Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 1 | .. currentmodule:: asyncio |
| 2 | |
Victor Stinner | 9592edb | 2014-02-02 15:03:02 +0100 | [diff] [blame] | 3 | .. _asyncio-streams: |
Victor Stinner | 4b4f9eb | 2014-01-24 17:33:20 +0100 | [diff] [blame] | 4 | |
Yury Selivanov | cba0053 | 2015-12-16 21:30:52 -0500 | [diff] [blame] | 5 | +++++++++++++++++++++++++++++ |
| 6 | Streams (coroutine based API) |
| 7 | +++++++++++++++++++++++++++++ |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 8 | |
lf | 627d2c8 | 2017-07-25 17:03:51 -0600 | [diff] [blame] | 9 | **Source code:** :source:`Lib/asyncio/streams.py` |
| 10 | |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 11 | Stream functions |
| 12 | ================ |
| 13 | |
Guido van Rossum | 19ff697 | 2015-10-19 13:18:04 -0700 | [diff] [blame] | 14 | .. note:: |
| 15 | |
Ned Deily | f38c93f | 2016-02-16 13:27:04 +1100 | [diff] [blame] | 16 | The top-level functions in this module are meant as convenience wrappers |
Guido van Rossum | 19ff697 | 2015-10-19 13:18:04 -0700 | [diff] [blame] | 17 | only; there's really nothing special there, and if they don't do |
| 18 | exactly what you want, feel free to copy their code. |
| 19 | |
| 20 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 21 | .. coroutinefunction:: open_connection(host=None, port=None, \*, loop=None, limit=None, ssl=None, family=0, proto=0, flags=0, sock=None, local_addr=None, server_hostname=None, ssl_handshake_timeout=None) |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 22 | |
Guido van Rossum | f68afd8 | 2016-08-08 09:41:21 -0700 | [diff] [blame] | 23 | A wrapper for :meth:`~AbstractEventLoop.create_connection()` returning a (reader, |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 24 | writer) pair. |
| 25 | |
| 26 | The reader returned is a :class:`StreamReader` instance; the writer is |
| 27 | a :class:`StreamWriter` instance. |
| 28 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 29 | When specified, the *loop* argument determines which event loop to use, |
| 30 | and the *limit* argument determines the buffer size limit used by the |
| 31 | returned :class:`StreamReader` instance. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 32 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 33 | The rest of the arguments are passed directly to |
| 34 | :meth:`AbstractEventLoop.create_connection`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 35 | |
Yury Selivanov | 37f15bc | 2014-02-20 16:20:44 -0500 | [diff] [blame] | 36 | This function is a :ref:`coroutine <coroutine>`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 37 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 38 | .. versionadded:: 3.7 |
| 39 | |
| 40 | The *ssl_handshake_timeout* parameter. |
| 41 | |
| 42 | .. coroutinefunction:: start_server(client_connected_cb, host=None, port=None, \*, loop=None, limit=None, family=socket.AF_UNSPEC, flags=socket.AI_PASSIVE, sock=None, backlog=100, ssl=None, reuse_address=None, reuse_port=None, ssl_handshake_timeout=None, start_serving=True) |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 43 | |
Victor Stinner | 8ebeb03 | 2014-07-11 23:47:40 +0200 | [diff] [blame] | 44 | Start a socket server, with a callback for each client connected. The return |
Guido van Rossum | f68afd8 | 2016-08-08 09:41:21 -0700 | [diff] [blame] | 45 | value is the same as :meth:`~AbstractEventLoop.create_server()`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 46 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 47 | The *client_connected_cb* callback is called whenever a new client |
| 48 | connection is established. It receives a reader/writer pair as two |
| 49 | arguments, the first is a :class:`StreamReader` instance, |
| 50 | and the second is a :class:`StreamWriter` instance. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 51 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 52 | *client_connected_cb* accepts a plain callable or a |
| 53 | :ref:`coroutine function <coroutine>`; if it is a coroutine function, |
