From 8cf0f36f7d917ce9f0f6759f27ba0553db00e82a Mon Sep 17 00:00:00 2001
From: Ali Mohammad Pur <ali.mpfard@gmail.com>
Date: Thu, 18 Jul 2024 03:41:06 +0200
Subject: [PATCH] LibWasm: Replace a hashtable with an RBTree to make
 instantiation faster

...by about 40%.
---
 .../Libraries/LibWasm/AbstractMachine/Validator.cpp   | 11 +++++++----
 .../Libraries/LibWasm/AbstractMachine/Validator.h     |  8 ++++++--
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/Userland/Libraries/LibWasm/AbstractMachine/Validator.cpp b/Userland/Libraries/LibWasm/AbstractMachine/Validator.cpp
index fb64c4e1b97..9c4d9bab444 100644
--- a/Userland/Libraries/LibWasm/AbstractMachine/Validator.cpp
+++ b/Userland/Libraries/LibWasm/AbstractMachine/Validator.cpp
@@ -124,15 +124,18 @@ ErrorOr<void, ValidationError> Validator::validate(Module& module)
     // - Exports
     auto scan_expression_for_function_indices = [&](auto& expression) {
         for (auto& instruction : expression.instructions()) {
-            if (instruction.opcode() == Instructions::ref_func)
-                m_context.references.set(instruction.arguments().template get<FunctionIndex>());
+            if (instruction.opcode() == Instructions::ref_func) {
+                auto index = instruction.arguments().template get<FunctionIndex>();
+                m_context.references->tree.insert(index.value(), index);
+            }
         }
     };
     module.for_each_section_of_type<ExportSection>([&](ExportSection const& section) {
         for (auto& export_ : section.entries()) {
             if (!export_.description().has<FunctionIndex>())
                 continue;
-            m_context.references.set(export_.description().get<FunctionIndex>());
+            auto index = export_.description().get<FunctionIndex>();
+            m_context.references->tree.insert(index.value(), index);
         }
     });
     module.for_each_section_of_type<ElementSection>([&](ElementSection const& section) {
@@ -1313,7 +1316,7 @@ VALIDATE_INSTRUCTION(ref_func)
     auto index = instruction.arguments().get<FunctionIndex>();
     TRY(validate(index));
 
-    if (!m_context.references.contains(index))
+    if (m_context.references->tree.find(index.value()) == nullptr)
         return Errors::invalid("function reference"sv);
 
     is_constant = true;
diff --git a/Userland/Libraries/LibWasm/AbstractMachine/Validator.h b/Userland/Libraries/LibWasm/AbstractMachine/Validator.h
index 61e62a37e1f..13863401196 100644
--- a/Userland/Libraries/LibWasm/AbstractMachine/Validator.h
+++ b/Userland/Libraries/LibWasm/AbstractMachine/Validator.h
@@ -8,7 +8,7 @@
 
 #include <AK/COWVector.h>
 #include <AK/Debug.h>
-#include <AK/HashTable.h>
+#include <AK/RedBlackTree.h>
 #include <AK/SourceLocation.h>
 #include <AK/Tuple.h>
 #include <AK/Vector.h>
@@ -18,6 +18,10 @@
 namespace Wasm {
 
 struct Context {
+    struct RefRBTree : RefCounted<RefRBTree> {
+        RedBlackTree<size_t, FunctionIndex> tree;
+    };
+
     COWVector<FunctionType> types;
     COWVector<FunctionType> functions;
     COWVector<TableType> tables;
@@ -27,7 +31,7 @@ struct Context {
     COWVector<bool> datas;
     COWVector<ValueType> locals;
     Optional<u32> data_count;
-    AK::HashTable<FunctionIndex> references;
+    RefPtr<RefRBTree> references { make_ref_counted<RefRBTree>() };
     size_t imported_function_count { 0 };
 };