rc@73: /**
rc@73:  * Module dependencies.
rc@73:  */
rc@73: 
rc@73: var mime = require('send').mime;
rc@73: var crc32 = require('buffer-crc32');
rc@73: var crypto = require('crypto');
rc@73: var basename = require('path').basename;
rc@73: var deprecate = require('util').deprecate;
rc@73: var proxyaddr = require('proxy-addr');
rc@73: 
rc@73: /**
rc@73:  * Simple detection of charset parameter in content-type
rc@73:  */
rc@73: var charsetRegExp = /;\s*charset\s*=/;
rc@73: 
rc@73: /**
rc@73:  * Deprecate function, like core `util.deprecate`,
rc@73:  * but with NODE_ENV and color support.
rc@73:  *
rc@73:  * @param {Function} fn
rc@73:  * @param {String} msg
rc@73:  * @return {Function}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.deprecate = function(fn, msg){
rc@73:   if (process.env.NODE_ENV === 'test') return fn;
rc@73: 
rc@73:   // prepend module name
rc@73:   msg = 'express: ' + msg;
rc@73: 
rc@73:   if (process.stderr.isTTY) {
rc@73:     // colorize
rc@73:     msg = '\x1b[31;1m' + msg + '\x1b[0m';
rc@73:   }
rc@73: 
rc@73:   return deprecate(fn, msg);
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Return strong ETag for `body`.
rc@73:  *
rc@73:  * @param {String|Buffer} body
rc@73:  * @param {String} [encoding]
rc@73:  * @return {String}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.etag = function etag(body, encoding){
rc@73:   if (body.length === 0) {
rc@73:     // fast-path empty body
rc@73:     return '"1B2M2Y8AsgTpgAmY7PhCfg=="'
rc@73:   }
rc@73: 
rc@73:   var hash = crypto
rc@73:     .createHash('md5')
rc@73:     .update(body, encoding)
rc@73:     .digest('base64')
rc@73:   return '"' + hash + '"'
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Return weak ETag for `body`.
rc@73:  *
rc@73:  * @param {String|Buffer} body
rc@73:  * @param {String} [encoding]
rc@73:  * @return {String}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.wetag = function wetag(body, encoding){
rc@73:   if (body.length === 0) {
rc@73:     // fast-path empty body
rc@73:     return 'W/"0-0"'
rc@73:   }
rc@73: 
rc@73:   var buf = Buffer.isBuffer(body)
rc@73:     ? body
rc@73:     : new Buffer(body, encoding)
rc@73:   var len = buf.length
rc@73:   return 'W/"' + len.toString(16) + '-' + crc32.unsigned(buf) + '"'
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Check if `path` looks absolute.
rc@73:  *
rc@73:  * @param {String} path
rc@73:  * @return {Boolean}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.isAbsolute = function(path){
rc@73:   if ('/' == path[0]) return true;
rc@73:   if (':' == path[1] && '\\' == path[2]) return true;
rc@73:   if ('\\\\' == path.substring(0, 2)) return true; // Microsoft Azure absolute path
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Flatten the given `arr`.
rc@73:  *
rc@73:  * @param {Array} arr
rc@73:  * @return {Array}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.flatten = function(arr, ret){
rc@73:   ret = ret || [];
rc@73:   var len = arr.length;
rc@73:   for (var i = 0; i < len; ++i) {
rc@73:     if (Array.isArray(arr[i])) {
rc@73:       exports.flatten(arr[i], ret);
rc@73:     } else {
rc@73:       ret.push(arr[i]);
rc@73:     }
rc@73:   }
rc@73:   return ret;
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Normalize the given `type`, for example "html" becomes "text/html".
rc@73:  *
rc@73:  * @param {String} type
rc@73:  * @return {Object}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.normalizeType = function(type){
rc@73:   return ~type.indexOf('/')
rc@73:     ? acceptParams(type)
rc@73:     : { value: mime.lookup(type), params: {} };
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Normalize `types`, for example "html" becomes "text/html".
rc@73:  *
rc@73:  * @param {Array} types
rc@73:  * @return {Array}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.normalizeTypes = function(types){
rc@73:   var ret = [];
rc@73: 
rc@73:   for (var i = 0; i < types.length; ++i) {
rc@73:     ret.push(exports.normalizeType(types[i]));
rc@73:   }
rc@73: 
rc@73:   return ret;
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Generate Content-Disposition header appropriate for the filename.
