Atrist

# configstore 存储

# 环境准备

git clone https://github.com/yeoman/configstore.git

# package.json

"scripts": {
    "test": "xo && ava"
},
"files": [
    "index.js"
],

# index.js

源码 
import path from 'path';
import os from 'os';
import fs from 'graceful-fs';
import {xdgConfig} from 'xdg-basedir';
import writeFileAtomic from 'write-file-atomic';
import dotProp from 'dot-prop';
import uniqueString from 'unique-string';

const configDirectory = xdgConfig || path.join(os.tmpdir(), uniqueString());
const permissionError = 'You don\'t have access to this file.';
const mkdirOptions = {mode: 0o0700, recursive: true};
const writeFileOptions = {mode: 0o0600};

export default class Configstore {
	constructor(id, defaults, options = {}) {
		const pathPrefix = options.globalConfigPath ?
			path.join(id, 'config.json') :
			path.join('configstore', `${id}.json`);

		this._path = options.configPath || path.join(configDirectory, pathPrefix);

		if (defaults) {
			this.all = {
				...defaults,
				...this.all
			};
		}
	}
	get all() {
		try {
			return JSON.parse(fs.readFileSync(this._path, 'utf8'));
		} catch (error) {
			// Create directory if it doesn't exist
			if (error.code === 'ENOENT') {
				return {};
			}

			// Improve the message of permission errors
			if (error.code === 'EACCES') {
				error.message = `${error.message}\n${permissionError}\n`;
			}

			// Empty the file if it encounters invalid JSON
			if (error.name === 'SyntaxError') {
				writeFileAtomic.sync(this._path, '', writeFileOptions);
				return {};
			}

			throw error;
		}
	}
	set all(value) {
		try {
			// Make sure the folder exists as it could have been deleted in the meantime
			fs.mkdirSync(path.dirname(this._path), mkdirOptions);

			writeFileAtomic.sync(this._path, JSON.stringify(value, undefined, '\t'), writeFileOptions);
		} catch (error) {
			// Improve the message of permission errors
			if (error.code === 'EACCES') {
				error.message = `${error.message}\n${permissionError}\n`;
			}

			throw error;
		}
	}
	get size() {
		return Object.keys(this.all || {}).length;
	}
	get(key) {
		return dotProp.get(this.all, key);
	}
	set(key, value) {
		const config = this.all;

		if (arguments.length === 1) {
			for (const k of Object.keys(key)) {
				dotProp.set(config, k, key[k]);
			}
		} else {
			dotProp.set(config, key, value);
		}

		this.all = config;
	}
	has(key) {
		return dotProp.has(this.all, key);
	}
	delete(key) {
		const config = this.all;
		dotProp.delete(config, key);
		this.all = config;
	}
	clear() {
		this.all = {};
	}
	get path() {
		return this._path;
	}
}

# 关于引入的包

import path from 'path';
import os from 'os';
import fs from 'graceful-fs';
import { xdgConfig } from 'xdg-basedir';
import writeFileAtomic from 'write-file-atomic';
import dotProp from 'dot-prop';
import uniqueString from 'unique-string';
  • path: 用于处理文件和目录的路径。
  • os: 提供了与操作系统相关的使用方法和属性。
  • graceful-fs： 三方的包，优化原生的fs模块，规范不同操作系统或环境的行为
  • xdg-basedir：获取 XDG 基本目录路径，<适用于linux系统>
  • write-file-atomic: 作为 fs.writeFile的扩展，使得写入操作具有原子性且允许设置文件所有权
  • dot-prop：用扁平的方式去获取, 设置或者删除嵌套对象中的一个属性
  • unique-string：返回一个 32 个字符的唯一字符串

# 几个变量

// 获取 xdgConfig的路径，如果没有则在tmpdir随机生成一个
const configDirectory = xdgConfig || path.join(os.tmpdir(), uniqueString());
const permissionError = 'You don\'t have access to this file.';
// rwx
const mkdirOptions = {mode: 0o0700, recursive: true};
// rw-
const writeFileOptions = {mode: 0o0600};

# constructor

constructor(id, defaults, options = {}) {
    // 根据配置生成对应的文件目录地址
    const pathPrefix = options.globalConfigPath ? path.join(id, 'config.json') : path.join('configstore', `${id}.json`);
    // 配置文件路径，如果有, 则直接使用
    this._path = options.configPath || path.join(configDirectory, pathPrefix);

    if (defaults) {
        this.all = {
            ...defaults,
            ...this.all
        };
    }
}

# get or set all

	get all() {
		try {
            // 将文件 path 内容读出，并将可能出现的错误呈现出来
			return JSON.parse(fs.readFileSync(this._path, 'utf8'));
		} catch (error) {
			// Create directory if it doesn't exist
			if (error.code === 'ENOENT') {
				return {};
			}
			// Improve the message of permission errors
			if (error.code === 'EACCES') {
				error.message = `${error.message}\n${permissionError}\n`;
			}
			// Empty the file if it encounters invalid JSON
			if (error.name === 'SyntaxError') {
				writeFileAtomic.sync(this._path, '', writeFileOptions);
				return {};
			}
			throw error;
		}
	}
	set all(value) {
		try {
			// Make sure the folder exists as it could have been deleted in the meantime
			fs.mkdirSync(path.dirname(this._path), mkdirOptions);
            // 原子写入所有值
			writeFileAtomic.sync(this._path, JSON.stringify(value, undefined, '\t'), writeFileOptions);
		} catch (error) {
			// Improve the message of permission errors
			if (error.code === 'EACCES') {
				error.message = `${error.message}\n${permissionError}\n`;
			}
			throw error;
		}
	}

# get or set key

	get(key) {
        // 借助 dotProp 从  this.all 获取数据
		return dotProp.get(this.all, key);
	}

	set(key, value) {
        // 设置值
		const config = this.all;
        // length === 1 以 对象的方式进行 设置
		if (arguments.length === 1) {
			for (const k of Object.keys(key)) {
				dotProp.set(config, k, key[k]);
			}
		} else {
			dotProp.set(config, key, value);
		}
        // 重新赋值
		this.all = config;
	}

# detele has clear

	has(key) {
		return dotProp.has(this.all, key);
	}

	delete(key) {
		const config = this.all;
		dotProp.delete(config, key);
		this.all = config;
	}

	clear() {
		this.all = {};
	}

# get path

	get path() {
		return this._path;
	}

# 参考资料

← 第十一期 玩具vite →