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swh/core/api/negotiate.py
- This file was added.
# This code is a partial and adapted copy of | |||||
# https://github.com/nickstenning/negotiate | |||||
# | |||||
vlorentz: The full license text should be included here ("The above copyright notice and this permission… | |||||
Done Inline Actionsdouardda: D1019 | |||||
# Copyright 2012-2013 Nick Stenning | |||||
# 2019 Software Heritage | |||||
# | |||||
# Permission is hereby granted, free of charge, to any person obtaining a copy | |||||
# of this software and associated documentation files (the "Software"), to deal | |||||
# in the Software without restriction, including without limitation the rights | |||||
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |||||
# copies of the Software, and to permit persons to whom the Software is | |||||
# furnished to do so, subject to the following conditions: | |||||
# | |||||
# The above copyright notice and this permission notice shall be included in | |||||
# all copies or substantial portions of the Software. | |||||
# | |||||
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |||||
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |||||
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |||||
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |||||
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |||||
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |||||
# SOFTWARE. | |||||
# | |||||
from collections import defaultdict | |||||
from decorator import decorator | |||||
from inspect import getcallargs | |||||
class FormatterNotFound(Exception): | |||||
pass | |||||
class Formatter: | |||||
format = None | |||||
mimetypes = [] | |||||
def __init__(self, request_mimetype=None): | |||||
if request_mimetype is None or request_mimetype not in self.mimetypes: | |||||
try: | |||||
self.response_mimetype = self.mimetypes[0] | |||||
except IndexError: | |||||
raise NotImplementedError( | |||||
"%s.mimetypes should be a non-empty list" % | |||||
self.__class__.__name__) | |||||
else: | |||||
self.response_mimetype = request_mimetype | |||||
def configure(self): | |||||
pass | |||||
def render(self, obj): | |||||
raise NotImplementedError( | |||||
"render() should be implemented by Formatter subclasses") | |||||
def __call__(self, obj): | |||||
return self._make_response( | |||||
self.render(obj), content_type=self.response_mimetype) | |||||
def _make_response(self, body, content_type): | |||||
raise NotImplementedError( | |||||
"_make_response() should be implemented by " | |||||
"framework-specific subclasses of Formatter" | |||||
) | |||||
class Negotiator: | |||||
def __init__(self, func): | |||||
self.func = func | |||||
self._formatters = [] | |||||
self._formatters_by_format = defaultdict(list) | |||||
self._formatters_by_mimetype = defaultdict(list) | |||||
def __call__(self, *args, **kwargs): | |||||
result = self.func(*args, **kwargs) | |||||
format = getcallargs(self.func, *args, **kwargs).get('format') | |||||
mimetype = self.best_mimetype() | |||||
try: | |||||
formatter = self.get_formatter(format, mimetype) | |||||
except FormatterNotFound as e: | |||||
return self._abort(404, str(e)) | |||||
return formatter(result) | |||||
def register_formatter(self, formatter, *args, **kwargs): | |||||
self._formatters.append(formatter) | |||||
self._formatters_by_format[formatter.format].append( | |||||
(formatter, args, kwargs)) | |||||
for mimetype in formatter.mimetypes: | |||||
self._formatters_by_mimetype[mimetype].append( | |||||
(formatter, args, kwargs)) | |||||
def get_formatter(self, format=None, mimetype=None): | |||||
if format is None and mimetype is None: | |||||
raise TypeError( | |||||
"get_formatter expects one of the 'format' or 'mimetype' " | |||||
"kwargs to be set") | |||||
if format is not None: | |||||
try: | |||||
# the first added will be the most specific | |||||
formatter_cls, args, kwargs = ( | |||||
self._formatters_by_format[format][0]) | |||||
except IndexError: | |||||
raise FormatterNotFound( | |||||
"Formatter for format '%s' not found!" % format) | |||||
elif mimetype is not None: | |||||
try: | |||||
# the first added will be the most specific | |||||
formatter_cls, args, kwargs = ( | |||||
self._formatters_by_mimetype[mimetype][0]) | |||||
except IndexError: | |||||
raise FormatterNotFound( | |||||
"Formatter for mimetype '%s' not found!" % mimetype) | |||||
formatter = formatter_cls(request_mimetype=mimetype) | |||||
formatter.configure(*args, **kwargs) | |||||
return formatter | |||||
@property | |||||
def accept_mimetypes(self): | |||||
return [m for f in self._formatters for m in f.mimetypes] | |||||
def best_mimetype(self): | |||||
raise NotImplementedError( | |||||
"best_mimetype() should be implemented in " | |||||
"framework-specific subclasses of Negotiator" | |||||
) | |||||
def _abort(self, status_code, err=None): | |||||
raise NotImplementedError( | |||||
"_abort() should be implemented in framework-specific " | |||||
"subclasses of Negotiator" | |||||
) | |||||
def negotiate(negotiator_cls, formatter_cls, *args, **kwargs): | |||||
def _negotiate(f, *args, **kwargs): | |||||
return f.negotiator(*args, **kwargs) | |||||
def decorate(f): | |||||
if not hasattr(f, 'negotiator'): | |||||
f.negotiator = negotiator_cls(f) | |||||
f.negotiator.register_formatter(formatter_cls, *args, **kwargs) | |||||
return decorator(_negotiate, f) | |||||
return decorate |
The full license text should be included here ("The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.")
Also don't forget to update debian/copyright in the appropriate branch.