rc@73:  * non-ascii filenames are urlencoded and a filename* parameter is added
rc@73:  *
rc@73:  * @param {String} filename
rc@73:  * @return {String}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.contentDisposition = function(filename){
rc@73:   var ret = 'attachment';
rc@73:   if (filename) {
rc@73:     filename = basename(filename);
rc@73:     // if filename contains non-ascii characters, add a utf-8 version ala RFC 5987
rc@73:     ret = /[^\040-\176]/.test(filename)
rc@73:       ? 'attachment; filename="' + encodeURI(filename) + '"; filename*=UTF-8\'\'' + encodeURI(filename)
rc@73:       : 'attachment; filename="' + filename + '"';
rc@73:   }
rc@73: 
rc@73:   return ret;
rc@73: };
rc@73: 
rc@73: /**
rc@73:  * Parse accept params `str` returning an
rc@73:  * object with `.value`, `.quality` and `.params`.
rc@73:  * also includes `.originalIndex` for stable sorting
rc@73:  *
rc@73:  * @param {String} str
rc@73:  * @return {Object}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: function acceptParams(str, index) {
rc@73:   var parts = str.split(/ *; */);
rc@73:   var ret = { value: parts[0], quality: 1, params: {}, originalIndex: index };
rc@73: 
rc@73:   for (var i = 1; i < parts.length; ++i) {
rc@73:     var pms = parts[i].split(/ *= */);
rc@73:     if ('q' == pms[0]) {
rc@73:       ret.quality = parseFloat(pms[1]);
rc@73:     } else {
rc@73:       ret.params[pms[0]] = pms[1];
rc@73:     }
rc@73:   }
rc@73: 
rc@73:   return ret;
rc@73: }
rc@73: 
rc@73: /**
rc@73:  * Compile "etag" value to function.
rc@73:  *
rc@73:  * @param  {Boolean|String|Function} val
rc@73:  * @return {Function}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.compileETag = function(val) {
rc@73:   var fn;
rc@73: 
rc@73:   if (typeof val === 'function') {
rc@73:     return val;
rc@73:   }
rc@73: 
rc@73:   switch (val) {
rc@73:     case true:
rc@73:       fn = exports.wetag;
rc@73:       break;
rc@73:     case false:
rc@73:       break;
rc@73:     case 'strong':
rc@73:       fn = exports.etag;
rc@73:       break;
rc@73:     case 'weak':
rc@73:       fn = exports.wetag;
rc@73:       break;
rc@73:     default:
rc@73:       throw new TypeError('unknown value for etag function: ' + val);
rc@73:   }
rc@73: 
rc@73:   return fn;
rc@73: }
rc@73: 
rc@73: /**
rc@73:  * Compile "proxy trust" value to function.
rc@73:  *
rc@73:  * @param  {Boolean|String|Number|Array|Function} val
rc@73:  * @return {Function}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.compileTrust = function(val) {
rc@73:   if (typeof val === 'function') return val;
rc@73: 
rc@73:   if (val === true) {
rc@73:     // Support plain true/false
rc@73:     return function(){ return true };
rc@73:   }
rc@73: 
rc@73:   if (typeof val === 'number') {
rc@73:     // Support trusting hop count
rc@73:     return function(a, i){ return i < val };
rc@73:   }
rc@73: 
rc@73:   if (typeof val === 'string') {
rc@73:     // Support comma-separated values
rc@73:     val = val.split(/ *, */);
rc@73:   }
rc@73: 
rc@73:   return proxyaddr.compile(val || []);
rc@73: }
rc@73: 
rc@73: /**
rc@73:  * Set the charset in a given Content-Type string.
rc@73:  *
rc@73:  * @param {String} type
rc@73:  * @param {String} charset
rc@73:  * @return {String}
rc@73:  * @api private
rc@73:  */
rc@73: 
rc@73: exports.setCharset = function(type, charset){
rc@73:   if (!type || !charset) return type;
rc@73: 
rc@73:   var exists = charsetRegExp.test(type);
rc@73: 
rc@73:   // removing existing charset
rc@73:   if (exists) {
rc@73:     var parts = type.split(';');
rc@73: 
rc@73:     for (var i = 1; i < parts.length; i++) {
rc@73:       if (charsetRegExp.test(';' + parts[i])) {
rc@73:         parts.splice(i, 1);
rc@73:         break;
rc@73:       }
rc@73:     }
rc@73: 
rc@73:     type = parts.join(';');
rc@73:   }
rc@73: 
rc@73:   return type + '; charset=' + charset;
rc@73: };