hyperf/doc/zh-cn/nsq.md

# NSQ

[NSQ](https://nsq.io) 是一个由 Go 语言编写的开源、轻量级、高性能的实时分布式消息中间件。

## 安装

```bash
composer requir hyperf/nsq
```

## 使用

### 配置

NSQ 组件的配置文件默认位于 `config/autoload/nsq.php` 内，如该文件不存在，可通过 `php bin/hyperf.php vendor:publish hyperf/nsq` 命令来将发布对应的配置文件。

默认配置文件如下：

```php
<?php
return [
    'default' => [
        'host' => '127.0.0.1',
        'port' => 4150,
        'pool' => [
            'min_connections' => 1,
            'max_connections' => 10,
            'connect_timeout' => 10.0,
            'wait_timeout' => 3.0,
            'heartbeat' => -1,
            'max_idle_time' => 60.0,
        ],
    ],
];
```

### 创建消费者

通过 `gen:nsq-consumer` 命令可以快速的生成一个 消费者(Consumer) 对消息进行消费。

```bash
php bin/hyperf.php gen:nsq-consumer DemoConsumer
```

您也可以通过使用 `Hyperf\Nsq\Annotation\Consumer` 注解来对一个 `Hyperf/Nsq/AbstractConsumer` 抽象类的子类进行声明，来完成一个 消费者(Consumer) 的定义，其中`Hyperf\Nsq\Annotation\Consumer` 注解和抽象类均包含以下属性：
 
|   配置  |  类型  |  注解或抽象类默认值 |       备注       |
|:-------:|:------:|:------:|:----------------:|
|  topic  | string |   ''   |  要监听的 topic   |
| channel | string |   ''   |  要监听的 channel |
|   name  | string | NsqConsumer |  消费者的名称     |
|   nums  |  int   |   1    |  消费者的进程数   |
|   pool  | string |   default   |  消费者对应的连接，对应配置文件的 key |

这些注解属性是可选的，因为 `Hyperf/Nsq/AbstractConsumer` 抽象类中也分别定义了对应的成员属性以及 getter 和 setter，当不对注解属性进行定义时，会使用抽象类的属性默认值。

```php
<?php

declare(strict_types=1);

namespace App\Nsq\Consumer;

use Hyperf\Nsq\AbstractConsumer;
use Hyperf\Nsq\Annotation\Consumer;
use Hyperf\Nsq\Message;
use Hyperf\Nsq\Result;

/**
 * @Consumer(
 *     topic="hyperf", 
 *     channel="hyperf", 
 *     name ="DemoNsqConsumer", 
 *     nums=1
 * )
 */
class DemoNsqConsumer extends AbstractConsumer
{
    public function consume(Message $payload): string 
    {
        var_dump($payload->getBody());

        return Result::ACK;
    }
}
```

### 禁止消费进程自启

默认情况下，使用了 `@Consumer` 注解定义后，框架会在启动时自动创建子进程来启动消费者，并且会在子进程异常退出后，自动重新拉起。但如果在处于开发阶段进行某些调试工作时，可能会因为消费者的自动消费导致调试的不便。

在这种情况下，我们只需要在对应的消费者中重写父类方法 `isEnable()` 并返回 `false` 即可关闭此消费者的自启功能；

```php
<?php

declare(strict_types=1);

namespace App\Nsq\Consumer;

use Hyperf\Nsq\AbstractConsumer;
use Hyperf\Nsq\Annotation\Consumer;
use Hyperf\Nsq\Message;
use Hyperf\Nsq\Result;
use Psr\Container\ContainerInterface;

/**
 * @Consumer(
 *     topic="demo_topic", 
 *     channel="demo_channel", 
 *     name ="DemoConsumer", 
 *     nums=1
 * )
 */
class DemoConsumer extends AbstractConsumer
{
    public function __construct(ContainerInterface $container)
    {
        parent::__construct($container);
    }

    public function isEnable(): bool 
    {
        return false;
    }

    public function consume(Message $payload): string
    {
        $body = json_decode($payload->getBody(), true);
        var_dump($body);
        return Result::ACK;
    }
}
```

### 投递消息

您可以通过调用 `Hyperf\Nsq\Nsq::publish(string $topic, $message, float $deferTime = 0.0)` 方法来向 NSQ 投递消息, 下面是在 Command 进行消息投递的一个示例：

```php
<?php

declare(strict_types=1);

namespace App\Command;

use Hyperf\Command\Command as HyperfCommand;
use Hyperf\Command\Annotation\Command;
use Hyperf\Nsq\Nsq;

/**
 * @Command
 */
class NsqCommand extends HyperfCommand
{
    protected $name = 'nsq:pub';

    public function handle()
    {
        /** @var Nsq $nsq */
        $nsq = make(Nsq::class);
        $topic = 'hyperf';
        $message = 'This is message at ' . time();
        $nsq->publish($topic, $message);

        $this->line('success', 'info');
    }
}
```

