php中Redis使用Lua脚本

主要使用到eval命令

 EVAL命令：

命令格式：EVAL script numkeys key [key …] arg [arg …]
- script参数是一段 Lua5.1 脚本程序。脚本不必(也不应该[^1])定义为一个 Lua 函数
- numkeys指定后续参数有几个key，即：key [key …]中key的个数。如没有key，则为0
- key [key …] 从 EVAL 的第三个参数开始算起，表示在脚本中所用到的那些 Redis 键(key)。在Lua脚本中通过KEYS[1], KEYS[2]获取。
- arg [arg …] 附加参数。在Lua脚本中通过ARGV[1],ARGV[2]获取。

示例

127.0.0.1:6379> EVAL "return KEYS[1]" 1 key1
"key1"
127.0.0.1:6379> EVAL "return ARGV[1]" 0 value1
"value1"
127.0.0.1:6379> eval "return {KEYS[1],KEYS[2],ARGV[1],ARGV[2]}" 2 key1 key2 first second
1) "key1"
2) "key2"
3) "first"
4) "second"

 简单创建php类，这里创建了两个方法，用于批量hmget和hgetall

<?php

class RedisClient {
	public static $redis_client;

    const CONNECT_TIMEOUT = 2;

    private static function _getInstance() {
        if (self::$redis_client instanceof RedisClient) {
            return self::$redis_client;
        }
        self::$redis_client = new \Redis;
        self::$redis_client->connect('127.0.0.1', '6379', self::CONNECT_TIMEOUT);
        return self::$redis_client;
    }
    
    /**
     * @param $keys
     * @param $fields
     * @return array
     */
    public static function hmgetbatch($keys, $fields = []) {
    	$res = [];
        $keyNum = count($keys);
        if (is_array($fields) && !empty($fields)) {
        	$argv_fields = implode("','", $fields);
            $argv_fields = "'" . $argv_fields . "'";
        } else {
        	return self::hgetallbatch($keys);
        }
        $lua_script = "local rtn = {};for i, v in ipairs(KEYS) do local item = redis.call('hmget', v, $argv_fields);if not item then rtn[i] = {} else rtn[i] = item;end;end;return rtn;";
        $data =  self::_getInstance()->eval($lua_script, $keys, $keyNum);

        foreach ($data as $key => $item) {
            $number = count($item);
            $tmp = [];
            for ($i = 0; $i < $number; $i++) {
                $tmp[$fields[$i]] = $item[$i];
            }
            $res[$keys[$key]] = $tmp;
        }
        return $res;
    }

    /**
     * @param $keys
     * @return array
     */
    public static function hgetallbatch($keys) {
    	$res = [];
        $keyNum = count($keys);
        if (is_array($fields) && !empty($fields)) {
        	$argv_fields = implode("','", $fields);
            $argv_fields = "'" . $argv_fields . "'";
        }
        $lua_script = "local rtn = {};for i, v in ipairs(KEYS) do local item = redis.call('hgetall', v);if not item then rtn[i] = {} else rtn[i] = item;end;end;return rtn;";
        $data =  self::_getInstance()->eval($lua_script, $keys, $keyNum);

        foreach ($data as $key => $item) {
            $number = count($item);
            $tmp = [];
            for ($i=0; $i<$number; $i++) {
                if ($i % 2 == 0) {
                    $tmp[$item[$i]] = $item[$i+1];
                }
            }
            $res[$keys[$key]] = $tmp;
        }
        return $res;
    }
}

调用方法

$keys = ["user.id:1000001", "user.id:1000002"];
$fields = ['username', 'email'];
$data1 = RedisClient::hmgetbatch($keys, $fields);

$data2 = RedisClient::hgetallbatch($keys);

var_dump($data1);
var_dump($data2);