forked from zhurui/management
93 lines
1.9 KiB
JavaScript
93 lines
1.9 KiB
JavaScript
/*
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MIT License http://www.opensource.org/licenses/mit-license.php
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Author Tobias Koppers @sokra
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*/
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"use strict";
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/** @typedef {{new(): Hash}} HashConstructor */
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/**
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* @typedef {Object} Hash
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* @property {function(string|Buffer, string=): Hash} update
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* @property {function(string): string} digest
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*/
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const BULK_SIZE = 1000;
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/**
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* @implements {Hash}
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*/
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class BulkUpdateDecorator {
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constructor(hash) {
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this.hash = hash;
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this.buffer = "";
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}
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update(data, inputEncoding) {
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if (
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inputEncoding !== undefined ||
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typeof data !== "string" ||
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data.length > BULK_SIZE
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) {
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if (this.buffer.length > 0) {
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this.hash.update(this.buffer);
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this.buffer = "";
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}
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this.hash.update(data, inputEncoding);
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} else {
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this.buffer += data;
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if (this.buffer.length > BULK_SIZE) {
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this.hash.update(this.buffer);
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this.buffer = "";
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}
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}
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return this;
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}
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digest(encoding) {
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if (this.buffer.length > 0) {
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this.hash.update(this.buffer);
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}
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var digestResult = this.hash.digest(encoding);
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return typeof digestResult === "string"
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? digestResult
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: digestResult.toString();
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}
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}
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/* istanbul ignore next */
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class DebugHash {
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constructor() {
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this.string = "";
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}
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update(data, inputEncoding) {
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if (typeof data !== "string") data = data.toString("utf-8");
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this.string += data;
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return this;
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}
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digest(encoding) {
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return this.string.replace(/[^a-z0-9]+/gi, m =>
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Buffer.from(m).toString("hex")
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);
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}
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}
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/**
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* Creates a hash by name or function
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* @param {string | HashConstructor} algorithm the algorithm name or a constructor creating a hash
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* @returns {Hash} the hash
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*/
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module.exports = algorithm => {
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if (typeof algorithm === "function") {
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return new BulkUpdateDecorator(new algorithm());
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}
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switch (algorithm) {
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// TODO add non-cryptographic algorithm here
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case "debug":
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return new DebugHash();
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default:
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return new BulkUpdateDecorator(require("crypto").createHash(algorithm));
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}
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};
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