1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
"""Abstract Transport class."""
__all__ = ['ReadTransport', 'WriteTransport', 'Transport']
class BaseTransport:
"""Base ABC for transports."""
def __init__(self, extra=None):
if extra is None:
extra = {}
self._extra = extra
def get_extra_info(self, name, default=None):
"""Get optional transport information."""
return self._extra.get(name, default)
def close(self):
"""Close the transport.
Buffered data will be flushed asynchronously. No more data
will be received. After all buffered data is flushed, the
protocol's connection_lost() method will (eventually) called
with None as its argument.
"""
raise NotImplementedError
class ReadTransport(BaseTransport):
"""ABC for read-only transports."""
def pause_reading(self):
"""Pause the receiving end.
No data will be passed to the protocol's data_received()
method until resume_reading() is called.
"""
raise NotImplementedError
def resume_reading(self):
"""Resume the receiving end.
Data received will once again be passed to the protocol's
data_received() method.
"""
raise NotImplementedError
class WriteTransport(BaseTransport):
"""ABC for write-only transports."""
def set_write_buffer_limits(self, high=None, low=None):
"""Set the high- and low-water limits for write flow control.
These two values control when to call the protocol's
pause_writing() and resume_writing() methods. If specified,
the low-water limit must be less than or equal to the
high-water limit. Neither value can be negative.
The defaults are implementation-specific. If only the
high-water limit is given, the low-water limit defaults to a
implementation-specific value less than or equal to the
high-water limit. Setting high to zero forces low to zero as
well, and causes pause_writing() to be called whenever the
buffer becomes non-empty. Setting low to zero causes
resume_writing() to be called only once the buffer is empty.
Use of zero for either limit is generally sub-optimal as it
reduces opportunities for doing I/O and computation
concurrently.
"""
raise NotImplementedError
def get_write_buffer_size(self):
"""Return the current size of the write buffer."""
raise NotImplementedError
def write(self, data):
"""Write some data bytes to the transport.
This does not block; it buffers the data and arranges for it
to be sent out asynchronously.
"""
raise NotImplementedError
def writelines(self, list_of_data):
"""Write a list (or any iterable) of data bytes to the transport.
The default implementation just calls write() for each item in
the list/iterable.
"""
for data in list_of_data:
self.write(data)
def write_eof(self):
"""Close the write end after flushing buffered data.
(This is like typing ^D into a UNIX program reading from stdin.)
Data may still be received.
"""
raise NotImplementedError
def can_write_eof(self):
"""Return True if this transport supports write_eof(), False if not."""
raise NotImplementedError
def abort(self):
"""Closs the transport immediately.
Buffered data will be lost. No more data will be received.
The protocol's connection_lost() method will (eventually) be
called with None as its argument.
"""
raise NotImplementedError
class Transport(ReadTransport, WriteTransport):
"""ABC representing a bidirectional transport.
There may be several implementations, but typically, the user does
not implement new transports; rather, the platform provides some
useful transports that are implemented using the platform's best
practices.
The user never instantiates a transport directly; they call a
utility function, passing it a protocol factory and other
information necessary to create the transport and protocol. (E.g.
EventLoop.create_connection() or EventLoop.create_server().)
The utility function will asynchronously create a transport and a
protocol and hook them up by calling the protocol's
connection_made() method, passing it the transport.
The implementation here raises NotImplemented for every method
except writelines(), which calls write() in a loop.
"""
class DatagramTransport(BaseTransport):
"""ABC for datagram (UDP) transports."""
def sendto(self, data, addr=None):
"""Send data to the transport.
This does not block; it buffers the data and arranges for it
to be sent out asynchronously.
addr is target socket address.
If addr is None use target address pointed on transport creation.
"""
raise NotImplementedError
def abort(self):
"""Close the transport immediately.
Buffered data will be lost. No more data will be received.
The protocol's connection_lost() method will (eventually) be
called with None as its argument.
"""
raise NotImplementedError
class SubprocessTransport(BaseTransport):
def get_pid(self):
"""Get subprocess id."""
raise NotImplementedError
def get_returncode(self):
"""Get subprocess returncode.
See also
http://docs.python.org/3/library/subprocess#subprocess.Popen.returncode
"""
raise NotImplementedError
def get_pipe_transport(self, fd):
"""Get transport for pipe with number fd."""
raise NotImplementedError
def send_signal(self, signal):
"""Send signal to subprocess.
See also:
docs.python.org/3/library/subprocess#subprocess.Popen.send_signal
"""
raise NotImplementedError
def terminate(self):
"""Stop the subprocess.
Alias for close() method.
On Posix OSs the method sends SIGTERM to the subprocess.
On Windows the Win32 API function TerminateProcess()
is called to stop the subprocess.
See also:
http://docs.python.org/3/library/subprocess#subprocess.Popen.terminate
"""
raise NotImplementedError
def kill(self):
"""Kill the subprocess.
On Posix OSs the function sends SIGKILL to the subprocess.
On Windows kill() is an alias for terminate().
See also:
http://docs.python.org/3/library/subprocess#subprocess.Popen.kill
"""
raise NotImplementedError
|
