Rails Brotli Cache

This gem enables support for compressing Ruby on Rails cache entries using the Brotli compression algorithm. Brotli is a modern compression algorithm developed by Google that provides superior compression ratios and performance compared to the default Gzip algorithm.

The gem is currently in an early stage of development. Ideas on how to improve it and PRs are welcome.

Benchmarks

Brotli offers a better compression and faster performance.

~25% better compression of a sample JSON object:

json = File.read("sample.json") # sample 565kb JSON text
json.size # => 562033
Rails.cache.write("json", json)
RailsBrotliCache.write("json", json)

## Check the size of cache entry stored in Redis
$redis.get("json").size # => 41697
$redis.get("br-json").size # => 31601

~20% better compression of a sample ActiveRecord objects array:

users = User.limit(100).to_a # 100 ActiveRecord objects
Rails.cache.write("users", users)
RailsBrotliCache.write("users", users)
$redis.get("users").size # => 12331
$redis.get("br-users").size # => 10299

~25% faster performance for reading/writing a larger JSON file:

json = File.read("sample.json") # sample 565kb JSON text

Benchmark.bm do |x|
  x.report("Rails.cache") do
    1000.times do
      Rails.cache.write("test", json)
      Rails.cache.read("test")
    end
  end

  x.report("RailsBrotliCache") do
    1000.times do
      RailsBrotliCache.write("test", json)
      RailsBrotliCache.read("test")
    end
  end
end

# user     system      total        real
# Rails.cache  5.177678   0.216435   5.394113 (  8.296072)
# RailsBrotliCache  3.513312   0.323601   3.836913 (  6.114179)

API

RailsBrotliCache module exposes methods that are compatible with the default Rails.cache. Values are stored in the underlying Rails.cache store but precompressed with Brotli algorithm.

You can use it just like the default Rails.cache API:

RailsBrotliCache.read("test-key") # => nil
RailsBrotliCache.fetch("test-key") { 123 } # => 123
RailsBrotliCache.delete("test-key")
RailsBrotliCache.read("test-key") # => nil
RailsBrotliCache.write("test-key", 123, expires_in: 5.seconds)
sleep 6
RailsBrotliCache.read("test-key") # => nil

Gem appends br- to the cache key names to prevent conflicts with previously saved cache entries. You can disable this behaviour by adding the following initializer file:

app/config/initializers/rails-brotli-cache.rb

RailsBrotliCache.disable_prefix!

Testing

cp docker-compose.yml.sample docker-compose.yml
docker compose up -d
rake test_all