字数
438 字
阅读时间
3 分钟
实现一个静态资源服务器
可实现以下功能:
- 命令行的方式，可传入端口号及目标目录
- 处理 404
- 流式返回资源，处理 Content-Length
- 处理目录，如果请求路径是目录，则自动请求其目录中的 index.html
以下功能选做:
- rewrites
- redirects
- cleanUrls
- trailingSlash
- etag
- symlink
ts
import path from "node:path";
import http, { IncomingMessage, ServerResponse } from "node:http";
import fs from "node:fs";
import { URL } from "node:url";
import arg from "arg";
type Rewrite = {
source: string;
destination: string;
};
type Redirect = Rewrite;
interface Config {
entry?: string;
rewrites?: Rewrite[];
redirects?: Redirect[];
etag?: boolean;
cleanUrls?: boolean;
trailingSlash?: boolean;
symlink?: boolean;
}
async function processDirectory(
absolutePath: string
): Promise<[fs.Stats | null, string]> {
const newAbsolutePath = path.join(absolutePath, "index.html");
try {
const newStat = await fs.promises.lstat(newAbsolutePath);
return [newStat, newAbsolutePath];
} catch (e) {
return [null, newAbsolutePath];
}
}
// 响应 404，此处可做一个优化，比如读取文件系统中的 404.html 文件
function responseNotFound(res: ServerResponse) {
res.statusCode = 404;
res.end("NNNNNNot Found");
}
// mime:
export default async function handler(
req: IncomingMessage,
res: ServerResponse,
config: Config
) {
const pathname = new URL("http://localhost:3000" + req.url ?? "").pathname;
let absolutePath = path.resolve(config.entry ?? "", path.join(".", pathname));
let statusCode = 200;
let stat = null;
try {
stat = await fs.promises.lstat(absolutePath);
} catch (e) {}
if (stat?.isDirectory()) {
// 如果是目录，则去寻找目录中的 index.html
[stat, absolutePath] = await processDirectory(absolutePath);
}
if (stat === null) {
return responseNotFound(res);
}
let headers = {
// 取其文件系统中的体积作为其大小
// 问: 文件的大小与其编码格式有关，那么文件系统的体积应该是如何确定的？
"Content-Length": stat.size,
};
res.writeHead(statusCode, headers);
fs.createReadStream(absolutePath).pipe(res);
}
const args = arg({
"--port": Number,
"-p": "--port",
});
function startEndpoint(port: number, entry: string) {
const server = http.createServer((req, res) => {
handler(req, res, { entry });
});
server.on("error", (err) => {
// 表示端口号已被占用
if ((err as any).code === "EADDRINUSE") {
startEndpoint(port + 1, entry);
return;
}
process.exit(1);
});
server.listen(port, () => {
console.log(`Open http://localhost:${port}`);
});
}
startEndpoint(args["--port"] ?? 3000, args._[0]);贡献者
jiechen