fastdfs go client implement

1 support

upload(UploadByFilename,UploadByBuffer)

download(DownloadToFile,DownloadToBuffer)

delete(DeleteFile)

2 append is not support(limited by fastdfs server)

you can implement append with delete origin && upload new again

3 UploadByFilename realized with sendfile syscall in linux,so UploadByBuffer is depracated

4 realized conn_pool,pool_size control by config file

5 details see client_test.go,good luck ^_^