1 files changed, 96 insertions, 0 deletions

diff --git a/src/core/file_sys/fssystem/fssystem_pooled_buffer.h b/src/core/file_sys/fssystem/fssystem_pooled_buffer.h
new file mode 100644
index 000000000..1df3153a1
--- /dev/null
+++ b/src/core/file_sys/fssystem/fssystem_pooled_buffer.h
@@ -0,0 +1,96 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/common_funcs.h"
+#include "common/common_types.h"
+#include "common/literals.h"
+#include "core/hle/result.h"
+
+namespace FileSys {
+
+using namespace Common::Literals;
+
+constexpr inline size_t BufferPoolAlignment = 4_KiB;
+constexpr inline size_t BufferPoolWorkSize = 320;
+
+class PooledBuffer {
+    YUZU_NON_COPYABLE(PooledBuffer);
+
+private:
+    char* m_buffer;
+    size_t m_size;
+
+private:
+    static size_t GetAllocatableSizeMaxCore(bool large);
+
+public:
+    static size_t GetAllocatableSizeMax() {
+        return GetAllocatableSizeMaxCore(false);
+    }
+    static size_t GetAllocatableParticularlyLargeSizeMax() {
+        return GetAllocatableSizeMaxCore(true);
+    }
+
+private:
+    void Swap(PooledBuffer& rhs) {
+        std::swap(m_buffer, rhs.m_buffer);
+        std::swap(m_size, rhs.m_size);
+    }
+
+public:
+    // Constructor/Destructor.
+    constexpr PooledBuffer() : m_buffer(), m_size() {}
+
+    PooledBuffer(size_t ideal_size, size_t required_size) : m_buffer(), m_size() {
+        this->Allocate(ideal_size, required_size);
+    }
+
+    ~PooledBuffer() {
+        this->Deallocate();
+    }
+
+    // Move and assignment.
+    explicit PooledBuffer(PooledBuffer&& rhs) : m_buffer(rhs.m_buffer), m_size(rhs.m_size) {
+        rhs.m_buffer = nullptr;
+        rhs.m_size = 0;
+    }
+
+    PooledBuffer& operator=(PooledBuffer&& rhs) {
+        PooledBuffer(std::move(rhs)).Swap(*this);
+        return *this;
+    }
+
+    // Allocation API.
+    void Allocate(size_t ideal_size, size_t required_size) {
+        return this->AllocateCore(ideal_size, required_size, false);
+    }
+
+    void AllocateParticularlyLarge(size_t ideal_size, size_t required_size) {
+        return this->AllocateCore(ideal_size, required_size, true);
+    }
+
+    void Shrink(size_t ideal_size);
+
+    void Deallocate() {
+        // Shrink the buffer to empty.
+        this->Shrink(0);
+        ASSERT(m_buffer == nullptr);
+    }
+
+    char* GetBuffer() const {
+        ASSERT(m_buffer != nullptr);
+        return m_buffer;
+    }
+
+    size_t GetSize() const {
+        ASSERT(m_buffer != nullptr);
+        return m_size;
+    }
+
+private:
+    void AllocateCore(size_t ideal_size, size_t required_size, bool large);
+};
+
+} // namespace FileSys