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
|
#include "ring_buffer.h"
#include <gtest/gtest.h>
#include <algorithm>
#include <cassert>
#include <vector>
namespace {
template <typename T>
class TypedRingBuffer;
template <typename T>
class TypedRingBuffer<T *> {
public:
explicit TypedRingBuffer(int size)
: rb_(rb_new(size))
{
}
~TypedRingBuffer() { rb_kill(rb_); }
TypedRingBuffer(TypedRingBuffer const &) = delete;
bool full() const { return rb_full(rb_); }
bool empty() const { return rb_empty(rb_); }
T *write(T *p) { return static_cast<T *>(rb_write(rb_, p)); }
bool read(T **p)
{
void *vp;
bool res = rb_read(rb_, &vp);
*p = static_cast<T *>(vp);
return res;
}
uint16_t size() const { return rb_size(rb_); }
uint16_t data(T **dest) const
{
std::vector<void *> vdest(size());
uint16_t res = rb_data(rb_, vdest.data());
for (uint16_t i = 0; i < size(); i++) {
dest[i] = static_cast<T *>(vdest.at(i));
}
return res;
}
bool contains(T *p) const
{
std::vector<T *> elts(size());
data(elts.data());
return std::find(elts.begin(), elts.end(), p) != elts.end();
}
bool ok() const { return rb_ != nullptr; }
private:
RingBuffer *rb_;
};
TEST(RingBuffer, EmptyBufferReportsEmpty)
{
TypedRingBuffer<int *> rb(10);
ASSERT_TRUE(rb.ok());
EXPECT_TRUE(rb.empty());
}
TEST(RingBuffer, EmptyBufferReportsNotFull)
{
TypedRingBuffer<int *> rb(10);
ASSERT_TRUE(rb.ok());
EXPECT_FALSE(rb.full());
}
TEST(RingBuffer, ZeroSizedRingBufferIsBothEmptyAndFull)
{
TypedRingBuffer<int *> rb(0);
ASSERT_TRUE(rb.ok());
EXPECT_TRUE(rb.empty());
EXPECT_TRUE(rb.full());
}
TEST(RingBuffer, WritingMakesBufferNotEmpty)
{
TypedRingBuffer<int *> rb(2);
ASSERT_TRUE(rb.ok());
int value0 = 123;
rb.write(&value0);
EXPECT_FALSE(rb.empty());
}
TEST(RingBuffer, WritingOneElementMakesBufferNotFull)
{
TypedRingBuffer<int *> rb(2);
ASSERT_TRUE(rb.ok());
int value0 = 123;
rb.write(&value0);
EXPECT_FALSE(rb.full());
}
TEST(RingBuffer, WritingAllElementsMakesBufferFull)
{
TypedRingBuffer<int *> rb(2);
ASSERT_TRUE(rb.ok());
int value0 = 123;
int value1 = 231;
rb.write(&value0);
rb.write(&value1);
EXPECT_TRUE(rb.full());
}
TEST(RingBuffer, ReadingElementFromFullBufferMakesItNotFull)
{
TypedRingBuffer<int *> rb(2);
ASSERT_TRUE(rb.ok());
int value0 = 123;
int value1 = 231;
rb.write(&value0);
rb.write(&value1);
EXPECT_TRUE(rb.full());
int *retrieved;
// Reading deletes the element.
EXPECT_TRUE(rb.read(&retrieved));
EXPECT_FALSE(rb.full());
}
TEST(RingBuffer, ZeroSizeBufferCanBeWrittenToOnce)
{
TypedRingBuffer<int *> rb(0);
ASSERT_TRUE(rb.ok());
int value0 = 123;
// Strange behaviour: we can write one element to a 0-size buffer.
EXPECT_EQ(nullptr, rb.write(&value0));
EXPECT_EQ(&value0, rb.write(&value0));
int *retrieved = nullptr;
// But then we can't read it.
EXPECT_FALSE(rb.read(&retrieved));
EXPECT_EQ(nullptr, retrieved);
}
TEST(RingBuffer, ReadingFromEmptyBufferFails)
{
TypedRingBuffer<int *> rb(2);
ASSERT_TRUE(rb.ok());
int *retrieved;
EXPECT_FALSE(rb.read(&retrieved));
}
TEST(RingBuffer, WritingToBufferWhenFullOverwritesBeginning)
{
TypedRingBuffer<int *> rb(2);
ASSERT_TRUE(rb.ok());
int value0 = 123;
int value1 = 231;
int value2 = 312;
int value3 = 432;
EXPECT_EQ(nullptr, rb.write(&value0));
EXPECT_EQ(nullptr, rb.write(&value1));
EXPECT_TRUE(rb.contains(&value0));
EXPECT_TRUE(rb.contains(&value1));
// Adding another element evicts the first element.
EXPECT_EQ(&value0, rb.write(&value2));
EXPECT_FALSE(rb.contains(&value0));
EXPECT_TRUE(rb.contains(&value2));
// Adding another evicts the second.
EXPECT_EQ(&value1, rb.write(&value3));
EXPECT_FALSE(rb.contains(&value1));
EXPECT_TRUE(rb.contains(&value3));
}
TEST(RingBuffer, SizeIsNumberOfElementsInBuffer)
{
TypedRingBuffer<int *> rb(10);
ASSERT_TRUE(rb.ok());
int value0 = 123;
EXPECT_EQ(rb.size(), 0);
rb.write(&value0);
EXPECT_EQ(rb.size(), 1);
rb.write(&value0);
EXPECT_EQ(rb.size(), 2);
rb.write(&value0);
EXPECT_EQ(rb.size(), 3);
rb.write(&value0);
EXPECT_EQ(rb.size(), 4);
int *retrieved;
rb.read(&retrieved);
EXPECT_EQ(rb.size(), 3);
rb.read(&retrieved);
EXPECT_EQ(rb.size(), 2);
rb.read(&retrieved);
EXPECT_EQ(rb.size(), 1);
rb.read(&retrieved);
EXPECT_EQ(rb.size(), 0);
}
TEST(RingBuffer, SizeIsLimitedByMaxSize)
{
TypedRingBuffer<int *> rb(4);
ASSERT_TRUE(rb.ok());
int value0 = 123;
rb.write(&value0);
rb.write(&value0);
rb.write(&value0);
rb.write(&value0);
EXPECT_EQ(rb.size(), 4);
// Add one more.
rb.write(&value0);
// Still size is 4.
EXPECT_EQ(rb.size(), 4);
}
} // namespace
|
