tribedb/lib/pool.js

Unlimited expansion MySQL cluster storage system

/**
 *
 * 数据库连接池
 * 
 */

const util = require('util');
const mysql = require('mysql');
const config = require('./config.js');


// 数据库连接池集群
var poolMuster = []; // 全部
var poolMusterTable = {};
var poolMusterDbname = {};


// var poolCluster = mysql.createPoolCluster();


/**
 * 销毁所有连接
 */
exports.destroy = function()
{
    for (let i in poolMuster) {
        poolMuster[i].end();
    }
}


/**
 * 通过数据表  获取连接
 */
exports.conn = function(table, opt, callback)
{
    if( util.isFunction(opt) ){
        callback = opt;
        opt = {};
    }

    // 初始化连接池集群
    createPoolCluster(table, opt);

    // 挑选适合的集群
    var pool = choosePool(table, opt);

    // 返回连接
    pool.getConnection(callback);

}



/**
 * 挑选一个连接池（轮转调度）
 */
function choosePool(table, opt)
{
    let plty = 'general';
    opt.read && (plty='read');
    opt.write && (plty='write');
    
    // 轮转
    let pool = poolMusterTable[table][plty].shift();
    poolMusterTable[table][plty].push(pool);

    if( ! pool)
        throw new Error('TribeDB not find available configuration !');

    return pool;
}
    



/**
 * 创建数据库集群的连接池
 */
function createPoolCluster(table, opt)
{
    if( poolMusterTable[table] )
        return poolMusterTable[table];

    let dbname = config.tableRouter[table];
    dbname || (dbname = config.mainDatabaseName());

    if( ! poolMusterDbname[dbname] ){

        let poolobj = {
            general : [],
            write : [],
            read : [],
        };

        // 循环每一个库配置
        // log(dbname);
        if( !config.databases[dbname]){
            throw new Error('TribeDB not find database !');
        }
        config.databases[dbname].forEach(dbconf=>{

            // log(dbconf);
            let pool = mysql.createPool(dbconf);
            let pools = [pool];
            poolMuster.push( pool );
            // die( pool );
            if(dbconf.weight > 1) for (let i=1; i<dbconf.weight; i++) {
                pools.push( pool ); // 复制代表权重
            };

            if( dbconf.readonly ){

                poolobj.read = poolobj.read.concat( pools );

            }else if( dbconf.writeonly ){

                poolobj.write = poolobj.write.concat( pools );

            }else{

                poolobj.general = poolobj.general.concat( pools );
                poolobj.write = poolobj.write.concat( pools );
                poolobj.read = poolobj.read.concat( pools );

            }

        });

        poolMusterDbname[dbname] = poolobj;

    }

    // log( poolMusterDbname[dbname] );

    return poolMusterTable[table] = poolMusterDbname[dbname];
}