2024-11-07 stan

init_from_db, init_operlog, init_history初始化分析

一、init_from_db函数

1. 功能概述

负责从数据库恢复交易系统状态,是系统启动时的关键步骤。

2. 代码位置

int init_from_db(void)
{
    MYSQL *conn = mysql_connect(&settings.db_log);
    if (conn == NULL) {
        log_error("connect mysql fail");
        log_stderr("connect mysql fail");
        return -__LINE__;
    }

    time_t now = time(NULL);
    uint64_t last_oper_id  = 0;
    uint64_t last_order_id = 0;
    uint64_t last_deals_id = 0;
    int ret = get_last_slice(conn, &last_slice_time, &last_oper_id, &last_order_id, &last_deals_id);
    if (ret < 0) {
        return ret;
    }

    log_info("last_slice_time: %ld, last_oper_id: %"PRIu64", last_order_id: %"PRIu64", last_deals_id: %"PRIu64,
            last_slice_time, last_oper_id, last_order_id, last_deals_id);
    log_stderr("last_slice_time: %ld, last_oper_id: %"PRIu64", last_order_id: %"PRIu64", last_deals_id: %"PRIu64,
            last_slice_time, last_oper_id, last_order_id, last_deals_id);

    order_id_start = last_order_id;
    deals_id_start = last_deals_id;

    if (last_slice_time == 0) {
        ret = load_operlog_from_db(conn, now, &last_oper_id);
        if (ret < 0)
            goto cleanup;
    } else {
        ret = load_slice_from_db(conn, last_slice_time);
        if (ret < 0) {
            goto cleanup;
        }

        time_t begin = last_slice_time;
        time_t end = get_today_start() + 86400;
        while (begin < end) {
            ret = load_operlog_from_db(conn, begin, &last_oper_id);
            if (ret < 0) {
                goto cleanup;
            }
            begin += 86400;
        }
    }

    operlog_id_start = last_oper_id;

    mysql_close(conn);
    log_stderr("load success");

    return 0;

cleanup:
    mysql_close(conn);
    return ret;
}

3. 主要步骤

• 数据库连接
  • 使用settings.db_log配置连接MySQL
  • 处理连接失败情况
• 获取最新切片信息
  • 获取last_slice_time和相关ID
  • 设置order_id_start和deals_id_start全局变量
• 数据加载
  • 无切片时直接加载操作日志
  • 有切片时先加载切片数据再加载操作日志

4. 关键依赖函数

• load_orders(): 加载订单数据
• load_balance(): 加载余额数据
• load_operlog(): 加载操作日志

二、init_operlog函数

1. 功能概述

初始化操作日志系统,确保交易操作可被记录和追踪。

2. 代码位置

int init_operlog(void)
{
    mysql_conn = mysql_init(NULL);
    if (mysql_conn == NULL)
        return -__LINE__;
    if (mysql_options(mysql_conn, MYSQL_SET_CHARSET_NAME, settings.db_log.charset) != 0)
        return -__LINE__;

    nw_job_type type;
    memset(&type, 0, sizeof(type));
    type.on_init    = on_job_init;
    type.on_job     = on_job;
    type.on_cleanup = on_job_cleanup;
    type.on_release = on_job_release;

    job = nw_job_create(&type, 1);
    if (job == NULL)
        return -__LINE__;

    list_type lt;
    memset(&lt, 0, sizeof(lt));
    lt.free = on_list_free;
    list = list_create(&lt);
    if (list == NULL)
        return -__LINE__;

    nw_timer_set(&timer, 0.1, true, on_timer, NULL);
    nw_timer_start(&timer);

    return 0;
}