This needs to be a struct, not a class.

这需要是一个结构，而不是一个类。

Groups of variables like these can be bundled together into a Struct.

像这样的变量组可以捆绑在一起成为一个结构。

Let's take a look at this struct that's called a " node" .

让我们来看看这个称为“节点”的结构。

First you create a separate struct that implements IJob, like this.

首先，您创建一个实现 IJob 的单独结构，如下所示。

We'll use this to initialize our struct and then give it the data it needs to do its work.

我们将使用它来初始化我们的结构，然后为其提供完成工作所需的数据。

The 680 bytes is important, because this struct here is exactly 680 bytes.

680 字节很重要，因为这里的这个结构正好是 680 字节。

Each struct implements the logic in the execute method, as we've already mentioned.

正如我们已经提到的，每个结构体都实现了执行方法中的逻辑。

We can even make arrays of structs that we define, which are automatically bundled together in memory.

我们甚至可以创建我们定义的结构数组，它们会自动捆绑在内存中。

It's basically just a C struct, a binary blob that is being thrown over a bulk endpoint to the device.

它基本上只是一个 C 结构，一个二进制 blob，通过批量端点被抛到设备上。

In Swift, we use both value and reference types, and while NSCoding supports classes, it doesn't work at all with structs or enums.

在 Swift 里，我们会用到值类型和引用类型虽然 NSCoding 支持 类（class）但它对结构（struct） 或者 枚举型（enum） 就无能为力了。