Files
repertory/support/include/utils/ttl_cache.hpp
2025-08-12 18:28:15 -05:00

101 lines
2.4 KiB
C++

#ifndef REPERTORY_INCLUDE_UTILS_TTL_CACHE_HPP_
#define REPERTORY_INCLUDE_UTILS_TTL_CACHE_HPP_
#include "utils/config.hpp"
namespace repertory::utils {
template <typename data_t, template <typename> class atomic_t = std::atomic>
class ttl_cache final {
public:
using clock = std::chrono::steady_clock;
using duration = std::chrono::milliseconds;
using entry_t = atomic_t<data_t>;
using entry_ptr_t = std::shared_ptr<entry_t>;
static constexpr const auto default_expiration{duration(60000U)};
private:
struct entry final {
entry_ptr_t data;
clock::time_point expires_at;
};
public:
ttl_cache(duration ttl = default_expiration) : ttl_{ttl} {}
private:
duration ttl_;
private:
mutable std::mutex mutex_;
std::unordered_map<std::string, entry> entries_;
public:
void clear() {
mutex_lock lock(mutex_);
entries_.clear();
}
void erase(const std::string &api_path) {
mutex_lock lock(mutex_);
entries_.erase(api_path);
}
[[nodiscard]] auto contains(const std::string &api_path) -> bool {
mutex_lock lock(mutex_);
return entries_.contains(api_path);
}
[[nodiscard]] auto get(const std::string &api_path) -> entry_ptr_t {
mutex_lock lock(mutex_);
auto iter = entries_.find(api_path);
if (iter == entries_.end()) {
return nullptr;
}
iter->second.expires_at = clock::now() + ttl_;
return iter->second.data;
}
void purge_expired() {
mutex_lock lock(mutex_);
auto now = clock::now();
for (auto iter = entries_.begin(); iter != entries_.end();) {
if (iter->second.expires_at <= now) {
iter = entries_.erase(iter);
continue;
}
++iter;
}
}
[[nodiscard]] auto get_ttl() const -> duration {
mutex_lock lock(mutex_);
return ttl_;
}
void set(const std::string &api_path, const data_t &data) {
mutex_lock lock(mutex_);
if (entries_.contains(api_path)) {
auto &entry = entries_.at(api_path);
entry.data->store(data);
entry.expires_at = clock::now() + ttl_;
return;
}
entries_.emplace(api_path, entry{
.data = std::make_shared<entry_t>(data),
.expires_at = clock::now() + ttl_,
});
}
void set_ttl(duration ttl) {
mutex_lock lock(mutex_);
ttl_ = ttl;
}
};
} // namespace repertory::utils
#endif // REPERTORY_INCLUDE_UTILS_TTL_CACHE_HPP_