[bun.js] Improve `Buffer` creation perf a little

2 files changed, 45 insertions, 8 deletions

diff --git a/integration/bunjs-only-snippets/buffer.test.js b/integration/bunjs-only-snippets/buffer.test.js
index 19502b285..c934f872d 100644
--- a/integration/bunjs-only-snippets/buffer.test.js
+++ b/integration/bunjs-only-snippets/buffer.test.js
@@ -1,22 +1,32 @@
+import { gc } from "bun";
 import { describe, it, expect } from "bun:test";
 
 it("buffer", () => {
   var buf = new Buffer(20);
+  gc();
   // if this fails or infinitely loops, it means there is a memory issue with the JSC::Structure object
   expect(Object.keys(buf).length > 0).toBe(true);
-
+  gc();
   expect(buf.write("hello world ")).toBe(12);
+  gc();
   expect(buf.toString("utf8", 0, "hello world ".length)).toBe("hello world ");
+  gc();
   expect(buf.toString("base64url", 0, "hello world ".length)).toBe(
     btoa("hello world ")
   );
-
+  gc();
   expect(buf instanceof Uint8Array).toBe(true);
+  gc();
   expect(buf instanceof Buffer).toBe(true);
+  gc();
   expect(buf.slice() instanceof Uint8Array).toBe(true);
+  gc();
   expect(buf.slice(0, 1) instanceof Buffer).toBe(true);
+  gc();
   expect(buf.slice(0, 1) instanceof Uint8Array).toBe(true);
+  gc();
   expect(buf.slice(0, 1) instanceof Buffer).toBe(true);
+  gc();
 });
 
 it("Buffer", () => {
@@ -29,10 +39,31 @@ it("Buffer", () => {
   for (let i = 0; i < inputs.length; i++) {
     var input = inputs[i];
     expect(new Buffer(input).toString("utf8")).toBe(inputs[i]);
+    gc();
     expect(Array.from(new Buffer(input)).join(",")).toBe(good[i].join(","));
+    gc();
   }
 });
 
+it("Buffer.isBuffer", () => {
+  expect(Buffer.isBuffer(new Buffer(1))).toBe(true);
+  gc();
+  expect(Buffer.isBuffer(new Buffer(0))).toBe(true);
+  gc();
+  expect(Buffer.isBuffer(new Uint8Array(0))).toBe(false);
+  gc();
+  expect(Buffer.isBuffer(new Uint8Array(1))).toBe(false);
+  gc();
+  var a = new Uint8Array(1);
+  gc();
+  expect(Buffer.isBuffer(a)).toBe(false);
+  gc();
+  Buffer.toBuffer(a);
+  gc();
+  expect(Buffer.isBuffer(a)).toBe(true);
+  gc();
+});
+
 it("Buffer.toBuffer throws", () => {
   const checks = [
     [],
@@ -61,10 +92,13 @@ it("Buffer.toBuffer works", () => {
   expect(Object.keys(buf).length > 0).toBe(true);
 
   expect(buf.write("hello world ")).toBe(12);
+  gc();
   expect(buf.toString("utf8", 0, "hello world ".length)).toBe("hello world ");
+  gc();
   expect(buf.toString("base64url", 0, "hello world ".length)).toBe(
     btoa("hello world ")
   );
+  gc();
 
   expect(buf instanceof Uint8Array).toBe(true);
   expect(buf instanceof Buffer).toBe(true);
@@ -96,6 +130,7 @@ it("Buffer.from", () => {
   expect(Buffer.from("hello world", "latin1").toString("utf8")).toBe(
     "hello world"
   );
+  gc();
   expect(Buffer.from([254]).join(",")).toBe("254");
   expect(Buffer.from(123).join(",")).toBe(Uint8Array.from(123).join(","));
   expect(Buffer.from({ length: 124 }).join(",")).toBe(
@@ -109,6 +144,7 @@ it("Buffer.from", () => {
   expect(Buffer.from(new Buffer(new ArrayBuffer(1024), 0, 512)).join(",")).toBe(
     new Uint8Array(512).join(",")
   );
+  gc();
 });
 
