php使用redis的几种常见操作方式和用法示例

<?php
$redis = new Redis();
$redis->connect('127.0.0.1', 6379, 60);
$sql = 'select  from tb_order order by id desc limit 10';
//伪代码，从数据库中获取数据
$data = $db->query($sql);
$data = json_encode($data, JSON_UNESCAPED_UNICODE);
$key = md5($sql);
//缓存数据
$redis->set($key, $value, 60);
//获取数据
$data = $redis->get($key);
print_r(json_decode($data, true));

<?php
$redis = new Redis();
$redis->connect('127.0.0.1', 6379, 60);
//循环的把发送1000条邮件任务插入队列
for ($ix = 0; $ix < 1000; $ix++) {
  $redis->lPush('send_email_queue', json_encode([
    'id' => $ix,
    'send' => 'xxx@qq.',
    'receive' => 'yyy@qq.',
    'title' => 'xxx',
    'body' => 'xxx',
  ]));
}
sleep(3);
//从队列中取任务，执行任务
while ($count = $redis->lLen('send_email_queue')) {
  echo "当前任务队列数 {$count} <br>";
  $task = $redis->rpop('send_email_queue');
  $task = json_decode($task, true);
  //伪代码，发送邮件
  $mailer->send($task['send'], $task['receive'], $task['title'], $task['body']);
  echo "任务 {$task['id']} 邮件发送成功<br>";
}

<?php
$redis = new Redis();
$redis->connect('127.0.0.1', 6379, 60);
//设置商品的库存数为100
$redis->set('goods_stock_nums', 100);
//监视该key
$redis->watch('goods_stock_nums');
//开启事务
$redis->multi();
//修改库存数
$redis->decr('goods_stock_nums');
//提交事务，如果在此期间有其他请求修改了该key，那么事务会失败
if ($redis->exec()) {
  echo '抢购成功';
} else {
  echo '数据错误，请重新再试';
}

<?php
function getRedis()
{
  $redis = new Redis();
  $redis->connect('127.0.0.1', 6379, 60);
  return $redis;
}
function lock($key, $random)
{
  $redis = getRedis();
  return $redis->set($key, $random, ['nx', 'ex' => 3]);
}
function unlock($key, $random)
{
  $redis = getRedis();
  //使用lua脚本保证原子性
  $script = 'if redis.call("get",KEYS[1]) == ARGV[1] then return redis.call("del",KEYS[1]) else return 0 end';
  return $redis->eval($script, [$key, $random], 1);
}
function decrGoodsStockNums()
{
  $redis = getRedis();
  //获取商品库存数
  $ret = $redis->get('goods_stock_nums');
  if ($ret === false) {
    return false;
  }
  if ($ret <= 0) {
    return false;
  }
  $random = mt_rand();
  //先获取锁
  if (lock('goods_stock_nums_lock', $random)) {
    //修改库存数
    $redis->decr('goods_stock_nums');
    //释放锁
    unlock('goods_stock_nums_lock', $random);
    return true;
  } else {
    usleep(100);
    decrGoodsStockNums();
  }
}
decrGoodsStockNums();

<?php
$redis = new Redis();
$redis->pconnect('127.0.0.1', 6379);
$ix = 0;
//发布内容
while (true) {
  $redis->publish('news', json_encode([
    'title' => '我是新闻标题' . $ix,
    'content' => '我是新闻内容' . $ix,
    'time' => date('Y-m-d H:i:s'),
  ]));
  $ix++;
  sleep(1);
}

<?php
$redis = new Redis();
$redis->pconnect('127.0.0.1', 6379);
//订阅内容
$redis->subscribe(['news'], function ($redis, $channel, $msg) {
  $msg = json_decode($msg, true);
  echo "标题: {$msg['title']} 内容: {$msg['content']} 时间: {$msg['time']} <br>";
});