1 files changed, 73 insertions, 0 deletions
diff --git a/src/handle-page.inl b/src/handle-page.inl
new file mode 100644
index 00000000..7c9d5a39
--- /dev/null
+++ b/src/handle-page.inl
@@ -0,0 +1,73 @@
+#pragma once
+#include "handle-page.hpp"
+#include "compat/assert.hpp"
+#include "compat/pretty-function.hpp"
+
+namespace floormat::Handle {
+
+template<typename Obj, uint32_t PageSize>
+Page<Obj, PageSize>::~Page() noexcept
+{
+    fm_assert(used_count == 0);
+}
+
+template<typename Obj, uint32_t PageSize>
+Page<Obj, PageSize>::Page(uint32_t start_index):
+    used_map{ValueInit, PageSize},
+    start_index{start_index},
+    first_free{start_index}
+{
+    fm_assert(size_t{start_index} + size_t{PageSize} <= 1<<31 && start_index + PageSize > start_index);
+    auto val = start_index;
+    for (auto i = 0u; i < PageSize; i++)
+    {
+        auto& o = storage.data()[i];
+        o.handle = {val++, 0};
+        o.next = val;
+    }
+}
+
+template<typename Obj, uint32_t PageSize>
+Item<Obj, PageSize>& Page<Obj, PageSize>::allocate()
+{
+    fm_assert(used_count < PageSize);
+    auto first_freeʹ = first_free - start_index;
+    fm_debug_assert(first_freeʹ < PageSize);
+    fm_debug_assert(!used_map[first_freeʹ]);
+    auto& item = storage[first_freeʹ];
+    first_free = item.next;
+    used_count++;
+    used_map.set(first_freeʹ, true);
+    return item;
+}
+
+template<typename Obj, uint32_t PageSize>
+void Page<Obj, PageSize>::deallocate(Handle<Obj, PageSize> obj)
+{
+    auto index = obj.index - start_index;
+    fm_debug_assert(index < PageSize);
+    fm_assert(used_map[index]);
+    fm_debug_assert(used_count > 0);
+    fm_debug_assert(first_free != (uint32_t)-1);
+    auto& item = storage[index];
+    auto ctr = ++item.handle.counter;
+    if (ctr == uint32_t{0}) [[unlikely]]
+        Debug{} << "counter" << FM_PRETTY_FUNCTION << "overflowed";
+    item.next = first_free;
+    used_count--;
+    first_free = obj.index;
+}
+
+template<typename Obj, uint32_t PageSize>
+bool Page<Obj, PageSize>::is_empty()
+{
+    return used_count == 0;
+}
+
+template<typename Obj, uint32_t PageSize>
+bool Page<Obj, PageSize>::is_full()
+{
+    return used_count == PageSize;
+}
+
+} // namespace floormat::Handle