Hammer.Atomic (hammer v7.0.1)

A rate limiter implementation using Erlang's :atomics module for atomic counters.

This provides fast, atomic counter operations without the overhead of ETS or process messaging. Requires Erlang/OTP 21.2 or later.

The atomic backend supports the following algorithms:

:fix_window - Fixed window rate limiting (default) Simple counting within fixed time windows. See Hammer.Atomic.FixWindow for more details.
:leaky_bucket - Leaky bucket rate limiting Smooth rate limiting with a fixed rate of tokens. See Hammer.Atomic.LeakyBucket for more details.
:token_bucket - Token bucket rate limiting Flexible rate limiting with bursting capability. See Hammer.Atomic.TokenBucket for more details.

Summary

config()

start_option()

Returns a specification to start this module under a supervisor.

now()

Returns the current time in milliseconds.

start_link(opts)

Starts the atomic rate limiter process.

@type config() :: %{
  table: atom(),
  table_opts: list(),
  clean_period: pos_integer(),
  key_older_than: pos_integer(),
  algorithm: module()
}

@type start_option() ::
  {:clean_period, pos_integer()}
  | {:key_older_than, pos_integer()}
  | GenServer.option()

Returns a specification to start this module under a supervisor.

@spec now() :: pos_integer()

Returns the current time in milliseconds.

@spec start_link([start_option()]) :: GenServer.on_start()

Starts the atomic rate limiter process.

Options: