|
| 1 | +import select |
| 2 | +import socket |
| 3 | +import struct |
| 4 | +import sys |
| 5 | +import types |
| 6 | + |
| 7 | +VERBOSE = None |
| 8 | + |
| 9 | +class SocketProtocol: |
| 10 | + """A simple protocol for sending strings across a socket""" |
| 11 | + BUF_SIZE = 8192 |
| 12 | + |
| 13 | + def __init__(self, sock): |
| 14 | + self.sock = sock |
| 15 | + self._buffer = '' |
| 16 | + self._closed = 0 |
| 17 | + |
| 18 | + def close(self): |
| 19 | + self._closed = 1 |
| 20 | + self.sock.close() |
| 21 | + |
| 22 | + def send(self, buf): |
| 23 | + """Encode buf and write it on the socket""" |
| 24 | + if VERBOSE: |
| 25 | + VERBOSE.write('send %d:%s\n' % (len(buf), `buf`)) |
| 26 | + self.sock.send('%d:%s' % (len(buf), buf)) |
| 27 | + |
| 28 | + def receive(self, timeout=0): |
| 29 | + """Get next complete string from socket or return None |
| 30 | +
|
| 31 | + Raise EOFError on EOF |
| 32 | + """ |
| 33 | + buf = self._read_from_buffer() |
| 34 | + if buf is not None: |
| 35 | + return buf |
| 36 | + recvbuf = self._read_from_socket(timeout) |
| 37 | + if recvbuf is None: |
| 38 | + return None |
| 39 | + if recvbuf == '' and self._buffer == '': |
| 40 | + raise EOFError |
| 41 | + if VERBOSE: |
| 42 | + VERBOSE.write('recv %s\n' % `recvbuf`) |
| 43 | + self._buffer = self._buffer + recvbuf |
| 44 | + r = self._read_from_buffer() |
| 45 | + return r |
| 46 | + |
| 47 | + def _read_from_socket(self, timeout): |
| 48 | + """Does not block""" |
| 49 | + if self._closed: |
| 50 | + return '' |
| 51 | + if timeout is not None: |
| 52 | + r, w, x = select.select([self.sock], [], [], timeout) |
| 53 | + if timeout is None or r: |
| 54 | + return self.sock.recv(self.BUF_SIZE) |
| 55 | + else: |
| 56 | + return None |
| 57 | + |
| 58 | + def _read_from_buffer(self): |
| 59 | + buf = self._buffer |
| 60 | + i = buf.find(':') |
| 61 | + if i == -1: |
| 62 | + return None |
| 63 | + buflen = int(buf[:i]) |
| 64 | + enclen = i + 1 + buflen |
| 65 | + if len(buf) >= enclen: |
| 66 | + s = buf[i+1:enclen] |
| 67 | + self._buffer = buf[enclen:] |
| 68 | + return s |
| 69 | + else: |
| 70 | + self._buffer = buf |
| 71 | + return None |
| 72 | + |
| 73 | +# helpers for registerHandler method below |
| 74 | + |
| 75 | +def get_methods(obj): |
| 76 | + methods = [] |
| 77 | + for name in dir(obj): |
| 78 | + attr = getattr(obj, name) |
| 79 | + if callable(attr): |
| 80 | + methods.append(name) |
| 81 | + if type(obj) == types.InstanceType: |
| 82 | + methods = methods + get_methods(obj.__class__) |
| 83 | + if type(obj) == types.ClassType: |
| 84 | + for super in obj.__bases__: |
| 85 | + methods = methods + get_methods(super) |
| 86 | + return methods |
| 87 | + |
| 88 | +class CommandProtocol: |
| 89 | + def __init__(self, sockp): |
| 90 | + self.sockp = sockp |
| 91 | + self.seqno = 0 |
| 92 | + self.handlers = {} |
| 93 | + |
| 94 | + def close(self): |
| 95 | + self.sockp.close() |
| 96 | + self.handlers.clear() |
| 97 | + |
| 98 | + def registerHandler(self, handler): |
| 99 | + """A Handler is an object with handle_XXX methods""" |
| 100 | + for methname in get_methods(handler): |
| 101 | + if methname[:7] == "handle_": |
| 102 | + name = methname[7:] |
| 103 | + self.handlers[name] = getattr(handler, methname) |
| 104 | + |
| 105 | + def send(self, cmd, arg='', seqno=None): |
| 106 | + if arg: |
| 107 | + msg = "%s %s" % (cmd, arg) |
| 108 | + else: |
| 109 | + msg = cmd |
| 110 | + if seqno is None: |
| 111 | + seqno = self.get_seqno() |
| 112 | + msgbuf = self.encode_seqno(seqno) + msg |
| 113 | + self.sockp.send(msgbuf) |
| 114 | + if cmd == "reply": |
| 115 | + return |
| 116 | + reply = self.sockp.receive(timeout=None) |
