'use strict'
/**
* static files (404.html, sw.js, conf.js)
*/
const ASSET_URL = 'https://hunshcn.github.io/gh-proxy/'
// 前缀，如果自定义路由为example.com/gh/*，将PREFIX改为 '/gh/'，注意，少一个杠都会错！
const PREFIX = '/'
// git使用cnpmjs镜像、分支文件使用jsDelivr镜像的开关，0为关闭，默认开启
const Config = {
jsdelivr: 1,
cnpmjs: 1
}
/** @type {RequestInit} */
const PREFLIGHT_INIT = {
status: 204,
headers: new Headers({
'access-control-allow-origin': '*',
'access-control-allow-methods': 'GET,POST,PUT,PATCH,TRACE,DELETE,HEAD,OPTIONS',
'access-control-max-age': '1728000',
}),
}
/**
* @param {any} body
* @param {number} status
* @param {Object<string, string>} headers
*/
function makeRes(body, status = 200, headers = {}) {
headers['access-control-allow-origin'] = '*'
return new Response(body, {status, headers})
}
/**
* @param {string} urlStr
*/
function newUrl(urlStr) {
try {
return new URL(urlStr)
} catch (err) {
return null
}
}
addEventListener('fetch', e => {
const ret = fetchHandler(e)
.catch(err => makeRes('cfworker error:\n' + err.stack, 502))
e.respondWith(ret)
})
/**
* @param {FetchEvent} e
*/
async function fetchHandler(e) {
const req = e.request
const urlStr = req.url
const urlObj = new URL(urlStr)
let path = urlObj.searchParams.get('q')
if (path) {
return Response.redirect('https://' + urlObj.host + PREFIX + path, 301)
}
// cfworker 会把路径中的 `//` 合并成 `/`
path = urlObj.href.substr(urlObj.origin.length + PREFIX.length).replace(/^https?:\/+/, 'https://')
const exp1 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:releases|archive)\/.*$/i
const exp2 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:blob)\/.*$/i
const exp3 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:info|git-).*$/i
const exp4 = /^(?:https?:\/\/)?raw\.githubusercontent\.com\/.+?\/.+?\/.+?\/.+$/i
const exp5 = /^(?:https?:\/\/)?gist\.(?:githubusercontent|github)\.com\/.+?\/.+?\/.+$/i
if (path.search(exp1) === 0 || path.search(exp5) === 0 || !Config.cnpmjs && (path.search(exp3) === 0 || path.search(exp4) === 0)) {
return httpHandler(req, path)
} else if (path.search(exp2) === 0) {
if (Config.jsdelivr){
const newUrl = path.replace('/blob/', '@').replace(/^(?:https?:\/\/)?github\.com/, 'https://cdn.jsdelivr.net/gh')
return Response.redirect(newUrl, 302)
}else{
path = path.replace('/blob/', '/raw/')
return httpHandler(req, path)
}
} else if (path.search(exp3) === 0) {
const newUrl = path.replace(/^(?:https?:\/\/)?github\.com/, 'https://github.com.cnpmjs.org')
return Response.redirect(newUrl, 302)
} else if (path.search(exp4) === 0) {
const newUrl = path.replace(/(?<=com\/.+?\/.+?)\/(.+?\/)/, '@$1').replace(/^(?:https?:\/\/)?raw\.githubusercontent\.com/, 'https://cdn.jsdelivr.net/gh')
return Response.redirect(newUrl, 302)
} else {
return fetch(ASSET_URL + path)
}
}
/**
* @param {Request} req
* @param {string} pathname
*/
function httpHandler(req, pathname) {
const reqHdrRaw = req.headers
// preflight
if (req.method === 'OPTIONS' &&
reqHdrRaw.has('access-control-request-headers')
) {
return new Response(null, PREFLIGHT_INIT)
}
let rawLen = ''
const reqHdrNew = new Headers(reqHdrRaw)
let urlStr = pathname
if (urlStr.startsWith('github')) {
urlStr = 'https://' + urlStr
}
const urlObj = newUrl(urlStr)
/** @type {RequestInit} */
const reqInit = {
method: req.method,
headers: reqHdrNew,
redirect: 'follow',
body: req.body
}
return proxy(urlObj, reqInit, rawLen, 0)
}
/**
*
* @param {URL} urlObj
* @param {RequestInit} reqInit
*/
async function proxy(urlObj, reqInit, rawLen) {
const res = await fetch(urlObj.href, reqInit)
const resHdrOld = res.headers
const resHdrNew = new Headers(resHdrOld)
// verify
if (rawLen) {
const newLen = resHdrOld.get('content-length') || ''
const badLen = (rawLen !== newLen)
if (badLen) {
return makeRes(res.body, 400, {
'--error': `bad len: ${newLen}, except: ${rawLen}`,
'access-control-expose-headers': '--error',
})
}
}
const status = res.status
resHdrNew.set('access-control-expose-headers', '*')
resHdrNew.set('access-control-allow-origin', '*')
resHdrNew.delete('content-security-policy')
resHdrNew.delete('content-security-policy-report-only')
resHdrNew.delete('clear-site-data')
return new Response(res.body, {
status,
headers: resHdrNew,
})
}
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