1
|
|
|
"""Utilities functions used in Kytos.""" |
2
|
2 |
|
from concurrent.futures import ThreadPoolExecutor |
3
|
2 |
|
from datetime import datetime, timezone |
4
|
2 |
|
from threading import Thread |
5
|
|
|
|
6
|
2 |
|
from kytos.core.config import KytosConfig |
7
|
|
|
|
8
|
2 |
|
__all__ = ['listen_to', 'now', 'run_on_thread', 'get_time'] |
9
|
|
|
|
10
|
|
|
|
11
|
|
|
# APP_MSG = "[App %s] %s | ID: %02d | R: %02d | P: %02d | F: %s" |
12
|
|
|
|
13
|
|
|
|
14
|
2 |
|
def get_thread_pool_max_workers(): |
15
|
|
|
"""Get the number of thread pool max workers.""" |
16
|
2 |
|
return int(KytosConfig().options["daemon"].thread_pool_max_workers) |
17
|
|
|
|
18
|
|
|
|
19
|
2 |
|
if get_thread_pool_max_workers(): |
20
|
2 |
|
executor = ThreadPoolExecutor(max_workers=get_thread_pool_max_workers()) |
21
|
|
|
|
22
|
|
|
|
23
|
2 |
|
def listen_to(event, *events): |
24
|
|
|
"""Decorate Event Listener methods. |
25
|
|
|
|
26
|
|
|
This decorator was built to be used on NAPPs methods to define which |
27
|
|
|
type of event the method will handle. With this, we will be able to |
28
|
|
|
'schedule' the app/method to receive an event when a new event is |
29
|
|
|
registered on the controller buffers. |
30
|
|
|
By using the run_on_thread decorator, we also guarantee that the method |
31
|
|
|
(handler) will be called from inside a new thread, avoiding this method to |
32
|
|
|
block its caller. |
33
|
|
|
|
34
|
|
|
The decorator will add an attribute to the method called 'events', that |
35
|
|
|
will be a list of the events that the method will handle. |
36
|
|
|
|
37
|
|
|
The event that will be listened to is always a string, but it can represent |
38
|
|
|
a regular expression to match against multiple Event Types. All listened |
39
|
|
|
events are documented in :doc:`/developer/listened_events` section. |
40
|
|
|
|
41
|
|
|
Example of usage: |
42
|
|
|
|
43
|
|
|
.. code-block:: python3 |
44
|
|
|
|
45
|
|
|
class MyAppClass(KytosApp): |
46
|
|
|
@listen_to('kytos/of_core.messages.in') |
47
|
|
|
def my_handler_of_message_in(self, event): |
48
|
|
|
# Do stuff here... |
49
|
|
|
|
50
|
|
|
@listen_to('kytos/of_core.messages.out') |
51
|
|
|
def my_handler_of_message_out(self, event): |
52
|
|
|
# Do stuff here... |
53
|
|
|
|
54
|
|
|
@listen_to('kytos/of_core.messages.in.ofpt_hello', |
55
|
|
|
'kytos/of_core.messages.out.ofpt_hello') |
56
|
|
|
def my_handler_of_hello_messages(self, event): |
57
|
|
|
# Do stuff here... |
58
|
|
|
|
59
|
|
|
@listen_to('kytos/of_core.message.*.hello') |
60
|
|
|
def my_other_handler_of_hello_messages(self, event): |
61
|
|
|
# Do stuff here... |
62
|
|
|
|
63
|
|
|
@listen_to('kytos/of_core.message.*.hello') |
64
|
|
|
def my_handler_of_hello_messages(self, event): |
65
|
|
|
# Do stuff here... |
66
|
|
|
|
67
|
|
|
@listen_to('kytos/of_core.message.*') |
68
|
|
|
def my_stats_handler_of_any_message(self, event): |
69
|
|
|
# Do stuff here... |
70
|
|
|
""" |
71
|
|
|
def thread_decorator(handler): |
72
|
|
|
"""Decorate the handler method. |
73
|
|
|
|
74
|
|
|
Returns: |
75
|
|
|
A method with an `events` attribute (list of events to be listened) |
76
|
|
|
and also decorated to run on a new thread. |
77
|
|
|
|
78
|
