Brett Sheffield authored Feb 20, 2017 and Ondřej Kuzník committed Jun 23, 2020

ldif_open_mem() is the fmemopen(3) equivalent of ldif_open() which opens
an ldif steam from memory, rather than from a file.

Sergio Gelato authored Dec 06, 2015 and Quanah Gibson-Mount committed Jun 22, 2020

The fallback to a straight Fisher-Yates shuffle needs to occur whenever the
sum of the *remaining* weights is zero, or else the remaining records will
not be reordered. Testing only once at the beginning covers the case when
all weights are zero, and obviously no shuffling is needed when only one
weight is zero; but other weight combinations are possible, such as (1, 0, 0).

Sergio Gelato authored Dec 06, 2015 and Quanah Gibson-Mount committed Jun 22, 2020

Prior to this change, given two records of weight 1 the algorithm would
return them in the order (0,1) with 100% probability instead of the
desired 50%. This was due to an off-by-one error in the range test.

srv_rand() returns a float in the range [0.0, 1.0[, so r is an integer in the
range [0, total[. The correct probability for record 0 to be chosen is
a[0].weight/total, not (a[0].weight+1)/total.

Ondřej Kuzník authored Jun 11, 2020 and Quanah Gibson-Mount committed Jun 21, 2020

cn=config changes might cause slapi_plugins_used transition from 0
during the lifetime of operation (cn=config change or syncrepl) or
a connection and we should be able to deal with that.