SlowDown

gem "slow_down"

require "slow_down"

SlowDown.config do |c|
  c.requests_per_second = 10
  c.retries = 50 # times
  c.timeout = 5 # seconds
  c.raise_on_timeout = true # will raise SlowDown::Timeout
  c.redis_url = "redis://localhost:6379/0" # or set the REDIS_URL environment variable
end

SlowDown.run do
  some_throttled_api_call # accepting only 10 req/sec
end

SlowDown.config(:github) do |c|
  c.requests_per_second = 50
  c.timeout = 10
end

SlowDown.config(:twitter) do |c|
  c.requests_per_second = 10
  c.timeout = 1
end

# Acquire a lock for the :github group
SlowDown.run(:github) { ... }

# Acquire a lock for the :twitter group
SlowDown.run(:twitter) { ... }

# Configure the :default group and run a call
SlowDown.run(requests_per_second: 5, timeout: 15, raise_on_timeout: true) do
  # ...
end

# Configure a different group and run a call within that group
SlowDown.run(:my_group, requests_per_second: 2, timeout: 1) do
  # ...
end

SlowDown.config do |c|
  # The allowed number of calls per second.
  c.requests_per_second = 10

  # The number of seconds during which SlowDown will try and acquire the resource
  # for a given call.
  c.timeout = 5

  # Whether to raise an error when the timeout was reached and the resource could
  # not be acquired.
  # Raises SlowDown::Timeout.
  c.raise_on_timeout = false

  # How many retries should be performed til the timeout is reached.
  c.retries = 30

  # The algorithm used to schedule the amount of time to wait between retries.
  # Available strategies: :linear, :inverse_exponential, :fibonacci or a class
  # extending SlowDown::Strategy::Base.
  c.retry_strategy = :linear

  # Redis can be configured either directly, by setting a Redis instance to this
  # variable, or via the REDIS_URL environment variable or via the redis_url
  # setting.
  c.redis = nil

  # Configure Redis via the instance URL.
  c.redis_url = nil

  # The Redis namespace to apply to all locks.
  c.redis_namespace = :slow_down

  # The namespace to apply to the default group.
  # Individual groups will overwrite this with the group name.
  c.lock_namespace = :default

  # Set this to a path or file descriptor in order to log to file.
  c.log_path = STDOUT

  # By default, the SlowDown logger is disabled.
  # Set this to Logger::DEBUG, Logger::INFO or Logger::ERROR for logging various
  # runtime information.
  c.log_level = Logger::UNKNOWN
end

SlowDown.config do |c|
  c.requests_per_second = 2
end

SlowDown.free? # true
SlowDown.free? # true
SlowDown.free? # false (won't wait)
sleep(1)
SlowDown.free? # true

def register_user(name, address, phone)
  user.name = name

  # Optional: geocode address, if we didn't exceed the request limit
  if SlowDown.free?(:geocoding, requests_per_second: 5)
    user.coordinates = geocode(address)
  end

  # Optional: send SMS, if we didn't exceed the request limit
  if SlowDown.free?(:sms, requests_per_second: 10)
    send_sms(phone)
  end

  user.save
end

SlowDown.reset(:group_name)