Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/httpcore/_async/connection.py: 26%

1import itertools 

2import logging 

3import ssl 

4from types import TracebackType 

5from typing import Iterable, Iterator, Optional, Type 

6 

7from .._backends.auto import AutoBackend 

8from .._backends.base import SOCKET_OPTION, AsyncNetworkBackend, AsyncNetworkStream 

9from .._exceptions import ConnectError, ConnectionNotAvailable, ConnectTimeout 

10from .._models import Origin, Request, Response 

11from .._ssl import default_ssl_context 

12from .._synchronization import AsyncLock 

13from .._trace import Trace 

14from .http11 import AsyncHTTP11Connection 

15from .interfaces import AsyncConnectionInterface 

16 

17RETRIES_BACKOFF_FACTOR = 0.5 # 0s, 0.5s, 1s, 2s, 4s, etc. 

18 

19 

20logger = logging.getLogger("httpcore.connection") 

21 

22 

23def exponential_backoff(factor: float) -> Iterator[float]: 

24 """ 

25 Generate a geometric sequence that has a ratio of 2 and starts with 0. 

26 

27 For example: 

28 - `factor = 2`: `0, 2, 4, 8, 16, 32, 64, ...` 

29 - `factor = 3`: `0, 3, 6, 12, 24, 48, 96, ...` 

30 """ 

31 yield 0 

32 for n in itertools.count(): 

33 yield factor * 2**n 

34 

35 

36class AsyncHTTPConnection(AsyncConnectionInterface): 

37 def __init__( 

38 self, 

39 origin: Origin, 

40 ssl_context: Optional[ssl.SSLContext] = None, 

41 keepalive_expiry: Optional[float] = None, 

42 http1: bool = True, 

43 http2: bool = False, 

44 retries: int = 0, 

45 local_address: Optional[str] = None, 

46 uds: Optional[str] = None, 

47 network_backend: Optional[AsyncNetworkBackend] = None, 

48 socket_options: Optional[Iterable[SOCKET_OPTION]] = None, 

49 ) -> None: 

50 self._origin = origin 

51 self._ssl_context = ssl_context 

52 self._keepalive_expiry = keepalive_expiry 

53 self._http1 = http1 

54 self._http2 = http2 

55 self._retries = retries 

56 self._local_address = local_address 

57 self._uds = uds 

58 

59 self._network_backend: AsyncNetworkBackend = ( 

60 AutoBackend() if network_backend is None else network_backend 

61 ) 

62 self._connection: Optional[AsyncConnectionInterface] = None 

63 self._connect_failed: bool = False 

64 self._request_lock = AsyncLock() 

65 self._socket_options = socket_options 

66 

67 async def handle_async_request(self, request: Request) -> Response: 

68 if not self.can_handle_request(request.url.origin): 

69 raise RuntimeError( 

70 f"Attempted to send request to {request.url.origin} on connection to {self._origin}" 

71 ) 

72 

73 async with self._request_lock: 

74 if self._connection is None: 

75 try: 

76 stream = await self._connect(request) 

77 

78 ssl_object = stream.get_extra_info("ssl_object") 

79 http2_negotiated = ( 

80 ssl_object is not None 

81 and ssl_object.selected_alpn_protocol() == "h2" 

82 ) 

83 if http2_negotiated or (self._http2 and not self._http1): 

84 from .http2 import AsyncHTTP2Connection 

85 

86 self._connection = AsyncHTTP2Connection( 

87 origin=self._origin, 

88 stream=stream, 

89 keepalive_expiry=self._keepalive_expiry, 

90 ) 

91 else: 

92 self._connection = AsyncHTTP11Connection( 

93 origin=self._origin, 

94 stream=stream, 

95 keepalive_expiry=self._keepalive_expiry, 

96 ) 

97 except Exception as exc: 

98 self._connect_failed = True 

99 raise exc 

100 elif not self._connection.is_available(): 

101 raise ConnectionNotAvailable() 

102 

103 return await self._connection.handle_async_request(request) 

104 

105 async def _connect(self, request: Request) -> AsyncNetworkStream: 

106 timeouts = request.extensions.get("timeout", {}) 

