/**

*

* @file 03_lru_cache_eviction.cpp

* @author Gaspard Kirira

*

* Copyright 2025, Gaspard Kirira.

* All rights reserved.

* https://github.com/vixcpp/vix

*

* Use of this source code is governed by a MIT license

* that can be found in the License file.

*

* Vix.cpp

*

*/

// Run:

// vix run examples/cache/03_lru_cache_eviction.cpp

#include <chrono>

#include <iostream>

#include <memory>

#include <vix/cache/Cache.hpp>

#include <vix/cache/CacheContext.hpp>

#include <vix/cache/CacheEntry.hpp>

#include <vix/cache/CachePolicy.hpp>

#include <vix/cache/LruMemoryStore.hpp>

static std::int64_t now_ms()

{

using namespace std::chrono;

return duration_cast<milliseconds>(

steady_clock::now().time_since_epoch())

.count();

}

static vix::cache::CacheEntry make_entry(

const std::string &body,

std::int64_t t)

{

vix::cache::CacheEntry e;

e.status = 200;

e.body = body;

e.created_at_ms = t;

return e;

}

int main()

{

using namespace vix::cache;

auto store = std::make_shared<LruMemoryStore>(

LruMemoryStore::Config{.max_entries = 2});

CachePolicy policy;

policy.ttl_ms = 10'000;

Cache cache(policy, store);

const auto t0 = now_ms();

cache.put("k1", make_entry("A", t0));

cache.put("k2", make_entry("B", t0));

// Touch k1 -> k2 becomes least recently used

(void)cache.get("k1", t0 + 1, CacheContext::Online());

cache.put("k3", make_entry("C", t0 + 2));

auto k1 = cache.get("k1", t0 + 3, CacheContext::Online());

auto k2 = cache.get("k2", t0 + 3, CacheContext::Online());

auto k3 = cache.get("k3", t0 + 3, CacheContext::Online());

std::cout << "k1: " << (k1 ? "present" : "missing") << "\n";

std::cout << "k2: " << (k2 ? "present" : "missing") << "\n";

std::cout << "k3: " << (k3 ? "present" : "missing") << "\n";

return 0;

}