Test Failed
Pull Request — master (#96)
by Jose
02:05
created

build.storehouse.StoreHouse._create_box_callback()   A

Complexity

Conditions 2

Size

Total Lines 7
Code Lines 4

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
cc 2
eloc 4
nop 4
dl 0
loc 7
rs 10
c 0
b 0
f 0
1
"""Module to handle the storehouse."""
2
import time
3
4
from kytos.core import log
5
from kytos.core.events import KytosEvent
6
from napps.kytos.flow_manager import settings
7
8
DEFAULT_WAIT_PERSISTENCE_BOX_TIMER = 0.1
9
10
11
class StoreHouse:
12
    """Class to handle storehouse."""
13
14
    @classmethod
15
    def __new__(cls, *args, **kwargs):
16
        # pylint: disable=unused-argument
17
        """Make this class a Singleton."""
18
        instance = cls.__dict__.get("__instance__")
19
        if instance is not None:
20
            return instance
21
        cls.__instance__ = instance = object.__new__(cls)
22
        return instance
23
24
    def __init__(self, controller):
25
        """Create a storehouse client instance."""
26
        self.controller = controller
27
        self.namespace = 'kytos.flow.persistence'
28
        self.wait_persistence_box = getattr(settings,
29
                                            'WAIT_PERSISTENCE_BOX_TIMER',
30
                                            DEFAULT_WAIT_PERSISTENCE_BOX_TIMER)
31
32
        if 'box' not in self.__dict__:
33
            self.box = None
34
        self.list_stored_boxes()
35
36
    def get_data(self):
37
        """Return the persistence box data."""
38
        # Wait retrieve or create box in storehouse
39
        while not self.box:
40
            time.sleep(self.wait_persistence_box)
41
        return self.box.data
42
43
    def create_box(self):
44
        """Create a persistence box to store administrative changes."""
45
        content = {'namespace': self.namespace,
46
                   'callback': self._create_box_callback,
47
                   'data': {}}
48
        event = KytosEvent(name='kytos.storehouse.create', content=content)
49
        self.controller.buffers.app.put(event)
50
51
    def _create_box_callback(self, _event, data, error):
52
        """Execute the callback to handle create_box."""
53
        if error:
54
            log.error(f'Can\'t create persistence'
55
                      f'box with namespace {self.namespace}')
56
57
        self.box = data
58
59
    def list_stored_boxes(self):
60
        """List all persistence box stored in storehouse."""
61
        name = 'kytos.storehouse.list'
62
        content = {'namespace': self.namespace,
63
                   'callback': self._get_or_create_a_box_from_list_of_boxes}
64
65
        event = KytosEvent(name=name, content=content)
66
        self.controller.buffers.app.put(event)
67
68
    def _get_or_create_a_box_from_list_of_boxes(self, _event, data, _error):
69
        """Create a persistence box or retrieve the stored box."""
70
        if data:
71
            self.get_stored_box(data[0])
72
        else:
73
            self.create_box()
74
75
    def get_stored_box(self, box_id):
76
        """Get persistence box from storehouse."""
77
        content = {'namespace': self.namespace,
78
                   'callback': self._get_box_callback,
79
                   'box_id': box_id,
80
                   'data': {}}
81
        name = 'kytos.storehouse.retrieve'
82
        event = KytosEvent(name=name, content=content)
83
        self.controller.buffers.app.put(event)
84
85
    def _get_box_callback(self, _event, data, error):
86
        """Handle get_box method saving the box or logging with the error."""
87
        if error:
88
            log.error('Persistence box not found.')
89
90
        self.box = data
91
92
    def save_flow(self, flows):
93
        """Save flows in storehouse."""
94
        self.box.data[flows['id']] = flows
95
        content = {'namespace': self.namespace,
96
                   'box_id': self.box.box_id,
97
                   'data': self.box.data,
98
                   'callback': self._save_flow_callback}
99
100
        event = KytosEvent(name='kytos.storehouse.update', content=content)
101
        self.controller.buffers.app.put(event)
102
103
    def _save_flow_callback(self, _event, data, error):
104
        """Display stored flow."""
105
        if error:
106
            log.error(f'Can\'t update persistence box {data.box_id}.')
107
108
        log.info(f'Flow saved in {self.namespace}.{data.box_id}')
109