From a527f5576861f9b1f82069ca5a5fa87f3e133c2d Mon Sep 17 00:00:00 2001
From: Andrew Kaster <akaster@serenityos.org>
Date: Mon, 11 Sep 2023 18:05:30 -0600
Subject: [PATCH] LibWeb: Create StructuredSerialize helpers for Bytes

Call them from the helpers for strings. We'll have other object classes
soon that need to serialize ByteBuffers, so let's take advantage of the
encoding scheme we are already using for Strings.
---
 .../LibWeb/HTML/StructuredSerialize.cpp       | 28 ++++++++++++-------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp b/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp
index 96bb3b60e0..0f8525492b 100644
--- a/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp
+++ b/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp
@@ -206,14 +206,13 @@ private:
     SerializationMemory& m_memory; // JS value -> index
     SerializationRecord m_serialized;
 
-    WebIDL::ExceptionOr<void> serialize_string(Vector<u32>& vector, String const& string)
+    WebIDL::ExceptionOr<void> serialize_bytes(Vector<u32>& vector, ReadonlyBytes bytes)
     {
-        u64 const size = string.code_points().byte_length();
-        // Append size of the string to the serialized structure.
+        // Append size of the buffer to the serialized structure.
+        u64 const size = bytes.size();
         TRY_OR_THROW_OOM(m_vm, vector.try_append(bit_cast<u32*>(&size), 2));
-        // Append the bytes of the string to the serialized structure.
+        // Append the bytes of the buffer to the serialized structure.
         u64 byte_position = 0;
-        ReadonlyBytes const bytes = { string.code_points().bytes(), string.code_points().byte_length() };
         while (byte_position < size) {
             u32 combined_value = 0;
             for (u8 i = 0; i < 4; ++i) {
@@ -228,6 +227,11 @@ private:
         return {};
     }
 
+    WebIDL::ExceptionOr<void> serialize_string(Vector<u32>& vector, String const& string)
+    {
+        return serialize_bytes(vector, { string.code_points().bytes(), string.code_points().byte_length() });
+    }
+
     WebIDL::ExceptionOr<void> serialize_string(Vector<u32>& vector, JS::PrimitiveString const& primitive_string)
     {
         auto string = primitive_string.utf8_string();
@@ -344,25 +348,29 @@ private:
     JS::MarkedVector<JS::Value> m_memory; // Index -> JS value
     Optional<FlyString> m_error;
 
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::PrimitiveString>> deserialize_string_primitive(JS::VM& vm, Vector<u32> const& vector, u32& position)
+    static WebIDL::ExceptionOr<ByteBuffer> deserialize_bytes(JS::VM& vm, Vector<u32> const& vector, u32& position)
     {
         u32 size_bits[2];
         size_bits[0] = vector[position++];
         size_bits[1] = vector[position++];
         u64 const size = *bit_cast<u64*>(&size_bits);
 
-        Vector<u8> bytes;
-        TRY_OR_THROW_OOM(vm, bytes.try_ensure_capacity(size));
+        auto bytes = TRY_OR_THROW_OOM(vm, ByteBuffer::create_uninitialized(size));
         u64 byte_position = 0;
         while (position < vector.size() && byte_position < size) {
             for (u8 i = 0; i < 4; ++i) {
-                bytes.append(vector[position] >> (i * 8) & 0xFF);
-                byte_position++;
+                bytes[byte_position++] = (vector[position] >> (i * 8) & 0xFF);
                 if (byte_position == size)
                     break;
             }
             position++;
         }
+        return bytes;
+    }
+
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::PrimitiveString>> deserialize_string_primitive(JS::VM& vm, Vector<u32> const& vector, u32& position)
+    {
+        auto bytes = TRY(deserialize_bytes(vm, vector, position));
 
         return TRY(Bindings::throw_dom_exception_if_needed(vm, [&vm, &bytes]() {
             return JS::PrimitiveString::create(vm, StringView { bytes });