#include "session_pool.h"

struct session_pool
{
    uint64_t count;
    struct session *sess;
};

struct session_pool *session_pool_create(uint64_t count)
{
    struct session_pool *pool = (struct session_pool *)calloc(1, sizeof(struct session_pool) + count * sizeof(struct session));
    if (pool == NULL)
    {
        return NULL;
    }

    pool->count = count;
    pool->sess = (struct session *)(pool + 1);

    for (uint64_t i = 0; i < count; i++)
    {
        pool->sess[i].next = &pool->sess[i + 1];
    }
    pool->sess[count - 1].next = NULL;

    return pool;
}

void session_pool_destroy(struct session_pool *pool)
{
    if (pool)
    {
        free(pool);
        pool = NULL;
    }
}

struct session *session_pool_pop(struct session_pool *pool)
{
    if (pool == NULL)
    {
        return NULL;
    }

    struct session *sess = pool->sess;
    if (sess == NULL)
    {
        return NULL;
    }

    pool->sess = sess->next;
    sess->next = NULL;

    return sess;
}

void session_pool_push(struct session_pool *pool, struct session *sess)
{
    if (pool == NULL || sess == NULL)
    {
        return;
    }

    sess->next = pool->sess;
    pool->sess = sess;
}