Data storage and update strategy for PHP development cache

PHP development cache data storage and update strategy requires specific code examples

In web applications, caching is an important tool to improve performance and response speed. Caching can greatly reduce resource acquisition time and response delay, thereby improving system efficiency and user satisfaction. In PHP development, the application and optimization of caching technology are very important. This article will focus on the data storage and update strategy of caching in PHP development, and provide specific code examples.

Cached data storage strategy

There are many ways to store cached data. The most common way to store cached data is to store data in memory, which can be achieved using memory caching tools such as APC, Memcached, and Redis. Additionally, cache data can be stored in a file system or database.

The advantage of storing cached data in memory is that it is very fast, which may be orders of magnitude slower in other ways. Therefore, in-memory caching is one of the most common and effective caching methods. The following is sample code for using APC memory cache:

<?php
// 定义缓存的关键字
$cache_key = 'my_cache_key';

// 判断缓存是否存在
if (apc_exists($cache_key)) {
    // 如果缓存存在，从缓存中获取数据
    $data = apc_fetch($cache_key);
} else {
    // 如果缓存不存在，执行数据库查询，并将查询结果存储在缓存中
    $data = mysql_query($query);
    apc_store($cache_key, $data);
}

// 输出查询结果
print_r($data);

The advantage of storing cache data in the file system is that cache data can be shared among multiple servers. The following is a sample code using file system caching:

<?php
// 定义缓存文件存储路径
$cache_file = '/tmp/my_cache_file';

// 判断缓存文件是否存在
if (file_exists($cache_file)) {
    // 如果缓存文件存在，从缓存文件中读取数据
    $data = file_get_contents($cache_file);
} else {
    // 如果缓存文件不存在，执行数据库查询，并将查询结果存储在缓存文件中
    $data = mysql_query($query);
    file_put_contents($cache_file, serialize($data));
}

// 输出查询结果
print_r(unserialize($data));

The advantage of storing cached data in a MySQL database is that it facilitates centralized management and backup, but the read and write speed of cached data is relatively slow. The following is a sample code using MySQL database caching:

<?php
// 定义MySQL数据库连接参数
$db_host = 'localhost';
$db_user = 'root';
$db_password = '123456';
$db_name = 'my_database';

// 建立MySQL数据库连接
$link = mysql_connect($db_host, $db_user, $db_password);
mysql_select_db($db_name, $link);

// 定义MySQL表名和字段名
$table_name = 'my_cache_table';
$column_name = 'my_cache_column';

// 定义SQL语句
$sql = "SELECT {$column_name} FROM {$table_name} WHERE my_key = '{$cache_key}'";

// 执行SQL语句
$result = mysql_query($sql);

// 判断是否有查询结果
if (mysql_num_rows($result) > 0) {
    // 如果有查询结果，从数据库中读取缓存数据
    $data = mysql_fetch_assoc($result);
} else {
    // 如果没有查询结果，执行数据库查询，并将查询结果存储在数据库中
    $data = mysql_query($query);
    $sql = "INSERT INTO {$table_name} SET my_key = '{$cache_key}', {$column_name} = '{$data}'";
    mysql_query($sql);
}

// 输出查询结果
print_r($data);

Cached data update strategy

For updating cached data, the following two strategies can be adopted:

1. Automatic expiration update policy

When cached data has not been accessed for a certain period of time, the data will be automatically deleted and re-obtained. The specific implementation can be achieved by setting the cache expiration time. The following is a sample code that uses APC memory cache to implement an automatic expiration update strategy:

<?php
// 定义缓存的关键字和过期时间
$cache_key = 'my_cache_key';
$cache_expire = 60; // 设置缓存过期时间为60秒

// 判断缓存是否存在
if (apc_exists($cache_key)) {
    // 如果缓存存在，从缓存中获取数据
    $data = apc_fetch($cache_key);
} else {
    // 如果缓存不存在，执行数据库查询，并将查询结果存储在缓存中
    $data = mysql_query($query);
    apc_store($cache_key, $data, $cache_expire);
}

// 输出查询结果
print_r($data);

2. Manual update strategy

When the cache data is updated, manually delete the cache data and restart Obtain. The specific implementation can delete the corresponding cached data when the data is updated. The following is sample code:

<?php
// 定义缓存的关键字和过期时间
$cache_key = 'my_cache_key';

// 获取数据库查询结果
$data = mysql_query($query);

// 更新数据库数据
mysql_query($update_query);

// 删除缓存数据
apc_delete($cache_key);

// 重新存储缓存数据
apc_store($cache_key, $data);

// 输出查询结果
print_r($data);

Conclusion

Caching technology is an important tool to improve the performance and response speed of web applications. In PHP development, cache data storage and update strategies need to be selected and optimized according to specific circumstances. Compared with memory cache, file system cache and MySQL database cache have higher reliability and scalability, but the read and write speed of cached data is relatively slow. When data is updated, an automatic expiration update strategy or a manual update strategy can be adopted. In actual development, the cache needs to be selected and optimized according to actual needs to achieve the best performance and response speed.

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