|
|
""" |
79
|
|
|
@run_on_thread |
80
|
|
|
def threaded_handler(*args): |
81
|
|
|
"""Decorate the handler to run from a new thread.""" |
82
|
|
|
handler(*args) |
83
|
|
|
|
84
|
|
|
threaded_handler.events = [event] |
85
|
|
|
threaded_handler.events.extend(events) |
86
|
|
|
return threaded_handler |
87
|
|
|
|
88
|
|
|
def thread_pool_decorator(handler): |
89
|
|
|
"""Decorate the handler method. |
90
|
|
|
|
91
|
|
|
Returns: |
92
|
|
|
A method with an `events` attribute (list of events to be listened) |
93
|
|
|
and also decorated to run on in the thread pool |
94
|
|
|
|
95
|
|
|
""" |
96
|
|
|
def inner(*args): |
97
|
|
|
"""Decorate the handler to run in the thread pool.""" |
98
|
|
|
executor.submit(handler, *args) |
|
|
|
|
99
|
|
|
|
100
|
|
|
inner.events = [event] |
101
|
|
|
inner.events.extend(events) |
102
|
|
|
return inner |
103
|
|
|
|
104
|
|
|
if get_thread_pool_max_workers(): |
105
|
|
|
return thread_pool_decorator |
106
|
|
|
return thread_decorator |
107
|
|
|
|
108
|
|
|
|
109
|
2 |
|
def now(tzone=timezone.utc): |
110
|
|
|
"""Return the current datetime (default to UTC). |
111
|
|
|
|
112
|
|
|
Args: |
113
|
|
|
tzone (datetime.timezone): Specific time zone used in datetime. |
114
|
|
|
|
115
|
|
|
Returns: |
116
|
|
|
datetime.datetime.now: Date time with specific time zone. |
117
|
|
|
|
118
|
|
|
""" |
119
|
2 |
|
return datetime.now(tzone) |
120
|
|
|
|
121
|
|
|
|
122
|
2 |
|
def run_on_thread(method): |
123
|
|
|
"""Decorate to run the decorated method inside a new thread. |
124
|
|
|
|
125
|
|
|
Args: |
126
|
|
|
method (function): function used to run as a new thread. |
127
|
|
|
|
128
|
|
|
Returns: |
129
|
|
|
Decorated method that will run inside a new thread. |
130
|
|
|
When the decorated method is called, it will not return the created |
131
|
|
|
thread to the caller. |
132
|
|
|
|
133
|
|
|
""" |
134
|
2 |
|
def threaded_method(*args): |
135
|
|
|
"""Ensure the handler method runs inside a new thread.""" |
136
|
2 |
|
thread = Thread(target=method, args=args) |
137
|
|
|
|
138
|
|
|
# Set daemon mode so that we don't have to wait for these threads |
139
|
|
|
# to finish when exiting Kytos |
140
|
2 |
|
thread.daemon = True |
141
|
2 |
|
thread.start() |
142
|
2 |
|
return threaded_method |
143
|
|
|
|
144
|
|
|
|
145
|
2 |
|
def get_time(data=None): |
146
|
|
|
"""Receive a dictionary or a string and return a datatime instance. |
147
|
|
|
|
148
|
|
|
data = {"year": 2006, |
149
|
|
|
"month": 11, |
150
|
|
|
"day": 21, |
151
|
|
|
"hour": 16, |
152
|
|
|
"minute": 30 , |
153
|
|
|
"second": 00} |
154
|
|
|
|
155
|
|
|
or |
156
|
|
|
|
157
|
|
|
data = "21/11/06 16:30:00" |
158
|
|
|
|
159
|
|
|
2018-04-17T17:13:50Z |
160
|
|
|
|
161
|
|
|
Args: |
162
|
|
|
data (str, dict): python dict or string to be converted to datetime |
163
|
|
|
|
164
|
|
|
Returns: |
165
|
|
|
datetime: datetime instance. |
166
|
|
|
|
167
|
|
|
""" |
168
|
2 |
|
if isinstance(data, str): |
169
|
2 |
|
date = datetime.strptime(data, "%Y-%m-%dT%H:%M:%S") |
170
|
2 |
|
elif isinstance(data, dict): |
171
|
2 |
|
date = datetime(**data) |
172
|
|
|
else: |
173
|
2 |
|
return None |
174
|
|
|
return date.replace(tzinfo=timezone.utc) |
175
|
|
|
|