Laravel DatabaseQueue 基本知识点

基本知识点包括：Container; php serialize, deseriaize; json_encode, json_decode.

framework/src/Illuminate/Queue/DatabaseQueue.php

    /**     * Create a payload string from the given job and data.     *     * @param  string  $job     * @param  mixed   $data     * @param  string  $queue     * @return string     */    protected function createPayload($job, $data = '', $queue = null)    {        if ($job instanceof Closure) {            return json_encode($this->createClosurePayload($job, $data));        }        if (is_object($job)) {            return json_encode([                'job' => 'Illuminate\Queue\CallQueuedHandler@call',                'data' => ['commandName' => get_class($job), 'command' => serialize(clone $job)],            ]);        }        return json_encode($this->createPlainPayload($job, $data));    }

framework/src/Illuminate/Queue/Jobs/Job.php

    protected function resolveAndFire(array $payload)    {        list($class, $method) = $this->parseJob($payload['job']);        $this->instance = $this->resolve($class);        $this->instance->{$method}($this, $this->resolveQueueableEntities($payload['data']));    }    /**     * Parse the job declaration into class and method.     *     * @param  string  $job     * @return array     */    protected function parseJob($job)    {        $segments = explode('@', $job);        return count($segments) > 1 ? $segments : [$segments[0], 'fire'];    }    /**     * Resolve the given job handler.     *     * @param  string  $class     * @return mixed     */    protected function resolve($class)    {        return $this->container->make($class);    }    /**     * Resolve all of the queueable entities in the given payload.     *     * @param  mixed  $data     * @return mixed     */    protected function resolveQueueableEntities($data)    {        if (is_string($data)) {            return $this->resolveQueueableEntity($data);        }        if (is_array($data)) {            $data = array_map(function ($d) {                if (is_array($d)) {                    return $this->resolveQueueableEntities($d);                }                return $this->resolveQueueableEntity($d);            }, $data);        }        return $data;    }     /**     * Resolve a single queueable entity from the resolver.     *     * @param  mixed  $value     * @return \Illuminate\Contracts\Queue\QueueableEntity     */    protected function resolveQueueableEntity($value)    {        if (is_string($value) && Str::startsWith($value, '::entity::')) {            list($marker, $type, $id) = explode('|', $value, 3);            return $this->getEntityResolver()->resolve($type, $id);        }        return $value;    }