| 117 | + r_cmd, r_arg, r_seqno = self._decode_msg(reply) |
| 118 | + assert r_seqno == seqno and r_cmd == "reply", "bad reply" |
| 119 | + return r_arg |
| 120 | + |
| 121 | + def _decode_msg(self, msg): |
| 122 | + seqno = self.decode_seqno(msg[:self.SEQNO_ENC_LEN]) |
| 123 | + msg = msg[self.SEQNO_ENC_LEN:] |
| 124 | + parts = msg.split(" ", 2) |
| 125 | + if len(parts) == 1: |
| 126 | + cmd = msg |
| 127 | + arg = '' |
| 128 | + else: |
| 129 | + cmd = parts[0] |
| 130 | + arg = parts[1] |
| 131 | + return cmd, arg, seqno |
| 132 | + |
| 133 | + def dispatch(self): |
| 134 | + msg = self.sockp.receive() |
| 135 | + if msg is None: |
| 136 | + return |
| 137 | + cmd, arg, seqno = self._decode_msg(msg) |
| 138 | + self._current_reply = seqno |
| 139 | + h = self.handlers.get(cmd, self.default_handler) |
| 140 | + try: |
| 141 | + r = h(arg) |
| 142 | + except TypeError, msg: |
| 143 | + raise TypeError, "handle_%s: %s" % (cmd, msg) |
| 144 | + if self._current_reply is None: |
| 145 | + if r is not None: |
| 146 | + sys.stderr.write("ignoring %s return value type %s\n" % \ |
| 147 | + (cmd, type(r).__name__)) |
| 148 | + return |
| 149 | + if r is None: |
| 150 | + r = '' |
| 151 | + if type(r) != types.StringType: |
| 152 | + raise ValueError, "invalid return type for %s" % cmd |
| 153 | + self.send("reply", r, seqno=seqno) |
| 154 | + |
| 155 | + def reply(self, arg=''): |
| 156 | + """Send a reply immediately |
| 157 | +
|
| 158 | + otherwise reply will be sent when handler returns |
| 159 | + """ |
| 160 | + self.send("reply", arg, self._current_reply) |
| 161 | + self._current_reply = None |
| 162 | + |
| 163 | + def default_handler(self, arg): |
| 164 | + sys.stderr.write("WARNING: unhandled message %s\n" % arg) |
| 165 | + return '' |
| 166 | + |
| 167 | + SEQNO_ENC_LEN = 4 |
| 168 | + |
| 169 | + def get_seqno(self): |
| 170 | + seqno = self.seqno |
| 171 | + self.seqno = seqno + 1 |
| 172 | + return seqno |
| 173 | + |
| 174 | + def encode_seqno(self, seqno): |
| 175 | + return struct.pack("I", seqno) |
| 176 | + |
| 177 | + def decode_seqno(self, buf): |
| 178 | + return struct.unpack("I", buf)[0] |
| 179 | + |
| 180 | + |
| 181 | +class StdioRedirector: |
| 182 | + """Redirect sys.std{in,out,err} to a set of file-like objects""" |
| 183 | + |
| 184 | + def __init__(self, stdin, stdout, stderr): |
| 185 | + self.stdin = stdin |
| 186 | + self.stdout = stdout |
| 187 | + self.stderr = stderr |
| 188 | + |
| 189 | + def redirect(self): |
| 190 | + self.save() |
| 191 | + sys.stdin = self.stdin |
| 192 | + sys.stdout = self.stdout |
| 193 | + sys.stderr = self.stderr |
| 194 | + |
| 195 | + def save(self): |
| 196 | + self._stdin = sys.stdin |
| 197 | + self._stdout = sys.stdout |
| 198 | + self._stderr = sys.stderr |
| 199 | + |
| 200 | + def restore(self): |
| 201 | + sys.stdin = self._stdin |
| 202 | + sys.stdout = self._stdout |
| 203 | + sys.stderr = self._stderr |
| 204 | + |
| 205 | +class IOWrapper: |
| 206 | + """Send output from a file-like object across a SocketProtocol |
| 207 | +
|
| 208 | + XXX Should this be more tightly integrated with the CommandProtocol? |
| 209 | + """ |
| 210 | + |
| 211 | + def __init__(self, name, cmdp): |
| 212 | + self.name = name |
| 213 | + self.cmdp = cmdp |
| 214 | + self.buffer = [] |
| 215 | + |
| 216 | +class InputWrapper(IOWrapper): |
| 217 | + def write(self, buf): |
| 218 | + # XXX what should this do on Windows? |
| 219 | + raise IOError, (9, '[Errno 9] Bad file descriptor') |
| 220 | + |
| 221 | + def read(self, arg=None): |
| 222 | + if arg is not None: |
| 223 | + if arg <= 0: |
| 224 | + return '' |
| 225 | + else: |
| 226 | + arg = 0 |
