Sub-Store/backend/src/utils/download.js
2025-01-08 19:49:34 +08:00

276 lines
9.3 KiB
JavaScript

import { SETTINGS_KEY } from '@/constants';
import { HTTP, ENV } from '@/vendor/open-api';
import { hex_md5 } from '@/vendor/md5';
import { getPolicyDescriptor } from '@/utils';
import resourceCache from '@/utils/resource-cache';
import headersResourceCache from '@/utils/headers-resource-cache';
import {
getFlowField,
getFlowHeaders,
parseFlowHeaders,
validCheck,
} from '@/utils/flow';
import $ from '@/core/app';
import PROXY_PREPROCESSORS from '@/core/proxy-utils/preprocessors';
const clashPreprocessor = PROXY_PREPROCESSORS.find(
(processor) => processor.name === 'Clash Pre-processor',
);
const tasks = new Map();
export default async function download(
rawUrl = '',
ua,
timeout,
customProxy,
skipCustomCache,
awaitCustomCache,
noCache,
preprocess,
) {
let $arguments = {};
let url = rawUrl.replace(/#noFlow$/, '');
const rawArgs = url.split('#');
url = url.split('#')[0];
if (rawArgs.length > 1) {
try {
// 支持 `#${encodeURIComponent(JSON.stringify({arg1: "1"}))}`
$arguments = JSON.parse(decodeURIComponent(rawArgs[1]));
} catch (e) {
for (const pair of rawArgs[1].split('&')) {
const key = pair.split('=')[0];
const value = pair.split('=')[1];
// 部分兼容之前的逻辑 const value = pair.split('=')[1] || true;
$arguments[key] =
value == null || value === ''
? true
: decodeURIComponent(value);
}
}
}
const { isNode, isStash, isLoon, isShadowRocket, isQX } = ENV();
const {
defaultProxy,
defaultUserAgent,
defaultTimeout,
cacheThreshold: defaultCacheThreshold,
} = $.read(SETTINGS_KEY);
const cacheThreshold = defaultCacheThreshold || 1024;
let proxy = customProxy || defaultProxy;
if ($.env.isNode) {
proxy = proxy || eval('process.env.SUB_STORE_BACKEND_DEFAULT_PROXY');
}
const userAgent = ua || defaultUserAgent || 'clash.meta';
const requestTimeout = timeout || defaultTimeout || 8000;
const id = hex_md5(userAgent + url);
if ($arguments?.cacheKey === true) {
$.error(`使用自定义缓存时 cacheKey 的值不能为空`);
$arguments.cacheKey = undefined;
}
const customCacheKey = $arguments?.cacheKey
? `#sub-store-cached-custom-${$arguments?.cacheKey}`
: undefined;
if (customCacheKey && !skipCustomCache) {
const customCached = $.read(customCacheKey);
const cached = resourceCache.get(id);
if (!noCache && !$arguments?.noCache && cached) {
$.info(
`乐观缓存: URL ${url}\n存在有效的常规缓存\n使用常规缓存以避免重复请求`,
);
return cached;
}
if (customCached) {
if (awaitCustomCache) {
$.info(`乐观缓存: URL ${url}\n本次进行请求 尝试更新缓存`);
try {
await download(
rawUrl.replace(/(\?|&)cacheKey=.*?(&|$)/, ''),
ua,
timeout,
proxy,
true,
undefined,
undefined,
preprocess,
);
} catch (e) {
$.error(
`乐观缓存: URL ${url} 更新缓存发生错误 ${
e.message ?? e
}`,
);
$.info('使用乐观缓存的数据刷新缓存, 防止后续请求');
resourceCache.set(id, customCached);
}
} else {
$.info(
`乐观缓存: URL ${url}\n本次返回自定义缓存 ${$arguments?.cacheKey}\n并进行请求 尝试异步更新缓存`,
);
download(
rawUrl.replace(/(\?|&)cacheKey=.*?(&|$)/, ''),
ua,
timeout,
proxy,
true,
undefined,
undefined,
preprocess,
).catch((e) => {
$.error(
`乐观缓存: URL ${url} 异步更新缓存发生错误 ${
e.message ?? e
