Searching for a Fast Hash Algorithm
I am searching for a fast hash algorithm. Actually, I am trying to build a hash table whose keys are URL's. I have used MD5 to hash the U开发者_开发技巧RL's, however it is too slow (I have used java's built in function). Can anybody help me by informing about some fast hash algorithm.
Java's String
class already implements .hashCode()
. This is likely going to be the fastest, 32bit hash, for Java, as its heavily optimized at the core. This is also the hash in use when using the built-in collections, such as java.util.HashMap
.
Google open-sourced a very fast hashing algo: CityHash
MD5 is a cryptographic hash, so it will be slow compared to non-cryptographic hashes. As Yann says, the Java hash is likely to be fastest if you want a 64 bit hash.
If that doesn't suit then there are other fast non-cryptographic hashes available in various sizes, such as Fowler–Noll–Vo.
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