> Ouch. Not simply the Java hash function? That will work for Clojure > objects that don't contain identities, only values. Whereas the above > has issues with sets and maps that are semantically equal but get put > together differently: Yeah, with-out-str can be replaced to suit your data. I think in most cases obj is string. So we can ignore details.
2012/2/4 Cedric Greevey <cgree...@gmail.com>: > On Thu, Feb 2, 2012 at 8:30 PM, Takahiro Hozumi <fat...@googlemail.com> wrote: >> 1. Resolve a server name which client should be connected to. >> If a client need to be connected to specific resource (chat room etc) >> consistent hashing is useful. >> http://nakkaya.com/2010/05/05/consistent-hashing-with-clojure/ > >> (defn sha1 [obj] >> (let [bytes (.getBytes (with-out-str (pr obj)))] >> (apply vector (.digest (MessageDigest/getInstance "SHA1") bytes)))) > > Ouch. Not simply the Java hash function? That will work for Clojure > objects that don't contain identities, only values. Whereas the above > has issues with sets and maps that are semantically equal but get put > together differently: > > user=> (def x (array-map :a 1 :b 2)) > #'user/x > user=> (def y (array-map :b 2 :a 1)) > #'user/y > user=> (= (sha1 x) (sha1 y)) > false > > Oopsie. > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with your > first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
