feat(random): add randomBytesFrom(), update UUID fns

- add thi.ng/hex dependency
- update uuidv4Bytes() to take opt IRandom arg
- refactor/optimize uuid()
- add tests

packages/random/package.json

@@ -50,7 +50,8 @@
     },
     "dependencies": {
         "@thi.ng/api": "^6.13.1",
-        "@thi.ng/checks": "^2.7.9"
+        "@thi.ng/checks": "^2.7.9",
+        "@thi.ng/hex": "^0.0.1"
     },
     "files": [
         "*.js",
@@ -59,8 +60,10 @@
     ],
     "keywords": [
         "binary",
+        "datastructure",
         "generator",
         "random",
+        "typedarray",
         "typescript"
     ],
     "publishConfig": {

packages/random/src/random-bytes.ts

@@ -1,17 +1,26 @@
 import { hasCrypto } from "@thi.ng/checks";
+import type { IRandom } from "./api";
 import { SYSTEM } from "./system";
 
+/**
+ * Fills given byte array with random values sourced from given {@link IRandom}
+ * instance.
+ *
+ * @param rnd -
+ * @param buf -
+ */
+export const randomBytesFrom = (rnd: IRandom, buf: Uint8Array) => {
+    for (let i = buf.length; --i >= 0; ) {
+        buf[i] = rnd.int() & 0xff;
+    }
+    return buf;
+};
+
 /**
  * Fills given byte array with random values. Wrapper for
- * `crypto.getRandomValues()` with automatic fallback to using
- * `Math.random` if platform doesn't provide global crypto instance.
+ * `crypto.getRandomValues()` with automatic fallback to using `Math.random` if
+ * platform doesn't provide global crypto instance.
  */
 export const randomBytes = hasCrypto()
     ? (buf: Uint8Array) => window.crypto.getRandomValues(buf)
-    : (buf: Uint8Array) => {
-          const n = buf.length;
-          for (let i = 0; i < n; i++) {
-              buf[i] = SYSTEM.int() & 0xff;
-          }
-          return buf;
-      };
+    : (buf: Uint8Array) => randomBytesFrom(SYSTEM, buf);

packages/random/src/uuid.ts

@@ -1,14 +1,41 @@
-import { randomBytes } from "./random-bytes";
+import { U16BE, U32BE, U48BE } from "@thi.ng/hex";
+import type { IRandom } from "./api";
+import { randomBytes, randomBytesFrom } from "./random-bytes";
 
 /**
- * Uses {@link randomBytes} to fill given (optional) byte array with a UUIDv4.
+ * Depending on if `rnd` is given, uses {@link randomBytesFrom} or
+ * {@link randomBytes} to fill given (optional) byte array with a new UUIDv4.
  * Creates new Uint8Array if none given.
  *
  * @param buf -
+ * @param rnd -
  */
-export const uuidv4Bytes = (buf?: Uint8Array) => {
-    buf = randomBytes(buf || new Uint8Array(16));
+export const uuidv4Bytes = (buf?: Uint8Array, rnd?: IRandom) => {
+    buf = buf || new Uint8Array(16);
+    buf = rnd ? randomBytesFrom(rnd, buf) : randomBytes(buf);
     buf[6] = 0x40 | (buf[6] & 0x0f);
     buf[8] = 0x80 | (buf[8] & 0x3f);
     return buf;
 };
+
+/**
+ * Returns a UUID string, either from given byte array, of if omitted, a new
+ * UUID v4 produced by {@link uuidv4Bytes}.
+ *
+ * @param id - byte array
+ * @param i - start index
+ */
+export const uuid = (id?: ArrayLike<number>) => {
+    id = id || uuidv4Bytes();
+    return (
+        U32BE(id, 0) +
+        "-" +
+        U16BE(id, 4) +
+        "-" +
+        U16BE(id, 6) +
+        "-" +
+        U16BE(id, 8) +
+        "-" +
+        U48BE(id, 10)
+    );
+};

packages/random/test/uuid.ts

@@ -0,0 +1,22 @@
+import * as assert from "assert";
+import { uuid, uuidv4Bytes, Xoshiro128 } from "../src";
+
+describe("uuid", () => {
+    it("from seeded rnd", () => {
+        const rnd = new Xoshiro128();
+        let buf = uuidv4Bytes(undefined, rnd);
+        assert.deepStrictEqual(
+            buf,
+            // prettier-ignore
+            new Uint8Array([44,98,107,50,243,204,71,35,138,45,143,201,148,141,255,157])
+        );
+        assert.strictEqual(uuid(buf), "2c626b32-f3cc-4723-8a2d-8fc9948dff9d");
+        buf = uuidv4Bytes(undefined, rnd);
+        assert.deepStrictEqual(
+            buf,
+            // prettier-ignore
+            new Uint8Array([197,193,190,153,60,45,73,45,185,35,233,127,29,138,9,147])
+        );
+        assert.strictEqual(uuid(buf), "c5c1be99-3c2d-492d-b923-e97f1d8a0993");
+    });
+});