add benchmark for parse-headers

parse-headers.js

@@ -0,0 +1,111 @@
+  'use strict';
+
+function intern(str) {
+  let obj = {};
+  obj[str] = 1;
+  for (let key in obj) {
+    if (key === str) {
+      return key;
+    }
+  }
+  return str;
+}
+
+function _toArray(arr) {
+  return Array.isArray(arr) ? arr : Array.from(arr);
+}
+
+var CLRF = '\r\n';
+function parseResponseHeaders(headersString) {
+  var headers = Object.create(null);
+
+  if (!headersString) {
+    return headers;
+  }
+
+  var headerPairs = headersString.split(CLRF);
+
+  headerPairs.forEach(function (header) {
+    var _header$split = header.split(':');
+
+    var _header$split2 = _header$split;
+
+    var field = _header$split2[0];
+
+    var value = _header$split2.slice(1);
+
+    field = field.trim();
+    value = value.join(':').trim();
+
+    if (value) {
+      headers[field] = value;
+    }
+  });
+
+  return headers;
+}
+
+var HEADER_MATCH = /^([^:]*):(.*)$/m;
+
+function parseResponseHeadersNew(headersString) {
+  var headers = Object.create(null);
+
+  if (!headersString) {
+    return headers;
+  }
+
+  var headerPairs = headersString.split(CLRF);
+  for (var i = 0; i < headerPairs.length; i++) {
+    var header = headerPairs[i];
+    var j = 0;
+    var foundColon = false;
+
+     for (; j < header.length; j++) {
+       if (header.charCodeAt(j) === 58) {
+         foundColon = true;
+         break;
+       }
+     }
+
+     if (foundColon === false) {
+       break;
+     }
+
+    var field = header.substring(0, j).trim();
+    var value = header.substring(j + 1, header.length).trim();
+
+    if (value) {
+      headers[field] = value;
+    }
+  }
+
+  return headers;
+}
+
+// I don't believe they are ropes when we get them from the platform
+const HEADER = intern([
+  'Date: Wed, 15 Mar 2017 15:57:19 GMT',
+  'Cache-Control: private, max-age=0, must-revalidate',
+  'Last-Modified: Tue, 14 Mar 2017 21:25:26 GMT',
+  'Content-Encoding: gzip',
+  'X-Powered-By: Express',
+  'Vary: Accept-Encoding',
+  'Content-Type: application/json'
+].join(CLRF));
+
+console.log(parseResponseHeaders(HEADER));
+console.log(parseResponseHeadersNew(HEADER));
+require('do-you-even-bench')([
+  {
+    name: 'new',
+    fn() {
+      parseResponseHeadersNew(HEADER);
+    }
+  },
+  {
+    name: 'current',
+    fn() {
+      parseResponseHeaders(HEADER);
+    }
+  }
+])