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#pragma once
#include <atomic>
#include <chrono>
#include <functional>
#include <map>
#include <memory>
#include <string>
#include <vector>
#include "PyUtil.h"
template <class Key, class Value> class Cache {
private:
std::atomic<uint64_t> hits, misses;
protected:
unsigned int capacity;
Cache(unsigned int size = UINT16_MAX) : hits{0}, misses{0}, capacity{size} {};
std::map<Key, Value> content;
std::vector<std::string> allowed_keys = {"osd_map", "pg_dump", "pg_stats"};
void mark_miss() {
misses++;
}
void mark_hit() {
hits++;
}
unsigned int get_misses() { return misses; }
unsigned int get_hits() { return hits; }
void throw_key_not_found(Key key) {
std::stringstream ss;
ss << "Key " << key << " couldn't be found\n";
throw std::out_of_range(ss.str());
}
public:
void insert(Key key, Value value) {
mark_miss();
if (content.size() < capacity) {
content.insert({key, value});
}
}
Value get(Key key, bool count_hit = true) {
if (count_hit) {
mark_hit();
}
return content[key];
}
void erase(Key key) { content.erase(content.find(key)); }
void clear() { content.clear(); }
bool exists(Key key) { return content.find(key) != content.end(); }
std::pair<uint64_t, uint64_t> get_hit_miss_ratio() {
return std::make_pair(hits.load(), misses.load());
}
bool is_cacheable(Key key) {
for (auto k : allowed_keys) {
if (key == k) return true;
}
return false;
}
int size() { return content.size(); }
~Cache(){};
};
using ttl_time_point = std::chrono::time_point<std::chrono::steady_clock>;
template <class Key, class Value>
class TTLCacheBase : public Cache<Key, std::pair<Value, ttl_time_point>> {
private:
uint16_t ttl;
float ttl_spread_ratio;
using value_type = std::pair<Value, ttl_time_point>;
using cache = Cache<Key, value_type>;
protected:
Value get_value(Key key, bool count_hit = true);
ttl_time_point get_value_time_point(Key key);
bool exists(Key key);
bool expired(Key key);
void finish_get(Key key);
void finish_erase(Key key);
void throw_key_not_found(Key key);
public:
TTLCacheBase(uint16_t ttl_ = 0, uint16_t size = UINT16_MAX,
float spread = 0.25)
: Cache<Key, value_type>(size), ttl{ttl_}, ttl_spread_ratio{spread} {}
~TTLCacheBase(){};
void insert(Key key, Value value);
Value get(Key key);
void erase(Key key);
void clear();
uint16_t get_ttl() { return ttl; };
void set_ttl(uint16_t ttl);
};
template <class Key, class Value>
class TTLCache : public TTLCacheBase<Key, Value> {
public:
TTLCache(uint16_t ttl_ = 0, uint16_t size = UINT16_MAX, float spread = 0.25)
: TTLCacheBase<Key, Value>(ttl_, size, spread) {}
~TTLCache(){};
};
template <class Key>
class TTLCache<Key, PyObject*> : public TTLCacheBase<Key, PyObject*> {
public:
TTLCache(uint16_t ttl_ = 0, uint16_t size = UINT16_MAX, float spread = 0.25)
: TTLCacheBase<Key, PyObject*>(ttl_, size, spread) {}
~TTLCache(){};
PyObject* get(Key key);
void erase(Key key);
private:
using ttl_base = TTLCacheBase<Key, PyObject*>;
};
#include "TTLCache.cc"
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