Support different hash functions in HashingVectorizer

[rth]

Currently, we use the MurmurHash3 hash function from the rust-fasthash (to be more similar to scikit-learn implementation). That crate also supports a number of other hash functions,

City Hash
Farm Hash
Metro Hash
Mum Hash
Sea Hash
Spooky Hash
T1 Hash
xx Hash

I'm not convinced hashing is currently the performance bottleneck, but in any case using a faster hash function such as xxhash would not hurt.

This would involve updating the text-vectorize crate and adding hasher parameter to the HashingVectorizer python estimator.

Another use case could to use different hash functions to reduce the effect of collisions Svenstrup et. al. 2017, discussed e.g. in https://stackoverflow.com/q/53767469/1791279

[rth]

Just to confirm, that choice of the hash function has mostly no impact on performance as it is not the bottleneck.

[rth]

Just to confirm, that choice of the hash function has mostly no impact on performance as it is not the bottleneck.

Closing.