improve jsstring toarray performance

cloudflare · Oct 1, 2024 · 0d049d7 · 0d049d7
1 parent 38cbdaf
commit 0d049d7
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/src/workerd/jsg/jsvalue.h b/src/workerd/jsg/jsvalue.h
@@ -433,8 +433,10 @@ inline kj::Array<T> JsString::toArray(Lock& js, WriteOptions options) const {
     inner->WriteOneByte(js.v8Isolate, buf.begin(), 0, buf.size(), options);
     return kj::mv(buf);
   } else {
-    auto buf = kj::heapArray<uint16_t>(inner->Length());
-    inner->Write(js.v8Isolate, buf.begin(), 0, buf.size(), options);
+    v8::String::ValueView view(js.v8Isolate, inner);
+    KJ_ASSERT(!view.is_one_byte());
+    auto buf = kj::heapArray<uint16_t>(view.length());
+    memcpy(buf.begin(), view.data16(), view.length());
     return kj::mv(buf);
   }
 }