 it("Buffer.copy", () => {
@@ -120,6 +156,7 @@ it("Buffer.copy", () => {
   Buffer.toBuffer(array2);
   var array3 = new Uint8Array(128);
   Buffer.toBuffer(array3);
+  gc();
   expect(array1.copy(array2)).toBe(128);
   expect(array1.join("")).toBe(array2.join(""));
 });
@@ -131,6 +168,7 @@ it("Buffer.concat", () => {
   array2.fill(200);
   var array3 = new Uint8Array(128);
   array3.fill(300);
+  gc();
   expect(Buffer.concat([array1, array2, array3]).join("")).toBe(
     array1.join("") + array2.join("") + array3.join("")
   );
diff --git a/src/javascript/jsc/bindings/JSBuffer.cpp b/src/javascript/jsc/bindings/JSBuffer.cpp
index 7a5ea8c7b..eab0a7734 100644
--- a/src/javascript/jsc/bindings/JSBuffer.cpp
+++ b/src/javascript/jsc/bindings/JSBuffer.cpp
@@ -376,10 +376,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_concatBody(JSC::JS
     for (size_t i = 0; i < arrayLength; i++) {
         auto element = array->getIndex(lexicalGlobalObject, i);
         RETURN_IF_EXCEPTION(throwScope, {});
-        if (!element.isObject()) {
-            throwTypeError(lexicalGlobalObject, throwScope, "Buffer.concat expects Uint8Array"_s);
-            return JSValue::encode(jsUndefined());
-        }
+
         auto* typedArray = JSC::jsDynamicCast<JSC::JSUint8Array*>(vm, element);
         if (!typedArray) {
             throwTypeError(lexicalGlobalObject, throwScope, "Buffer.concat expects Uint8Array"_s);
@@ -1123,6 +1120,9 @@ void JSBufferPrototype::finishCreation(VM& vm, JSC::JSGlobalObject* globalThis)
     reifyStaticProperties(vm, JSBuffer::info(), JSBufferPrototypeTableValues, *this);
     JSC_TO_STRING_TAG_WITHOUT_TRANSITION();
     this->setPrototypeDirect(vm, globalThis->m_typedArrayUint8.prototype(globalThis));
+    auto clientData = WebCore::clientData(vm);
+    this->putDirect(vm, clientData->builtinNames().dataViewPublicName(), JSC::jsUndefined(), JSC::PropertyAttribute::DontEnum | JSC::PropertyAttribute::DontDelete | JSC::PropertyAttribute::ReadOnly);
+    this->putDirect(vm, clientData->builtinNames().dataViewPrivateName(), JSC::JSValue(true), JSC::PropertyAttribute::DontEnum | JSC::PropertyAttribute::DontDelete | JSC::PropertyAttribute::ReadOnly);
 }
 
 const ClassInfo JSBufferPrototype::s_info = { "Buffer"_s, nullptr, nullptr, nullptr, CREATE_METHOD_TABLE(JSBufferPrototype) };
@@ -1249,6 +1249,5 @@ static void toBuffer(JSC::JSGlobalObject* lexicalGlobalObject, JSC::JSUint8Array
 
     auto* dataView = JSC::JSDataView::create(lexicalGlobalObject, lexicalGlobalObject->typedArrayStructure(JSC::TypeDataView), uint8Array->possiblySharedBuffer(), uint8Array->byteOffset(), uint8Array->length());
     // putDirectWithTransition doesn't work here
-    object->putDirect(vm, clientData->builtinNames().dataViewPublicName(), dataView, JSC::PropertyAttribute::DontEnum | JSC::PropertyAttribute::DontDelete | JSC::PropertyAttribute::ReadOnly);
-    object->putDirect(vm, clientData->builtinNames().dataViewPrivateName(), JSC::JSValue(true), JSC::PropertyAttribute::DontEnum | JSC::PropertyAttribute::DontDelete | JSC::PropertyAttribute::ReadOnly);
+    object->putDirectWithoutTransition(vm, clientData->builtinNames().dataViewPublicName(), dataView, JSC::PropertyAttribute::DontEnum | JSC::PropertyAttribute::DontDelete | JSC::PropertyAttribute::ReadOnly);
 }
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