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String#blank? Ruby Extension

Gem Version Build Status

fast_blank is a simple C extension which provides a fast implementation of Active Support's String#blank? method.

How do you use it?

require 'fast_blank'

or add it to your Bundler Gemfile

gem 'fast_blank'

How fast is "Fast"?

About 1.2–20x faster than Active Support on my machine (your mileage my vary, depends on string length):

$ bundle exec ./benchmark

================== Test String Length: 0 ==================
Calculating -------------------------------------
          Fast Blank   225.251k i/100ms
  Fast ActiveSupport   225.676k i/100ms
          Slow Blank   110.934k i/100ms
      New Slow Blank   221.792k i/100ms
          Fast Blank     29.673M (± 2.7%) i/s -    148.215M
  Fast ActiveSupport     28.249M (± 3.5%) i/s -    141.048M
          Slow Blank      2.158M (± 3.3%) i/s -     10.872M
      New Slow Blank     23.558M (± 3.2%) i/s -    117.772M

          Fast Blank: 29673200.1 i/s
  Fast ActiveSupport: 28248894.5 i/s - 1.05x slower
      New Slow Blank: 23557900.0 i/s - 1.26x slower
          Slow Blank:  2157787.7 i/s - 13.75x slower

================== Test String Length: 6 ==================
Calculating -------------------------------------
          Fast Blank   201.185k i/100ms
  Fast ActiveSupport   205.076k i/100ms
          Slow Blank   102.061k i/100ms
      New Slow Blank   123.087k i/100ms
          Fast Blank     13.894M (± 2.3%) i/s -     69.409M
  Fast ActiveSupport     14.627M (± 3.5%) i/s -     73.212M
          Slow Blank      1.943M (± 2.3%) i/s -      9.798M
      New Slow Blank      2.796M (± 1.8%) i/s -     14.032M

  Fast ActiveSupport: 14627063.7 i/s
          Fast Blank: 13893631.2 i/s - 1.05x slower
      New Slow Blank:  2795783.3 i/s - 5.23x slower
          Slow Blank:  1943025.9 i/s - 7.53x slower

================== Test String Length: 14 ==================
Calculating -------------------------------------
          Fast Blank   220.004k i/100ms
  Fast ActiveSupport   219.716k i/100ms
          Slow Blank   147.399k i/100ms
      New Slow Blank   106.651k i/100ms
          Fast Blank     24.949M (± 3.0%) i/s -    124.742M
  Fast ActiveSupport     24.491M (± 3.3%) i/s -    122.382M
          Slow Blank      4.292M (± 1.6%) i/s -     21.520M
      New Slow Blank      2.115M (± 2.4%) i/s -     10.665M

          Fast Blank: 24948558.8 i/s
  Fast ActiveSupport: 24491245.1 i/s - 1.02x slower
          Slow Blank:  4292490.5 i/s - 5.81x slower
      New Slow Blank:  2115097.6 i/s - 11.80x slower

================== Test String Length: 24 ==================
Calculating -------------------------------------
          Fast Blank   206.555k i/100ms
  Fast ActiveSupport   208.513k i/100ms
          Slow Blank   137.733k i/100ms
      New Slow Blank   101.215k i/100ms
          Fast Blank     16.761M (± 2.7%) i/s -     83.861M
  Fast ActiveSupport     17.710M (± 3.2%) i/s -     88.618M
          Slow Blank      3.744M (± 2.0%) i/s -     18.732M
      New Slow Blank      1.962M (± 2.7%) i/s -      9.818M

  Fast ActiveSupport: 17709936.5 i/s
          Fast Blank: 16760839.7 i/s - 1.06x slower
          Slow Blank:  3744048.4 i/s - 4.73x slower
      New Slow Blank:  1961831.1 i/s - 9.03x slower

================== Test String Length: 136 ==================
Calculating -------------------------------------
          Fast Blank   201.772k i/100ms
  Fast ActiveSupport   189.120k i/100ms
          Slow Blank   129.439k i/100ms
      New Slow Blank    90.677k i/100ms
          Fast Blank     16.718M (± 2.8%) i/s -     83.534M
  Fast ActiveSupport     17.617M (± 3.6%) i/s -     87.941M
          Slow Blank      3.725M (± 3.0%) i/s -     18.639M
      New Slow Blank      1.940M (± 4.8%) i/s -      9.702M

  Fast ActiveSupport: 17616782.1 i/s
          Fast Blank: 16718307.8 i/s - 1.05x slower
          Slow Blank:  3725097.6 i/s - 4.73x slower
      New Slow Blank:  1940271.2 i/s - 9.08x slower

Additionally, this gem allocates no strings during the test, making it less of a GC burden.

Compatibility note:

fast_blank supports MRI Ruby 1.9.3, 2.0, 2.1, and 2.2, as well as Rubinius 2.x. Earlier versions of MRI are untested.

fast_blank implements String#blank? as MRI would have implemented it, meaning it has 100% parity with String#strip.length == 0.

Active Support's version also considers Unicode spaces. For example, "\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u202F\u205F\u3000".blank? is true in Active Support even though fast_blank would treat it as not blank. Therefore, fast_blank also provides blank_as? which is a 100%-compatible Active Support blank? replacement.


Change log:


  • Minor, avoid warnings if redefining blank?



  • Removed rake dependency (@tmm1#2)
  • Unrolled internal loop to improve perf (@tmm1#2)