class DontRepeatFor

Runs a block only once in the given time frame Uses redis to know if we've run the block before. Example 1: “`ruby

20.times do
  DontRepeatFor.new("test_dont_repeat/test", 5.minutes) { puts "This message will only be displayed once every 5 minutes.";
  sleep(1.minute)
end

“`

@hint: You can include an ID in the key to enforce rate limiting for a specific store.

Constants

VERSION

Attributes

key[RW]

time[RW]

Public Class Methods

new(time, key) { || ... } click to toggle source

@param time [Integer] The amount of seconds that we don't want to repeat the process for @param key [String] A unique key to identify the process that we don't want to repeat for the given time

# File lib/dont_repeat_for.rb, line 21
def initialize(time, key)
  @key = key
  @time = time.to_i

  return nil if ran_recently?

  set_key_expiry

  yield
end

Private Class Methods

redis() click to toggle source

# File lib/dont_repeat_for.rb, line 56
def self.redis
  @redis ||= Redis.new
end

Private Instance Methods

ran_recently?() click to toggle source

Using an incr to atomically get & set the value. If incr === 1 then the key was empty before incrementing Otherwise, it has already been incremented before expiring

# File lib/dont_repeat_for.rb, line 42
def ran_recently?
  redis.incr(storage_key) != 1
end

redis() click to toggle source

# File lib/dont_repeat_for.rb, line 50
def redis
  return $redis if defined?($redis)

  self.class.redis
end

set_key_expiry() click to toggle source

# File lib/dont_repeat_for.rb, line 34
def set_key_expiry
  redis.expire(storage_key, time)
end

storage_key() click to toggle source

# File lib/dont_repeat_for.rb, line 46
def storage_key
  @storage_key ||= "DontRepeatFor/v1/Keys/#{@key}"
end