Kmp
This gem is KMP (Knuth–Morris–Pratt algorithm) implemantation with c Extension. A super first substring find technique in a big string.
Installation
Add this line to your application's Gemfile:
gem 'kmp'
And then execute:
$ bundle
Or install it yourself as:
$ gem install kmp
Usage
require 'kmp'
k = Kmp::String.new 'abcdeab'
k.match 'ab' #=> [0, 5]
k.length #=> 7
k.replace 'ab', 'X' #=> 'XcdeX'
Complexity
- match function complexity O(N+M), N original text string length, M match string length
- replace function complexity O(N+M)
- length complexity O(1)
Benchmark
This benchmark between kmp implementation in c-extenstion vs pure ruby. Benchmark module use for comparison.
lenght of string: 500
Rehearsal -----------------------------------------------
c-extension 0.000000 0.000000 0.000000 ( 0.000028)
ruby 0.000000 0.000000 0.000000 ( 0.001067)
-------------------------------------- total: 0.000000sec
user system total real
c-extension 0.000000 0.000000 0.000000 ( 0.000019)
ruby 0.000000 0.000000 0.000000 ( 0.000731)
lenght of string: 5000
Rehearsal -----------------------------------------------
c-extension 0.000000 0.000000 0.000000 ( 0.000074)
ruby 0.000000 0.000000 0.000000 ( 0.006990)
-------------------------------------- total: 0.000000sec
user system total real
c-extension 0.000000 0.000000 0.000000 ( 0.000059)
ruby 0.000000 0.000000 0.000000 ( 0.003058)
lenght of string: 50000
Rehearsal -----------------------------------------------
c-extension 0.000000 0.000000 0.000000 ( 0.000276)
ruby 0.030000 0.000000 0.030000 ( 0.022061)
-------------------------------------- total: 0.030000sec
user system total real
c-extension 0.000000 0.000000 0.000000 ( 0.000117)
ruby 0.010000 0.000000 0.010000 ( 0.014624)
lenght of string: 500000
Rehearsal -----------------------------------------------
c-extension 0.000000 0.000000 0.000000 ( 0.001346)
ruby 0.140000 0.000000 0.140000 ( 0.147500)
-------------------------------------- total: 0.140000sec
user system total real
c-extension 0.000000 0.000000 0.000000 ( 0.001188)
ruby 0.140000 0.000000 0.140000 ( 0.146642)
lenght of string: 5000000
Rehearsal -----------------------------------------------
c-extension 0.010000 0.000000 0.010000 ( 0.013171)
ruby 1.480000 0.010000 1.490000 ( 1.482893)
-------------------------------------- total: 1.500000sec
user system total real
c-extension 0.010000 0.000000 0.010000 ( 0.013098)
ruby 1.510000 0.000000 1.510000 ( 1.508361)
lenght of string: 50000000
Rehearsal -----------------------------------------------
c-extension 0.120000 0.020000 0.140000 ( 0.143160)
ruby 16.320000 0.020000 16.340000 ( 16.356332)
------------------------------------- total: 16.480000sec
user system total real
c-extension 0.120000 0.010000 0.130000 ( 0.143203)
ruby 15.130000 0.050000 15.180000 ( 15.191924)
lenght of string: 500000000
Rehearsal -----------------------------------------------
c-extension 1.190000 0.200000 1.390000 ( 1.491211)
ruby 159.510000 0.210000 159.720000 (159.723059)
------------------------------------ total: 161.110000sec
user system total real
c-extension 1.270000 0.200000 1.470000 ( 1.568321)
ruby 161.190000 0.250000 161.440000 (161.449839)
Development
After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment. For compile c extension run rake compile.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/tanvir002700/kmp. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The gem is available as open source under the terms of the MIT License.
Code of Conduct
Everyone interacting in the Kmp project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.