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
|
#include "TTLCache.h"
#include <chrono>
#include <functional>
#include <string>
#include "PyUtil.h"
template <class Key, class Value>
void TTLCacheBase<Key, Value>::insert(Key key, Value value) {
auto now = std::chrono::steady_clock::now();
if (!ttl) return;
int16_t random_ttl_offset =
ttl * ttl_spread_ratio * (2l * rand() / float(RAND_MAX) - 1);
// in order not to have spikes of misses we increase or decrease by 25% of
// the ttl
int16_t spreaded_ttl = ttl + random_ttl_offset;
auto expiration_date = now + std::chrono::seconds(spreaded_ttl);
cache::insert(key, {value, expiration_date});
}
template <class Key, class Value> Value TTLCacheBase<Key, Value>::get(Key key) {
if (!exists(key)) {
throw_key_not_found(key);
}
if (expired(key)) {
erase(key);
throw_key_not_found(key);
}
Value value = {get_value(key)};
return value;
}
template <class Key> PyObject* TTLCache<Key, PyObject*>::get(Key key) {
if (!this->exists(key)) {
this->throw_key_not_found(key);
}
if (this->expired(key)) {
this->erase(key);
this->throw_key_not_found(key);
}
PyObject* cached_value = this->get_value(key);
Py_INCREF(cached_value);
return cached_value;
}
template <class Key, class Value>
void TTLCacheBase<Key, Value>::erase(Key key) {
cache::erase(key);
}
template <class Key> void TTLCache<Key, PyObject*>::erase(Key key) {
Py_DECREF(this->get_value(key, false));
ttl_base::erase(key);
}
template <class Key, class Value>
bool TTLCacheBase<Key, Value>::expired(Key key) {
ttl_time_point expiration_date = get_value_time_point(key);
auto now = std::chrono::steady_clock::now();
if (now >= expiration_date) {
return true;
} else {
return false;
}
}
template <class Key, class Value> void TTLCacheBase<Key, Value>::clear() {
cache::clear();
}
template <class Key, class Value>
Value TTLCacheBase<Key, Value>::get_value(Key key, bool count_hit) {
value_type stored_value = cache::get(key, count_hit);
Value value = std::get<0>(stored_value);
return value;
}
template <class Key, class Value>
ttl_time_point TTLCacheBase<Key, Value>::get_value_time_point(Key key) {
value_type stored_value = cache::get(key, false);
ttl_time_point tp = std::get<1>(stored_value);
return tp;
}
template <class Key, class Value>
void TTLCacheBase<Key, Value>::set_ttl(uint16_t ttl) {
this->ttl = ttl;
}
template <class Key, class Value>
bool TTLCacheBase<Key, Value>::exists(Key key) {
return cache::exists(key);
}
template <class Key, class Value>
void TTLCacheBase<Key, Value>::throw_key_not_found(Key key) {
cache::throw_key_not_found(key);
}
|
