wrappers.etag import ETagResponseMixin
|
|
|
|
from superset import app, cache
|
|
from superset.stats_logger import BaseStatsLogger
|
|
from superset.utils.dates import now_as_float
|
|
|
|
# If a user sets `max_age` to 0, for long the browser should cache the
|
|
# resource? Flask-Caching will cache forever, but for the HTTP header we need
|
|
# to specify a "far future" date.
|
|
FAR_FUTURE = 365 * 24 * 60 * 60 # 1 year in seconds
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
@contextmanager
|
|
def stats_timing(stats_key: str, stats_logger: BaseStatsLogger) -> Iterator[float]:
|
|
"""Provide a transactional scope around a series of operations."""
|
|
start_ts = now_as_float()
|
|
try:
|
|
yield start_ts
|
|
except Exception as ex:
|
|
raise ex
|
|
finally:
|
|
stats_logger.timing(stats_key, now_as_float() - start_ts)
|
|
|
|
|
|
def etag_cache(max_age: int, check_perms: Callable[..., Any]) -> Callable[..., Any]:
|
|
"""
|
|
A decorator for caching views and handling etag conditional requests.
|
|
|
|
The decorator adds headers to GET requests that help with caching: Last-
|
|
Modified, Expires and ETag. It also handles conditional requests, when the
|
|
client send an If-Matches header.
|
|
|
|
If a cache is set, the decorator will cache GET responses, bypassing the
|
|
dataframe serialization. POST requests will still benefit from the
|
|
dataframe cache for requests that produce the same SQL.
|
|
|
|
"""
|
|
|
|
def decorator(f: Callable[..., Any]) -> Callable[..., Any]:
|
|
@wraps(f)
|
|
def wrapper(*args: Any, **kwargs: Any) -> ETagResponseMixin:
|
|
# check if the user can access the resource
|
|
check_perms(*args, **kwargs)
|
|
|
|
# for POST requests we can't set cache headers, use the response
|
|
# cache nor use conditional requests; this will still use the
|
|
# dataframe cache in `superset/viz.py`, though.
|
|
if request.method == "POST":
|
|
return f(*args, **kwargs)
|
|
|
|
response = None
|
|
if cache:
|
|
try:
|
|
# build the cache key from the function arguments and any
|
|
# other additional GET arguments (like `form_data`, eg).
|
|
key_args = list(args)
|
|
key_kwargs = kwargs.copy()
|
|
key_kwargs.update(request.args)
|
|
cache_key = wrapper.make_cache_key( # type: ignore
|
|
f, *key_args, **key_kwargs
|
|
)
|
|
response = cache.get(cache_key)
|
|
except Exception: # pylint: disable=broad-except
|
|
if app.debug:
|
|
raise
|
|
logger.exception("Exception possibly due to cache backend.")
|
|
|
|
# if no response was cached, compute it using the wrapped function
|
|
if response is None:
|
|
response = f(*args, **kwargs)
|
|
|
|
# add headers for caching: Last Modified, Expires and ETag
|
|
response.cache_control.public = True
|
|
response.last_modified = datetime.utcnow()
|
|
expiration = max_age if max_age != 0 else FAR_FUTURE
|
|
response.expires = response.last_modified + timedelta(
|
|
seconds=expiration
|
|
)
|
|
response.add_etag()
|
|
|
|
# if we have a cache, store the response from the request
|
|
if cache:
|
|
try:
|
|
cache.set(cache_key, response, timeout=max_age)
|
|
except Exception: # pylint: disable=broad-except
|
|
if app.debug:
|
|
raise
|
|
logger.exception("Exception possibly due to cache backend.")
|
|
|
|
return response.make_conditional(request)
|
|
|
|
if cache:
|
|
wrapper.uncached = f # type: ignore
|
|
wrapper.cache_timeout = max_age # type: ignore
|
|
wrapper.make_cache_key = cache._memoize_make_cache_key( # type: ignore # pylint: disable=protected-access
|
|
make_name=None, timeout=max_age
|
|
)
|
|
|
|
return wrapper
|
|
|
|
return decorator
|