起源

从第一次用ChatGPT到现在已经过了一年多了，Copilot 也在慢慢改变我们的编程方式。当初学 Rust 的时候就想着要不要写一个简化版的 Redis，现在正好可以用 Copilot 来帮助我们完成这个任务。

基本设想

  • 全程使用 Copilot 辅助。
  • 记录下所有交互过程。

功能要求：

  • 兼容 Redis 协议。
  • 实现包括 String, Hash, List, Set, Sorted Set 等数据结构及其指令。
  • 单进程数据安全。
  • 不支持持久化、集群、主从复制、数据库等功能。

迈出第一步

  • Me:

use rust create a tcp server

  • Copilot:

Here is a basic example of a TCP server in Rust:

use std::io::prelude::*;
use std::net::TcpListener;
use std::net::TcpStream;

fn main() {
    let listener = TcpListener::bind("127.0.0.1:7878").unwrap();

    for stream in listener.incoming() {
        let stream = stream.unwrap();

        handle_connection(stream);
    }
}

fn handle_connection(mut stream: TcpStream) {
    let mut buffer = [0; 512];

    stream.read(&mut buffer).unwrap();

    println!("Request: {}", String::from_utf8_lossy(&buffer[..]));
}

his code creates a TCP server that listens on localhost at port 7878. When a connection is made, it reads the incoming data into a buffer and prints it out.

让它跑起来

  • Me:

how to run main.rs

  • Copilot:

To run the main.rs file in Rust, you need to use the cargo run command in the terminal. Here’s how you do it:

  1. Open the terminal in Visual Studio Code by going to View -> Terminal or by pressing Control + backtick ().

  2. Navigate to the directory containing your main.rs file. You can do this using the cd command. For example, if your main.rs file is in a directory named my_project, you would type cd my_project.

  3. Once you’re in the correct directory, type cargo run and press Enter. This will compile and run your main.rs file.

Here’s what the commands look like:

cd path_to_your_project
cargo run

Replace path_to_your_project with the actual path to your project.

pythias: error: could not find Cargo.toml in ./rust/ai-redis or any parent directory

GitHub Copilot: The error message you’re seeing indicates that the cargo command can’t find a Cargo.toml file in your current directory or any parent directory. The Cargo.toml file is necessary for managing Rust packages.

Here’s how you can create a new Cargo.toml file:

  1. Navigate to the root directory of your project (the directory that should contain Cargo.toml).

  2. Run the command cargo init in your terminal. This will create a new Cargo.toml file and a src directory if they don’t already exist.

  3. Move your main.rs file into the src directory.

  4. Now you should be able to run cargo run from the root directory of your project.

Here are the commands:

cd path_to_your_project
cargo init
mv main.rs src/
cargo run

Replace path_to_your_project with the actual path to your project.

发现Cargo没有安装

  • Me:

error: could not find Cargo.toml in ./rust/ai-redis or any parent directory

  • Copilot:

The error message you’re seeing indicates that the cargo command can’t find a Cargo.toml file in your current directory or any parent directory. The Cargo.toml file is necessary for managing Rust packages.

Here’s how you can create a new Cargo.toml file:

  1. Navigate to the root directory of your project (the directory that should contain Cargo.toml).

  2. Run the command cargo init in your terminal. This will create a new Cargo.toml file and a src directory if they don’t already exist.

  3. Move your main.rs file into the src directory.

  4. Now you should be able to run cargo run from the root directory of your project.

Here are the commands:

cd path_to_your_project
cargo init
mv main.rs src/
cargo run

Replace path_to_your_project with the actual path to your project.

点评

此处它有错误，cargo init时会自动根据 main.rs 的位置生成Cargo.toml，不需要手动移动main.rs。但是使用src目录更符合Rust的项目结构。所以可以这么操作

cd path_to_your_project
mkdir src
mv main.rs src/
cargo init

我试着跟它交流一下这个问题

  • Me:

cargo run Compiling ai-redis v0.1.0 (./rust/ai-redis) error: couldn’t read main.rs: No such file or directory (os error 2)

error: could not compile ai-redis (bin “ai-redis”) due to 1 previous error

  • Copilot:

The error message indicates that the Rust compiler cannot find the main.rs file in the expected location.

Ensure that your main.rs file is located in the src directory of your project. The structure should look like this:

your_project
├── Cargo.toml
└── src
    └── main.rs

If your main.rs file is not in the src directory, move it there. You can use the mv command in the terminal to move files:

mv path_to_your_main.rs src/main.rs

Replace path_to_your_main.rs with the actual path to your main.rs file.

After moving main.rs to the src directory, try running cargo run again.

  • Me:

main.rs已经在src目录下

  • Copilot:

The Cargo.toml file is incorrectly pointing to main.rs in the root directory. Since you’ve mentioned that main.rs is already in the src directory, you need to update the path under [[bin]] to point to src/main.rs.

Here’s how your Cargo.toml should look:

[package]
name = "ai-redis"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]

[[bin]]
name = "ai-redis"
path = "src/main.rs"

After updating Cargo.toml, try running cargo run again.

点评

我问得不对，它没意识到之前处理顺序问题，导致main.rs在src目录下，但是Cargo.toml中的path字段指向了错误的位置。第二次提交时它知道了。但它还有几个地方有错，比如配置文件它用了plaintext没用toml；比如 [[bin]] 其实可以省略，因为默认就是src/main.rs。

总结

Copilot 在这个过程中帮助我完成了一个简单的TCP Server的创建，但是在配置Cargo时有一些问题。我发现Copilot在处理问题时，有时候会忽略之前的问题，导致后续的问题无法解决。但是总体来说，Copilot还是一个很好的工具，可以帮助我们快速完成一些简单的任务。

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