cleanup code

发现有性能问题,
response time in 0~50 ms      : 0    0.00%
response time in 50_100 ms    : 0    0.00%
response time in 100_250 ms   : 326    33.23%
response time in 250_500 ms   : 654    66.67%
response time in 500_1000 ms  : 1    0.10%
response time out             : 0    0.00%
================================
total : 981
total time : 30.770092 s
speed : 31.881608 rpc/s