Fix memory leak in response.clone(), further reduce memory usage of Request & Response (#3902)

* Atomize respsone.url & response.statusText

* Fix warning

* Atomize Request & Response URLs when possible

* Fix memory leak in response.clone()

bun/bench/snippets on  jarred/atomize
❯ mem bun --smol request-response-clone.mjs
cpu: Apple M1 Max
runtime: bun 0.7.2 (arm64-darwin)

benchmark             time (avg)             (min … max)       p75       p99      p995
-------------------------------------------------------- -----------------------------
req.clone().url     77.3 ns/iter  (40.35 ns … 222.64 ns)  91.53 ns 128.11 ns 172.78 ns
resp.clone().url  162.43 ns/iter    (116 ns … 337.77 ns)  177.4 ns 232.38 ns 262.65 ns

Peak memory usage: 60 MB

bun/bench/snippets on  jarred/atomize
❯ mem bun-0.7.1 --smol request-response-clone.mjs
cpu: Apple M1 Max
runtime: bun 0.7.1 (arm64-darwin)

benchmark             time (avg)             (min … max)       p75       p99      p995
-------------------------------------------------------- -----------------------------
req.clone().url   115.85 ns/iter  (80.35 ns … 247.39 ns) 128.19 ns 181.93 ns 207.23 ns
resp.clone().url  252.32 ns/iter  (202.6 ns … 351.07 ns) 266.56 ns 325.88 ns 334.73 ns

Peak memory usage: 1179 MB

* Update tests

* Update js_ast.zig

* Update test

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

1 files changed, 18 insertions, 7 deletions

diff --git a/src/bun.js/bindings/BunString.cpp b/src/bun.js/bindings/BunString.cpp
index 5eb5f9f9b..7864ee94e 100644
--- a/src/bun.js/bindings/BunString.cpp
+++ b/src/bun.js/bindings/BunString.cpp
@@ -6,6 +6,7 @@
 #include "wtf/text/ExternalStringImpl.h"
 #include "GCDefferalContext.h"
 #include <JavaScriptCore/JSONObject.h>
+#include <wtf/text/AtomString.h>
 
 using namespace JSC;
 
@@ -25,11 +26,23 @@ extern "C" void Bun__WTFStringImpl__ref(WTF::StringImpl* impl)
 
 extern "C" bool BunString__fromJS(JSC::JSGlobalObject* globalObject, JSC::EncodedJSValue encodedValue, BunString* bunString)
 {
+
     JSC::JSValue value = JSC::JSValue::decode(encodedValue);
     *bunString = Bun::toString(globalObject, value);
     return bunString->tag != BunStringTag::Dead;
 }
 
+extern "C" BunString BunString__createAtom(const char* bytes, size_t length)
+{
+    if (simdutf::validate_ascii(bytes, length)) {
+        auto atom = makeAtomString(String(StringImpl::createWithoutCopying(bytes, length)));
+        atom.impl()->ref();
+        return { BunStringTag::WTFStringImpl, { .wtf = atom.impl() } };
+    }
+
+    return { BunStringTag::Dead, {} };
+}
+
 namespace Bun {
 JSC::JSValue toJS(JSC::JSGlobalObject* globalObject, BunString bunString)
 {
@@ -179,7 +192,6 @@ extern "C" BunString BunString__fromUTF16Unitialized(size_t length)
     if (UNLIKELY(!ptr))
         return { BunStringTag::Dead };
 
-    impl->ref();
     return { BunStringTag::WTFStringImpl, { .wtf = &impl.leakRef() } };
 }
 
@@ -190,7 +202,6 @@ extern "C" BunString BunString__fromLatin1Unitialized(size_t length)
     auto impl = WTF::StringImpl::createUninitialized(latin1Length, ptr);
     if (UNLIKELY(!ptr))
         return { BunStringTag::Dead };
-    impl->ref();
     return { BunStringTag::WTFStringImpl, { .wtf = &impl.leakRef() } };
 }
 
@@ -302,10 +313,10 @@ extern "C" EncodedJSValue BunString__createArray(
 extern "C" void BunString__toWTFString(BunString* bunString)
 {
     if (bunString->tag == BunStringTag::ZigString) {
-        if (Zig::isTaggedUTF8Ptr(bunString->impl.zig.ptr)) {
-            bunString->impl.wtf = Zig::toStringCopy(bunString->impl.zig).impl();
-        } else {
+        if (Zig::isTaggedExternalPtr(bunString->impl.zig.ptr)) {
             bunString->impl.wtf = Zig::toString(bunString->impl.zig).impl();
+        } else {
+            bunString->impl.wtf = Zig::toStringCopy(bunString->impl.zig).impl();
         }
 
         bunString->tag = BunStringTag::WTFStringImpl;
@@ -356,7 +367,7 @@ extern "C" BunString URL__getHrefFromJS(EncodedJSValue encodedValue, JSC::JSGlob
 
 extern "C" BunString URL__getHref(BunString* input)
 {
-    auto str = Bun::toWTFString(*input);
+    auto&& str = Bun::toWTFString(*input);
     auto url = WTF::URL(str);
     if (!url.isValid() || url.isEmpty())
         return { BunStringTag::Dead };
@@ -366,7 +377,7 @@ extern "C" BunString URL__getHref(BunString* input)
 
 extern "C" WTF::URL* URL__fromString(BunString* input)
 {
-    auto str = Bun::toWTFString(*input);
+    auto&& str = Bun::toWTFString(*input);
     auto url = WTF::URL(str);
     if (!url.isValid())
         return nullptr;