Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 1 | """Stream-related things.""" |
| 2 | |
Guido van Rossum | 49c96fb | 2013-11-25 15:07:18 -0800 | [diff] [blame] | 3 | __all__ = ['StreamReader', 'StreamWriter', 'StreamReaderProtocol', |
Guido van Rossum | 1540b16 | 2013-11-19 11:43:38 -0800 | [diff] [blame] | 4 | 'open_connection', 'start_server', |
| 5 | ] |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 6 | |
| 7 | import collections |
| 8 | |
| 9 | from . import events |
| 10 | from . import futures |
| 11 | from . import protocols |
| 12 | from . import tasks |
| 13 | |
| 14 | |
| 15 | _DEFAULT_LIMIT = 2**16 |
| 16 | |
| 17 | |
| 18 | @tasks.coroutine |
| 19 | def open_connection(host=None, port=None, *, |
| 20 | loop=None, limit=_DEFAULT_LIMIT, **kwds): |
| 21 | """A wrapper for create_connection() returning a (reader, writer) pair. |
| 22 | |
| 23 | The reader returned is a StreamReader instance; the writer is a |
Victor Stinner | 183e347 | 2014-01-23 17:40:03 +0100 | [diff] [blame^] | 24 | StreamWriter instance. |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 25 | |
| 26 | The arguments are all the usual arguments to create_connection() |
| 27 | except protocol_factory; most common are positional host and port, |
| 28 | with various optional keyword arguments following. |
| 29 | |
| 30 | Additional optional keyword arguments are loop (to set the event loop |
| 31 | instance to use) and limit (to set the buffer limit passed to the |
| 32 | StreamReader). |
| 33 | |
| 34 | (If you want to customize the StreamReader and/or |
| 35 | StreamReaderProtocol classes, just copy the code -- there's |
| 36 | really nothing special here except some convenience.) |
| 37 | """ |
| 38 | if loop is None: |
| 39 | loop = events.get_event_loop() |
| 40 | reader = StreamReader(limit=limit, loop=loop) |
Guido van Rossum | efef9d3 | 2014-01-10 13:26:38 -0800 | [diff] [blame] | 41 | protocol = StreamReaderProtocol(reader, loop=loop) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 42 | transport, _ = yield from loop.create_connection( |
| 43 | lambda: protocol, host, port, **kwds) |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 44 | writer = StreamWriter(transport, protocol, reader, loop) |
| 45 | return reader, writer |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 46 | |
| 47 | |
Guido van Rossum | 1540b16 | 2013-11-19 11:43:38 -0800 | [diff] [blame] | 48 | @tasks.coroutine |
| 49 | def start_server(client_connected_cb, host=None, port=None, *, |
| 50 | loop=None, limit=_DEFAULT_LIMIT, **kwds): |
| 51 | """Start a socket server, call back for each client connected. |
| 52 | |
| 53 | The first parameter, `client_connected_cb`, takes two parameters: |
| 54 | client_reader, client_writer. client_reader is a StreamReader |
| 55 | object, while client_writer is a StreamWriter object. This |
| 56 | parameter can either be a plain callback function or a coroutine; |
| 57 | if it is a coroutine, it will be automatically converted into a |
| 58 | Task. |
| 59 | |
| 60 | The rest of the arguments are all the usual arguments to |
| 61 | loop.create_server() except protocol_factory; most common are |
| 62 | positional host and port, with various optional keyword arguments |
| 63 | following. The return value is the same as loop.create_server(). |
| 64 | |
| 65 | Additional optional keyword arguments are loop (to set the event loop |
| 66 | instance to use) and limit (to set the buffer limit passed to the |
| 67 | StreamReader). |
| 68 | |
| 69 | The return value is the same as loop.create_server(), i.e. a |
| 70 | Server object which can be used to stop the service. |
| 71 | """ |
| 72 | if loop is None: |
| 73 | loop = events.get_event_loop() |
| 74 | |
| 75 | def factory(): |
| 76 | reader = StreamReader(limit=limit, loop=loop) |
| 77 | protocol = StreamReaderProtocol(reader, client_connected_cb, |
| 78 | loop=loop) |
| 79 | return protocol |
| 80 | |
| 81 | return (yield from loop.create_server(factory, host, port, **kwds)) |
| 82 | |
| 83 | |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 84 | class StreamReaderProtocol(protocols.Protocol): |
| 85 | """Trivial helper class to adapt between Protocol and StreamReader. |
| 86 | |
| 87 | (This is a helper class instead of making StreamReader itself a |
| 88 | Protocol subclass, because the StreamReader has other potential |
| 89 | uses, and to prevent the user of the StreamReader to accidentally |
| 90 | call inappropriate methods of the protocol.) |
| 91 | """ |
| 92 | |
Guido van Rossum | 1540b16 | 2013-11-19 11:43:38 -0800 | [diff] [blame] | 93 | def __init__(self, stream_reader, client_connected_cb=None, loop=None): |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 94 | self._stream_reader = stream_reader |
Guido van Rossum | 1540b16 | 2013-11-19 11:43:38 -0800 | [diff] [blame] | 95 | self._stream_writer = None |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 96 | self._drain_waiter = None |
| 97 | self._paused = False |
Guido van Rossum | 1540b16 | 2013-11-19 11:43:38 -0800 | [diff] [blame] | 98 | self._client_connected_cb = client_connected_cb |
