FitKit

Not production ready yet.

fit_kit is a small ruby gem wraps Rust's crate fitparse-rs to provide effecient and fast Garmin fit files parsing.

Install the gem and add to the application's Gemfile by executing:

$ bundle add fit_kit

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install fit_kit

test_fit_file = File.join(Dir.pwd, "example.fit")
fit_data_records = ::FitKit.parse_fit_file(test_fit_file)
# { record: [{...}, {...}], session: [{...}], lap: [..], activity: [...] }

There are couple of more built-in features can simplify the consuming of the data significantly:

• records_hash - All records in a ruby hash format
• avg_for - Average of a given field
• elevation_gain - Elevation gain. Calculate the overall elevation gain. Also allow to pass in a field.
• calculate_partition_indices - Calculate the partition indices for a given field
• partition_stats_for_fields - Calculate the partition stats for a given field. Useful for calculating splits data.
• sample_series_for_records - Sample series for a given field, useful for plotting
• zone_time_for - Heart Rate Zones data

Here is the performance parsing 4090 fit files on my M1 Mac Mini (16G, 8 Cores) took 6 seconds (in parallel):

❯ ruby app.rb
Parsing 4090 fit files...
       user     system      total        real
  0.129862   0.102642  45.192900 (  6.121117)

Code to parse a given folder (contains 4090 fit files) in parallel:

require 'fit_kit'
require 'benchmark'
require 'parallel'

def parse_concurrently
  puts "Parsing all fit files here"
  fit_files = Dir.glob("/Users/mikeli/docs/HealthFit/*.{fit,FIT}")
  puts "Parsing #{fit_files.size} fit files..."

  # Determine the number of processors
  num_processors = Parallel.processor_count

  # Parse files concurrently
  Parallel.each(fit_files, in_processes: num_processors) do |file|
    begin
      FitKit.parse_fit_file(file)
    rescue => e
      puts "Error parsing #{file}: #{e.message}"
    end
  end
end


Benchmark.bm do |x|
  x.report do
    parse_concurrently
  end
end

Bug reports and pull requests are welcome on GitHub at https://github.com/29decibel/fit_kit. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the FitKit project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.