http2-express-autopush/lib/esm/index.js

http2 autopush middleware for express

///<reference types='express'/>
import * as path from 'path';
import * as fs from 'fs';
import staticServe from 'serve-static';
import * as h2Auto from 'h2-auto-push';
import * as cookie from 'cookie';
function isHttp2Request(req) {
    return !!req.stream;
}
function isHttp2Response(res) {
    return !!res.stream;
}
function isStatic(url, root) {
    try {
        const filePath = path.join(root, url);
        const stat = fs.statSync(filePath);
        return stat.isFile();
    }
    catch (err) {
        return false;
    }
}
const CACHE_COOKIE_KEY = '__ap_cache__';
export default function serveAutoPush(root, staticOptions, cacheConfig) {
    if (!root) {
        throw Error('root path required');
    }
    if (typeof root !== 'string') {
        throw Error('root path must be a string');
    }
    const rootDir = path.resolve(root);
    let ap;
    if (cacheConfig) {
        ap = new h2Auto.AutoPush(root, cacheConfig);
    }
    else {
        ap = new h2Auto.AutoPush(root);
    }
    return [
        async function (req, res, next) {
            if (isHttp2Request(req) && isHttp2Response(res)) {
                try {
                    const reqPath = req.url;
                    const reqStream = req.stream;
                    const cookies = cookie.parse(req.headers['cookie'] || '');
                    const cacheKey = cookies[CACHE_COOKIE_KEY];
                    const { newCacheCookie, pushFn } = await ap.preprocessRequest(reqPath, reqStream, cacheKey);
                    res.setHeader('set-cookie', cookie.serialize(CACHE_COOKIE_KEY, newCacheCookie, { path: '/' }));
                    reqStream.on('pushError', err => {
                        console.error('Error while pushing', err);
                    });
                    const resStream = res.stream;
                    if (isStatic(req.url, rootDir)) {
                        ap.recordRequestPath(resStream.session, reqPath, true);
                    }
                    else {
                        ap.recordRequestPath(resStream.session, reqPath, false);
                    }
                    pushFn().then(noop, noop);
                }
                catch (err) {
                    console.error('Error while autopush', err);
                }
            }
            next();
        },
        staticServe(rootDir, staticOptions)
    ];
}
function noop() { }
module.exports = serveAutoPush;
module.exports.default = serveAutoPush;