61 lines
1.7 KiB
JavaScript
Executable file
61 lines
1.7 KiB
JavaScript
Executable file
/*
|
|
MIT License http://www.opensource.org/licenses/mit-license.php
|
|
Author Tobias Koppers @sokra
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
/** @typedef {import("webpack-sources").Source} Source */
|
|
|
|
/** @type {WeakMap<Source, WeakMap<Source, boolean>>} */
|
|
const equalityCache = new WeakMap();
|
|
|
|
/**
|
|
* @param {Source} a a source
|
|
* @param {Source} b another source
|
|
* @returns {boolean} true, when both sources are equal
|
|
*/
|
|
const _isSourceEqual = (a, b) => {
|
|
// prefer .buffer(), it's called anyway during emit
|
|
/** @type {Buffer|string} */
|
|
let aSource = typeof a.buffer === "function" ? a.buffer() : a.source();
|
|
/** @type {Buffer|string} */
|
|
let bSource = typeof b.buffer === "function" ? b.buffer() : b.source();
|
|
if (aSource === bSource) return true;
|
|
if (typeof aSource === "string" && typeof bSource === "string") return false;
|
|
if (!Buffer.isBuffer(aSource)) aSource = Buffer.from(aSource, "utf-8");
|
|
if (!Buffer.isBuffer(bSource)) bSource = Buffer.from(bSource, "utf-8");
|
|
return aSource.equals(bSource);
|
|
};
|
|
|
|
/**
|
|
* @param {Source} a a source
|
|
* @param {Source} b another source
|
|
* @returns {boolean} true, when both sources are equal
|
|
*/
|
|
const isSourceEqual = (a, b) => {
|
|
if (a === b) return true;
|
|
const cache1 = equalityCache.get(a);
|
|
if (cache1 !== undefined) {
|
|
const result = cache1.get(b);
|
|
if (result !== undefined) return result;
|
|
}
|
|
const result = _isSourceEqual(a, b);
|
|
if (cache1 !== undefined) {
|
|
cache1.set(b, result);
|
|
} else {
|
|
const map = new WeakMap();
|
|
map.set(b, result);
|
|
equalityCache.set(a, map);
|
|
}
|
|
const cache2 = equalityCache.get(b);
|
|
if (cache2 !== undefined) {
|
|
cache2.set(a, result);
|
|
} else {
|
|
const map = new WeakMap();
|
|
map.set(a, result);
|
|
equalityCache.set(b, map);
|
|
}
|
|
return result;
|
|
};
|
|
exports.isSourceEqual = isSourceEqual;
|