| 227 | + return self.cmdp.send(self.name, "read,%s" % arg) |
| 228 | + |
| 229 | + def readline(self): |
| 230 | + return self.cmdp.send(self.name, "readline") |
| 231 | + |
| 232 | +class OutputWrapper(IOWrapper): |
| 233 | + def write(self, buf): |
| 234 | + self.cmdp.send(self.name, buf) |
| 235 | + |
| 236 | + def read(self, arg=None): |
| 237 | + return '' |
| 238 | + |
| 239 | +class RemoteInterp: |
| 240 | + def __init__(self, sock): |
| 241 | + self._sock = SocketProtocol(sock) |
| 242 | + self._cmd = CommandProtocol(self._sock) |
| 243 | + self._cmd.registerHandler(self) |
| 244 | + |
| 245 | + def run(self): |
| 246 | + try: |
| 247 | + while 1: |
| 248 | + self._cmd.dispatch() |
| 249 | + except EOFError: |
| 250 | + pass |
| 251 | + |
| 252 | + def handle_execfile(self, arg): |
| 253 | + self._cmd.reply() |
| 254 | + io = StdioRedirector(InputWrapper("stdin", self._cmd), |
| 255 | + OutputWrapper("stdout", self._cmd), |
| 256 | + OutputWrapper("stderr", self._cmd)) |
| 257 | + io.redirect() |
| 258 | + execfile(arg, {'__name__':'__main__'}) |
| 259 | + io.restore() |
| 260 | + self._cmd.send("terminated") |
| 261 | + |
| 262 | + def handle_quit(self, arg): |
| 263 | + self._cmd.reply() |
| 264 | + self._cmd.close() |
| 265 | + |
| 266 | +def startRemoteInterp(id): |
| 267 | + import os |
| 268 | + # UNIX domain sockets are simpler for starters |
| 269 | + sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) |
| 270 | + sock.bind("/var/tmp/ri.%s" % id) |
| 271 | + try: |
| 272 | + sock.listen(1) |
| 273 | + cli, addr = sock.accept() |
| 274 | + rinterp = RemoteInterp(cli) |
| 275 | + rinterp.run() |
| 276 | + finally: |
| 277 | + os.unlink("/var/tmp/ri.%s" % id) |
| 278 | + |
| 279 | +class RIClient: |
| 280 | + """Client of the remote interpreter""" |
| 281 | + def __init__(self, sock): |
| 282 | + self._sock = SocketProtocol(sock) |
| 283 | + self._cmd = CommandProtocol(self._sock) |
| 284 | + self._cmd.registerHandler(self) |
| 285 | + |
| 286 | + def execfile(self, file): |
| 287 | + self._cmd.send("execfile", file) |
| 288 | + |
| 289 | + def run(self): |
| 290 | + try: |
| 291 | + while 1: |
| 292 | + self._cmd.dispatch() |
| 293 | + except EOFError: |
| 294 | + pass |
| 295 | + |
| 296 | + def handle_stdout(self, buf): |
| 297 | + sys.stdout.write(buf) |
| 298 | +## sys.stdout.flush() |
| 299 | + |
| 300 | + def handle_stderr(self, buf): |
| 301 | + sys.stderr.write(buf) |
| 302 | + |
| 303 | + def handle_stdin(self, arg): |
| 304 | + if arg == "readline": |
| 305 | + return sys.stdin.readline() |
| 306 | + i = arg.find(",") + 1 |
| 307 | + bytes = int(arg[i:]) |
| 308 | + if bytes == 0: |
| 309 | + return sys.stdin.read() |
| 310 | + else: |
| 311 | + return sys.stdin.read(bytes) |
| 312 | + |
| 313 | + def handle_terminated(self, arg): |
| 314 | + self._cmd.reply() |
| 315 | + self._cmd.send("quit") |
| 316 | + self._cmd.close() |
| 317 | + |
| 318 | +def riExec(id, file): |
| 319 | + sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) |
| 320 | + sock.connect("/var/tmp/ri.%s" % id) |
| 321 | + cli = RIClient(sock) |
| 322 | + cli.execfile(file) |
| 323 | + cli.run() |
| 324 | + |
| 325 | +if __name__ == "__main__": |
| 326 | + import sys |
| 327 | + import getopt |
| 328 | + |
| 329 | + SERVER = 1 |
| 330 | + opts, args = getopt.getopt(sys.argv[1:], 'cv') |
| 331 | + for o, v in opts: |
| 332 | + if o == '-c': |
| 333 | + SERVER = 0 |
| 334 | + elif o == '-v': |
| 335 | + VERBOSE = sys.stderr |
| 336 | + id = args[0] |
| 337 | + |
| 338 | + if SERVER: |
| 339 | + startRemoteInterp(id) |
| 340 | + else: |
| 341 | + file = args[1] |
| 342 | + riExec(id, file) |
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