chiark / gitweb /
hashmap: introduce hashmap_reserve()
With the current hashmap implementation that uses chaining, placing a
reservation can serve two purposes:
- To optimize putting of entries if the number of entries to put is
known. The reservation allocates buckets, so later resizing can be
avoided.
- To avoid having very long bucket chains after using
hashmap_move(_one).
In an alternative hashmap implementation it will serve an additional
purpose:
- To guarantee a subsequent hashmap_move(_one) will not fail with
-ENOMEM (this never happens in the current implementation).