MultiEval.php

<?php
namespace PHPDaemon\Clients\Redis;

use PHPDaemon\Core\CallbackWrapper;

/**
 * Easy wrapper for queue of eval's
 *
 * @package    NetworkClients
 * @subpackage RedisClient
 * @author     Efimenko Dmitriy <ezheg89@gmail.com>
 *
 * Use exampe 1:
 * var $eval = $this->redis->meval($cb);
 * $eval->add('redis.call("set",KEYS[1],ARGV[1])', [$key1], [$arg1]);
 * $eval->add('redis.call("del",KEYS[1])', [$key2]);
 * $eval->add('redis.call("expireat",KEYS[1],ARGV[1])', $key1, $arg2);
 * $eval->exec();
 *
 * Use exampe 2:
 * var $eval = $this->redis->meval($cb);
 * $eval('redis.call("set",KEYS[1],ARGV[1])', [$key1], [$arg1]);
 * $eval('redis.call("del",KEYS[1])', [$key2]);
 * $eval('redis.call("expireat",KEYS[1],ARGV[1])', $key1, $arg2);
 * $eval();
 *
 * Result request:
 * eval 'redis.call("set",KEYS[1],ARGV[1]);redis.call("del",KEYS[2]);redis.call("expireat",KEYS[1],ARGV[2])' 2 $key1 $key2 $arg1 $arg2
 */
class MultiEval
{
    use \PHPDaemon\Traits\ClassWatchdog;
    use \PHPDaemon\Traits\StaticObjectWatchdog;

    /**
     * @var array Listeners
     */
    public $listeners = [];
    protected $pool;
    protected $stack = [];
    protected $cachedParams = false;

    /**
     * Constructor
     * @param callable $cb Callback
     * @param Pool $pool Redis pool
     */
    public function __construct($cb, $pool)
    {
        $this->pool = $pool;
        if ($cb !== null) {
            $this->addListener($cb);
        }
    }

    /**
     * Adds listener
     * @param callable $cb
     */
    public function addListener($cb)
    {
        $this->listeners[] = CallbackWrapper::wrap($cb);
    }

    /**
     * Clean up
     */
    public function cleanup()
    {
        $this->listeners = [];
    }

    /**
     * Adds eval command or calls execute() method
     * @return void
     */
    public function __invoke(...$args)
    {
        if (!count($args)) {
            $this->execute();
            return;
        }
        $this->add(...$args);
    }

    /**
     * Runs the stack of commands
     */
    public function execute()
    {
        if (!count($this->stack)) {
            foreach ($this->listeners as $cb) {
                $cb($this->pool);
            }
            return;
        }

        $params = $this->getParams();
        $params[] = function ($redis) {
            foreach ($this->listeners as $cb) {
                $cb($redis);
            }
        };
        $this->pool->eval(...$params);
    }

    /**
     * Return params for eval command
     * @return array
     */
    public function getParams()
    {
        if ($this->cachedParams) {
            return $this->cachedParams;
        }

        $CMDS = [];
        $KEYS = [];
        $ARGV = [];
        $KEYNUM = 0;
        $ARGNUM = 0;

        foreach ($this->stack as $part) {
            list($cmd, $keys, $argv) = $part;

            if (!empty($keys)) {
                $cmd = preg_replace_callback('~KEYS\[(\d+)\]~', function ($m) use (&$KEYS, &$KEYNUM, $keys) {
                    $key = $keys[$m[1] - 1];
                    if (!isset($KEYS[$key])) {
                        $KEYS[$key] = ++$KEYNUM;
                    }
                    return 'KEYS[' . $KEYS[$key] . ']';
                }, $cmd);
            }

            if (!empty($argv)) {
                $cmd = preg_replace_callback('~ARGV\[(\d+)\]~', function ($m) use (&$ARGV, &$ARGNUM, $argv) {
                    $arg = $argv[$m[1] - 1];
                    if (!isset($ARGV[$arg])) {
                        $ARGV[$arg] = ++$ARGNUM;
                    }
                    return 'ARGV[' . $ARGV[$arg] . ']';
                }, $cmd);
            }

            $CMDS[] = $cmd;
        }

        return $this->cachedParams = array_merge(
            [implode(';', $CMDS), count($KEYS)],
            array_keys($KEYS),
            array_keys($ARGV)
        );
    }

    /**
     * Adds eval command in stack
     * @param string $cmd Lua script
     * @param mixed $keys Keys
     * @param mixed $argv Arguments
     */
    public function add($cmd, $keys = null, $argv = null)
    {
        if ($keys !== null) {
            if (is_scalar($keys)) {
                $keys = [(string)$keys];
            } elseif (!is_array($keys)) {
                throw new \Exception("Keys must be an array or scalar");
            }
        }
        if ($argv !== null) {
            if (is_scalar($argv)) {
                $argv = [(string)$argv];
            } elseif (!is_array($argv)) {
                throw new \Exception("Argv must be an array or scalar");
            }
        }

        $this->cachedParams = false;
        $this->stack[] = [$cmd, $keys, $argv];
    }
}