From 7935895480b74fb9fe02e5f26a82265a72604d77 Mon Sep 17 00:00:00 2001
From: fschildt <florian.schildt@protonmail.com>
Date: Fri, 17 Oct 2025 12:03:56 +0200
Subject: add arena allocator

---
 src/common/Arena.hpp | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 src/common/Arena.hpp

(limited to 'src/common')

diff --git a/src/common/Arena.hpp b/src/common/Arena.hpp
new file mode 100644
index 0000000..b5e1eb7
--- /dev/null
+++ b/src/common/Arena.hpp
@@ -0,0 +1,53 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <cassert>
+
+#include <vector>
+
+
+class Arena {
+public:
+    Arena(size_t size) : buffer(size)
+    {
+    }
+
+    template<typename T>
+    size_t
+    Align() const
+    {
+        size_t alignment = alignof(T);
+        return (offset + alignment - 1) & ~(alignment - 1);
+    }
+
+    template<typename T, typename... Args>
+    T&
+    Allocate(Args&&... args)
+    {
+        offset = Align<T>();
+        assert(offset + sizeof(T) <= buffer.size() && "Arena out of memory");
+
+        T* ptr = new (&buffer[offset]) T(std::forward<Args>(args)...);
+        objects.emplace_back(ptr, [](void* p) { static_cast<T*>(p)->~T(); });
+
+        offset += sizeof(T);
+        return *ptr;
+    }
+
+    void
+    Reset()
+    {
+        for (auto& [ptr, dtor] : objects) {
+            dtor(ptr);
+        }
+        objects.clear();
+        offset = 0;
+    }
+
+
+    size_t offset = 0;
+    std::vector<uint8_t> buffer;
+    std::vector<std::pair<void*, void (*)(void*)>> objects;
+};
+
-- 
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