const fs = require('fs');
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const { join, normalize, resolve } = require('path');
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const { parse } = require('@polka/url');
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const list = require('totalist/sync');
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const { lookup } = require('mrmime');
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const noop = () => {};
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function isMatch(uri, arr) {
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for (let i=0; i < arr.length; i++) {
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if (arr[i].test(uri)) return true;
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}
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}
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function toAssume(uri, extns) {
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let i=0, x, len=uri.length - 1;
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if (uri.charCodeAt(len) === 47) {
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uri = uri.substring(0, len);
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}
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let arr=[], tmp=`${uri}/index`;
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for (; i < extns.length; i++) {
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x = extns[i] ? `.${extns[i]}` : '';
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if (uri) arr.push(uri + x);
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arr.push(tmp + x);
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}
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return arr;
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}
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function viaCache(cache, uri, extns) {
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let i=0, data, arr=toAssume(uri, extns);
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for (; i < arr.length; i++) {
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if (data = cache[arr[i]]) return data;
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}
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}
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function viaLocal(dir, isEtag, uri, extns) {
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let i=0, arr=toAssume(uri, extns);
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let abs, stats, name, headers;
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for (; i < arr.length; i++) {
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abs = normalize(join(dir, name=arr[i]));
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if (abs.startsWith(dir) && fs.existsSync(abs)) {
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stats = fs.statSync(abs);
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if (stats.isDirectory()) continue;
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headers = toHeaders(name, stats, isEtag);
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headers['Cache-Control'] = isEtag ? 'no-cache' : 'no-store';
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return { abs, stats, headers };
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}
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}
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}
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function is404(req, res) {
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return (res.statusCode=404,res.end());
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}
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function send(req, res, file, stats, headers) {
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let code=200, tmp, opts={};
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headers = { ...headers };
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for (let key in headers) {
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tmp = res.getHeader(key);
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if (tmp) headers[key] = tmp;
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}
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|
if (tmp = res.getHeader('content-type')) {
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headers['Content-Type'] = tmp;
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}
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if (req.headers.range) {
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code = 206;
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let [x, y] = req.headers.range.replace('bytes=', '').split('-');
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let end = opts.end = parseInt(y, 10) || stats.size - 1;
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let start = opts.start = parseInt(x, 10) || 0;
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|
if (start >= stats.size || end >= stats.size) {
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res.setHeader('Content-Range', `bytes */${stats.size}`);
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res.statusCode = 416;
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return res.end();
|
}
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|
headers['Content-Range'] = `bytes ${start}-${end}/${stats.size}`;
|
headers['Content-Length'] = (end - start + 1);
|
headers['Accept-Ranges'] = 'bytes';
|
}
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|
res.writeHead(code, headers);
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fs.createReadStream(file, opts).pipe(res);
|
}
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|
const ENCODING = {
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'.br': 'br',
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'.gz': 'gzip',
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};
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|
function toHeaders(name, stats, isEtag) {
|
let enc = ENCODING[name.slice(-3)];
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|
let ctype = lookup(name.slice(0, enc && -3)) || '';
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if (ctype === 'text/html') ctype += ';charset=utf-8';
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|
let headers = {
|
'Content-Length': stats.size,
|
'Content-Type': ctype,
|
'Last-Modified': stats.mtime.toUTCString(),
|
};
|
|
if (enc) headers['Content-Encoding'] = enc;
|
if (isEtag) headers['ETag'] = `W/"${stats.size}-${stats.mtime.getTime()}"`;
|
|
return headers;
|
}
|
|
module.exports = function (dir, opts={}) {
|
dir = resolve(dir || '.');
|
|
let isNotFound = opts.onNoMatch || is404;
|
let setHeaders = opts.setHeaders || noop;
|
|
let extensions = opts.extensions || ['html', 'htm'];
|
let gzips = opts.gzip && extensions.map(x => `${x}.gz`).concat('gz');
|
let brots = opts.brotli && extensions.map(x => `${x}.br`).concat('br');
|
|
const FILES = {};
|
|
let fallback = '/';
|
let isEtag = !!opts.etag;
|
let isSPA = !!opts.single;
|
if (typeof opts.single === 'string') {
|
let idx = opts.single.lastIndexOf('.');
|
fallback += !!~idx ? opts.single.substring(0, idx) : opts.single;
|
}
|
|
let ignores = [];
|
if (opts.ignores !== false) {
|
ignores.push(/[/]([A-Za-z\s\d~$._-]+\.\w+){1,}$/); // any extn
|
if (opts.dotfiles) ignores.push(/\/\.\w/);
|
else ignores.push(/\/\.well-known/);
|
[].concat(opts.ignores || []).forEach(x => {
|
ignores.push(new RegExp(x, 'i'));
|
});
|
}
|
|
let cc = opts.maxAge != null && `public,max-age=${opts.maxAge}`;
|
if (cc && opts.immutable) cc += ',immutable';
|
else if (cc && opts.maxAge === 0) cc += ',must-revalidate';
|
|
if (!opts.dev) {
|
list(dir, (name, abs, stats) => {
|
if (/\.well-known[\\+\/]/.test(name)) {} // keep
|
else if (!opts.dotfiles && /(^\.|[\\+|\/+]\.)/.test(name)) return;
|
|
let headers = toHeaders(name, stats, isEtag);
|
if (cc) headers['Cache-Control'] = cc;
|
|
FILES['/' + name.normalize().replace(/\\+/g, '/')] = { abs, stats, headers };
|
});
|
}
|
|
let lookup = opts.dev ? viaLocal.bind(0, dir, isEtag) : viaCache.bind(0, FILES);
|
|
return function (req, res, next) {
|
let extns = [''];
|
let pathname = parse(req).pathname;
|
let val = req.headers['accept-encoding'] || '';
|
if (gzips && val.includes('gzip')) extns.unshift(...gzips);
|
if (brots && /(br|brotli)/i.test(val)) extns.unshift(...brots);
|
extns.push(...extensions); // [...br, ...gz, orig, ...exts]
|
|
if (pathname.indexOf('%') !== -1) {
|
try { pathname = decodeURIComponent(pathname) }
|
catch (err) { /* malform uri */ }
|
}
|
|
let data = lookup(pathname, extns) || isSPA && !isMatch(pathname, ignores) && lookup(fallback, extns);
|
if (!data) return next ? next() : isNotFound(req, res);
|
|
if (isEtag && req.headers['if-none-match'] === data.headers['ETag']) {
|
res.writeHead(304);
|
return res.end();
|
}
|
|
if (gzips || brots) {
|
res.setHeader('Vary', 'Accept-Encoding');
|
}
|
|
setHeaders(res, pathname, data.stats);
|
send(req, res, data.abs, data.stats, data.headers);
|
};
|
}
|
