opusdev/vector-similarity-api

1/*!2 * send3 * Copyright(c) 2012 TJ Holowaychuk4 * Copyright(c) 2014-2022 Douglas Christopher Wilson5 * MIT Licensed6 */7 8'use strict'9 10/**11 * Module dependencies.12 * @private13 */14 15var createError = require('http-errors')16var debug = require('debug')('send')17var deprecate = require('depd')('send')18var destroy = require('destroy')19var encodeUrl = require('encodeurl')20var escapeHtml = require('escape-html')21var etag = require('etag')22var fresh = require('fresh')23var fs = require('fs')24var mime = require('mime')25var ms = require('ms')26var onFinished = require('on-finished')27var parseRange = require('range-parser')28var path = require('path')29var statuses = require('statuses')30var Stream = require('stream')31var util = require('util')32 33/**34 * Path function references.35 * @private36 */37 38var extname = path.extname39var join = path.join40var normalize = path.normalize41var resolve = path.resolve42var sep = path.sep43 44/**45 * Regular expression for identifying a bytes Range header.46 * @private47 */48 49var BYTES_RANGE_REGEXP = /^ *bytes=/50 51/**52 * Maximum value allowed for the max age.53 * @private54 */55 56var MAX_MAXAGE = 60 * 60 * 24 * 365 * 1000 // 1 year57 58/**59 * Regular expression to match a path with a directory up component.60 * @private61 */62 63var UP_PATH_REGEXP = /(?:^|[\\/])\.\.(?:[\\/]|$)/64 65/**66 * Module exports.67 * @public68 */69 70module.exports = send71module.exports.mime = mime72 73/**74 * Return a `SendStream` for `req` and `path`.75 *76 * @param {object} req77 * @param {string} path78 * @param {object} [options]79 * @return {SendStream}80 * @public81 */82 83function send (req, path, options) {84  return new SendStream(req, path, options)85}86 87/**88 * Initialize a `SendStream` with the given `path`.89 *90 * @param {Request} req91 * @param {String} path92 * @param {object} [options]93 * @private94 */95 96function SendStream (req, path, options) {97  Stream.call(this)98 99  var opts = options || {}100 101  this.options = opts102  this.path = path103  this.req = req104 105  this._acceptRanges = opts.acceptRanges !== undefined106    ? Boolean(opts.acceptRanges)107    : true108 109  this._cacheControl = opts.cacheControl !== undefined110    ? Boolean(opts.cacheControl)111    : true112 113  this._etag = opts.etag !== undefined114    ? Boolean(opts.etag)115    : true116 117  this._dotfiles = opts.dotfiles !== undefined118    ? opts.dotfiles119    : 'ignore'120 121  if (this._dotfiles !== 'ignore' && this._dotfiles !== 'allow' && this._dotfiles !== 'deny') {122    throw new TypeError('dotfiles option must be "allow", "deny", or "ignore"')123  }124 125  this._hidden = Boolean(opts.hidden)126 127  if (opts.hidden !== undefined) {128    deprecate('hidden: use dotfiles: \'' + (this._hidden ? 'allow' : 'ignore') + '\' instead')129  }130 131  // legacy support132  if (opts.dotfiles === undefined) {133    this._dotfiles = undefined134  }135 136  this._extensions = opts.extensions !== undefined137    ? normalizeList(opts.extensions, 'extensions option')138    : []139 140  this._immutable = opts.immutable !== undefined141    ? Boolean(opts.immutable)142    : false143 144  this._index = opts.index !== undefined145    ? normalizeList(opts.index, 'index option')146    : ['index.html']147 148  this._lastModified = opts.lastModified !== undefined149    ? Boolean(opts.lastModified)150    : true151 152  this._maxage = opts.maxAge || opts.maxage153  this._maxage = typeof this._maxage === 'string'154    ? ms(this._maxage)155    : Number(this._maxage)156  this._maxage = !isNaN(this._maxage)157    ? Math.min(Math.max(0, this._maxage), MAX_MAXAGE)158    : 0159 160  this._root = opts.root161    ? resolve(opts.root)162    : null163 164  if (!this._root && opts.from) {165    this.from(opts.from)166  }167}168 169/**170 * Inherits from `Stream`.171 */172 173util.inherits(SendStream, Stream)174 175/**176 * Enable or disable etag generation.177 *178 * @param {Boolean} val179 * @return {SendStream}180 * @api public181 */182 183SendStream.prototype.etag = deprecate.function(function etag (val) {184  this._etag = Boolean(val)185  debug('etag %s', this._etag)186  return this187}, 'send.etag: pass etag as option')188 189/**190 * Enable or disable "hidden" (dot) files.191 *192 * @param {Boolean} path193 * @return {SendStream}194 * @api public195 */196 197SendStream.prototype.hidden = deprecate.function(function hidden (val) {198  this._hidden = Boolean(val)199  this._dotfiles = undefined200  debug('hidden %s', this._hidden)201  return this202}, 'send.hidden: use dotfiles option')203 204/**205 * Set index `paths`, set to a falsy206 * value to disable index support.207 *208 * @param {String|Boolean|Array} paths209 * @return {SendStream}210 * @api public211 */212 213SendStream.prototype.index = deprecate.function(function index (paths) {214  var index = !paths ? [] : normalizeList(paths, 'paths argument')215  debug('index %o', paths)216  this._index = index217  return this218}, 'send.index: pass index as option')219 220/**221 * Set root `path`.222 *223 * @param {String} path224 * @return {SendStream}225 * @api public226 */227 228SendStream.prototype.root = function root (path) {229  this._root = resolve(String(path))230  debug('root %s', this._root)231  return this232}233 234SendStream.prototype.from = deprecate.function(SendStream.prototype.root,235  'send.from: pass root as option')236 237SendStream.prototype.root = deprecate.function(SendStream.prototype.root,238  'send.root: pass root as option')239 240/**241 * Set max-age to `maxAge`.242 *243 * @param {Number} maxAge244 * @return {SendStream}245 * @api public246 */247 248SendStream.prototype.maxage = deprecate.function(function maxage (maxAge) {249  this._maxage = typeof maxAge === 'string'250    ? ms(maxAge)251    : Number(maxAge)252  this._maxage = !isNaN(this._maxage)253    ? Math.min(Math.max(0, this._maxage), MAX_MAXAGE)254    : 0255  debug('max-age %d', this._maxage)256  return this257}, 'send.maxage: pass maxAge as option')258 259/**260 * Emit error with `status`.261 *262 * @param {number} status263 * @param {Error} [err]264 * @private265 */266 267SendStream.prototype.error = function error (status, err) {268  // emit if listeners instead of responding269  if (hasListeners(this, 'error')) {270    return this.emit('error', createHttpError(status, err))271  }272 273  var res = this.res274  var msg = statuses.message[status] || String(status)275  var doc = createHtmlDocument('Error', escapeHtml(msg))276 277  // clear existing headers278  clearHeaders(res)279 280  // add error headers281  if (err && err.headers) {282    setHeaders(res, err.headers)283  }284 285  // send basic response286  res.statusCode = status287  res.setHeader('Content-Type', 'text/html; charset=UTF-8')288  res.setHeader('Content-Length', Buffer.byteLength(doc))289  res.setHeader('Content-Security-Policy', "default-src 'none'")290  res.setHeader('X-Content-Type-Options', 'nosniff')291  res.end(doc)292}293 294/**295 * Check if the pathname ends with "/".296 *297 * @return {boolean}298 * @private299 */300 301SendStream.prototype.hasTrailingSlash = function hasTrailingSlash () {302  return this.path[this.path.length - 1] === '/'303}304 305/**306 * Check if this is a conditional GET request.307 *308 * @return {Boolean}309 * @api private310 */311 312SendStream.prototype.isConditionalGET = function isConditionalGET () {313  return this.req.headers['if-match'] ||314    this.req.headers['if-unmodified-since'] ||315    this.req.headers['if-none-match'] ||316    this.req.headers['if-modified-since']317}318 319/**320 * Check if the request preconditions failed.321 *322 * @return {boolean}323 * @private324 */325 326SendStream.prototype.isPreconditionFailure = function isPreconditionFailure () {327  var req = this.req328  var res = this.res329 330  // if-match331  var match = req.headers['if-match']332  if (match) {333    var etag = res.getHeader('ETag')334    return !etag || (match !== '*' && parseTokenList(match).every(function (match) {335      return match !== etag && match !== 'W/' + etag && 'W/' + match !