better practice for work with saved buffer

[Rudra Banerjee <rudra banerjee aol co uk>]

hello friends, 
I am working on a gtk_list_store, that will save the rows to a file
(set_contents(file, buffer))
After saving the datas to a file, without exiting, I will like to edit
the file (as buffer) again. For that I have 2 option in my knowledge:

1) save the data, g_free(buffer), list_store_clear, reload the saved
file
2) save the buffer to the file, but continue working with that without
g_free(buffer)

both seems to work, but which is the better practice?