kapi/memory: move buffered allocator

2 files changed, 6 insertions, 144 deletions

diff --git a/arch/x86_64/include/arch/memory/buffered_allocator.hpp b/arch/x86_64/include/arch/memory/buffered_allocator.hpp
deleted file mode 100644
index 87ebbf6..0000000
--- a/arch/x86_64/include/arch/memory/buffered_allocator.hpp
+++ /dev/null
@@ -1,138 +0,0 @@
-#ifndef TEACHOS_X86_64_BUFFERED_ALLOCATOR_HPP
-#define TEACHOS_X86_64_BUFFERED_ALLOCATOR_HPP
-
-#include "kapi/memory.hpp"
-#include "kapi/system.hpp"
-
-#include <algorithm>
-#include <array>
-#include <cstddef>
-#include <optional>
-#include <utility>
-
-namespace arch::memory
-{
-
-  template<std::size_t BufferSize>
-  struct buffered_allocator : kapi::memory::frame_allocator
-  {
-    explicit buffered_allocator(frame_allocator * underlying)
-        : m_underlying{underlying}
-        , m_free{BufferSize}
-    {
-      auto from_underlying = m_underlying->allocate_many(BufferSize);
-      if (!from_underlying)
-      {
-        kapi::system::panic("[x86_64:MEM] Not enough frames available from underlying allocator.");
-      }
-      auto [first_frame, count] = *from_underlying;
-      std::ranges::generate_n(m_pool.begin(), count, [first_frame]() mutable { return first_frame++; });
-    }
-
-    buffered_allocator(buffered_allocator const &) = delete;
-    buffered_allocator(buffered_allocator && other) noexcept = delete;
-
-    ~buffered_allocator() override
-    {
-      std::ranges::for_each(m_pool, [this](auto const & maybe_frame) {
-        if (maybe_frame)
-        {
-          m_underlying->release_many({*maybe_frame, 1});
-        }
-      });
-    }
-
-    auto operator=(buffered_allocator const &) = delete;
-    auto operator=(buffered_allocator &&) = delete;
-
-    auto allocate_many(std::size_t count = 1) noexcept
-        -> std::optional<std::pair<kapi::memory::frame, std::size_t>> override
-    {
-      if (count > m_free)
-      {
-        return m_underlying->allocate_many(count);
-      }
-
-      auto start_of_set = std::ranges::find_if(m_pool, [](auto const & candidate) { return candidate.has_value(); });
-      if (start_of_set == m_pool.end())
-      {
-        return m_underlying->allocate_many(count);
-      }
-
-      if (std::distance(start_of_set, m_pool.end()) < static_cast<std::ptrdiff_t>(count))
-      {
-        return m_underlying->allocate_many(count);
-      }
-
-      auto number_of_consecutive_frames = 1uz;
-      for (auto current = std::next(start_of_set); current != m_pool.end() && number_of_consecutive_frames < count;
-           ++current)
-      {
-        if (*current && *start_of_set && **current == (**start_of_set) + 1)
-        {
-          ++number_of_consecutive_frames;
-          continue;
-        }
-        number_of_consecutive_frames = 0;
-        start_of_set = current;
-      }
-
-      if (std::distance(start_of_set, m_pool.end()) >= static_cast<std::ptrdiff_t>(count))
-      {
-        auto result = std::make_pair(**start_of_set, count);
-        m_free -= count;
-        std::ranges::for_each(start_of_set, start_of_set + count, [](auto & frame) { frame.reset(); });
-        sort_pool();
-        return result;
-      }
-      return m_underlying->allocate_many(count);
-    }
-
-    auto release_many(std::pair<kapi::memory::frame, std::size_t> frame_set) -> void override
-    {
-      if (m_free == BufferSize)
-      {
-        return m_underlying->release_many(frame_set);
-      }
-
-      auto [first_frame, count] = frame_set;
-      auto start_of_set = std::ranges::find_if(m_pool, [](auto const & candidate) { return !candidate.has_value(); });
-
-      for (auto current = start_of_set; current != m_pool.end() && count; ++current)
-      {
-        *current = first_frame++;
-        ++m_free;
-        --count;
-      }
-      sort_pool();
-
-      if (count)
-      {
-        m_underlying->release_many({first_frame, count});
-      }
-    }
-
-  private:
-    auto sort_pool() -> void
-    {
-      std::ranges::sort(m_pool, [](auto lhs, auto rhs) -> bool {
-        if (lhs && rhs)
-        {
-          return *lhs < *rhs;
-        }
-        if (!lhs)
-        {
-          return false;
-        }
-        return true;
-      });
-    }
-
-    frame_allocator * m_underlying;
-    std::size_t m_free;
-    std::array<std::optional<kapi::memory::frame>, BufferSize> m_pool{};
-  };
-
-}  // namespace arch::memory
-
-#endif
\ No newline at end of file
diff --git a/arch/x86_64/kapi/memory.cpp b/arch/x86_64/kapi/memory.cpp
index e366ee1..b71fa17 100644
--- a/arch/x86_64/kapi/memory.cpp
+++ b/arch/x86_64/kapi/memory.cpp
@@ -1,12 +1,12 @@
 #include "kapi/memory.hpp"
 
 #include "kapi/boot.hpp"
+#include "kapi/memory/buffered_allocator.hpp"
 #include "kapi/system.hpp"
 
 #include "arch/boot/boot.hpp"
 #include "arch/boot/ld.hpp"
 #include "arch/cpu/registers.hpp"
-#include "arch/memory/buffered_allocator.hpp"
 #include "arch/memory/kernel_mapper.hpp"
 #include "arch/memory/mmu.hpp"
 #include "arch/memory/page_table.hpp"
@@ -151,7 +151,7 @@ namespace kapi::memory
     }
 
     auto constinit region_based_allocator = std::optional<arch::memory::region_allocator>{};
-    auto constinit buffered_allocator = std::optional<arch::memory::buffered_allocator<4>>{};
+    auto constinit allocation_buffer = std::optional<buffered_allocator<4>>{};
     auto constinit recursive_page_mapper = std::optional<arch::memory::recursive_page_mapper>{};
 
   }  // namespace
@@ -170,12 +170,12 @@ namespace kapi::memory
     enable_cpu_protections();
 
     region_based_allocator.emplace(collect_memory_information());
-    buffered_allocator.emplace(&*region_based_allocator);
-    recursive_page_mapper.emplace(*buffered_allocator);
+    allocation_buffer.emplace(&*region_based_allocator);
+    recursive_page_mapper.emplace(*allocation_buffer);
 
     kstd::println("[x86_64:MEM] Preparing new paging hierarchy.");
 
-    auto new_pml4_frame = inject_faux_pml4(*buffered_allocator, *recursive_page_mapper);
+    auto new_pml4_frame = inject_faux_pml4(*allocation_buffer, *recursive_page_mapper);
 
     remap_kernel(*recursive_page_mapper);
     remap_vga_text_mode_buffer(*recursive_page_mapper);
@@ -187,7 +187,7 @@ namespace kapi::memory
     cr3.frame(new_pml4_frame);
     arch::cpu::cr3::write(cr3);
 
-    set_frame_allocator(*buffered_allocator);
+    set_frame_allocator(*allocation_buffer);
     set_page_mapper(*recursive_page_mapper);
   }