0280-KVS-将日志记录到文件

环境

• Time 2022-12-11
• WSL-Ubuntu 22.04
• Rust 1.65.0

前言

说明

参考：https://github.com/pingcap/talent-plan

目标

在上一节的基础上，将转为 JSON 的日志操作记录到文件。

Cargo.toml

[package]
edition = "2021"
name = "kvs"
version = "1.0.0"

[dependencies]
clap = {version = "4", features = ["derive"]}
serde = {version = "1", features = ["derive"]}
serde_json = "1"

lib.rs

use cmd::Command;
use log::CommandLog;

mod cmd;
mod log;

#[derive(Default)]
pub struct KvStore {
    log: CommandLog,
}

impl KvStore {
    pub fn get(&mut self, key: &str) -> Option<String> {
        self.log.get(key)
    }

    pub fn set(&mut self, key: String, value: String) -> Option<String> {
        let command = Command::Set { key, value };
        self.log.set(command)
    }

    pub fn remove(&mut self, key: String) -> Option<String> {
        let command = Command::Remove { key };
        self.log.remove(command)
    }
}

log.rs

use std::fs::{File, OpenOptions};
use std::io::{BufWriter, Write};

use crate::cmd::Command;

pub struct CommandLog {
    writer: BufWriter<File>,
}

impl Default for CommandLog {
    fn default() -> Self {
        let path = "/root/log/1.log";
        Self {
            writer: new_writer(path),
        }
    }
}

impl CommandLog {
    pub fn get(&mut self, _: &str) -> Option<String> {
        None
    }

    pub fn set(&mut self, command: Command) -> Option<String> {
        let json = serde_json::to_string(&command).unwrap();
        self.writer.write_all(json.as_bytes()).unwrap();
        None
    }

    pub fn remove(&mut self, command: Command) -> Option<String> {
        let json = serde_json::to_string(&command).unwrap();
        self.writer.write_all(json.as_bytes()).unwrap();
        None
    }
}

fn new_writer(path: &str) -> BufWriter<File> {
    let file = OpenOptions::new()
        .append(true)
        .create(true)
        .open(path)
        .unwrap();
    BufWriter::new(file)
}

运行

使用 cargo build --release 构建后运行。

root@jiangbo12490:~/git/game/target/release# ./kvs set name JiangBo
SET KEY: name, VALUE: None
root@jiangbo12490:~/git/game/target/release# ./kvs set age 44
SET KEY: age, VALUE: None
root@jiangbo12490:~/git/game/target/release# ./kvs get name
GET KEY: name, VALUE: None
root@jiangbo12490:~/git/game/target/release# ./kvs rm name
REM KEY: name, VALUE: None

查看文件

root@jiangbo12490:~/log# cat /root/log/1.log
{"Set":{"key":"name","value":"JiangBo"}}{"Set":{"key":"age","value":"44"}}{"Remove":{"key":"name"}}

总结

将命令操作转为 JSON 后，存储到文件中。

附录