On 21 February 2010 20:59, Slawomir Lisznianski <slisznia@paramay.com> wrote:
http://svn.boost.org/svn/boost/sandbox/tokenmap/libs/tokenmap/doc/html/index...
A tokenmap is a data structure that uniquely maps pseudo-random generated keys with elements of the collection.
I think it looks useful. I have some comments. It looks like the code for finding a free slot could get slow as the index fills up. I suppose a small load factor would help, but a better alternative might be to use the pointers in empty slots to maintain a linked list of free slots. There would be an additional cost when creating and resizing the container, but I think inserting should be faster and it would avoid the need for a load factor. It would also be useful to be able choose the random number generator, probably using Boost.Random, as your generator doesn't look very strong. It might also be useful to able to obfuscate the key by some means, so that the index isn't exposed. A single customization point might be useful; say, a stateful object with two functions, one which takes an index and capacity and returns a token, and one which takes a token and capacity and returns an index (with a suitable guarantee that the index would be unique for larger capacities). That might overcomplicate things though, since obfuscation could be done outside of the container. Daniel