| 54 | it will be automatically converted into a :class:`Task`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 55 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 56 | When specified, the *loop* argument determines which event loop to use, |
| 57 | and the *limit* argument determines the buffer size limit used by the |
| 58 | :class:`StreamReader` instance passed to *client_connected_cb*. |
| 59 | |
| 60 | The rest of the arguments are passed directly to |
| 61 | :meth:`~AbstractEventLoop.create_server()`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 62 | |
Yury Selivanov | 37f15bc | 2014-02-20 16:20:44 -0500 | [diff] [blame] | 63 | This function is a :ref:`coroutine <coroutine>`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 64 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 65 | .. versionadded:: 3.7 |
| 66 | |
| 67 | The *ssl_handshake_timeout* and *start_serving* parameters. |
| 68 | |
| 69 | .. coroutinefunction:: open_unix_connection(path=None, \*, loop=None, limit=None, ssl=None, sock=None, server_hostname=None, ssl_handshake_timeout=None) |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 70 | |
Guido van Rossum | f68afd8 | 2016-08-08 09:41:21 -0700 | [diff] [blame] | 71 | A wrapper for :meth:`~AbstractEventLoop.create_unix_connection()` returning |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 72 | a (reader, writer) pair. |
| 73 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 74 | When specified, the *loop* argument determines which event loop to use, |
| 75 | and the *limit* argument determines the buffer size limit used by the |
| 76 | returned :class:`StreamReader` instance. |
| 77 | |
| 78 | The rest of the arguments are passed directly to |
| 79 | :meth:`~AbstractEventLoop.create_unix_connection()`. |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 80 | |
Yury Selivanov | 37f15bc | 2014-02-20 16:20:44 -0500 | [diff] [blame] | 81 | This function is a :ref:`coroutine <coroutine>`. |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 82 | |
| 83 | Availability: UNIX. |
| 84 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 85 | .. versionadded:: 3.7 |
| 86 | |
| 87 | The *ssl_handshake_timeout* parameter. |
| 88 | |
| 89 | .. versionchanged:: 3.7 |
| 90 | |
| 91 | The *path* parameter can now be a :term:`path-like object` |
| 92 | |
| 93 | .. coroutinefunction:: start_unix_server(client_connected_cb, path=None, \*, loop=None, limit=None, sock=None, backlog=100, ssl=None, ssl_handshake_timeout=None, start_serving=True) |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 94 | |
| 95 | Start a UNIX Domain Socket server, with a callback for each client connected. |
| 96 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 97 | The *client_connected_cb* callback is called whenever a new client |
| 98 | connection is established. It receives a reader/writer pair as two |
| 99 | arguments, the first is a :class:`StreamReader` instance, |
| 100 | and the second is a :class:`StreamWriter` instance. |
| 101 | |
| 102 | *client_connected_cb* accepts a plain callable or a |
| 103 | :ref:`coroutine function <coroutine>`; if it is a coroutine function, |
| 104 | it will be automatically converted into a :class:`Task`. |
| 105 | |
| 106 | When specified, the *loop* argument determines which event loop to use, |
| 107 | and the *limit* argument determines the buffer size limit used by the |
| 108 | :class:`StreamReader` instance passed to *client_connected_cb*. |
| 109 | |
| 110 | The rest of the arguments are passed directly to |
| 111 | :meth:`~AbstractEventLoop.create_unix_server()`. |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 112 | |
Yury Selivanov | 37f15bc | 2014-02-20 16:20:44 -0500 | [diff] [blame] | 113 | This function is a :ref:`coroutine <coroutine>`. |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 114 | |
| 115 | Availability: UNIX. |
| 116 | |
Elvis Pranskevichus | c0d062f | 2018-06-08 11:36:00 -0400 | [diff] [blame] | 117 | .. versionadded:: 3.7 |