== etag336    }))337  }338 339  // if-unmodified-since340  var unmodifiedSince = parseHttpDate(req.headers['if-unmodified-since'])341  if (!isNaN(unmodifiedSince)) {342    var lastModified = parseHttpDate(res.getHeader('Last-Modified'))343    return isNaN(lastModified) || lastModified > unmodifiedSince344  }345 346  return false347}348 349/**350 * Strip various content header fields for a change in entity.351 *352 * @private353 */354 355SendStream.prototype.removeContentHeaderFields = function removeContentHeaderFields () {356  var res = this.res357 358  res.removeHeader('Content-Encoding')359  res.removeHeader('Content-Language')360  res.removeHeader('Content-Length')361  res.removeHeader('Content-Range')362  res.removeHeader('Content-Type')363}364 365/**366 * Respond with 304 not modified.367 *368 * @api private369 */370 371SendStream.prototype.notModified = function notModified () {372  var res = this.res373  debug('not modified')374  this.removeContentHeaderFields()375  res.statusCode = 304376  res.end()377}378 379/**380 * Raise error that headers already sent.381 *382 * @api private383 */384 385SendStream.prototype.headersAlreadySent = function headersAlreadySent () {386  var err = new Error('Can\'t set headers after they are sent.')387  debug('headers already sent')388  this.error(500, err)389}390 391/**392 * Check if the request is cacheable, aka393 * responded with 2xx or 304 (see RFC 2616 section 14.2{5,6}).394 *395 * @return {Boolean}396 * @api private397 */398 399SendStream.prototype.isCachable = function isCachable () {400  var statusCode = this.res.statusCode401  return (statusCode >= 200 && statusCode < 300) ||402    statusCode === 304403}404 405/**406 * Handle stat() error.407 *408 * @param {Error} error409 * @private410 */411 412SendStream.prototype.onStatError = function onStatError (error) {413  switch (error.code) {414    case 'ENAMETOOLONG':415    case 'ENOENT':416    case 'ENOTDIR':417      this.error(404, error)418      break419    default:420      this.error(500, error)421      break422  }423}424 425/**426 * Check if the cache is fresh.427 *428 * @return {Boolean}429 * @api private430 */431 432SendStream.prototype.isFresh = function isFresh () {433  return fresh(this.req.headers, {434    etag: this.res.getHeader('ETag'),435    'last-modified': this.res.getHeader('Last-Modified')436  })437}438 439/**440 * Check if the range is fresh.441 *442 * @return {Boolean}443 * @api private444 */445 446SendStream.prototype.isRangeFresh = function isRangeFresh () {447  var ifRange = this.req.headers['if-range']448 449  if (!ifRange) {450    return true451  }452 453  // if-range as etag454  if (ifRange.indexOf('"') !== -1) {455    var etag = this.res.getHeader('ETag')456    return Boolean(etag && ifRange.indexOf(etag) !== -1)457  }458 459  // if-range as modified date460  var lastModified = this.res.getHeader('Last-Modified')461  return parseHttpDate(lastModified) <= parseHttpDate(ifRange)462}463 464/**465 * Redirect to path.466 *467 * @param {string} path468 * @private469 */470 471SendStream.prototype.redirect = function redirect (path) {472  var res = this.res473 474  if (hasListeners(this, 'directory')) {475    this.emit('directory', res, path)476    return477  }478 479  if (this.hasTrailingSlash()) {480    this.error(403)481    return482  }483 484  var loc = encodeUrl(collapseLeadingSlashes(this.path + '/'))485  var doc = createHtmlDocument('Redirecting', 'Redirecting to ' + escapeHtml(loc))486 487  // redirect488  res.statusCode = 301489  res.setHeader('Content-Type', 'text/html; charset=UTF-8')490  res.setHeader('Content-Length', Buffer.byteLength(doc))491  res.setHeader('Content-Security-Policy', "default-src 'none'")492  res.setHeader('X-Content-Type-Options', 'nosniff')493  res.setHeader('Location', loc)494  res.end(doc)495}496 497/**498 * Pipe to `res.499 *500 * @param {Stream} res501 * @return {Stream} res502 * @api public503 */504 505SendStream.prototype.pipe = function pipe (res) {506  // root path507  var root = this._root508 509  // references510  this.res = res511 512  // decode the path513  var path = decode(this.path)514  if (path === -1) {515    this.error(400)516    return res517  }518 519  // null byte(s)520  if (~path.indexOf('\0')) {521    this.error(400)522    return res523  }524 525  var parts526  if (root !== null) {527    // normalize528    if (path) {529      path = normalize('.' + sep + path)530    }531 532    // malicious path533    if (UP_PATH_REGEXP.test(path)) {534      debug('malicious path "%s"', path)535      this.error(403)536      return res537    }538 539    // explode path parts540    parts = path.split(sep)541 542    // join / normalize from optional root dir543    path = normalize(join(root, path))544  } else {545    // ".." is malicious without "root"546    if (UP_PATH_REGEXP.test(path)) {547      debug('malicious path "%s"', path)548      this.error(403)549      return res550    }551 552    // explode path parts553    parts = normalize(path).split(sep)554 555    // resolve the path556    path = resolve(path)557  }558 559  // dotfile handling560  if (containsDotFile(parts)) {561    var access = this._dotfiles562 563    // legacy support564    if (access === undefined) {565      access = parts[parts.length - 1][0] === '.'566        ? (this._hidden ? 