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