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
|
/*
* Copyright 2010-2016, Tarantool AUTHORS, please see AUTHORS file.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "trivia/util.h"
#include "memory.h"
#include "histogram.h"
#include <assert.h>
struct histogram *
histogram_new(const int64_t *buckets, size_t n_buckets)
{
struct histogram *hist;
assert(n_buckets > 0);
for (size_t i = 1; i < n_buckets; i++)
assert(buckets[i - 1] < buckets[i]);
hist = malloc(sizeof(*hist) + n_buckets * sizeof(*hist->buckets));
if (hist == NULL)
return NULL;
hist->max = buckets[n_buckets - 1];
hist->total = 0;
hist->n_buckets = n_buckets;
for (size_t i = 0; i < n_buckets; i++) {
hist->buckets[i].count = 0;
hist->buckets[i].max = buckets[i];
}
return hist;
}
void
histogram_delete(struct histogram *hist)
{
free(hist);
}
void
histogram_reset(struct histogram *hist)
{
hist->total = 0;
for (size_t i = 0; i < hist->n_buckets; i++)
hist->buckets[i].count = 0;
hist->max = hist->buckets[hist->n_buckets - 1].max;
}
static struct histogram_bucket *
histogram_lookup_bucket(struct histogram *hist, int64_t val)
{
size_t begin, end, mid;
struct histogram_bucket *bucket;
begin = 0;
end = hist->n_buckets - 1;
while (1) {
if (begin == end) {
bucket = &hist->buckets[begin];
if (val > bucket->max)
bucket = &hist->buckets[end];
break;
} else {
mid = begin / 2 + end / 2;
bucket = &hist->buckets[mid];
}
if (val > hist->buckets[mid].max)
begin = mid + 1;
else
end = mid;
};
if (val <= bucket->max)
return bucket;
return NULL;
}
void
histogram_collect(struct histogram *hist, int64_t val)
{
struct histogram_bucket *bucket;
bucket = histogram_lookup_bucket(hist, val);
if (bucket != NULL)
bucket->count++;
if (hist->max < val)
hist->max = val;
hist->total++;
}
void
histogram_discard(struct histogram *hist, int64_t val)
{
struct histogram_bucket *bucket;
bucket = histogram_lookup_bucket(hist, val);
if (bucket != NULL) {
assert(bucket->count > 0);
bucket->count--;
}
assert(hist->total > 0);
hist->total--;
}
int64_t
histogram_percentile(struct histogram *hist, int pct)
{
size_t count = 0;
for (size_t i = 0; i < hist->n_buckets; i++) {
struct histogram_bucket *bucket = &hist->buckets[i];
count += bucket->count;
if (count * 100 > hist->total * pct)
return bucket->max;
}
return hist->max;
}
int64_t
histogram_percentile_lower(struct histogram *hist, int pct)
{
size_t count = 0;
for (size_t i = 0; i < hist->n_buckets; i++) {
count += hist->buckets[i].count;
if (count * 100 > hist->total * pct)
return hist->buckets[i > 0 ? i - 1 : 0].max;
}
return hist->max;
}
int
histogram_snprint(char *buf, int size, struct histogram *hist)
{
int total = 0;
bool first = true;
for (size_t i = 0; i < hist->n_buckets; i++) {
int64_t count = hist->buckets[i].count;
if (count == 0)
continue;
int64_t min = (i > 0) ? hist->buckets[i - 1].max + 1 : 0;
int64_t max = hist->buckets[i].max;
if (!first)
SNPRINT(total, snprintf, buf, size, " ");
SNPRINT(total, snprintf, buf, size, "[%"PRIi64, min);
if (max != min)
SNPRINT(total, snprintf, buf, size, "-%"PRIi64, max);
SNPRINT(total, snprintf, buf, size, "]:%"PRIi64, count);
first = false;
}
return total;
}
|