strong-tie/inbound-calls

1"use strict";2 3const fastDecode = require("fast-decode-uri-component");4 5const plusRegex = /\+/g;6const Empty = function () {};7Empty.prototype = Object.create(null);8 9/**10 * @callback parse11 * @param {string} input12 */13function parse(input) {14  // Optimization: Use new Empty() instead of Object.create(null) for performance15  // v8 has a better optimization for initializing functions compared to Object16  const result = new Empty();17 18  if (typeof input !== "string") {19    return result;20  }21 22  let inputLength = input.length;23  let key = "";24  let value = "";25  let startingIndex = -1;26  let equalityIndex = -1;27  let shouldDecodeKey = false;28  let shouldDecodeValue = false;29  let keyHasPlus = false;30  let valueHasPlus = false;31  let hasBothKeyValuePair = false;32  let c = 0;33 34  // Have a boundary of input.length + 1 to access last pair inside the loop.35  for (let i = 0; i < inputLength + 1; i++) {36    c = i !== inputLength ? input.charCodeAt(i) : 38;37 38    // Handle '&' and end of line to pass the current values to result39    if (c === 38) {40      hasBothKeyValuePair = equalityIndex > startingIndex;41 42      // Optimization: Reuse equality index to store the end of key43      if (!hasBothKeyValuePair) {44        equalityIndex = i;45      }46 47      key = input.slice(startingIndex + 1, equalityIndex);48 49      // Add key/value pair only if the range size is greater than 1; a.k.a. contains at least "="50      if (hasBothKeyValuePair || key.length > 0) {51        // Optimization: Replace '+' with space52        if (keyHasPlus) {53          key = key.replace(plusRegex, " ");54        }55 56        // Optimization: Do not decode if it's not necessary.57        if (shouldDecodeKey) {58          key = fastDecode(key) || key;59        }60 61        if (hasBothKeyValuePair) {62          value = input.slice(equalityIndex + 1, i);63 64          if (valueHasPlus) {65            value = value.replace(plusRegex, " ");66          }67 68          if (shouldDecodeValue) {69            value = fastDecode(value) || value;70          }71        }72        const currentValue = result[key];73 74        if (currentValue === undefined) {75          result[key] = value;76        } else {77          // Optimization: value.pop is faster than Array.isArray(value)78          if (currentValue.pop) {79            currentValue.push(value);80          } else {81            result[key] = [currentValue, value];82          }83        }84      }85 86      // Reset reading key value pairs87      value = "";88      startingIndex = i;89      equalityIndex = i;90      shouldDecodeKey = false;91      shouldDecodeValue = false;92      keyHasPlus = false;93      valueHasPlus = false;94    }95    // Check '='96    else if (c === 61) {97      if (equalityIndex <= startingIndex) {98        equalityIndex = i;99      }100      // If '=' character occurs again, we should decode the input.101      else {102        shouldDecodeValue = true;103      }104    }105    // Check '+', and remember to replace it with empty space.106    else if (c === 43) {107      if (equalityIndex > startingIndex) {108        valueHasPlus = true;109      } else {110        keyHasPlus = true;111      }112    }113    // Check '%' character for encoding114    else if (c === 37) {115      if (equalityIndex > startingIndex) {116        shouldDecodeValue = true;117      } else {118        shouldDecodeKey = true;119      }120    }121  }122 123  return result;124}125 126module.exports = parse;127