| 99 | self._loop = loop # May be None; we may never need it. |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 100 | |
| 101 | def connection_made(self, transport): |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 102 | self._stream_reader.set_transport(transport) |
Guido van Rossum | 1540b16 | 2013-11-19 11:43:38 -0800 | [diff] [blame] | 103 | if self._client_connected_cb is not None: |
| 104 | self._stream_writer = StreamWriter(transport, self, |
| 105 | self._stream_reader, |
| 106 | self._loop) |
| 107 | res = self._client_connected_cb(self._stream_reader, |
| 108 | self._stream_writer) |
| 109 | if tasks.iscoroutine(res): |
| 110 | tasks.Task(res, loop=self._loop) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 111 | |
| 112 | def connection_lost(self, exc): |
| 113 | if exc is None: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 114 | self._stream_reader.feed_eof() |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 115 | else: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 116 | self._stream_reader.set_exception(exc) |
| 117 | # Also wake up the writing side. |
| 118 | if self._paused: |
| 119 | waiter = self._drain_waiter |
| 120 | if waiter is not None: |
| 121 | self._drain_waiter = None |
| 122 | if not waiter.done(): |
| 123 | if exc is None: |
| 124 | waiter.set_result(None) |
| 125 | else: |
| 126 | waiter.set_exception(exc) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 127 | |
| 128 | def data_received(self, data): |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 129 | self._stream_reader.feed_data(data) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 130 | |
| 131 | def eof_received(self): |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 132 | self._stream_reader.feed_eof() |
| 133 | |
| 134 | def pause_writing(self): |
| 135 | assert not self._paused |
| 136 | self._paused = True |
| 137 | |
| 138 | def resume_writing(self): |
| 139 | assert self._paused |
| 140 | self._paused = False |
| 141 | waiter = self._drain_waiter |
| 142 | if waiter is not None: |
| 143 | self._drain_waiter = None |
| 144 | if not waiter.done(): |
| 145 | waiter.set_result(None) |
| 146 | |
| 147 | |
| 148 | class StreamWriter: |
| 149 | """Wraps a Transport. |
| 150 | |
| 151 | This exposes write(), writelines(), [can_]write_eof(), |
| 152 | get_extra_info() and close(). It adds drain() which returns an |
| 153 | optional Future on which you can wait for flow control. It also |
Guido van Rossum | efef9d3 | 2014-01-10 13:26:38 -0800 | [diff] [blame] | 154 | adds a transport property which references the Transport |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 155 | directly. |
| 156 | """ |
| 157 | |
| 158 | def __init__(self, transport, protocol, reader, loop): |
| 159 | self._transport = transport |
| 160 | self._protocol = protocol |
| 161 | self._reader = reader |
| 162 | self._loop = loop |
| 163 | |
| 164 | @property |
| 165 | def transport(self): |
| 166 | return self._transport |
| 167 | |
| 168 | def write(self, data): |
| 169 | self._transport.write(data) |
| 170 | |
| 171 | def writelines(self, data): |
| 172 | self._transport.writelines(data) |
| 173 | |
| 174 | def write_eof(self): |
| 175 | return self._transport.write_eof() |
| 176 | |
| 177 | def can_write_eof(self): |
| 178 | return self._transport.can_write_eof() |
| 179 | |
| 180 | def close(self): |
| 181 | return self._transport.close() |
| 182 | |
| 183 | def get_extra_info(self, name, default=None): |
| 184 | return self._transport.get_extra_info(name, default) |
| 185 | |
| 186 | def drain(self): |
| 187 | """This method has an unusual return value. |
| 188 | |
| 189 | The intended use is to write |
| 190 | |
| 191 | w.write(data) |
| 192 | yield from w.drain() |
| 193 | |
| 194 | When there's nothing to wait for, drain() returns (), and the |
| 195 | yield-from continues immediately. When the transport buffer |
| 196 | is full (the protocol is paused), drain() creates and returns |
| 197 | a Future and the yield-from will block until that Future is |
| 198 | completed, which will happen when the buffer is (partially) |
| 199 | drained and the protocol is resumed. |
| 200 | """ |
| 201 | if self._reader._exception is not None: |
Guido van Rossum | 6188bd4 | 2014-01-07 17:03:26 -0800 | [diff] [blame] | 202 | raise self._reader._exception |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 203 | if self._transport._conn_lost: # Uses private variable. |
| 204 | raise ConnectionResetError('Connection lost') |
| 205 | if not self._protocol._paused: |
| 206 | return () |
| 207 | waiter = self._protocol._drain_waiter |
| 208 | assert waiter is None or waiter.cancelled() |
| 209 | waiter = futures.Future(loop=self._loop) |
| 210 | self._protocol._drain_waiter = waiter |
| 211 | return waiter |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 212 | |
| 213 | |
| 214 | class StreamReader: |
| 215 | |
| 216 | def __init__(self, limit=_DEFAULT_LIMIT, loop=None): |
| 217 | # The line length limit is a security feature; |
| 218 | # it also doubles as half the buffer limit. |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 219 | self._limit = limit |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 220 | if loop is None: |
