fix fn tool with []string

Use mutex map (#13)

* add

* add map

remove obj pool

Revert "remove obj pool"

This reverts commit f3c692a.

add obj pool

optimized shallow copy mutex performance

code optimized

Add object pool for shallow copy (#12)

Add shallow / deep copy mode (#11)

Gen tool skip optimized (#10)

make tool ouput result more easy to read

code style

log optimized