Why the 1000 key limit? Is that an ecore_config limit or something that you just made up? Bubblesort may not be a good choice for this as it maybe too slow. One option is to use the ecore heap implementation and dump it to a list. EWL does this to sort files I believe. It's nice and fast. (And since we're in ecore we can probably use ecore_data.)
It's ecore_file_ls in particular that uses the heap sort. If you know the number of data items prior to reading the whole dataset, you can avoid the initial list and just push the data directly into a heap, then pop off the maximum until it's empty to get a complete sorted list.
