#ifndef DEPTHGUIDE_MEMORY_POOL_IMPL_H
#define DEPTHGUIDE_MEMORY_POOL_IMPL_H

#include "core/memory_pool.h"

#include <boost/asio/io_context.hpp>

#include <list>
#include <map>
#include <mutex>
#include <thread>

struct memory_pool::impl {

    // reuse_length * reuse_threshold >= request_length
    static constexpr auto reuse_threshold = 0.5;

    enum memory_layout : uint8_t {
        MEM_LINEAR, MEM_PITCH
    };

    struct mem_info_type {
        void *ptr;
        memory_location loc;
        memory_layout lay;

        // for MEM_LINEAR and MEM_PITCH
        size_t count;

        cudaEvent_t event = nullptr;
    };

    using malloc_pool_type = std::map<void *, mem_info_type, std::greater<>>;
    malloc_pool_type malloc_pool;

    using reuse_pool_type = std::multimap<size_t, mem_info_type>;
    reuse_pool_type reuse_host_pool;
    reuse_pool_type reuse_cuda_pool;

    std::mutex mu;

    void reg_allocate(mem_info_type mem_info);

    void *try_reuse_host(size_t count);

    void *try_reuse_cuda(size_t count);

    void *direct_allocate_host(size_t count);

    void *direct_allocate_cuda(size_t count);

    void *allocate_host(size_t count);

    void *allocate_cuda(size_t count);

    void *allocate(size_t count, memory_location mem_loc);

    void *allocate_pitch(size_t width, size_t rows, memory_location mem_loc, size_t *pitch);

    cudaEvent_t get_event(void *ptr);

    static void system_deallocate(mem_info_type mem_info);

    void deallocate(void *ptr);

    void purge();
};

#endif //DEPTHGUIDE_MEMORY_POOL_IMPL_H