refactor: uses traditional for loop for small copy

rinsuki · Jun 21, 2021 · 8589ea9 · 8589ea9
1 parent f612a5b
commit 8589ea9
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/src/index.ts b/src/index.ts
@@ -63,7 +63,14 @@ function copy(
     si: number,
     len: number
 ): void {
-    dest.set(src.subarray(si, si + len), di);
+    // traditional for loop is faster than Uint8Array#set if length is small (<20?)
+    if (len < 20) {
+        for (let i = 0; i<len; i++) {
+            dest[di + i] = src[si + i]
+        }
+    } else {
+        dest.set(src.subarray(si, si + len), di);
+    }
 }
 
 export function calcUncompressedLen(src: Uint8Array): number {