| 221 | loop = events.get_event_loop() |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 222 | self._loop = loop |
Guido van Rossum | 3845521 | 2014-01-06 16:09:18 -0800 | [diff] [blame] | 223 | # TODO: Use a bytearray for a buffer, like the transport. |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 224 | self._buffer = collections.deque() # Deque of bytes objects. |
| 225 | self._byte_count = 0 # Bytes in buffer. |
| 226 | self._eof = False # Whether we're done. |
| 227 | self._waiter = None # A future. |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 228 | self._exception = None |
| 229 | self._transport = None |
| 230 | self._paused = False |
| 231 | |
| 232 | def exception(self): |
| 233 | return self._exception |
| 234 | |
| 235 | def set_exception(self, exc): |
| 236 | self._exception = exc |
| 237 | |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 238 | waiter = self._waiter |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 239 | if waiter is not None: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 240 | self._waiter = None |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 241 | if not waiter.cancelled(): |
| 242 | waiter.set_exception(exc) |
| 243 | |
| 244 | def set_transport(self, transport): |
| 245 | assert self._transport is None, 'Transport already set' |
| 246 | self._transport = transport |
| 247 | |
| 248 | def _maybe_resume_transport(self): |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 249 | if self._paused and self._byte_count <= self._limit: |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 250 | self._paused = False |
Guido van Rossum | 57497ad | 2013-10-18 07:58:20 -0700 | [diff] [blame] | 251 | self._transport.resume_reading() |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 252 | |
| 253 | def feed_eof(self): |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 254 | self._eof = True |
| 255 | waiter = self._waiter |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 256 | if waiter is not None: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 257 | self._waiter = None |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 258 | if not waiter.cancelled(): |
| 259 | waiter.set_result(True) |
| 260 | |
| 261 | def feed_data(self, data): |
| 262 | if not data: |
| 263 | return |
| 264 | |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 265 | self._buffer.append(data) |
| 266 | self._byte_count += len(data) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 267 | |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 268 | waiter = self._waiter |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 269 | if waiter is not None: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 270 | self._waiter = None |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 271 | if not waiter.cancelled(): |
| 272 | waiter.set_result(False) |
| 273 | |
| 274 | if (self._transport is not None and |
| 275 | not self._paused and |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 276 | self._byte_count > 2*self._limit): |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 277 | try: |
Guido van Rossum | 57497ad | 2013-10-18 07:58:20 -0700 | [diff] [blame] | 278 | self._transport.pause_reading() |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 279 | except NotImplementedError: |
| 280 | # The transport can't be paused. |
| 281 | # We'll just have to buffer all data. |
| 282 | # Forget the transport so we don't keep trying. |
| 283 | self._transport = None |
| 284 | else: |
| 285 | self._paused = True |
| 286 | |
Victor Stinner | 183e347 | 2014-01-23 17:40:03 +0100 | [diff] [blame^] | 287 | def _create_waiter(self, func_name): |
| 288 | # StreamReader uses a future to link the protocol feed_data() method |
| 289 | # to a read coroutine. Running two read coroutines at the same time |
| 290 | # would have an unexpected behaviour. It would not possible to know |
| 291 | # which coroutine would get the next data. |
| 292 | if self._waiter is not None: |
| 293 | raise RuntimeError('%s() called while another coroutine is ' |
| 294 | 'already waiting for incoming data' % func_name) |
| 295 | return futures.Future(loop=self._loop) |
| 296 | |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 297 | @tasks.coroutine |
| 298 | def readline(self): |
| 299 | if self._exception is not None: |
| 300 | raise self._exception |
| 301 | |
| 302 | parts = [] |
| 303 | parts_size = 0 |
| 304 | not_enough = True |
| 305 | |
| 306 | while not_enough: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 307 | while self._buffer and not_enough: |
| 308 | data = self._buffer.popleft() |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 309 | ichar = data.find(b'\n') |
| 310 | if ichar < 0: |
| 311 | parts.append(data) |
| 312 | parts_size += len(data) |
| 313 | else: |
| 314 | ichar += 1 |
| 315 | head, tail = data[:ichar], data[ichar:] |
| 316 | if tail: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 317 | self._buffer.appendleft(tail) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 318 | not_enough = False |
