owncloud/core

<?php
/**
 * @author Robin Appelman <icewind@owncloud.com>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\Command;

use Closure;
use InvalidArgumentException;
use Laravel\SerializableClosure\SerializableClosure;
use OCP\BackgroundJob\IJobList;
use OCP\Command\IBus;
use OCP\Command\ICommand;
use function array_search;
use function class_uses;
use function is_callable;
use function serialize;
use function trim;

/**
 * Asynchronous command bus that uses the background job system as backend
 */
class AsyncBus implements IBus {
    private IJobList $jobList;

    /**
     * List of traits for command which require sync execution
     *
     * @var string[]
     */
    private $syncTraits = [];

    /**
     * @param IJobList $jobList
     */
    public function __construct(IJobList $jobList) {
        $this->jobList = $jobList;
    }

    /**
     * Schedule a command to be fired
     *
     * @param ICommand | callable $command
     */
    public function push($command) {
        if ($this->canRunAsync($command)) {
            $this->jobList->add($this->getJobClass($command), $this->serializeCommand($command));
        } else {
            $this->runCommand($command);
        }
    }

    /**
     * Require all commands using a trait to be run synchronous
     *
     * @param string $trait
     */
    public function requireSync($trait) {
        $this->syncTraits[] = trim($trait, '\\');
    }

    /**
     * @param ICommand | callable $command
     */
    private function runCommand($command) {
        if ($command instanceof ICommand) {
            $command->handle();
        } else {
            $command();
        }
    }

    /**
     * @param ICommand | callable $command
     * @return string
     */
    private function getJobClass($command) {
        if ($command instanceof Closure) {
            return 'OC\Command\ClosureJob';
        }

        if (\is_callable($command)) {
            return 'OC\Command\CallableJob';
        }

        if ($command instanceof ICommand) {
            return 'OC\Command\CommandJob';
        }

        throw new InvalidArgumentException('Invalid command');
    }

    /**
     * @param ICommand | callable $command
     * @return string
     */
    private function serializeCommand($command) {
        if ($command instanceof Closure) {
            return serialize(new SerializableClosure($command));
        }

        if (\is_callable($command) || $command instanceof ICommand) {
            return serialize($command);
        }

        throw new InvalidArgumentException('Invalid command');
    }

    /**
     * @param ICommand | callable $command
     * @return bool
     */
    private function canRunAsync($command) {
        $traits = $this->getTraits($command);
        foreach ($traits as $trait) {
            if (array_search($trait, $this->syncTraits) !== false) {
                return false;
            }
        }
        return true;
    }

    /**
     * @param ICommand | callable $command
     * @return string[]
     */
    private function getTraits($command) {
        if ($command instanceof ICommand) {
            return class_uses($command);
        }

        return [];
    }
}