| 118 | |
| 119 | The *ssl_handshake_timeout* and *start_serving* parameters. |
| 120 | |
| 121 | .. versionchanged:: 3.7 |
| 122 | |
| 123 | The *path* parameter can now be a :term:`path-like object`. |
| 124 | |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 125 | |
| 126 | StreamReader |
| 127 | ============ |
| 128 | |
Victor Stinner | 0844438 | 2014-02-02 22:43:39 +0100 | [diff] [blame] | 129 | .. class:: StreamReader(limit=None, loop=None) |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 130 | |
Victor Stinner | 8370496 | 2015-02-25 14:24:15 +0100 | [diff] [blame] | 131 | This class is :ref:`not thread safe <asyncio-multithreading>`. |
| 132 | |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 133 | .. method:: exception() |
| 134 | |
| 135 | Get the exception. |
| 136 | |
| 137 | .. method:: feed_eof() |
| 138 | |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 139 | Acknowledge the EOF. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 140 | |
| 141 | .. method:: feed_data(data) |
| 142 | |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 143 | Feed *data* bytes in the internal buffer. Any operations waiting |
| 144 | for the data will be resumed. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 145 | |
| 146 | .. method:: set_exception(exc) |
| 147 | |
| 148 | Set the exception. |
| 149 | |
| 150 | .. method:: set_transport(transport) |
| 151 | |
| 152 | Set the transport. |
| 153 | |
Victor Stinner | bdd574d | 2015-02-12 22:49:18 +0100 | [diff] [blame] | 154 | .. coroutinemethod:: read(n=-1) |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 155 | |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 156 | Read up to *n* bytes. If *n* is not provided, or set to ``-1``, |
| 157 | read until EOF and return all read bytes. |
| 158 | |
| 159 | If the EOF was received and the internal buffer is empty, |
| 160 | return an empty ``bytes`` object. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 161 | |
Yury Selivanov | 37f15bc | 2014-02-20 16:20:44 -0500 | [diff] [blame] | 162 | This method is a :ref:`coroutine <coroutine>`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 163 | |
Victor Stinner | bdd574d | 2015-02-12 22:49:18 +0100 | [diff] [blame] | 164 | .. coroutinemethod:: readline() |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 165 | |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 166 | Read one line, where "line" is a sequence of bytes ending with ``\n``. |
| 167 | |
| 168 | If EOF is received, and ``\n`` was not found, the method will |
| 169 | return the partial read bytes. |
| 170 | |
| 171 | If the EOF was received and the internal buffer is empty, |
| 172 | return an empty ``bytes`` object. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 173 | |
Yury Selivanov | 37f15bc | 2014-02-20 16:20:44 -0500 | [diff] [blame] | 174 | This method is a :ref:`coroutine <coroutine>`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 175 | |
Victor Stinner | bdd574d | 2015-02-12 22:49:18 +0100 | [diff] [blame] | 176 | .. coroutinemethod:: readexactly(n) |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 177 | |
Victor Stinner | b7f19ff | 2014-01-27 11:58:49 +0100 | [diff] [blame] | 178 | Read exactly *n* bytes. Raise an :exc:`IncompleteReadError` if the end of |
| 179 | the stream is reached before *n* can be read, the |
| 180 | :attr:`IncompleteReadError.partial` attribute of the exception contains |
| 181 | the partial read bytes. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 182 | |
Yury Selivanov | 37f15bc | 2014-02-20 16:20:44 -0500 | [diff] [blame] | 183 | This method is a :ref:`coroutine <coroutine>`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 184 | |
Berker Peksag | e5b0bd1 | 2016-10-18 00:34:46 +0300 | [diff] [blame] | 185 | .. coroutinemethod:: readuntil(separator=b'\\n') |
Yury Selivanov | 950204d | 2016-05-16 16:23:00 -0400 | [diff] [blame] | 186 | |
| 187 | Read data from the stream until ``separator`` is found. |
| 188 | |
| 189 | On success, the data and separator will be removed from the |
