1# Copyright 2024 Google LLC
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7# http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15"""Transport - Asynchronous HTTP client library support.
16
17:mod:`google.auth.aio` is designed to work with various asynchronous client libraries such
18as aiohttp. In order to work across these libraries with different
19interfaces some abstraction is needed.
20
21This module provides two interfaces that are implemented by transport adapters
22to support HTTP libraries. :class:`Request` defines the interface expected by
23:mod:`google.auth` to make asynchronous requests. :class:`Response` defines the interface
24for the return value of :class:`Request`.
25"""
26
27import abc
28from typing import AsyncGenerator, Mapping, Optional
29
30import google.auth.transport
31
32
33_DEFAULT_TIMEOUT_SECONDS = 180
34
35DEFAULT_RETRYABLE_STATUS_CODES = google.auth.transport.DEFAULT_RETRYABLE_STATUS_CODES
36"""Sequence[int]: HTTP status codes indicating a request can be retried.
37"""
38
39
40DEFAULT_MAX_RETRY_ATTEMPTS = 3
41"""int: How many times to retry a request."""
42
43
44class Response(metaclass=abc.ABCMeta):
45 """Asynchronous HTTP Response Interface."""
46
47 @property
48 @abc.abstractmethod
49 def status_code(self) -> int:
50 """
51 The HTTP response status code.
52
53 Returns:
54 int: The HTTP response status code.
55
56 """
57 raise NotImplementedError("status_code must be implemented.")
58
59 @property
60 @abc.abstractmethod
61 def headers(self) -> Mapping[str, str]:
62 """The HTTP response headers.
63
64 Returns:
65 Mapping[str, str]: The HTTP response headers.
66 """
67 raise NotImplementedError("headers must be implemented.")
68
69 @abc.abstractmethod
70 async def content(self, chunk_size: int) -> AsyncGenerator[bytes, None]:
71 """The raw response content.
72
73 Args:
74 chunk_size (int): The size of each chunk.
75
76 Yields:
77 AsyncGenerator[bytes, None]: An asynchronous generator yielding
78 response chunks as bytes.
79 """
80 raise NotImplementedError("content must be implemented.")
81
82 @abc.abstractmethod
83 async def read(self) -> bytes:
84 """Read the entire response content as bytes.
85
86 Returns:
87 bytes: The entire response content.
88 """
89 raise NotImplementedError("read must be implemented.")
90
91 @abc.abstractmethod
92 async def close(self):
93 """Close the response after it is fully consumed to resource."""
94 raise NotImplementedError("close must be implemented.")
95
96
97class Request(metaclass=abc.ABCMeta):
98 """Interface for a callable that makes HTTP requests.
99
100 Specific transport implementations should provide an implementation of
101 this that adapts their specific request / response API.
102
103 .. automethod:: __call__
104 """
105
106 @abc.abstractmethod
107 async def __call__(
108 self,
109 url: str,
110 method: str,
111 body: Optional[bytes],
112 headers: Optional[Mapping[str, str]],
113 timeout: float,
114 **kwargs
115 ) -> Response:
116 """Make an HTTP request.
117
118 Args:
119 url (str): The URI to be requested.
120 method (str): The HTTP method to use for the request. Defaults
121 to 'GET'.
122 body (Optional[bytes]): The payload / body in HTTP request.
123 headers (Mapping[str, str]): Request headers.
124 timeout (float): The number of seconds to wait for a
125 response from the server. If not specified or if None, the
126 transport-specific default timeout will be used.
127 kwargs: Additional arguments passed on to the transport's
128 request method.
129
130 Returns:
131 google.auth.aio.transport.Response: The HTTP response.
132
133 Raises:
134 google.auth.exceptions.TransportError: If any exception occurred.
135 """
136 # pylint: disable=redundant-returns-doc, missing-raises-doc
137 # (pylint doesn't play well with abstract docstrings.)
138 raise NotImplementedError("__call__ must be implemented.")
139
140 async def close(self) -> None:
141 """
142 Close the underlying session.
143 """
144 raise NotImplementedError("close must be implemented.")