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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
|
# frozen_string_literal: true
require 'fast_spec_helper'
require 'rspec-benchmark'
RSpec.configure do |config|
config.include RSpec::Benchmark::Matchers
end
RSpec.describe Gitlab::Utils::StrongMemoize do
let(:klass) do
strong_memoize_class = described_class
Struct.new(:value) do
include strong_memoize_class
def self.method_added_list
@method_added_list ||= []
end
def self.method_added(name)
method_added_list << name
end
def method_name
strong_memoize(:method_name) do # rubocop: disable Gitlab/StrongMemoizeAttr
trace << value
value
end
end
def method_name_attr
trace << value
value
end
strong_memoize_attr :method_name_attr
def different_method_name_attr
trace << value
value
end
strong_memoize_attr :different_method_name_attr, :different_member_name_attr
def enabled?
true
end
strong_memoize_attr :enabled?
def method_name_with_args(*args)
strong_memoize_with(:method_name_with_args, args) do
trace << [value, args]
value
end
end
def trace
@trace ||= []
end
protected
def private_method; end
private :private_method
strong_memoize_attr :private_method
public
def protected_method; end
protected :protected_method
strong_memoize_attr :protected_method
private
def public_method; end
public :public_method
strong_memoize_attr :public_method
end
end
subject(:object) { klass.new(value) }
shared_examples 'caching the value' do
it 'only calls the block once' do
value0 = object.send(method_name)
value1 = object.send(method_name)
expect(value0).to eq(value)
expect(value1).to eq(value)
expect(object.trace).to contain_exactly(value)
end
it 'returns and defines the instance variable for the exact value' do
returned_value = object.send(method_name)
memoized_value = object.instance_variable_get(:"@#{member_name}")
expect(returned_value).to eql(value)
expect(memoized_value).to eql(value)
end
end
describe '#strong_memoize' do
[nil, false, true, 'value', 0, [0]].each do |value|
context "with value #{value}" do
let(:value) { value }
let(:method_name) { :method_name }
let(:member_name) { :method_name }
it_behaves_like 'caching the value'
it 'raises exception for invalid type as key' do
expect { object.strong_memoize(10) { 20 } }.to raise_error /Invalid type of '10'/
end
it 'raises exception for invalid characters in key' do
expect { object.strong_memoize(:enabled?) { 20 } }
.to raise_error /is not allowed as an instance variable name/
end
end
end
context "memory allocation", type: :benchmark do
let(:value) { 'aaa' }
before do
object.method_name # warmup
end
[:method_name, "method_name"].each do |argument|
context "for #{argument.class}" do
it 'does allocate exactly one string when fetching value' do
expect do
object.strong_memoize(argument) { 10 }
end.to perform_allocation(1)
end
it 'does allocate exactly one string when storing value' do
object.clear_memoization(:method_name) # clear to force set
expect do
object.strong_memoize(argument) { 10 }
end.to perform_allocation(1)
end
end
end
end
end
describe '#strong_memoize_with' do
[nil, false, true, 'value', 0, [0]].each do |value|
context "with value #{value}" do
let(:value) { value }
it 'only calls the block once' do
value0 = object.method_name_with_args(1)
value1 = object.method_name_with_args(1)
value2 = object.method_name_with_args([2, 3])
value3 = object.method_name_with_args([2, 3])
expect(value0).to eq(value)
expect(value1).to eq(value)
expect(value2).to eq(value)
expect(value3).to eq(value)
expect(object.trace).to contain_exactly([value, [1]], [value, [[2, 3]]])
end
it 'returns and defines the instance variable for the exact value' do
returned_value = object.method_name_with_args(1, 2, 3)
memoized_value = object.instance_variable_get(:@method_name_with_args)
expect(returned_value).to eql(value)
expect(memoized_value).to eql({ [[1, 2, 3]] => value })
end
end
end
end
describe '#strong_memoized?' do
let(:value) { :anything }
subject { object.strong_memoized?(:method_name) }
it 'returns false if the value is uncached' do
is_expected.to be(false)
end
it 'returns true if the value is cached' do
object.method_name
is_expected.to be(true)
end
end
describe '#clear_memoization' do
let(:value) { 'mepmep' }
it 'removes the instance variable' do
object.method_name
object.clear_memoization(:method_name)
expect(object.instance_variable_defined?(:@method_name)).to be(false)
end
end
describe '.strong_memoize_attr' do
[nil, false, true, 'value', 0, [0]].each do |value|
let(:value) { value }
context "memoized after method definition with value #{value}" do
let(:method_name) { :method_name_attr }
let(:member_name) { :method_name_attr }
it_behaves_like 'caching the value'
it 'calls the existing .method_added' do
expect(klass.method_added_list).to include(:method_name_attr)
end
end
context "memoized before method definition with different member name and value #{value}" do
let(:method_name) { :different_method_name_attr }
let(:member_name) { :different_member_name_attr }
it_behaves_like 'caching the value'
it 'calls the existing .method_added' do
expect(klass.method_added_list).to include(:different_method_name_attr)
end
end
context 'with valid method name' do
let(:method_name) { :enabled? }
context 'with invalid member name' do
let(:member_name) { :enabled? }
it 'is invalid' do
expect { object.send(method_name) { value } }.to raise_error /is not allowed as an instance variable name/
end
end
end
end
describe 'method visibility' do
it 'sets private visibility' do
expect(klass.private_instance_methods).to include(:private_method)
expect(klass.protected_instance_methods).not_to include(:private_method)
expect(klass.public_instance_methods).not_to include(:private_method)
end
it 'sets protected visibility' do
expect(klass.private_instance_methods).not_to include(:protected_method)
expect(klass.protected_instance_methods).to include(:protected_method)
expect(klass.public_instance_methods).not_to include(:protected_method)
end
it 'sets public visibility' do
expect(klass.private_instance_methods).not_to include(:public_method)
expect(klass.protected_instance_methods).not_to include(:public_method)
expect(klass.public_instance_methods).to include(:public_method)
end
end
context "when method doesn't exist" do
let(:klass) do
strong_memoize_class = described_class
Struct.new(:value) do
include strong_memoize_class
end
end
subject { klass.strong_memoize_attr(:nonexistent_method) }
it 'fails when strong-memoizing a nonexistent method' do
expect { subject }.to raise_error(NameError, %r{undefined method `nonexistent_method' for class})
end
end
end
end
|