| 190 | internal buffer (consumed). Returned data will include the |
| 191 | separator at the end. |
| 192 | |
| 193 | Configured stream limit is used to check result. Limit sets the |
| 194 | maximal length of data that can be returned, not counting the |
| 195 | separator. |
| 196 | |
| 197 | If an EOF occurs and the complete separator is still not found, |
| 198 | an :exc:`IncompleteReadError` exception will be |
| 199 | raised, and the internal buffer will be reset. The |
| 200 | :attr:`IncompleteReadError.partial` attribute may contain the |
| 201 | separator partially. |
| 202 | |
| 203 | If the data cannot be read because of over limit, a |
| 204 | :exc:`LimitOverrunError` exception will be raised, and the data |
| 205 | will be left in the internal buffer, so it can be read again. |
| 206 | |
| 207 | .. versionadded:: 3.5.2 |
| 208 | |
Yury Selivanov | d3f8e30 | 2014-02-20 14:10:02 -0500 | [diff] [blame] | 209 | .. method:: at_eof() |
| 210 | |
| 211 | Return ``True`` if the buffer is empty and :meth:`feed_eof` was called. |
| 212 | |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 213 | |
| 214 | StreamWriter |
| 215 | ============ |
| 216 | |
| 217 | .. class:: StreamWriter(transport, protocol, reader, loop) |
| 218 | |
| 219 | Wraps a Transport. |
| 220 | |
| 221 | This exposes :meth:`write`, :meth:`writelines`, :meth:`can_write_eof()`, |
| 222 | :meth:`write_eof`, :meth:`get_extra_info` and :meth:`close`. It adds |
| 223 | :meth:`drain` which returns an optional :class:`Future` on which you can |
| 224 | wait for flow control. It also adds a transport attribute which references |
| 225 | the :class:`Transport` directly. |
| 226 | |
Victor Stinner | 8370496 | 2015-02-25 14:24:15 +0100 | [diff] [blame] | 227 | This class is :ref:`not thread safe <asyncio-multithreading>`. |
| 228 | |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 229 | .. attribute:: transport |
| 230 | |
| 231 | Transport. |
| 232 | |
Victor Stinner | ffbe3c6 | 2014-02-08 22:50:07 +0100 | [diff] [blame] | 233 | .. method:: can_write_eof() |
| 234 | |
| 235 | Return :const:`True` if the transport supports :meth:`write_eof`, |
| 236 | :const:`False` if not. See :meth:`WriteTransport.can_write_eof`. |
| 237 | |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 238 | .. method:: close() |
| 239 | |
| 240 | Close the transport: see :meth:`BaseTransport.close`. |
| 241 | |
Andrew Svetlov | fe133aa | 2018-01-25 00:30:30 +0200 | [diff] [blame] | 242 | .. method:: is_closing() |
| 243 | |
| 244 | Return ``True`` if the writer is closing or is closed. |
| 245 | |
| 246 | .. versionadded:: 3.7 |
| 247 | |
| 248 | .. coroutinemethod:: wait_closed() |
| 249 | |
| 250 | Wait until the writer is closed. |
| 251 | |
| 252 | Should be called after :meth:`close` to wait until the underlying |
| 253 | connection (and the associated transport/protocol pair) is closed. |
| 254 | |
| 255 | .. versionadded:: 3.7 |
| 256 | |
Victor Stinner | bdd574d | 2015-02-12 22:49:18 +0100 | [diff] [blame] | 257 | .. coroutinemethod:: drain() |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 258 | |
Victor Stinner | e718297 | 2014-11-28 17:45:41 +0100 | [diff] [blame] | 259 | Let the write buffer of the underlying transport a chance to be flushed. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 260 | |
Victor Stinner | d71dcbb | 2014-08-25 17:04:12 +0200 | [diff] [blame] | 261 | The intended use is to write:: |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 262 | |
| 263 | w.write(data) |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 264 | await w.drain() |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 265 | |
Victor Stinner | e718297 | 2014-11-28 17:45:41 +0100 | [diff] [blame] | 266 | When the size of the transport buffer reaches the high-water limit (the |
| 267 | protocol is paused), block until the size of the buffer is drained down |
| 268 | to the low-water limit and the protocol is resumed. When there is nothing |
| 269 | to wait for, the yield-from continues immediately. |