}`,
);
});
}
return customCached;
}
}
// const downloadUrlMatch = url.match(/^\/api\/(file|module)\/(.+)/);
// if (downloadUrlMatch) {
// let type = downloadUrlMatch?.[1];
// let name = downloadUrlMatch?.[2];
// if (name == null) {
// throw new Error(`本地 ${type} URL 无效: ${url}`);
// }
// name = decodeURIComponent(name);
// const key = type === 'module' ? MODULES_KEY : FILES_KEY;
// const item = findByName($.read(key), name);
// if (!item) {
// throw new Error(`找不到本地 ${type}: ${name}`);
// }
// return item.content;
// }
if (!isNode && tasks.has(id)) {
return tasks.get(id);
}
const http = HTTP({
headers: {
'User-Agent': userAgent,
...(isStash && proxy
? { 'X-Stash-Selected-Proxy': encodeURIComponent(proxy) }
: {}),
...(isShadowRocket && proxy ? { 'X-Surge-Policy': proxy } : {}),
},
timeout: requestTimeout,
});
let result;
// try to find in app cache
const cached = resourceCache.get(id);
if (!noCache && !$arguments?.noCache && cached) {
$.info(`使用缓存: ${url}, ${userAgent}`);
result = cached;
if (customCacheKey) {
$.info(`URL ${url}\n写入自定义缓存 ${$arguments?.cacheKey}`);
$.write(cached, customCacheKey);
}
} else {
const insecure = $arguments?.insecure
? isNode
? { strictSSL: false }
: { insecure: true }
: undefined;
$.info(
`Downloading...\nUser-Agent: ${userAgent}\nTimeout: ${requestTimeout}\nProxy: ${proxy}\nInsecure: ${!!insecure}\nPreprocess: ${preprocess}\nURL: ${url}`,
);
try {
let { body, headers, statusCode } = await http.get({
url,
...(proxy ? { proxy } : {}),
...(isLoon && proxy ? { node: proxy } : {}),
...(isQX && proxy ? { opts: { policy: proxy } } : {}),
...(proxy ? getPolicyDescriptor(proxy) : {}),
...(insecure ? insecure : {}),
});
$.info(`statusCode: ${statusCode}`);
if (statusCode < 200 || statusCode >= 400) {
throw new Error(`statusCode: ${statusCode}`);
}
if (headers) {
const flowInfo = getFlowField(headers);
if (flowInfo) {
headersResourceCache.set(id, flowInfo);
}
}
if (body.replace(/\s/g, '').length === 0)
throw new Error(new Error('远程资源内容为空'));
if (preprocess) {
try {
if (clashPreprocessor.test(body)) {
body = clashPreprocessor.parse(body, true);
}
} catch (e) {
$.error(`Clash Pre-processor error: ${e}`);
}
}
let shouldCache = true;
if (cacheThreshold) {
const size = body.length / 1024;
if (size > cacheThreshold) {
$.info(
`资源大小 ${size.toFixed(
2,
)} KB 超过了 ${cacheThreshold} KB, 不缓存`,
);
shouldCache = false;
}
}
if (shouldCache) {
resourceCache.set(id, body);
if (customCacheKey) {
$.info(
`URL ${url}\n写入自定义缓存 ${$arguments?.cacheKey}`,
);
$.write(body, customCacheKey);
}
}
result = body;
} catch (e) {
if (customCacheKey) {
const cached = $.read(customCacheKey);
if (cached) {
$.info(
`无法下载 URL ${url}: ${
e.message ?? e
}\n使用自定义缓存 ${$arguments?.cacheKey}`,
);
return cached;
}
}
throw new Error(`无法下载 URL ${url}: ${e.message ?? e}`);
}
}
// 检查订阅有效性
if ($arguments?.validCheck) {
await validCheck(
parseFlowHeaders(
await getFlowHeaders(
url,
$arguments.flowUserAgent,
undefined,
proxy,
$arguments.flowUrl,
),
),
);
}
if (!isNode) {
tasks.set(id, result);
}
return result;
}