@zkochan/pnpm/cached_node_modules/superstatic/lib/responder.js

A fast implementation of npm install

/**
 * Copyright 2015 Google Inc. All Rights Reserved.
 * Use of this source code is governed by a BSD-style
 * license that can be found in the LICENSE file or at
 * https://github.com/firebase/superstatic/blob/master/LICENSE
 */
'use strict';

var RSVP = require('rsvp');
var _ = require('lodash');
var mime = require('mime-types');
var path = require('path');
var awaitFinished = RSVP.denodeify(require('on-finished'));
var destroy = require('destroy');
var compress = require('compression')();

var Responder = function(req, res, options) {
  this.req = req;
  this.res = res;
  this.provider = options.provider;
  this.config = options.config || {};
  this.gzip = options.gzip;
};

Responder.prototype.isNotModified = function(stats) {
  if (stats.etag && stats.etag === this.req.headers['if-none-match']) {
    return true;
  }

  var reqModified = this.req.headers['if-modified-since'];
  if (reqModified) {
    reqModified = new Date(reqModified).getTime();
  }
  if (stats.modified && reqModified && stats.modified < reqModified) {
    return true;
  }

  return false;
};

Responder.prototype.handle = function(item, next) {
  var self = this;
  return this._handle(item).then(function(responded) {
    if (!responded && next) {
      next();
    }
    return responded;
  }).catch(function(err) {
    return self.handleError(err);
  });
};

Responder.prototype._handle = function(item) {
  if (_.isArray(item)) {
    return this.handleStack(item);
  } else if (_.isString(item)) {
    return this.handleFile({file: item});
  } else if (_.isObject(item)) {
    if (item.file) {
      return this.handleFile(item);
    } else if (item.redirect) {
      return this.handleRedirect(item);
    } else if (item.data) {
      return this.handleData(item);
    }
  }

  return RSVP.reject(new Error(JSON.stringify(item) + ' is not a recognized responder directive'));
};

Responder.prototype.handleError = function(err) {
  this.res.statusCode = 500;
  console.log(err.stack);
  this.res.end('Unexpected error occurred.');
};

Responder.prototype.handleStack = function(stack) {
  var self = this;
  if (stack.length) {
    return this._handle(stack.shift()).then(function(responded) {
      return responded ? true : self.handleStack(stack);
    });
  }

  return RSVP.resolve(false);
};

Responder.prototype.handleFile = function(file) {
  var self = this;
  return this.provider(this.req, file.file).then(function(result) {
    if (!result) {
      return false;
    }

    if (self.isNotModified(result)) {
      return self.handleNotModified(result);
    }

    return self.handleFileStream(file, result);
  });
};

Responder.prototype.handleFileStream = function(file, result) {
  var self = this;

  this.streamedFile = file;
  this.res.statusCode = file.status || 200;
  if (this.res.statusCode === 200 && file.file === this.config.errorPage) {
    this.res.statusCode = 404;
  }
  this.res.setHeader('Content-Type', result.contentType || mime.contentType(path.extname(file.file)));
  if (result.size) { this.res.setHeader('Content-Length', result.size); }
  if (result.etag) { this.res.setHeader('ETag', result.etag); }
  if (result.modified) {
    this.res.setHeader('Last-Modified', new Date(result.modified).toUTCString());
  }
  if (this.gzip) {
    compress(this.req, this.res, function() {
      result.stream.pipe(self.res);
    });
  } else {
    result.stream.pipe(self.res);
  }

  return awaitFinished(this.res).then(function() {
    destroy(result.stream);
    return true;
  });
};

Responder.prototype.handleNotModified = function() {
  this.res.statusCode = 304;
  this.res.removeHeader('Content-Type');
  this.res.removeHeader('Content-Length');
  this.res.removeHeader('Transfer-Encoding');
  this.res.end();
};

Responder.prototype.handleRedirect = function(redirect) {
  this.res.statusCode = redirect.status || 301;
  this.res.setHeader('Location', redirect.redirect);
  this.res.setHeader('Content-Type', 'text/html; charset=utf-8');
  this.res.end('Redirecting to ' + redirect.redirect);
  return RSVP.resolve(true);
};

Responder.prototype.handleData = function(data) {
  this.res.statusCode = data.status || 200;
  this.res.setHeader('Content-Type', data.contentType || 'text/html; charset=utf-8');
  this.res.end(data.data);
  return RSVP.resolve(true);
};

module.exports = Responder;