I'm working on a small clojure program which pulls data from a custom memory-backed data store via a java api. When looking at performance, there is a hotspot at the point of interaction with this API. One of the fields of each record being exported contains a list of lists of strings (List<List<String>>) with about 60-150 items in the outer list and 5 items in the inner list. The problem is that at the point of assimilating this java data type into clojure, there are a couple calls taking ~30-40% of the execution time. Here are the senarios; I'm just starting to get familiar with clojure internals, so forgive obvious blunders in this.
Processing it as: (map parse-field (.getAllFields datastore)) with parse-field defined like: (defn parse-field [^List field] ...) or (if I change the API call) (defn parse-field [^"[Ljava.lang.String;" field] ...) it calls clojure.lang.RestFn.invoke() which wants to build an ArraySeq, which calls java.lang.Class.getComponentType, which is a killer (20 of 50 seconds on 500 records). With parse-field using destructuring, on either the List or String array, clojure.lang.RT.nthFrom() is invoked, which calls java.lang.Class.isArray (https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/RT.java#L773), which is a killer as well. So I inlined parse-field and used loop/recur (instead of map) and .get on the list to get the next item, but this still results in the RestFn.invoke()->ArraysSeq->Class.getComponentType path. This is related to http://dev.clojure.org/jira/browse/CLJ-1200, although called via a different path. Does anyone have any ideas on how I could avoid these calls? Thanks, Tim -- -- 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 unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
