X-Git-Url: http://source.bookstackapp.com/bookstack/blobdiff_plain/5164375b18f0af6dfb6b3bd35542e40bf2406176..refs/pull/5676/head:/resources/js/services/util.ts

diff --git a/resources/js/services/util.ts b/resources/js/services/util.ts
index c5a5d2db8..61a02a3d2 100644
--- a/resources/js/services/util.ts
+++ b/resources/js/services/util.ts
@@ -144,4 +144,25 @@ function getVersion(): string {
 export function importVersioned(moduleName: string): Promise<object> {
     const importPath = window.baseUrl(`dist/${moduleName}.js?version=${getVersion()}`);
     return import(importPath);
+}
+
+/*
+    cyrb53 (c) 2018 bryc (github.com/bryc)
+    License: Public domain (or MIT if needed). Attribution appreciated.
+    A fast and simple 53-bit string hash function with decent collision resistance.
+    Largely inspired by MurmurHash2/3, but with a focus on speed/simplicity.
+    Taken from: https://github.com/bryc/code/blob/master/jshash/experimental/cyrb53.js
+*/
+export function cyrb53(str: string, seed: number = 0): string {
+    let h1 = 0xdeadbeef ^ seed, h2 = 0x41c6ce57 ^ seed;
+    for(let i = 0, ch; i < str.length; i++) {
+        ch = str.charCodeAt(i);
+        h1 = Math.imul(h1 ^ ch, 2654435761);
+        h2 = Math.imul(h2 ^ ch, 1597334677);
+    }
+    h1  = Math.imul(h1 ^ (h1 >>> 16), 2246822507);
+    h1 ^= Math.imul(h2 ^ (h2 >>> 13), 3266489909);
+    h2  = Math.imul(h2 ^ (h2 >>> 16), 2246822507);
+    h2 ^= Math.imul(h1 ^ (h1 >>> 13), 3266489909);
+    return String((4294967296 * (2097151 & h2) + (h1 >>> 0)));
 }
\ No newline at end of file