'allow' : 'ignore')567        : 'allow'568    }569 570    debug('%s dotfile "%s"', access, path)571    switch (access) {572      case 'allow':573        break574      case 'deny':575        this.error(403)576        return res577      case 'ignore':578      default:579        this.error(404)580        return res581    }582  }583 584  // index file support585  if (this._index.length && this.hasTrailingSlash()) {586    this.sendIndex(path)587    return res588  }589 590  this.sendFile(path)591  return res592}593 594/**595 * Transfer `path`.596 *597 * @param {String} path598 * @api public599 */600 601SendStream.prototype.send = function send (path, stat) {602  var len = stat.size603  var options = this.options604  var opts = {}605  var res = this.res606  var req = this.req607  var ranges = req.headers.range608  var offset = options.start || 0609 610  if (headersSent(res)) {611    // impossible to send now612    this.headersAlreadySent()613    return614  }615 616  debug('pipe "%s"', path)617 618  // set header fields619  this.setHeader(path, stat)620 621  // set content-type622  this.type(path)623 624  // conditional GET support625  if (this.isConditionalGET()) {626    if (this.isPreconditionFailure()) {627      this.error(412)628      return629    }630 631    if (this.isCachable() && this.isFresh()) {632      this.notModified()633      return634    }635  }636 637  // adjust len to start/end options638  len = Math.max(0, len - offset)639  if (options.end !== undefined) {640    var bytes = options.end - offset + 1641    if (len > bytes) len = bytes642  }643 644  // Range support645  if (this._acceptRanges && BYTES_RANGE_REGEXP.test(ranges)) {646    // parse647    ranges = parseRange(len, ranges, {648      combine: true649    })650 651    // If-Range support652    if (!this.isRangeFresh()) {653      debug('range stale')654      ranges = -2655    }656 657    // unsatisfiable658    if (ranges === -1) {659      debug('range unsatisfiable')660 661      // Content-Range662      res.setHeader('Content-Range', contentRange('bytes', len))663 664      // 416 Requested Range Not Satisfiable665      return this.error(416, {666        headers: { 'Content-Range': res.getHeader('Content-Range') }667      })668    }669 670    // valid (syntactically invalid/multiple ranges are treated as a regular response)671    if (ranges !== -2 && ranges.length === 1) {672      debug('range %j', ranges)673 674      // Content-Range675      res.statusCode = 206676      res.setHeader('Content-Range', contentRange('bytes', len, ranges[0]))677 678      // adjust for requested range679      offset += ranges[0].start680      len = ranges[0].end - ranges[0].start + 1681    }682  }683 684  // clone options685  for (var prop in options) {686    opts[prop] = options[prop]687  }688 689  // set read options690  opts.start = offset691  opts.end = Math.max(offset, offset + len - 1)692 693  // content-length694  res.setHeader('Content-Length', len)695 696  // HEAD support697  if (req.method === 'HEAD') {698    res.end()699    return700  }701 702  this.stream(path, opts)703}704 705/**706 * Transfer file for `path`.707 *708 * @param {String} path709 * @api private710 */711SendStream.prototype.sendFile = function sendFile (path) {712  var i = 0713  var self = this714 715  debug('stat "%s"', path)716  fs.stat(path, function onstat (err, stat) {717    if (err && err.code === 'ENOENT' && !extname(path) && path[path.length - 1] !