https://github.com/zcfan/p-task
https://github.com/zcfan/p-task
Last synced: 5 months ago
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- Host: GitHub
- URL: https://github.com/zcfan/p-task
- Owner: zcfan
- Created: 2025-07-25T08:48:11.000Z (11 months ago)
- Default Branch: main
- Last Pushed: 2025-07-28T03:22:55.000Z (11 months ago)
- Last Synced: 2025-08-09T00:44:40.436Z (10 months ago)
- Language: TypeScript
- Size: 45.9 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
@zcfan/p-task
----
```bash
npm i @zcfan/p-task
```
A tool for creating and managing the dependencies between asynchronous tasks.
For example, you have three tasks:
- task1/2 has no dependencies, so after being created, they can run immediately after creation.
- task3 depends on task1/2, so it'll run after task1/2 are `success`.
You can write them like this:
```typescript
const task1 = new PTask(
[],
() => new Promise(resolve => setTimeout(() => resolve(1), 500))
)
const task2 = new PTask(
[],
() => new Promise(resolve => setTimeout(() => resolve('2'), 1000))
)
const task3 = new PTask(
[task1, task2],
([result1, result2]) =>
new Promise(resolve => setTimeout(() => resolve(result1 + Number(result2)), 500))
)
```
Together they form a bigger task(task3) which can help you treak all three tasks as a single task:
- Get the final status:
- any task is `error`, the bigger task is `error`.
- if there is no `error`, any task is `pending`, the bigger task is `pending`.
- if all tasks are `success`, the bigger task is `success`.
- Retry the bigger task:
- if the bigger task is `error`, you can retry it by calling `retry()`.
- it will only retry those `error` dependent tasks(or the bigger task itself, if it's `error`).
- those `success` or `pending` dependent tasks will not be retried.
> A real example: to implement a "send messages that contain images" feature in an instant chat system, there are two backend endpoints:
> - upload images that will be used in message.
> - send the message.
>
> Before sending a message, you need to upload all the images it uses first, and then send the message (images are represented by ids).
>
> If the image upload fails, or the image upload is successful but the message send fails, user are allowed to retry.
----
一个用于创建和管理异步任务之间的依赖关系的工具。
比如有三个任务：
- task1/2 没有依赖，所以在创建后可以立即运行。
- task3 依赖于 task1/2，所以它会在 task1/2 成功后运行。
你可以这样写：
```typescript
const task1 = new PTask(
[],
() => new Promise(resolve => setTimeout(() => resolve(1), 500))
)
const task2 = new PTask(
[],
() => new Promise(resolve => setTimeout(() => resolve('2'), 1000))
)
const task3 = new PTask(
[task1, task2],
([result1, result2]) =>
new Promise(resolve => setTimeout(() => resolve(result1 + Number(result2)), 500))
)
```
这三个任务组合起来，形成一个更大的任务(task3)，你可以把它们作为一个单独的任务来看待。
- 获取大任务的整体状态：
- 任何任务是 `error`，则较大的任务是 `error`。
- 如果没有 `error`，任何任务是 `pending`，则较大的任务是 `pending`。
- 如果所有任务都是 `success`，则较大的任务是 `success`。
- 重试大任务：
- 如果大任务是 `error`，你可以通过调用 `retry()` 来重试它。
- 它只会重试那些 `error` 的依赖任务（或者如果 task3 自己是 `error`，则会重试 task3）。
- 那些依赖于 `success` 或 `pending` 的任务不会被重试。
> 一个现实的例子：要实现一个即时聊天系统的发送图文消息功能，后台有两个接口：
> - 上传图片
> - 发送消息
>
> 在发送一条消息之前，需要先把它用到的图片上传完，然后再发送消息（其中图片用 id 表示）。
>
> 如果图片发送失败，或图片上传成功但发送消息失败，都需要允许用户重试。