import hashlib
import json
from operator import itemgetter
from typing import Iterable, List, Mapping, Optional, Tuple, Union
from urllib.parse import parse_qsl, urlencode, urlparse, urlunparse
from requests import PreparedRequest, Request, Session
from requests.models import CaseInsensitiveDict
from requests.utils import default_headers
from url_normalize import url_normalize
DEFAULT_HEADERS = default_headers()
RequestContent = Union[Mapping, str, bytes]
[docs]def create_key(
request: PreparedRequest,
ignored_params: Iterable[str] = None,
include_get_headers: bool = False,
**kwargs,
) -> str:
"""Create a normalized cache key from a request object"""
key = hashlib.sha256()
key.update(encode((request.method or '').upper()))
url = remove_ignored_url_params(request.url, ignored_params)
url = url_normalize(url)
key.update(encode(url))
key.update(encode(kwargs.get('verify', True)))
body = remove_ignored_body_params(request, ignored_params)
if body:
key.update(body)
if include_get_headers and request.headers != DEFAULT_HEADERS:
for name, value in normalize_dict(request.headers).items(): # type: ignore
key.update(encode(f'{name}={value}'))
return key.hexdigest()
def remove_ignored_params(
request: PreparedRequest, ignored_params: Optional[Iterable[str]]
) -> PreparedRequest:
if not ignored_params:
return request
request.headers = remove_ignored_headers(request.headers, ignored_params)
request.url = remove_ignored_url_params(request.url, ignored_params)
request.body = remove_ignored_body_params(request, ignored_params)
return request
[docs]def remove_ignored_url_params(url: Optional[str], ignored_parameters: Optional[Iterable[str]]) -> str:
"""Remove any ignored request parameters from the URL"""
if not ignored_parameters or not url:
return url or ''
url_tokens = urlparse(url)
query = _filter_params(parse_qsl(url_tokens.query), ignored_parameters)
return urlunparse(
(
url_tokens.scheme,
url_tokens.netloc,
url_tokens.path,
url_tokens.params,
urlencode(query),
url_tokens.fragment,
)
)
def remove_ignored_body_params(
request: PreparedRequest, ignored_parameters: Optional[Iterable[str]]
) -> bytes:
original_body = request.body
content_type = request.headers.get('content-type')
if not ignored_parameters or not original_body or not content_type:
return encode(original_body)
if content_type == 'application/x-www-form-urlencoded':
body = _filter_params(parse_qsl(decode(original_body)), ignored_parameters)
filtered_body = urlencode(body)
elif content_type == 'application/json':
body = json.loads(decode(original_body)).items()
body = _filter_params(sorted(body), ignored_parameters)
filtered_body = json.dumps(body)
else:
filtered_body = original_body # type: ignore
return encode(filtered_body)
def _filter_params(data: List[Tuple[str, str]], ignored_params: Iterable[str]) -> List[Tuple[str, str]]:
return [(k, v) for k, v in data if k not in set(ignored_params)]
[docs]def normalize_dict(
items: Optional[RequestContent], normalize_data: bool = True
) -> Optional[RequestContent]:
"""Sort items in a dict
Args:
items: Request params, data, or json
normalize_data: Also normalize stringified JSON
"""
def sort_dict(d):
return dict(sorted(d.items(), key=itemgetter(0)))
if not items:
return None
if isinstance(items, Mapping):
return sort_dict(items)
if normalize_data and isinstance(items, (bytes, str)):
# Attempt to load body as JSON; not doing this by default as it could impact performance
try:
dict_items = json.loads(decode(items))
dict_items = json.dumps(sort_dict(dict_items))
return dict_items.encode('utf-8') if isinstance(items, bytes) else dict_items
except Exception:
pass
return items
def url_to_key(url: str, *args, **kwargs) -> str:
request = Session().prepare_request(Request('GET', url))
return create_key(request, *args, **kwargs)
[docs]def encode(value, encoding='utf-8') -> bytes:
"""Encode a value to bytes, if it hasn't already been"""
return value if isinstance(value, bytes) else str(value).encode(encoding)
[docs]def decode(value, encoding='utf-8') -> str:
"""Decode a value from bytes, if hasn't already been.
Note: PreparedRequest.body is always encoded in utf-8.
"""
return value.decode(encoding) if isinstance(value, bytes) else value