#ifndef __MEMORY_POOL_H__
#define __MEMORY_POOL_H__

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MEMPOOL_PAGE_SIZE           4096
#define MEMPOOL_BLOCK_MAX_SIZE      512
#define MEMPOOL_ALIGNMENT           8
#define MEMPOOL_NUM_CLASSES         (MEMPOOL_BLOCK_MAX_SIZE / MEMPOOL_ALIGNMENT)
#define MEMPOOL_CACHE_PAGE          2

typedef struct mp_page_s   mp_page_t;
typedef struct mp_bucket_s mp_bucket_t;
typedef struct mp_pool_s   mp_pool_t;
typedef struct mp_large_s  mp_large_t;

typedef enum{
    MEMPOOL_INVALID_INPUT   = -1,
    MEMPOOL_MALLOC_ERROR    = -2,
    MEMPOOL_DOUBLE_FREE     = -3,
}mp_err_t;

struct mp_page_s{
    mp_bucket_t     *owner;

    mp_page_t       *next;
    mp_page_t       *prev;

    void            *free_list;

    uint16_t        free_count;
    uint16_t        capacity;

    uint64_t        bitmap[8];  // 最多支持 512 个块 (64*8)
};

struct mp_bucket_s{
    size_t          block_size;         // 桶中块大小
    uint32_t        page_count;         // 桶中页数
    uint32_t        empty_count;        // 空闲页数

    mp_page_t       *empty_pages;     // 完全空闲page
    mp_page_t       *partial_pages;     // 空闲page
    mp_page_t       *full_pages;        // 满page
};

struct mp_large_s{
    mp_large_t *next;
    mp_large_t *prev;
};

struct mp_pool_s{
    mp_bucket_t     buckets[MEMPOOL_NUM_CLASSES];

    mp_large_t      *large_list;
};

int mp_create(mp_pool_t *pool);
int mp_destroy(mp_pool_t *pool);

void *mp_alloc(mp_pool_t *pool, size_t size);
int mp_free(mp_pool_t *pool, void *ptr);

#endif