55 lines
2.0 KiB
JavaScript
55 lines
2.0 KiB
JavaScript
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/*---------------------------------------------------------------------------------------------
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* Copyright (c) Microsoft Corporation. All rights reserved.
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* Licensed under the MIT License. See License.txt in the project root for license information.
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*--------------------------------------------------------------------------------------------*/
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/**
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* Return a hash value for an object.
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*/
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export function hash(obj, hashVal) {
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if (hashVal === void 0) { hashVal = 0; }
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switch (typeof obj) {
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case 'object':
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if (obj === null) {
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return numberHash(349, hashVal);
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}
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else if (Array.isArray(obj)) {
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return arrayHash(obj, hashVal);
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}
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return objectHash(obj, hashVal);
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case 'string':
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return stringHash(obj, hashVal);
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case 'boolean':
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return booleanHash(obj, hashVal);
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case 'number':
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return numberHash(obj, hashVal);
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case 'undefined':
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return numberHash(0, 937);
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default:
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return numberHash(0, 617);
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}
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}
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function numberHash(val, initialHashVal) {
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return (((initialHashVal << 5) - initialHashVal) + val) | 0; // hashVal * 31 + ch, keep as int32
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}
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function booleanHash(b, initialHashVal) {
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return numberHash(b ? 433 : 863, initialHashVal);
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}
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function stringHash(s, hashVal) {
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hashVal = numberHash(149417, hashVal);
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for (var i = 0, length_1 = s.length; i < length_1; i++) {
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hashVal = numberHash(s.charCodeAt(i), hashVal);
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}
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return hashVal;
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}
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function arrayHash(arr, initialHashVal) {
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initialHashVal = numberHash(104579, initialHashVal);
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return arr.reduce(function (hashVal, item) { return hash(item, hashVal); }, initialHashVal);
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}
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function objectHash(obj, initialHashVal) {
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initialHashVal = numberHash(181387, initialHashVal);
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return Object.keys(obj).sort().reduce(function (hashVal, key) {
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hashVal = stringHash(key, hashVal);
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return hash(obj[key], hashVal);
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}, initialHashVal);
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}
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