| // Copyright 2014 Cognitect. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS-IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| goog.provide("com.cognitect.transit.eq"); |
| goog.require("com.cognitect.transit.util"); |
| |
| goog.scope(function() { |
| |
| var eq = com.cognitect.transit.eq, |
| util = com.cognitect.transit.util; |
| |
| /** |
| * @const |
| * @type {string} |
| */ |
| eq.hashCodeProperty = "transit$hashCode$"; |
| |
| /** |
| * @type {number} |
| */ |
| eq.hashCodeCounter = 1; |
| |
| eq.equals = function (x, y) { |
| if(x == null) { |
| return y == null; |
| } else if(x === y) { |
| return true; |
| } else if(typeof x === "object") { |
| if(util.isArray(x)) { |
| if(util.isArray(y)) { |
| if(x.length === y.length) { |
| for(var i = 0; i < x.length; i++) { |
| if(!eq.equals(x[i], y[i])) { |
| return false; |
| } |
| } |
| return true; |
| } else { |
| return false; |
| } |
| } else { |
| return false; |
| } |
| } else if(x.com$cognitect$transit$equals) { |
| return x.com$cognitect$transit$equals(y); |
| } else if((y != null) && (typeof y === "object")) { |
| if(y.com$cognitect$transit$equals) { |
| return y.com$cognitect$transit$equals(x); |
| } else { |
| var xklen = 0, |
| yklen = util.objectKeys(y).length; |
| for(var p in x) { |
| if(!x.hasOwnProperty(p)) continue; |
| xklen++; |
| if(!y.hasOwnProperty(p)) { |
| return false; |
| } else { |
| if(!eq.equals(x[p], y[p])) { |
| return false; |
| } |
| } |
| } |
| return xklen === yklen; |
| } |
| } else { |
| return false; |
| } |
| } else { |
| return false |
| } |
| }; |
| |
| eq.hashCombine = function(seed, hash) { |
| return seed ^ (hash + 0x9e3779b9 + (seed << 6) + (seed >> 2)); |
| }; |
| |
| eq.stringCodeCache = {}; |
| eq.stringCodeCacheSize = 0; |
| |
| /** |
| * @const |
| * @type {number} |
| */ |
| eq.STR_CACHE_MAX = 256; |
| |
| eq.hashString = function(str) { |
| // a la goog.string.HashCode |
| // http://docs.closure-library.googlecode.com/git/local_closure_goog_string_string.js.source.html#line1206 |
| var cached = eq.stringCodeCache[str]; |
| if(cached != null) { |
| return cached; |
| } |
| var code = 0; |
| for (var i = 0; i < str.length; ++i) { |
| code = 31 * code + str.charCodeAt(i); |
| code %= 0x100000000; |
| } |
| eq.stringCodeCacheSize++; |
| if(eq.stringCodeCacheSize >= eq.STR_CACHE_MAX) { |
| eq.stringCodeCache = {}; |
| eq.stringCodeCacheSize = 1; |
| } |
| eq.stringCodeCache[str] = code; |
| return code; |
| }; |
| |
| eq.hashMapLike = function(m) { |
| var code = 0; |
| // ES6 Map-like case |
| if(m.forEach != null) { |
| m.forEach(function(val, key, m) { |
| code = (code + (eq.hashCode(key) ^ eq.hashCode(val))) % 4503599627370496; |
| }); |
| } else { |
| // JS Object case |
| var keys = util.objectKeys(m); |
| for(var i = 0; i < keys.length; i++) { |
| var key = keys[i]; |
| var val = m[key]; |
| code = (code + (eq.hashCode(key) ^ eq.hashCode(val))) % 4503599627370496; |
| } |
| } |
| return code; |
| }; |
| |
| eq.hashArrayLike = function(arr) { |
| var code = 0; |
| if(util.isArray(arr)) { |
| for(var i = 0; i < arr.length; i++) { |
| code = eq.hashCombine(code, eq.hashCode(arr[i])); |
| } |
| } else if(arr.forEach) { |
| arr.forEach(function(x, i) { |
| code = eq.hashCombine(code, eq.hashCode(x)); |
| }); |
| } |
| return code; |
| }; |
| |
| eq.hashCode = function(x) { |
| if(x == null) { |
| return 0; |
| } else { |
| switch(typeof x) { |
| case 'number': |
| return x; |
| break; |
| case 'boolean': |
| return x === true ? 1 : 0; |
| break; |
| case 'string': |
| return eq.hashString(x); |
| break; |
| case 'function': |
| var code = x[eq.hashCodeProperty]; |
| if(code) { |
| return code; |
| } else { |
| code = eq.hashCodeCounter; |
| if(typeof Object.defineProperty != "undefined") { |
| Object.defineProperty(x, eq.hashCodeProperty, { |
| value: code, |
| enumerable: false |
| }); |
| } else { |
| x[eq.hashCodeProperty] = code; |
| } |
| eq.hashCodeCounter++; |
| return code; |
| } |
| break; |
| default: |
| if(x instanceof Date) { |
| return x.valueOf(); |
| } else if(util.isArray(x)) { |
| return eq.hashArrayLike(x); |
| } if(x.com$cognitect$transit$hashCode) { |
| return x.com$cognitect$transit$hashCode(); |
| } else { |
| return eq.hashMapLike(x); |
| } |
| break; |
| } |
| } |
| } |
| |
| eq.extendToEQ = function(obj, opts) { |
| obj.com$cognitect$transit$hashCode = opts["hashCode"]; |
| obj.com$cognitect$transit$equals = opts["equals"]; |
| return obj; |
| } |
| |
| }); |