== sep) {718      // not found, check extensions719      return next(err)720    }721    if (err) return self.onStatError(err)722    if (stat.isDirectory()) return self.redirect(path)723    self.emit('file', path, stat)724    self.send(path, stat)725  })726 727  function next (err) {728    if (self._extensions.length <= i) {729      return err730        ? self.onStatError(err)731        : self.error(404)732    }733 734    var p = path + '.' + self._extensions[i++]735 736    debug('stat "%s"', p)737    fs.stat(p, function (err, stat) {738      if (err) return next(err)739      if (stat.isDirectory()) return next()740      self.emit('file', p, stat)741      self.send(p, stat)742    })743  }744}745 746/**747 * Transfer index for `path`.748 *749 * @param {String} path750 * @api private751 */752SendStream.prototype.sendIndex = function sendIndex (path) {753  var i = -1754  var self = this755 756  function next (err) {757    if (++i >= self._index.length) {758      if (err) return self.onStatError(err)759      return self.error(404)760    }761 762    var p = join(path, self._index[i])763 764    debug('stat "%s"', p)765    fs.stat(p, function (err, stat) {766      if (err) return next(err)767      if (stat.isDirectory()) return next()768      self.emit('file', p, stat)769      self.send(p, stat)770    })771  }772 773  next()774}775 776/**777 * Stream `path` to the response.778 *779 * @param {String} path780 * @param {Object} options781 * @api private782 */783 784SendStream.prototype.stream = function stream (path, options) {785  var self = this786  var res = this.res787 788  // pipe789  var stream = fs.createReadStream(path, options)790  this.emit('stream', stream)791  stream.pipe(res)792 793  // cleanup794  function cleanup () {795    destroy(stream, true)796  }797 798  // response finished, cleanup799  onFinished(res, cleanup)800 801  // error handling802  stream.on('error', function onerror (err) {803    // clean up stream early804    cleanup()805 806    // error807    self.onStatError(err)808  })809 810  // end811  stream.on('end', function onend () {812    self.emit('end')813  })814}815 816/**817 * Set content-type based on `path`818 * if it hasn't been explicitly set.819 *820 * @param {String} path821 * @api private822 */823 824SendStream.prototype.type = function type (path) {825  var res = this.res826 827  if (res.getHeader('Content-Type')) return828 829  var type = mime.lookup(path)830 831  if (!type) {832    debug('no content-type')833    return834  }835 836  var charset = mime.charsets.lookup(type)837 838  debug('content-type %s', type)839  res.setHeader('Content-Type', type + (charset ? '; charset=' + charset : ''))840}841 842/**843 * Set response header fields, most844 * fields may be pre-defined.845 *846 * @param {String} path847 * @param {Object} stat848 * @api private849 */850 851SendStream.prototype.setHeader = function setHeader (path, stat) {852  var res = this.res853 854  this.emit('headers', res, path, stat)855 856  if (this._acceptRanges && !res.getHeader('Accept-Ranges')) {857    debug('accept ranges')858    res.setHeader('Accept-Ranges', 'bytes')859  }860 861  if (this._cacheControl && !res.getHeader('Cache-Control')) {862    var cacheControl = 'public, max-age=' + Math.floor(this._maxage / 1000)863 864    if (this._immutable) {865      cacheControl += ', immutable'866    }867 868    debug('cache-control %s', cacheControl)869    res.setHeader('Cache-Control', cacheControl)870  }871 872  if (this._lastModified && !res.getHeader('Last-Modified')) {873    var modified = stat.mtime.toUTCString()874    debug('modified %s', modified)875    res.setHeader('Last-Modified', modified)876  }877 878  if (this._etag && !res.getHeader('ETag')) {879    var val = etag(stat)880    debug('etag %s', val)881    res.setHeader('ETag', val)882  }883}884 885/**886 * Clear all headers from a response.887 *888 * @param {object} res889 * @private890 */891 892function clearHeaders (res) {893  var headers = getHeaderNames(res)894 895  for (var i = 0; i < headers.length; i++) {896    res.removeHeader(headers[i])897  }898}899 900/**901 * Collapse all leading slashes into a single slash902 *903 * @param {string} str904 * @private905 */906function collapseLeadingSlashes (str) {907  for (var i = 0; i < str.length; i++) {908    if (str[i] !