| 270 | |
| 271 | Yielding from :meth:`drain` gives the opportunity for the loop to |
| 272 | schedule the write operation and flush the buffer. It should especially |
| 273 | be used when a possibly large amount of data is written to the transport, |
| 274 | and the coroutine does not yield-from between calls to :meth:`write`. |
Victor Stinner | d71dcbb | 2014-08-25 17:04:12 +0200 | [diff] [blame] | 275 | |
| 276 | This method is a :ref:`coroutine <coroutine>`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 277 | |
| 278 | .. method:: get_extra_info(name, default=None) |
| 279 | |
| 280 | Return optional transport information: see |
| 281 | :meth:`BaseTransport.get_extra_info`. |
| 282 | |
| 283 | .. method:: write(data) |
| 284 | |
| 285 | Write some *data* bytes to the transport: see |
| 286 | :meth:`WriteTransport.write`. |
| 287 | |
| 288 | .. method:: writelines(data) |
| 289 | |
| 290 | Write a list (or any iterable) of data bytes to the transport: |
| 291 | see :meth:`WriteTransport.writelines`. |
| 292 | |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 293 | .. method:: write_eof() |
| 294 | |
| 295 | Close the write end of the transport after flushing buffered data: |
| 296 | see :meth:`WriteTransport.write_eof`. |
| 297 | |
| 298 | |
| 299 | StreamReaderProtocol |
| 300 | ==================== |
| 301 | |
| 302 | .. class:: StreamReaderProtocol(stream_reader, client_connected_cb=None, loop=None) |
| 303 | |
| 304 | Trivial helper class to adapt between :class:`Protocol` and |
Jesus Cea | ded4c49 | 2016-04-19 21:50:19 +0200 | [diff] [blame] | 305 | :class:`StreamReader`. Subclass of :class:`Protocol`. |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 306 | |
| 307 | *stream_reader* is a :class:`StreamReader` instance, *client_connected_cb* |
| 308 | is an optional function called with (stream_reader, stream_writer) when a |
| 309 | connection is made, *loop* is the event loop instance to use. |
| 310 | |
| 311 | (This is a helper class instead of making :class:`StreamReader` itself a |
| 312 | :class:`Protocol` subclass, because the :class:`StreamReader` has other |
R David Murray | 87d0066 | 2015-09-27 12:36:19 -0400 | [diff] [blame] | 313 | potential uses, and to prevent the user of the :class:`StreamReader` from |
| 314 | accidentally calling inappropriate methods of the protocol.) |
Victor Stinner | 24f8ebf | 2014-01-23 11:05:01 +0100 | [diff] [blame] | 315 | |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 316 | |
Victor Stinner | b7f19ff | 2014-01-27 11:58:49 +0100 | [diff] [blame] | 317 | IncompleteReadError |
| 318 | =================== |
| 319 | |
| 320 | .. exception:: IncompleteReadError |
| 321 | |
Victor Stinner | 32970b8 | 2014-01-27 12:18:49 +0100 | [diff] [blame] | 322 | Incomplete read error, subclass of :exc:`EOFError`. |
Victor Stinner | b7f19ff | 2014-01-27 11:58:49 +0100 | [diff] [blame] | 323 | |
| 324 | .. attribute:: expected |
| 325 | |
| 326 | Total number of expected bytes (:class:`int`). |
| 327 | |
| 328 | .. attribute:: partial |
| 329 | |
| 330 | Read bytes string before the end of stream was reached (:class:`bytes`). |
| 331 | |
| 332 | |
Yury Selivanov | 950204d | 2016-05-16 16:23:00 -0400 | [diff] [blame] | 333 | LimitOverrunError |
| 334 | ================= |
| 335 | |
| 336 | .. exception:: LimitOverrunError |
| 337 | |
| 338 | Reached the buffer limit while looking for a separator. |
| 339 | |
| 340 | .. attribute:: consumed |
| 341 | |
| 342 | Total number of to be consumed bytes. |
| 343 | |
| 344 | |
Victor Stinner | 5121a9b | 2014-10-11 15:52:14 +0200 | [diff] [blame] | 345 | Stream examples |
| 346 | =============== |
| 347 | |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 348 | .. _asyncio-tcp-echo-client-streams: |
| 349 | |
| 350 | TCP echo client using streams |
| 351 | ----------------------------- |
| 352 | |
| 353 | TCP echo client using the :func:`asyncio.open_connection` function:: |
| 354 | |
| 355 | import asyncio |
