const pickle = require('chromium-pickle-js') const path = require('path') const UINT64 = require('cuint').UINT64 const fs = require('fs') /* global WIKI */ /** * Based of express-serve-asar (https://github.com/toyobayashi/express-serve-asar) * by Fenglin Li (https://github.com/toyobayashi) */ const packages = { 'twemoji': path.join(WIKI.ROOTPATH, `assets/svg/twemoji.asar`) } module.exports = { fdCache: {}, async serve (pkgName, req, res, next) { const file = this.readFilesystemSync(packages[pkgName]) const { filesystem, fd } = file const info = filesystem.getFile(req.path.substring(1)) if (info) { res.set({ 'Content-Type': 'image/svg+xml', 'Content-Length': info.size }) fs.createReadStream('', { fd, autoClose: false, start: 8 + filesystem.headerSize + parseInt(info.offset, 10), end: 8 + filesystem.headerSize + parseInt(info.offset, 10) + info.size - 1 }).on('error', (err) => { WIKI.logger.warn(err) res.sendStatus(404) }).pipe(res.status(200)) } else { res.sendStatus(404) } }, async unload () { if (this.fdCache) { WIKI.logger.info('Closing ASAR file descriptors...') for (const fdItem in this.fdCache) { fs.closeSync(this.fdCache[fdItem].fd) } this.fdCache = {} } }, readArchiveHeaderSync (fd) { let size let headerBuf const sizeBuf = Buffer.alloc(8) if (fs.readSync(fd, sizeBuf, 0, 8, null) !== 8) { throw new Error('Unable to read header size') } const sizePickle = pickle.createFromBuffer(sizeBuf) size = sizePickle.createIterator().readUInt32() headerBuf = Buffer.alloc(size) if (fs.readSync(fd, headerBuf, 0, size, null) !== size) { throw new Error('Unable to read header') } const headerPickle = pickle.createFromBuffer(headerBuf) const header = headerPickle.createIterator().readString() return { header: JSON.parse(header), headerSize: size } }, readFilesystemSync (archive) { if (!this.fdCache[archive]) { const fd = fs.openSync(archive, 'r') const header = this.readArchiveHeaderSync(fd) const filesystem = new Filesystem(archive) filesystem.header = header.header filesystem.headerSize = header.headerSize this.fdCache[archive] = { fd, filesystem: filesystem } } return this.fdCache[archive] } } class Filesystem { constructor (src) { this.src = path.resolve(src) this.header = { files: {} } this.offset = UINT64(0) } searchNodeFromDirectory (p) { let json = this.header const dirs = p.split(path.sep) for (const dir of dirs) { if (dir !== '.') { json = json.files[dir] } } return json } getNode (p) { const node = this.searchNodeFromDirectory(path.dirname(p)) const name = path.basename(p) if (name) { return node.files[name] } else { return node } } getFile (p, followLinks) { followLinks = typeof followLinks === 'undefined' ? true : followLinks const info = this.getNode(p) if (!info) { return false } if (info.link && followLinks) { return this.getFile(info.link) } else { return info } } }