On Fri, Jul 10, 2015 at 06:24:17PM +0100, Pablo de Lara wrote: > This patchset is to replace the existing hash library with > a more efficient and functional approach, using the Cuckoo hash > method to deal with collisions. This method is based on using > two different hash functions to have two possible locations > in the hash table where an entry can be. > So, if a bucket is full, a new entry can push one of the items > in that bucket to its alternative location, making space for itself. > > Advantages > ~~~~~ > - Offers the option to store more entries when the target bucket is full > (unlike the previous implementation) > - Memory efficient: for storing those entries, it is not necessary to > request new memory, as the entries will be stored in the same table > - Constant worst lookup time: in worst case scenario, it always takes > the same time to look up an entry, as there are only two possible locations > where an entry can be. > - Storing data: user can store data in the hash table, unlike the > previous implementation, but he can still use the old API > > This implementation tipically offers over 90% utilization. > Notice that API has been extended, but old API remains. > Check documentation included to know more about this new implementation > (including how entries are distributed as table utilization increases). > > Changes in v4: > - Unit tests enhancements are not part of this patchset anymore. > - rte_hash structure has been made internal in another patch, > so it is not part of this patchset anymore. > - Add function to iterate through the hash table, as rte_hash > structure has been made private. > - Added extra_flag parameter in rte_hash_parameter to be able > to add new parameters in the future without breaking the ABI > - Remove proposed lookup_bulk_with_hash function, as it is > not of much use with the existing hash functions > (there are no vector hash functions). > - User can store 8-byte integer or pointer as data, instead > of variable size data, as discussed in the mailing list. >
Hi Pablo, I'm getting some compile errors with this code, perhaps you could recheck e.g 32-bit and with clang. On the plus side, I like the docs included with this set. Regards, /Bruce
