PHPデータキャッシュの有効期限戦略と更新メカニズムの分析

// 设置缓存数据
$cacheKey = "user:1";
$userData = array("id" => 1, "name" => "John");
$expiryTime = 3600; // 1小时
$memcached = new Memcached();
$memcached->addServer("127.0.0.1", 11211);
$memcached->set($cacheKey, $userData, time() + $expiryTime);

// 获取缓存数据
$data = $memcached->get($cacheKey);
if (!$data) {
    // 缓存数据已过期，重新获取最新数据
    $data = fetchDataFromDatabase();
    $memcached->set($cacheKey, $data, time() + $expiryTime);
}
echo $data["name"];

// 设置缓存数据
$cacheKey = "product:1";
$productData = array("id" => 1, "name" => "iPhone X");
$redis = new Redis();
$redis->connect("127.0.0.1", 6379);
$redis->hMSet($cacheKey, $productData);

// 获取缓存数据
$redis->hIncrBy($cacheKey, "visitCount", 1);
$data = $redis->hGetAll($cacheKey);

if (!$data || $data["visitCount"] < 1000) {
    // 缓存数据已过期或访问次数较低，重新获取最新数据
    $data = fetchDataFromDatabase();
    $data["visitCount"] = 0;
    $redis->hMSet($cacheKey, $data);
}
echo $data["name"];

// 数据发生变化
updateDataInDatabase();

// 利用命令行工具更新缓存
exec("php cache_update.php");

<?php
$cacheKey = "product:1";
$productData = fetchDataFromDatabase();
$redis = new Redis();
$redis->connect("127.0.0.1", 6379);
$redis->hMSet($cacheKey, $productData);
?>

// 查询缓存数据
$cacheKey = "user:1";
$memcached = new Memcached();
$memcached->addServer("127.0.0.1", 11211);
$data = $memcached->get($cacheKey);

if ($data) {
    echo $data["name"];
} else {
    // 缓存数据已过期，重新获取最新数据
    $data = fetchDataFromDatabase();
    $memcached->set($cacheKey, $data);
    echo $data["name"];
}