| 356 | |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 357 | async def tcp_echo_client(message, loop): |
| 358 | reader, writer = await asyncio.open_connection('127.0.0.1', 8888, |
| 359 | loop=loop) |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 360 | |
| 361 | print('Send: %r' % message) |
| 362 | writer.write(message.encode()) |
| 363 | |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 364 | data = await reader.read(100) |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 365 | print('Received: %r' % data.decode()) |
| 366 | |
| 367 | print('Close the socket') |
| 368 | writer.close() |
| 369 | |
| 370 | message = 'Hello World!' |
| 371 | loop = asyncio.get_event_loop() |
| 372 | loop.run_until_complete(tcp_echo_client(message, loop)) |
| 373 | loop.close() |
| 374 | |
| 375 | .. seealso:: |
| 376 | |
| 377 | The :ref:`TCP echo client protocol <asyncio-tcp-echo-client-protocol>` |
Guido van Rossum | f68afd8 | 2016-08-08 09:41:21 -0700 | [diff] [blame] | 378 | example uses the :meth:`AbstractEventLoop.create_connection` method. |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 379 | |
| 380 | |
| 381 | .. _asyncio-tcp-echo-server-streams: |
| 382 | |
| 383 | TCP echo server using streams |
| 384 | ----------------------------- |
| 385 | |
| 386 | TCP echo server using the :func:`asyncio.start_server` function:: |
| 387 | |
| 388 | import asyncio |
| 389 | |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 390 | async def handle_echo(reader, writer): |
| 391 | data = await reader.read(100) |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 392 | message = data.decode() |
| 393 | addr = writer.get_extra_info('peername') |
| 394 | print("Received %r from %r" % (message, addr)) |
| 395 | |
| 396 | print("Send: %r" % message) |
| 397 | writer.write(data) |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 398 | await writer.drain() |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 399 | |
| 400 | print("Close the client socket") |
| 401 | writer.close() |
| 402 | |
| 403 | loop = asyncio.get_event_loop() |
| 404 | coro = asyncio.start_server(handle_echo, '127.0.0.1', 8888, loop=loop) |
| 405 | server = loop.run_until_complete(coro) |
| 406 | |
Serhiy Storchaka | 0424eaf | 2015-09-12 17:45:25 +0300 | [diff] [blame] | 407 | # Serve requests until Ctrl+C is pressed |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 408 | print('Serving on {}'.format(server.sockets[0].getsockname())) |
| 409 | try: |
| 410 | loop.run_forever() |
| 411 | except KeyboardInterrupt: |
| 412 | pass |
| 413 | |
| 414 | # Close the server |
| 415 | server.close() |
| 416 | loop.run_until_complete(server.wait_closed()) |
| 417 | loop.close() |
| 418 | |
| 419 | .. seealso:: |
| 420 | |
| 421 | The :ref:`TCP echo server protocol <asyncio-tcp-echo-server-protocol>` |
Guido van Rossum | f68afd8 | 2016-08-08 09:41:21 -0700 | [diff] [blame] | 422 | example uses the :meth:`AbstractEventLoop.create_server` method. |
Victor Stinner | ed05159 | 2014-10-12 20:18:16 +0200 | [diff] [blame] | 423 | |
| 424 | |
Victor Stinner | 5121a9b | 2014-10-11 15:52:14 +0200 | [diff] [blame] | 425 | Get HTTP headers |
| 426 | ---------------- |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 427 | |
| 428 | Simple example querying HTTP headers of the URL passed on the command line:: |
| 429 | |
| 430 | import asyncio |
| 431 | import urllib.parse |
| 432 | import sys |
| 433 | |
Mikhail Terekhov | d2ac400 | 2018-08-07 16:29:06 -0400 | [diff] [blame] | 434 | async def print_http_headers(url): |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 435 | url = urllib.parse.urlsplit(url) |
Victor Stinner | 5121a9b | 2014-10-11 15:52:14 +0200 | [diff] [blame] | 436 | if url.scheme == 'https': |
| 437 | connect = asyncio.open_connection(url.hostname, 443, ssl=True) |
| 438 | else: |
| 439 | connect = asyncio.open_connection(url.hostname, 80) |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 440 | reader, writer = await connect |
Victor Stinner | 5121a9b | 2014-10-11 15:52:14 +0200 | [diff] [blame] | 441 | query = ('HEAD {path} HTTP/1.0\r\n' |
