perf: drop base64-js dependency, smaller bundle

package.json

@@ -60,9 +60,6 @@
     "vitest": "^4.1.4",
     "yargs": "^18.0.0"
   },
-  "dependencies": {
-    "base64-js": "^1.2.0"
-  },
   "files": [
     ".",
     "dist"

src/JsHistogram.encoding.ts

@@ -5,8 +5,7 @@
  * and released to the public domain, as explained at
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
-// @ts-ignore
-import * as base64 from "base64-js";
+import * as base64 from "./base64";
 import { JsHistogram } from "./JsHistogram";
 import ByteBuffer from "./ByteBuffer";
 import { BitBucketSize } from "./Histogram";

src/base64.ts

@@ -0,0 +1,32 @@
+/*
+ * Minimal base64 codec replacing the `base64-js` dependency.
+ *
+ * Relies on the standard `btoa`/`atob` globals, available in Node >= 16 (this
+ * project requires >= 22) and all modern browsers. Produces and consumes
+ * standard base64 (`+`/`/`), matching what HdrHistogram encodes.
+ */
+
+// Uint8Array -> standard base64 string.
+// Build the binary string in chunks so large inputs (e.g. the WASM blob) don't
+// overflow String.fromCharCode's argument-stack limit.
+export function fromByteArray(bytes: Uint8Array): string {
+  const CHUNK = 0x8000;
+  let binary = "";
+  for (let i = 0; i < bytes.length; i += CHUNK) {
+    binary += String.fromCharCode.apply(
+      null,
+      bytes.subarray(i, i + CHUNK) as unknown as number[]
+    );
+  }
+  return btoa(binary);
+}
+
+// standard base64 string -> Uint8Array.
+export function toByteArray(b64: string): Uint8Array {
+  const binary = atob(b64);
+  const bytes = new Uint8Array(binary.length);
+  for (let i = 0; i < binary.length; i++) {
+    bytes[i] = binary.charCodeAt(i);
+  }
+  return bytes;
+}

src/encoding.ts

@@ -10,8 +10,7 @@ import ByteBuffer from "./ByteBuffer";
 import Histogram from "./Histogram";
 import { WasmHistogram } from "./wasm";
 
-// @ts-ignore
-import * as base64 from "base64-js";
+import * as base64 from "./base64";
 import { inflate, deflate } from "./JsHistogram.encoding";
 
 const V2CompressedEncodingCookieBase = 0x1c849304;

src/wasm/index.ts

@@ -5,8 +5,7 @@ import Histogram, {
   toSummary,
   HistogramSummary
 } from "../Histogram";
-// @ts-ignore
-import * as base64 from "base64-js";
+import * as base64 from "../base64";
 import { inflate } from "../JsHistogram.encoding";
 import { BuildRequest } from "../HistogramBuilder";