Line by line reading

gistfile1.clj

user> (defn c [p]
       (with-open [rdr (clojure.java.io/reader p)]
         (reduce + (map count (line-seq rdr)))))
#'user/c
user> (bench/quick-bench
       (c "/tmp/test"))
WARNING: Final GC required 356.7754050400232 % of runtime
Evaluation count : 6 in 6 samples of 1 calls.
             Execution time mean : 525.040480 ms
    Execution time std-deviation : 29.017225 ms
   Execution time lower quantile : 491.257955 ms ( 2.5%)
   Execution time upper quantile : 563.009360 ms (97.5%)
                   Overhead used : 2.812543 ns
nil

gistfile2.py

In [1]: def c(p):
   ...:     with open(p) as f:
   ...:         return sum(len(line.strip()) for line in f)
   ...:  


In [10]: %timeit -n100 c("/tmp/test")                                                                                                                                                                        
100 loops, best of 3: 288 ms per loop

reducers to the resque!

user> (require '[clojure.core.reducers :as r])
nil
user> (defn c3 [p]
       (with-open [rdr (clojure.java.io/reader p)]
         (r/reduce + 0 (r/map len (line-seq rdr)))))
#'user/c3
user> (bench/quick-bench
       (c3 "/tmp/test"))
WARNING: Final GC required 587.4416454410667 % of runtime
Evaluation count : 6 in 6 samples of 1 calls.
             Execution time mean : 319.255797 ms
    Execution time std-deviation : 74.168228 ms
   Execution time lower quantile : 259.756586 ms ( 2.5%)
   Execution time upper quantile : 436.680869 ms (97.5%)
                   Overhead used : 2.812543 ns
nil