buffer size

[zhihuidu]

https://github.com/y-256/libdivsufsort/blob/master/lib/divsufsort.c#L105
If m=n/2, then the buffer size will be zero. How the B star substring can be sorted in a zero-size buffer?

[akamiru]

Note that m at this point (the code is really poor on naming) is the number of bstar suffixes. There can never be n/2 bstar suffixes therefore there will always be a buffer (that's the whole idea of the improve two stage algorithm).

I didn't dig deep enough to tell you why the buffer has to be n / (2 * m) tough.

[zhihuidu]

@akamiru Thanks for your answer! Yes, m cannot be n/2. However, it can be very close to n/2 for some special cases.
I use
1212121212
as the input file and
n=11,m=5, bufsize =1.
then the bufsize is set to 2 (limit).
I have not got the reason why this will not overwrite the last m elements in SA .