### 一次性投递多条消息

`Hyperf\Nsq\Nsq::publish(string $topic, $message, float $deferTime = 0.0)` 方法的第二个参数除了可以传递一个字符串外，还可以传递一个字符串数组，来实现一次性向一个 Topic 投递多条消息的功能，示例如下：

```php
<?php

declare(strict_types=1);

namespace App\Command;

use Hyperf\Command\Command as HyperfCommand;
use Hyperf\Command\Annotation\Command;
use Hyperf\Nsq\Nsq;

/**
 * @Command
 */
class NsqCommand extends HyperfCommand
{
    protected $name = 'nsq:pub';

    public function handle()
    {
        /** @var Nsq $nsq */
        $nsq = make(Nsq::class);
        $topic = 'hyperf';
        $messages = [
            'This is message 1 at ' . time(),
            'This is message 2 at ' . time(),
            'This is message 3 at ' . time(),
        ];
        $nsq->publish($topic, $messages);

        $this->line('success', 'info');
    }
}
```

### 投递延迟消息

当您希望您投递的消息在特定的时间后再去消费，也可通过对 `Hyperf\Nsq\Nsq::publish(string $topic, $message, float $deferTime = 0.0)` 方法的第三个参数传递对应的延迟时长，单位为秒，示例如下：

```php
<?php

declare(strict_types=1);

namespace App\Command;

use Hyperf\Command\Command as HyperfCommand;
use Hyperf\Command\Annotation\Command;
use Hyperf\Nsq\Nsq;

/**
 * @Command
 */
class NsqCommand extends HyperfCommand
{
    protected $name = 'nsq:pub';

    public function handle()
    {
        /** @var Nsq $nsq */
        $nsq = make(Nsq::class);
        $topic = 'hyperf';
        $message = 'This is message at ' . time();
        $deferTime = 5.0;
        $nsq->publish($topic, $message, $deferTime);

        $this->line('success', 'info');
    }
}
```

## NSQ 协议

> https://nsq.io/clients/tcp_protocol_spec.html

- Socket 基础

```plantuml
@startuml

autonumber
hide footbox
title **Socket 基础**

participant "客户端" as client
participant "服务器" as server #orange

activate client
activate server

note right of server: 建立连接
client -> server: socket->connect(ip, port)

...
note right of server: 多次通信 send/recv
client -> server: socket->send()
server-> client: socket->recv()
...

note right of server: 关闭连接
client->server: socket->close()

deactivate client
deactivate server

@enduml
```

- NSQ 协议流程

```plantuml
@startuml

autonumber
hide footbox
title **NSQ 协议**

participant "客户端" as client
participant "服务器" as server #orange

activate client
activate server

== connect ==
note left of client: connect 后都为 socket->send/recv
client -> server: socket->connect(ip, host)
note left of client: protocol version
client->server: magic: V2

== auth ==
note left of client: client metadata
client->server: IDENTIFY
note right of server: 如果需要 auth
server->client: auth_required=true
client->server: AUTH
...

== pub ==
note left of client: 发送一条消息
client -> server: PUB <topic_name>
note left of client: 发送多条消息
client -> server: MPUB
note left of client: 发送一条延时消息
client -> server: DPUB
...

== sub ==
note left of client: client 使用 channel 订阅 topic
note right of server: SUB 成功后, client 出于 RDY 0 阶段
client -> server: SUB <topic_name> <channel_name>
note left of client: 使用 RDY 告诉 server 准备好消费 <count> 条消息
client -> server: RDY <count>
note right of server: server 返回 client <count> 条消息
server -> client: <count> msg
note left of client: 标记消息完成消费(消费成功)
client -> server: FIN <message_id>
note left of client: 消息重新入队(消费失败, 重新入队)
client -> server: REQ <message_id> <timeout>
note left of client: 重置消息超时时间
client -> server: TOUCH <message_id>
...

== heartbeat ==
server -> client: _heartbeat_
note right of server: client 2 次没有应答 NOP, server 将断开连接
client -> server: NOP
...

== close ==
note left of client: clean close connection, 表示没有消息了, 关闭连接
client -> server: CLS
note right of server: server 端成功应答
server -> client: CLOSE_WAIT

deactivate client
deactivate server

@enduml
```