PHP代码怎么处理缓存_ PHP缓存机制配置与数据存储步骤

<?php
// 文件缓存示例
class FileCache {
    private $cacheDir;
    private $ttl; // Time To Live in seconds

    public function __construct($cacheDir, $ttl = 3600) {
        $this->cacheDir = rtrim($cacheDir, '/') . '/';
        $this->ttl = $ttl;
        if (!is_dir($this->cacheDir)) {
            mkdir($this->cacheDir, 0777, true);
        }
    }

    private function getCacheFilePath($key) {
        return $this->cacheDir . md5($key) . '.cache';
    }

    public function set($key, $value) {
        $data = [
            'expires' => time() + $this->ttl,
            'value' => $value
        ];
        return file_put_contents($this->getCacheFilePath($key), serialize($data));
    }

    public function get($key) {
        $filePath = $this->getCacheFilePath($key);
        if (file_exists($filePath)) {
            $content = file_get_contents($filePath);
            $data = unserialize($content);
            if ($data['expires'] > time()) {
                return $data['value'];
            } else {
                // Cache expired, delete it
                unlink($filePath);
            }
        }
        return false; // Cache miss or expired
    }

    public function delete($key) {
        $filePath = $this->getCacheFilePath($key);
        if (file_exists($filePath)) {
            return unlink($filePath);
        }
        return false;
    }
}

// 使用示例
// $cache = new FileCache('/tmp/my_app_cache', 600); // 缓存10分钟
// $data = $cache->get('product_list');
// if ($data === false) {
//     // Cache miss, fetch from DB
//     // $data = fetchProductListFromDatabase();
//     // $cache->set('product_list', $data);
// }
// var_dump($data);
?>

php-redis

<?php
// Redis缓存示例 (假设已安装php-redis扩展)
try {
    $redis = new Redis();
    $redis->connect('127.0.0.1', 6379); // 连接Redis服务器
    // $redis->auth('your_password'); // 如果Redis有密码

    $cacheKey = 'user:123:profile';
    $cachedData = $redis->get($cacheKey);

    if ($cachedData) {
        // 缓存命中
        $userData = json_decode($cachedData, true);
        echo "Data from Redis: " . $userData['name'] . "\n";
    } else {
        // 缓存未命中，从数据库获取数据
        // 模拟从数据库获取
        $userData = [
            'id' => 123,
            'name' => 'John Doe',
            'email' => 'john.doe@example.com',
            'timestamp' => time()
        ];
        echo "Data from Database: " . $userData['name'] . "\n";

        // 将数据存入Redis，设置过期时间为1小时 (3600秒)
        $redis->setex($cacheKey, 3600, json_encode($userData));
        echo "Data cached in Redis.\n";
    }

    $redis->close();
} catch (RedisException $e) {
    echo "Redis connection failed: " . $e->getMessage() . "\n";
    // 降级处理，直接从数据库获取或采取其他措施
}
?>

php-redis

redis

<?php
class RedisCache {
    private $redis;
    private $host;
    private $port;
    private $password;
    private $timeout;

    public function __construct($host = '127.0.0.1', $port = 6379, $password = null, $timeout = 0.0) {
        $this->host = $host;
        $this->port = $port;
        $this->password = $password;
        $this->timeout = $timeout;
        $this->connect();
    }

    private function connect() {
        try {
            $this->redis = new Redis();
            $this->redis->connect($this->host, $this->port, $this->timeout);
            if ($this->password) {
                $this->redis->auth($this->password);
            }
        } catch (RedisException $e) {
            // 生产环境应该记录日志而不是直接echo
            error_log("Redis connection failed: " . $e->getMessage());
            $this->redis = null; // 连接失败，将redis对象设为null，后续操作会失败
        }
    }

    public function set($key, $value, $ttl = 3600) {
        if (!$this->redis) return false;
        // Redis的set方法可以直接设置过期时间
        // setex(key, ttl, value)
        // 或者 set(key, value) 后 expire(key, ttl)
        return $this->redis->setex($key, $ttl, serialize($value)); // 序列化以便存储复杂数据类型
    }

    public function get($key) {
        if (!$this->redis) return false;
        $data = $this->redis->get($key);
        return $data ? unserialize($data) : false;
    }

    public function delete($key) {
        if (!$this->redis) return false;
        return $this->redis->del($key);
    }

    public function close() {
        if ($this->redis) {
            $this->redis->close();
        }
    }
}

// 使用示例
$redisCache = new RedisCache('127.0.0.1', 6379, 'your_redis_password_if_any'); // 替换为你的密码

$cacheKey = 'app:settings:global';
$settings = $redisCache->get($cacheKey);

if ($settings === false) {
    echo "Cache miss for $cacheKey, fetching from source...\n";
    // 模拟从数据库或配置中获取
    $settings = ['theme' => 'dark', 'language' => 'en', 'items_per_page' => 20];
    $redisCache->set($cacheKey, $settings, 1800); // 缓存30分钟
    echo "Settings cached.\n";
} else {
    echo "Cache hit for $cacheKey.\n";
}
print_r($settings);

$redisCache->close();
?>

php-memcached

php-memcache

php-memcached

Memcached

<?php
class MemcachedCache {
    private $memcached;
    private $servers;

    public function __construct(array $servers = [['127.0.0.1', 11211]]) {
        $this->servers = $servers;
        $this->connect();
    }

    private function connect() {
        $this->memcached = new Memcached();
        // Memcached支持添加多个服务器，实现分布式缓存
        // 如果服务器宕机，Memcached客户端会自动尝试连接其他服务器
        foreach ($this->servers as $server) {
            $this->memcached->addServer($server[0], $server[1]);
        }
        // 可以设置一些选项，比如序列化方式、压缩等
        // $this->memcached->setOption(Memcached::OPT_COMPRESSION, true);
        // $this->memcached->setOption(Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY); // 需要安装igbinary扩展
    }

    public function set($key, $value, $ttl = 3600) {
        // Memcached的set方法直接支持过期时间
        return $this->memcached->set($key, $value, $ttl);
    }

    public function get($key) {
        $data = $this->memcached->get($key);
        // Memcached::getResultCode() 可以检查是否成功获取
        if ($this->memcached->getResultCode() == Memcached::RES_NOTFOUND) {
            return false; // 缓存未命中
        }
        return $data;
    }

    public function delete($key) {
        return $this->memcached->delete($key);
    }
}

// 使用示例
$memcachedCache = new MemcachedCache([['127.0.0.1', 11211]]);

$cacheKey = 'product:details:SKU001';
$productDetails = $memcachedCache->get($cacheKey);

if ($productDetails === false) {
    echo "Cache miss for $cacheKey, fetching from source...\n";
    // 模拟从数据库获取
    $productDetails = [
        'sku' => 'SKU001',
        'name' => 'Super Widget',
        'price' => 99.99,
        'description' => 'A very useful gadget.'
    ];
    $memcachedCache->set($cacheKey, $productDetails, 7200); // 缓存2小时
    echo "Product details cached.\n";
} else {
    echo "Cache hit for $cacheKey.\n";
}
print_r($productDetails);
?>