107 sni_hostname = request.extensions.get("sni_hostname", None) 

108 timeout = timeouts.get("connect", None) 

109 

110 retries_left = self._retries 

111 delays = exponential_backoff(factor=RETRIES_BACKOFF_FACTOR) 

112 

113 while True: 

114 try: 

115 if self._uds is None: 

116 kwargs = { 

117 "host": self._origin.host.decode("ascii"), 

118 "port": self._origin.port, 

119 "local_address": self._local_address, 

120 "timeout": timeout, 

121 "socket_options": self._socket_options, 

122 } 

123 async with Trace("connect_tcp", logger, request, kwargs) as trace: 

124 stream = await self._network_backend.connect_tcp(**kwargs) 

125 trace.return_value = stream 

126 else: 

127 kwargs = { 

128 "path": self._uds, 

129 "timeout": timeout, 

130 "socket_options": self._socket_options, 

131 } 

132 async with Trace( 

133 "connect_unix_socket", logger, request, kwargs 

134 ) as trace: 

135 stream = await self._network_backend.connect_unix_socket( 

136 **kwargs 

137 ) 

138 trace.return_value = stream 

139 

140 if self._origin.scheme == b"https": 

141 ssl_context = ( 

142 default_ssl_context() 

143 if self._ssl_context is None 

144 else self._ssl_context 

145 ) 

146 alpn_protocols = ["http/1.1", "h2"] if self._http2 else ["http/1.1"] 

147 ssl_context.set_alpn_protocols(alpn_protocols) 

148 

149 kwargs = { 

150 "ssl_context": ssl_context, 

151 "server_hostname": sni_hostname 

152 or self._origin.host.decode("ascii"), 

153 "timeout": timeout, 

154 } 

155 async with Trace("start_tls", logger, request, kwargs) as trace: 

156 stream = await stream.start_tls(**kwargs) 

157 trace.return_value = stream 

158 return stream 

159 except (ConnectError, ConnectTimeout): 

160 if retries_left <= 0: 

161 raise 

162 retries_left -= 1 

163 delay = next(delays) 

164 async with Trace("retry", logger, request, kwargs) as trace: 

165 await self._network_backend.sleep(delay) 

166 

167 def can_handle_request(self, origin: Origin) -> bool: 

168 return origin == self._origin 

169 

170 async def aclose(self) -> None: 

171 if self._connection is not None: 

172 async with Trace("close", logger, None, {}): 

173 await self._connection.aclose() 

174 

175 def is_available(self) -> bool: 

176 if self._connection is None: 

177 # If HTTP/2 support is enabled, and the resulting connection could 

178 # end up as HTTP/2 then we should indicate the connection as being 

179 # available to service multiple requests. 

180 return ( 

181 self._http2 

182 and (self._origin.scheme == b"https" or not self._http1) 

183 and not self._connect_failed 

184 ) 

185 return self._connection.is_available() 

186 

187 def has_expired(self) -> bool: 

188 if self._connection is None: 

189 return self._connect_failed 

190 return self._connection.has_expired() 

191 

192 def is_idle(self) -> bool: 

193 if self._connection is None: 

194 return self._connect_failed 

195 return self._connection.is_idle() 

196 

197 def is_closed(self) -> bool: 

198 if self._connection is None: 

199 return self._connect_failed 

200 return self._connection.is_closed() 

201 

202 def info(self) -> str: 

203 if self._connection is None: 

204 return "CONNECTION FAILED" if self._connect_failed else "CONNECTING" 

205 return self._connection.info() 

206 

207 def __repr__(self) -> str: 

208 return f"<{self.__class__.__name__} [{self.info()}]>" 

209 

210 # These context managers are not used in the standard flow, but are 

211 # useful for testing or working with connection instances directly. 

212 

213 async def __aenter__(self) -> "AsyncHTTPConnection": 

214 return self 

215 

216 async def __aexit__( 

217 self, 

218 exc_type: Optional[Type[BaseException]] = None, 

219 exc_value: Optional[BaseException] = None, 

220 traceback: Optional[TracebackType] = None, 

221 ) -> None: 

222 await self.aclose()