CacheHash

Simple hash with expiring values.

• Simple - Returns value or nil.
• Default - Returns value or default
• Block - Returns value, or refreshes the value by yielding to long running job.

Installation

Add this line to your application's Gemfile:

gem 'cache_hash'

And then execute:

$ bundle

Or install it yourself as:

$ gem install cache_hash

Usage

Simple

Returns value or nil.

c = CacheHash.new(ttl: 3)
c[:a] = "its here"
puts c[:a] # => "its here" or nil if called after 3 seconds

Default Value

Returns value or default.

x = 0
c[:foo] = "HAZ VALUE"
c.fetch(:foo, "NO VALUE") # => "HAZ VALUE"
# wait 3 seconds
c.fetch(:foo, "NO VALUE") # => "NO VALUE"

Block

Returns value, or refreshes the value by yielding to long running job.

c = CacheHash.new(ttl: 5)
users = ['smith', 'jones']

# first run loads cache

users.each do |user|
   row = c.fetch(user) {
    # long running job
    get_user(user)
  }
end

# second run hits cache

users.each do |user|
   row = c.fetch(user) {
    # long running job
    get_user(user)
  }
end


# third run refreshes cache

sleep 6
users.each do |user|
   row = c.fetch(user) {
    # long running job
    get_user(user)
  }
end


c = CacheHash.new(ttl: 2, gc_interval: 1)

Contributing

1. Fork it ( https://github.com/[my-github-username]/cache_hash/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request