| 442 | 'Host: {hostname}\r\n' |
| 443 | '\r\n').format(path=url.path or '/', hostname=url.hostname) |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 444 | writer.write(query.encode('latin-1')) |
| 445 | while True: |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 446 | line = await reader.readline() |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 447 | if not line: |
| 448 | break |
| 449 | line = line.decode('latin1').rstrip() |
| 450 | if line: |
| 451 | print('HTTP header> %s' % line) |
| 452 | |
Victor Stinner | 5121a9b | 2014-10-11 15:52:14 +0200 | [diff] [blame] | 453 | # Ignore the body, close the socket |
| 454 | writer.close() |
| 455 | |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 456 | url = sys.argv[1] |
| 457 | loop = asyncio.get_event_loop() |
Yury Selivanov | d7e19bb | 2015-05-11 16:33:41 -0400 | [diff] [blame] | 458 | task = asyncio.ensure_future(print_http_headers(url)) |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 459 | loop.run_until_complete(task) |
Victor Stinner | f40c663 | 2014-01-28 23:32:40 +0100 | [diff] [blame] | 460 | loop.close() |
Victor Stinner | c520edc | 2014-01-23 11:25:48 +0100 | [diff] [blame] | 461 | |
| 462 | Usage:: |
| 463 | |
| 464 | python example.py http://example.com/path/page.html |
| 465 | |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 466 | or with HTTPS:: |
| 467 | |
| 468 | python example.py https://example.com/path/page.html |
| 469 | |
| 470 | .. _asyncio-register-socket-streams: |
| 471 | |
| 472 | Register an open socket to wait for data using streams |
| 473 | ------------------------------------------------------ |
| 474 | |
| 475 | Coroutine waiting until a socket receives data using the |
| 476 | :func:`open_connection` function:: |
| 477 | |
| 478 | import asyncio |
Victor Stinner | ac577d7 | 2017-11-28 21:33:20 +0100 | [diff] [blame] | 479 | from socket import socketpair |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 480 | |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 481 | async def wait_for_data(loop): |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 482 | # Create a pair of connected sockets |
Victor Stinner | ccd8e34 | 2014-10-11 16:30:02 +0200 | [diff] [blame] | 483 | rsock, wsock = socketpair() |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 484 | |
| 485 | # Register the open socket to wait for data |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 486 | reader, writer = await asyncio.open_connection(sock=rsock, loop=loop) |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 487 | |
| 488 | # Simulate the reception of data from the network |
| 489 | loop.call_soon(wsock.send, 'abc'.encode()) |
| 490 | |
| 491 | # Wait for data |
Andrew Svetlov | 8874342 | 2017-12-11 17:35:49 +0200 | [diff] [blame] | 492 | data = await reader.read(100) |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 493 | |
| 494 | # Got data, we are done: close the socket |
| 495 | print("Received:", data.decode()) |
| 496 | writer.close() |
| 497 | |
| 498 | # Close the second socket |
| 499 | wsock.close() |
| 500 | |
| 501 | loop = asyncio.get_event_loop() |
| 502 | loop.run_until_complete(wait_for_data(loop)) |
| 503 | loop.close() |
| 504 | |
| 505 | .. seealso:: |
| 506 | |
| 507 | The :ref:`register an open socket to wait for data using a protocol |
| 508 | <asyncio-register-socket>` example uses a low-level protocol created by the |
Guido van Rossum | f68afd8 | 2016-08-08 09:41:21 -0700 | [diff] [blame] | 509 | :meth:`AbstractEventLoop.create_connection` method. |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 510 | |
| 511 | The :ref:`watch a file descriptor for read events |
| 512 | <asyncio-watch-read-event>` example uses the low-level |
Guido van Rossum | f68afd8 | 2016-08-08 09:41:21 -0700 | [diff] [blame] | 513 | :meth:`AbstractEventLoop.add_reader` method to register the file descriptor of a |
Victor Stinner | 04e6df3 | 2014-10-11 16:16:27 +0200 | [diff] [blame] | 514 | socket. |