From 5bf53933ebede741f283ca55b1fd331f15db6121 Mon Sep 17 00:00:00 2001
From: Yagiz Nizipli <yagiz@nizipli.com>
Date: Sat, 26 Apr 2025 22:19:13 -0400
Subject: [PATCH] buffer: improve byteLength performance

# Conflicts:
#	src/node_external_reference.h
---
 src/node_buffer.cc            | 24 ++++++++++++++++++------
 src/node_external_reference.h |  6 ++++++
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/src/node_buffer.cc b/src/node_buffer.cc
index 3507f5e3e2943a..adacf470306d81 100644
--- a/src/node_buffer.cc
+++ b/src/node_buffer.cc
@@ -728,16 +728,28 @@ void SlowByteLengthUtf8(const FunctionCallbackInfo<Value>& args) {
   args.GetReturnValue().Set(args[0].As<String>()->Utf8Length(env->isolate()));
 }
 
-uint32_t FastByteLengthUtf8(Local<Value> receiver,
-                            const v8::FastOneByteString& source) {
+uint32_t FastByteLengthUtf8(
+    Local<Value> receiver,
+    Local<Value> sourceValue,
+    v8::FastApiCallbackOptions& options) {  // NOLINT(runtime/references)
+  TRACK_V8_FAST_API_CALL("Buffer::FastByteLengthUtf8");
+  auto isolate = options.isolate;
+  HandleScope handleScope(isolate);
+  CHECK(sourceValue->IsString());
+  Local<String> sourceStr = sourceValue.As<String>();
+
+  if (!sourceStr->IsExternalOneByte()) {
+    return sourceStr->Utf8Length(isolate);
+  }
+  auto source = sourceStr->GetExternalOneByteStringResource();
   // For short inputs, the function call overhead to simdutf is maybe
   // not worth it, reserve simdutf for long strings.
-  if (source.length > 128) {
-    return simdutf::utf8_length_from_latin1(source.data, source.length);
+  if (source->length() > 128) {
+    return simdutf::utf8_length_from_latin1(source->data(), source->length());
   }
 
-  uint32_t length = source.length;
-  const auto input = reinterpret_cast<const uint8_t*>(source.data);
+  uint32_t length = source->length();
+  const auto input = reinterpret_cast<const uint8_t*>(source->data());
 
   uint32_t answer = length;
   uint32_t i = 0;
diff --git a/src/node_external_reference.h b/src/node_external_reference.h
index c652c6878c353d..b8f0b40b8dd8c5 100644
--- a/src/node_external_reference.h
+++ b/src/node_external_reference.h
@@ -17,6 +17,11 @@ using CFunctionCallbackWithMultipleValueAndOptions =
              v8::Local<v8::Value>,
              v8::Local<v8::Value>,
              v8::FastApiCallbackOptions&);
+using CFunctionA =
+    uint32_t (*)(v8::Local<v8::Value> receiver,
+                 v8::Local<v8::Value> sourceValue,
+                 // NOLINTNEXTLINE(runtime/references) This is V8 api.
+                 v8::FastApiCallbackOptions& options);
 using CFunctionCallbackWithOneByteString =
     uint32_t (*)(v8::Local<v8::Value>, const v8::FastOneByteString&);
 
@@ -98,6 +103,7 @@ class ExternalReferenceRegistry {
   ExternalReferenceRegistry();
 
 #define ALLOWED_EXTERNAL_REFERENCE_TYPES(V)                                    \
+  V(CFunctionA)                                                                \
   V(CFunctionCallback)                                                         \
   V(CFunctionCallbackWithalueAndOptions)                                       \
   V(CFunctionCallbackWithMultipleValueAndOptions)                              \