mock_task.py revision 25cdf79e17a73858ffa28db8a5b387210fea9e25 
1# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5"""This module defines the common mock tasks used by various unit tests.
6
7Part of the Chrome build flags optimization.
8"""
9
10__author__ = 'yuhenglong@google.com (Yuheng Long)'
11
12# Pick an integer at random.
13POISONPILL = 975
14
15
16class MockTask(object):
17  """This class emulates an actual task.
18
19  It does not do the actual work, but simply returns the result as given when
20  this task is constructed.
21  """
22
23  def __init__(self, stage, identifier, cost=0):
24    """Set up the results for this task.
25
26    Args:
27      stage: the stage of this test is in.
28      identifier: the identifier of this task.
29      cost: the mock cost of this task.
30
31      The _cost field stored the cost. Once this task is performed, i.e., by
32      calling the work method or by setting the result from other task, the
33      _cost field will have this cost. The stage field verifies that the module
34      being tested and the unitest are in the same stage. If the unitest does
35      not care about cost of this task, the cost parameter should be leaved
36      blank.
37    """
38
39    self._identifier = identifier
40    self._cost = cost
41    self._stage = stage
42
43    # Indicate that this method has not been performed yet.
44    self._performed = False
45
46  def __eq__(self, other):
47    if isinstance(other, MockTask):
48      return (self._identifier == other.GetIdentifier(self._stage) and
49              self._cost == other.GetResult(self._stage))
50    return False
51
52  def GetIdentifier(self, stage):
53    assert stage == self._stage
54    return self._identifier
55
56  def SetResult(self, stage, cost):
57    assert stage == self._stage
58    self._cost = cost
59    self._performed = True
60
61  def Work(self, stage):
62    assert stage == self._stage
63    self._performed = True
64
65  def GetResult(self, stage):
66    assert stage == self._stage
67    return self._cost
68
69  def Done(self, stage):
70    """Indicates whether the task has been performed."""
71
72    assert stage == self._stage
73    return self._performed
74
75  def LogSteeringCost(self):
76    pass
77
78
79class IdentifierMockTask(MockTask):
80  """This class defines the mock task that does not consider the cost.
81
82  The task instances will be inserted into a set. Therefore the hash and the
83  equal methods are overridden. The unittests that compares identities of the
84  tasks for equality can use this mock task instead of the base mock tack.
85  """
86
87  def __hash__(self):
88    return self._identifier
89
90  def __eq__(self, other):
91    if isinstance(other, MockTask):
92      return self._identifier == other.GetIdentifier(self._stage)
93    return False
94