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frontend/node_modules/@sveltejs/vite-plugin-svelte/src/utils/hash.js

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+import * as crypto from 'node:crypto';
+
+const hashes = Object.create(null);
+
+//TODO shorter?
+const hash_length = 12;
+
+/**
+ * replaces +/= in base64 output so they don't interfere
+ *
+ * @param {string} input
+ * @returns {string} base64 hash safe to use in any context
+ */
+export function safeBase64Hash(input) {
+	if (hashes[input]) {
+		return hashes[input];
+	}
+	//TODO if performance really matters, use a faster one like xx-hash etc.
+	// should be evenly distributed because short input length and similarities in paths could cause collisions otherwise
+	// OR DON'T USE A HASH AT ALL, what about a simple counter?
+	const md5 = crypto.createHash('md5');
+	md5.update(input);
+	const hash = toSafe(md5.digest('base64')).slice(0, hash_length);
+	hashes[input] = hash;
+	return hash;
+}
+
+/** @type {Record<string, string>} */
+const replacements = {
+	'+': '-',
+	'/': '_',
+	'=': ''
+};
+
+const replaceRE = new RegExp(`[${Object.keys(replacements).join('')}]`, 'g');
+
+/**
+ * @param {string} base64
+ * @returns {string}
+ */
+function toSafe(base64) {
+	return base64.replace(replaceRE, (x) => replacements[x]);
+}