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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
require "amq/bit_set"
# extracted from amqp gem. MK.
RSpec.describe AMQ::BitSet do
#
# Environment
#
let(:nbits) { (1 << 16) - 1 }
#
# Examples
#
describe "#new" do
it "has no bits set at the start" do
bs = AMQ::BitSet.new(128)
0.upto(127) do |i|
expect(bs[i]).to be_falsey
end
end # it
end # describe
describe "#word_index" do
subject do
described_class.new(nbits)
end
it "returns 0 when the word is between 0 and 63" do
expect(subject.word_index(0)).to eq(0)
expect(subject.word_index(63)).to eq(0)
end # it
it "returns 1 when the word is between 64 and 127" do
expect(subject.word_index(64)).to be(1)
expect(subject.word_index(127)).to be(1)
end # it
it "returns 2 when the word is between 128 and another number" do
expect(subject.word_index(128)).to be(2)
end # it
end # describe
describe "#get, #[]" do
describe "when bit at given position is set" do
subject do
o = described_class.new(nbits)
o.set(3)
o
end
it "returns true" do
expect(subject.get(3)).to be_truthy
end # it
end # describe
describe "when bit at given position is off" do
subject do
described_class.new(nbits)
end
it "returns false" do
expect(subject.get(5)).to be_falsey
end # it
end # describe
describe "when index out of range" do
subject do
described_class.new(nbits)
end
it "should raise IndexError for negative index" do
expect { subject.get(-1) }.to raise_error(IndexError)
end # it
it "should raise IndexError for index >= number of bits" do
expect { subject.get(nbits) }.to raise_error(IndexError)
end # it
end # describe
end # describe
describe "#set" do
describe "when bit at given position is set" do
subject do
described_class.new(nbits)
end
it "has no effect" do
subject.set(3)
expect(subject.get(3)).to be_truthy
subject.set(3)
expect(subject[3]).to be_truthy
end # it
end # describe
describe "when bit at given position is off" do
subject do
described_class.new(nbits)
end
it "sets that bit" do
subject.set(3)
expect(subject.get(3)).to be_truthy
subject.set(33)
expect(subject.get(33)).to be_truthy
subject.set(3387)
expect(subject.get(3387)).to be_truthy
end # it
end # describe
describe "when index out of range" do
subject do
described_class.new(nbits)
end
it "should raise IndexError for negative index" do
expect { subject.set(-1) }.to raise_error(IndexError)
end # it
it "should raise IndexError for index >= number of bits" do
expect { subject.set(nbits) }.to raise_error(IndexError)
end # it
end # describe
end # describe
describe "#unset" do
describe "when bit at a given position is set" do
subject do
described_class.new(nbits)
end
it "unsets that bit" do
subject.set(3)
expect(subject.get(3)).to be_truthy
subject.unset(3)
expect(subject.get(3)).to be_falsey
end # it
end # describe
describe "when bit at a given position is off" do
subject do
described_class.new(nbits)
end
it "has no effect" do
expect(subject.get(3)).to be_falsey
subject.unset(3)
expect(subject.get(3)).to be_falsey
end # it
end # describe
describe "when index out of range" do
subject do
described_class.new(nbits)
end
it "should raise IndexError for negative index" do
expect { subject.unset(-1) }.to raise_error(IndexError)
end # it
it "should raise IndexError for index >= number of bits" do
expect { subject.unset(nbits) }.to raise_error(IndexError)
end # it
end # describe
end # describe
describe "#clear" do
subject do
described_class.new(nbits)
end
it "clears all bits" do
subject.set(3)
expect(subject.get(3)).to be_truthy
subject.set(7668)
expect(subject.get(7668)).to be_truthy
subject.clear
expect(subject.get(3)).to be_falsey
expect(subject.get(7668)).to be_falsey
end # it
end # describe
describe "#number_of_trailing_ones" do
it "calculates them" do
expect(described_class.number_of_trailing_ones(0)).to eq(0)
expect(described_class.number_of_trailing_ones(1)).to eq(1)
expect(described_class.number_of_trailing_ones(2)).to eq(0)
expect(described_class.number_of_trailing_ones(3)).to eq(2)
expect(described_class.number_of_trailing_ones(4)).to eq(0)
end # it
end # describe
describe '#next_clear_bit' do
subject do
described_class.new(255)
end
it "returns sequential values when none have been returned" do
expect(subject.next_clear_bit).to eq(0)
subject.set(0)
expect(subject.next_clear_bit).to eq(1)
subject.set(1)
expect(subject.next_clear_bit).to eq(2)
subject.unset(1)
expect(subject.next_clear_bit).to eq(1)
end # it
it "returns the same number as long as nothing is set" do
expect(subject.next_clear_bit).to eq(0)
expect(subject.next_clear_bit).to eq(0)
end # it
it "handles more than 128 bits" do
0.upto(254) do |i|
subject.set(i)
expect(subject.next_clear_bit).to eq(i + 1)
end
subject.unset(254)
expect(subject.get(254)).to be_falsey
end # it
end # describe
end
|