== '/') {909      break910    }911  }912 913  return i > 1914    ? '/' + str.substr(i)915    : str916}917 918/**919 * Determine if path parts contain a dotfile.920 *921 * @api private922 */923 924function containsDotFile (parts) {925  for (var i = 0; i < parts.length; i++) {926    var part = parts[i]927    if (part.length > 1 && part[0] === '.') {928      return true929    }930  }931 932  return false933}934 935/**936 * Create a Content-Range header.937 *938 * @param {string} type939 * @param {number} size940 * @param {array} [range]941 */942 943function contentRange (type, size, range) {944  return type + ' ' + (range ? range.start + '-' + range.end : '*') + '/' + size945}946 947/**948 * Create a minimal HTML document.949 *950 * @param {string} title951 * @param {string} body952 * @private953 */954 955function createHtmlDocument (title, body) {956  return '<!DOCTYPE html>\n' +957    '<html lang="en">\n' +958    '<head>\n' +959    '<meta charset="utf-8">\n' +960    '<title>' + title + '</title>\n' +961    '</head>\n' +962    '<body>\n' +963    '<pre>' + body + '</pre>\n' +964    '</body>\n' +965    '</html>\n'966}967 968/**969 * Create a HttpError object from simple arguments.970 *971 * @param {number} status972 * @param {Error|object} err973 * @private974 */975 976function createHttpError (status, err) {977  if (!err) {978    return createError(status)979  }980 981  return err instanceof Error982    ? createError(status, err, { expose: false })983    : createError(status, err)984}985 986/**987 * decodeURIComponent.988 *989 * Allows V8 to only deoptimize this fn instead of all990 * of send().991 *992 * @param {String} path993 * @api private994 */995 996function decode (path) {997  try {998    return decodeURIComponent(path)999  } catch (err) {1000    return -11001  }1002}1003 1004/**1005 * Get the header names on a respnse.1006 *1007 * @param {object} res1008 * @returns {array[string]}1009 * @private1010 */1011 1012function getHeaderNames (res) {1013  return typeof res.getHeaderNames !== 'function'1014    ? Object.keys(res._headers || {})1015    : res.getHeaderNames()1016}1017 1018/**1019 * Determine if emitter has listeners of a given type.1020 *1021 * The way to do this check is done three different ways in Node.js >= 0.81022 * so this consolidates them into a minimal set using instance methods.1023 *1024 * @param {EventEmitter} emitter1025 * @param {string} type1026 * @returns {boolean}1027 * @private1028 */1029 1030function hasListeners (emitter, type) {1031  var count = typeof emitter.listenerCount !== 'function'1032    ? emitter.listeners(type).length1033    : emitter.listenerCount(type)1034 1035  return count > 01036}1037 1038/**1039 * Determine if the response headers have been sent.1040 *1041 * @param {object} res1042 * @returns {boolean}1043 * @private1044 */1045 1046function headersSent (res) {1047  return typeof res.headersSent !== 'boolean'1048    ? Boolean(res._header)1049    : res.headersSent1050}1051 1052/**1053 * Normalize the index option into an array.1054 *1055 * @param {boolean|string|array} val1056 * @param {string} name1057 * @private1058 */1059 1060function normalizeList (val, name) {1061  var list = [].concat(val || [])1062 1063  for (var i = 0; i < list.length; i++) {1064    if (typeof list[i] !== 'string') {1065      throw new TypeError(name + ' must be array of strings or false')1066    }1067  }1068 1069  return list1070}1071 1072/**1073 * Parse an HTTP Date into a number.1074 *1075 * @param {string} date1076 * @private1077 */1078 1079function parseHttpDate (date) {1080  var timestamp = date && Date.parse(date)1081 1082  return typeof timestamp === 'number'1083    ? timestamp1084    : NaN1085}1086 1087/**1088 * Parse a HTTP token list.1089 *1090 * @param {string} str1091 * @private1092 */1093 1094function parseTokenList (str) {1095  var end = 01096  var list = []1097  var start = 01098 1099  // gather tokens1100  for (var i = 0, len = str.length; i < len; i++) {1101    switch (str.charCodeAt(i)) {1102      case 0x20: /*   */1103        if (start === end) {1104          start = end = i + 11105        }1106        break1107      case 0x2c: /* , */1108        if (start !== end) {1109          list.push(str.substring(start, end))1110        }1111        start = end = i + 11112        break1113      default:1114        end = i + 11115        break1116    }1117  }1118 1119  // final token1120  if (start !== end) {1121    list.push(str.substring(start, end))1122  }1123 1124  return list1125}1126 1127/**1128 * Set an object of headers on a response.1129 *1130 * @param {object} res1131 * @param {object} headers1132 * @private1133 */1134 1135function setHeaders (res, headers) {1136  var keys = Object.keys(headers)1137 1138  for (var i = 0; i < keys.length; i++) {1139    var key = keys[i]1140    res.setHeader(key, headers[key])1141  }1142}1143