Fast CRC32

Description:

It's just an experiment. Use it on your own risk

Native eextension for CRC32 calculation.

It should be fast CRC32 implementation. But now it's slower than even Zlib.

Features/Problems:

Now it uses simplified version of Slice16 implementation of CRC32 algorithm.

Install:

Put it in your Gemfile:

gem 'fcrc32', github: 'dsnipe/fcrc32'

And then bund1le install

Synopsis:

API is under heavy development.

Calculate CRC32 for a string:

FCrc32.calculate('string')

Calculate CRC32 for a file:

FCrc32.file('paht/to/file')

Same as above, but chunk file by pieces (slower, but memory saver):

FCrc32.chunked_file('path/to/file', size_in_bytes)

By default size for chunks is 1024 bytes, so second argument could be omitted.

Developers:

After checking out the source, run:

  $ bundle install
  $ rake test:dummy
  $ rake test

rake test:dummy task creates dummy file of specific size. By default it is 5Mb. It's possible to create a file with any size, using environment variable SIZE.

For benchmarks, run:

  $ rake bench

Credits:

License:

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

dsnipe / fcrc32