/*********************************************************************************************
    Description: byte memory allocation with boundary aligned

    Copyright : All right reserved by NCIC.ICT

    Author : Zhang Zhonghai
    Date : 2023/08/23
***********************************************************************************************/

#include "byte_alloc.h"
#include <stdio.h>
#include <string.h>

// 创建
byte_mem_t *create_byte_mem()
{
    byte_mem_t *bmem = (byte_mem_t *)malloc(sizeof(byte_mem_t));
    bmem->occupied = bmem->capacity = 0;
    bmem->mem = 0;
    return bmem;
}

// 初始化
void init_byte_mem(byte_mem_t *bmem)
{
    bmem->occupied = bmem->capacity = 0;
    bmem->mem = 0;
}

// 初始化并开辟一定量的内存
void byte_mem_init_alloc(byte_mem_t *bmem, size_t byte_cnt)
{
    bmem->capacity = byte_cnt;
    bmem->mem = malloc(bmem->capacity);
    bmem->occupied = 0;
}

// 请求内存
void *byte_mem_request(byte_mem_t *bmem, size_t byte_cnt)
{
    // fprintf(stderr, "capacity:%ld, occupied: %ld, byte_cnt: %ld\n", bmem->capacity, bmem->occupied, byte_cnt);
    void *ret_mem = 0;
    if (bmem == 0)
    {
        ret_mem = 0;
    }
    else if (bmem->capacity == 0)
    {
        bmem->capacity = byte_cnt;
        bmem->mem = malloc(bmem->capacity);
        bmem->occupied = byte_cnt;
        ret_mem = bmem->mem;
    }
    else if (bmem->capacity - bmem->occupied >= byte_cnt)
    {
        ret_mem = bmem->mem + bmem->occupied;
        bmem->occupied += byte_cnt;
    }
    else
    {
        bmem->capacity = bmem->occupied + byte_cnt;
        bmem->mem = realloc(bmem->mem, bmem->capacity);
        ret_mem = bmem->mem + bmem->occupied;
        bmem->occupied += byte_cnt;
    }
    return ret_mem;
}

void *byte_mem_request_and_clean(byte_mem_t *bmem, size_t byte_cnt)
{
    void *mem = byte_mem_request(bmem, byte_cnt);
    memset(mem, 0, byte_cnt);
    return mem;
}

// 将不用的内存归还给byte mem
void byte_mem_release(byte_mem_t *bmem, size_t byte_cnt)
{
    bmem->occupied -= byte_cnt;
}

void byte_mem_clear(byte_mem_t *bmem)
{
    bmem->occupied = 0;
}
// 彻底释放内存
void byte_mem_free(byte_mem_t *bmem)
{
    bmem->capacity = bmem->occupied = 0;
    free(bmem->mem);
    bmem->mem = 0;
}

// 销毁byte_mem_t
void destroy_byte_mem(byte_mem_t *bmem)
{
    if (bmem != 0)
    {
        byte_mem_free(bmem);
        free(bmem);
    }
}