| 319 | parts.append(head) |
| 320 | parts_size += len(head) |
| 321 | |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 322 | if parts_size > self._limit: |
| 323 | self._byte_count -= parts_size |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 324 | self._maybe_resume_transport() |
| 325 | raise ValueError('Line is too long') |
| 326 | |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 327 | if self._eof: |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 328 | break |
| 329 | |
| 330 | if not_enough: |
Victor Stinner | 183e347 | 2014-01-23 17:40:03 +0100 | [diff] [blame^] | 331 | self._waiter = self._create_waiter('readline') |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 332 | try: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 333 | yield from self._waiter |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 334 | finally: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 335 | self._waiter = None |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 336 | |
| 337 | line = b''.join(parts) |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 338 | self._byte_count -= parts_size |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 339 | self._maybe_resume_transport() |
| 340 | |
| 341 | return line |
| 342 | |
| 343 | @tasks.coroutine |
| 344 | def read(self, n=-1): |
| 345 | if self._exception is not None: |
| 346 | raise self._exception |
| 347 | |
| 348 | if not n: |
| 349 | return b'' |
| 350 | |
| 351 | if n < 0: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 352 | while not self._eof: |
Victor Stinner | 183e347 | 2014-01-23 17:40:03 +0100 | [diff] [blame^] | 353 | self._waiter = self._create_waiter('read') |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 354 | try: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 355 | yield from self._waiter |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 356 | finally: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 357 | self._waiter = None |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 358 | else: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 359 | if not self._byte_count and not self._eof: |
Victor Stinner | 183e347 | 2014-01-23 17:40:03 +0100 | [diff] [blame^] | 360 | self._waiter = self._create_waiter('read') |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 361 | try: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 362 | yield from self._waiter |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 363 | finally: |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 364 | self._waiter = None |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 365 | |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 366 | if n < 0 or self._byte_count <= n: |
| 367 | data = b''.join(self._buffer) |
| 368 | self._buffer.clear() |
| 369 | self._byte_count = 0 |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 370 | self._maybe_resume_transport() |
| 371 | return data |
| 372 | |
| 373 | parts = [] |
| 374 | parts_bytes = 0 |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 375 | while self._buffer and parts_bytes < n: |
| 376 | data = self._buffer.popleft() |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 377 | data_bytes = len(data) |
| 378 | if n < parts_bytes + data_bytes: |
| 379 | data_bytes = n - parts_bytes |
| 380 | data, rest = data[:data_bytes], data[data_bytes:] |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 381 | self._buffer.appendleft(rest) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 382 | |
| 383 | parts.append(data) |
| 384 | parts_bytes += data_bytes |
Guido van Rossum | 355491d | 2013-10-18 15:17:11 -0700 | [diff] [blame] | 385 | self._byte_count -= data_bytes |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 386 | self._maybe_resume_transport() |
| 387 | |
| 388 | return b''.join(parts) |
| 389 | |
| 390 | @tasks.coroutine |
| 391 | def readexactly(self, n): |
| 392 | if self._exception is not None: |
| 393 | raise self._exception |
| 394 | |
Guido van Rossum | 3845521 | 2014-01-06 16:09:18 -0800 | [diff] [blame] | 395 | # There used to be "optimized" code here. It created its own |
| 396 | # Future and waited until self._buffer had at least the n |
| 397 | # bytes, then called read(n). Unfortunately, this could pause |
| 398 | # the transport if the argument was larger than the pause |
| 399 | # limit (which is twice self._limit). So now we just read() |
| 400 | # into a local buffer. |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 401 | |
Guido van Rossum | 3845521 | 2014-01-06 16:09:18 -0800 | [diff] [blame] | 402 | blocks = [] |
| 403 | while n > 0: |
| 404 | block = yield from self.read(n) |
| 405 | if not block: |
| 406 | break |
| 407 | blocks.append(block) |
| 408 | n -= len(block) |
Guido van Rossum | 27b7c7e | 2013-10-17 13:40:50 -0700 | [diff] [blame] | 409 | |
Guido van Rossum | 3845521 | 2014-01-06 16:09:18 -0800 | [diff] [blame] | 410 | # TODO: Raise EOFError if we break before n == 0? (That would |
| 411 | # be a change in specification, but I've always had to add an |
| 412 | # explicit size check to the caller.) |
| 413 | |
| 414 | return b''.join(blocks) |