test: Use murmurhash3 instead of sha256

for tree hashing

Signed-off-by: Marcel Klehr <[email protected]>

Author: marcelklehr

src/lib/Crypto.ts

@@ -1,9 +1,17 @@
 import { fromUint8Array, toUint8Array } from 'js-base64'
+import { murmurhash3_32_gc } from './murmurhash3'
 
 export default class Crypto {
   static iterations = 250000
   static ivLength = 16
 
+  static async murmurHash3(message: string): Promise<string> {
+    const buf32 = new Uint32Array([murmurhash3_32_gc(message, 0)])
+    const buf8 = new Uint8Array(buf32.buffer)
+    buf8.reverse()
+    return this.bufferToHexstr(buf8)
+  }
+
   static async sha256(message: string): Promise<string> {
     const msgBuffer = new TextEncoder().encode(message) // encode as UTF-8
     const hashBuffer = await crypto.subtle.digest('SHA-256', msgBuffer) // hash the message

src/lib/Tree.ts

@@ -80,7 +80,7 @@ export class Bookmark<L extends TItemLocation> {
 
   async hash():Promise<string> {
     if (!this.hashValue) {
-      this.hashValue = await Crypto.sha256(
+      this.hashValue = await Crypto.murmurHash3(
         JSON.stringify({ title: this.title, url: this.url })
       )
     }
@@ -329,7 +329,7 @@ export class Folder<L extends TItemLocation> {
       })
     }
     if (!this.hashValue) this.hashValue = {}
-    this.hashValue[String(preserveOrder)] = await Crypto.sha256(
+    this.hashValue[String(preserveOrder)] = await Crypto.murmurHash3(
       JSON.stringify({
         title: this.title,
         children: await Parallel.map(

src/lib/murmurhash3.js

@@ -0,0 +1,64 @@
+/**
+ * JS Implementation of MurmurHash3 (r136) (as of May 20, 2011)
+ *
+ * @author <a href="mailto:[email protected]">Gary Court</a>
+ * @see http://github.com/garycourt/murmurhash-js
+ * @author <a href="mailto:[email protected]">Austin Appleby</a>
+ * @see http://sites.google.com/site/murmurhash/
+ *
+ * @param {string} key ASCII only
+ * @param {number} seed Positive integer only
+ * @return {number} 32-bit positive integer hash
+ */
+
+export function murmurhash3_32_gc(key, seed) {
+  var remainder, bytes, h1, h1b, c1, c1b, c2, c2b, k1, i;
+
+  remainder = key.length & 3; // key.length % 4
+  bytes = key.length - remainder;
+  h1 = seed;
+  c1 = 0xcc9e2d51;
+  c2 = 0x1b873593;
+  i = 0;
+
+  while (i < bytes) {
+    k1 =
+      ((key.charCodeAt(i) & 0xff)) |
+      ((key.charCodeAt(++i) & 0xff) << 8) |
+      ((key.charCodeAt(++i) & 0xff) << 16) |
+      ((key.charCodeAt(++i) & 0xff) << 24);
+    ++i;
+
+    k1 = ((((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16))) & 0xffffffff;
+    k1 = (k1 << 15) | (k1 >>> 17);
+    k1 = ((((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16))) & 0xffffffff;
+
+    h1 ^= k1;
+    h1 = (h1 << 13) | (h1 >>> 19);
+    h1b = ((((h1 & 0xffff) * 5) + ((((h1 >>> 16) * 5) & 0xffff) << 16))) & 0xffffffff;
+    h1 = (((h1b & 0xffff) + 0x6b64) + ((((h1b >>> 16) + 0xe654) & 0xffff) << 16));
+  }
+
+  k1 = 0;
+
+  switch (remainder) {
+    case 3: k1 ^= (key.charCodeAt(i + 2) & 0xff) << 16;
+    case 2: k1 ^= (key.charCodeAt(i + 1) & 0xff) << 8;
+    case 1: k1 ^= (key.charCodeAt(i) & 0xff);
+
+      k1 = (((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & 0xffffffff;
+      k1 = (k1 << 15) | (k1 >>> 17);
+      k1 = (((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & 0xffffffff;
+      h1 ^= k1;
+  }
+
+  h1 ^= key.length;
+
+  h1 ^= h1 >>> 16;
+  h1 = (((h1 & 0xffff) * 0x85ebca6b) + ((((h1 >>> 16) * 0x85ebca6b) & 0xffff) << 16)) & 0xffffffff;
+  h1 ^= h1 >>> 13;
+  h1 = ((((h1 & 0xffff) * 0xc2b2ae35) + ((((h1 >>> 16) * 0xc2b2ae35) & 0xffff) << 16))) & 0xffffffff;
+  h1 ^= h1 >>> 16;
+
+  return h1 >>> 0;
+}