Ruby Benchmark: Counting the number of lines of a file

line_count_benchmark.rb

# gem install benchmark-ips

require "benchmark/ips"

path = "lib/rubycritic/cli/options.rb"

Benchmark.ips do |x|
  x.report("read + each_line") { File.read(path).each_line.count }

  x.report("open + each_line") { File.open(path, "r").each_line.count }

  x.report("open + readlines") { File.open(path, "r").readlines.length }

  x.report("foreach + count") { File.foreach(path).count }

  x.report("foreach + inject") { File.foreach(path).inject(0) {|count, line| count+1} }

  x.report("foreach") { count = 0; File.foreach(path) { count+=1}; count }

  x.report("wc") { `wc -l < "#{path}"`.to_i }

  x.compare!
end

results

Calculating -------------------------------------
    read + each_line     4.272k i/100ms
    open + each_line     4.075k i/100ms
    open + readlines     4.050k i/100ms
     foreach + count     3.569k i/100ms
    foreach + inject     2.979k i/100ms
             foreach     3.397k i/100ms
                  wc    26.000  i/100ms
-------------------------------------------------
    read + each_line     44.535k (± 2.7%) i/s -    226.416k
    open + each_line     42.232k (± 2.7%) i/s -    211.900k
    open + readlines     41.585k (± 5.8%) i/s -    210.600k
     foreach + count     38.254k (± 1.1%) i/s -    192.726k
    foreach + inject     31.478k (± 0.8%) i/s -    157.887k
             foreach     35.819k (± 3.2%) i/s -    180.041k
                  wc    260.809  (± 3.8%) i/s -      1.326k

Comparison:
    read + each_line:    44534.7 i/s
    open + each_line:    42232.2 i/s - 1.05x slower
    open + readlines:    41584.8 i/s - 1.07x slower
     foreach + count:    38254.1 i/s - 1.16x slower
             foreach:    35818.6 i/s - 1.24x slower
    foreach + inject:    31478.2 i/s - 1.41x slower
                  wc:      260.8 i/s - 170.76x slower

An updated benchmark results:

$ bundle exec rails r tmp/html_length_vs_count_vs_size_bench.rb
Warming up --------------------------------------
        lines + size    19.000  i/100ms
      lines + length   130.000  i/100ms
       lines + count   122.000  i/100ms
   each_line + count   127.000  i/100ms
           count($/)   172.000  i/100ms
each_line + take + count
                       159.000  i/100ms
each_line + lazy + take + count
                       155.000  i/100ms
each_line + lazy + take + count
                       145.000  i/100ms
Calculating -------------------------------------
        lines + size      1.205k (±28.3%) i/s -      5.548k in   5.007348s
      lines + length      1.117k (±24.5%) i/s -      4.940k in   5.074537s
       lines + count    999.275  (±43.0%) i/s -      3.904k in   5.142585s
   each_line + count    962.420  (±42.7%) i/s -      3.937k in   5.386932s
           count($/)      1.696k (± 3.4%) i/s -      8.600k in   5.077876s
each_line + take + count
                          1.050k (±42.9%) i/s -      4.134k in   5.084343s
each_line + lazy + take + count
                        918.077  (±50.5%) i/s -      3.565k in   5.057191s
each_line + lazy + take + count
                        941.035  (±49.4%) i/s -      3.770k in   5.265527s

Comparison:
           count($/):     1695.7 i/s
        lines + size:     1205.1 i/s - 1.41x  (± 0.00) slower
      lines + length:     1116.8 i/s - 1.52x  (± 0.00) slower
each_line + take + count:     1050.0 i/s - 1.61x  (± 0.00) slower
       lines + count:      999.3 i/s - 1.70x  (± 0.00) slower
   each_line + count:      962.4 i/s - 1.76x  (± 0.00) slower
each_line + lazy + take + count:      941.0 i/s - 1.80x  (± 0.00) slower

Code:

require "benchmark/ips"

Benchmark.ips do |x|
  x.report("lines + size") { html.lines.size < 50 }
  x.report("lines + length") { html.lines.length < 50 }
  x.report("lines + count") { html.lines.count < 50 }

  x.report("count($/)") { html.count($/) < 50 }

  x.report("each_line + count") { html.each_line.count < 50 }
  x.report("each_line + take + count") { html.each_line.take(50).count < 50 }
  x.report("each_line + lazy + take + count") { html.each_line.lazy.take(50).count < 50 }
  x.report("each_line + lazy + take + count") { !html.each_line.lazy.drop(49).any? }

  x.compare!
end