How can I config the max_file_size and enable it work well?

The max_file_size for leveldb seems not works well for me.
My env:
ubuntu 14.04 amd64

I clone the code, and edit the _**max_file_size**_, _**write_buffer_size**_, as follows:
1. init config in [util/options.cc](https://github.com/google/leveldb/blob/master/util/options.cc) :

2. _**max_file_size**_ limit in [db/db_impl.cc](https://github.com/google/leveldb/blob/master/db/db_impl.cc) :

And then, I run
`sudo cp -r include/leveldb /usr/local/include/`
`sudo cp -r out-shared/libleveldb.so* /usr/local/lib/`
`sudo ldconfig`
I use python wrapper for leveldb, without the _**max_file_size**_ config, it works well.
But the output *.ldb is not well as config specify, as follows:
I find that each four bigger ***.ldb** will be split more small ***.ldb** files, I think it should be became much larger than the current bigger ***.ldb** files or equal or increase the count of the bigger ***.ldb** files.
I have try my best to solve it, but find it`s not work as expect.
Thanks.