ThrottledQueue v0.4.0-dev ThrottledQueue View Source

This throttled queue performs actions asynchronously and keep the client informed of the status of the enqueued item through its lifecycle.

Messages

The queue process will send status updates to the client.

{:dequeued, ref}: The action has been dequeued and is about to be executed. ref is the message reference returned by ThrottledQueue.enqueue.
{:position, ref, position}: The new position in the queue with the message reference.
{:result, ref, result}: The result of the action with the message reference.
{:error, ref}: An error occured while executing the action.

Examples

iex> {:ok, _pid} = ThrottledQueue.start_link(wait: 1000)
iex> {:ok, _ref, 0} = ThrottledQueue.enqueue(fn ->
...> Process.sleep(3000)
...> :foo
...> end)
iex> {:ok, _ref, 1} = ThrottledQueue.enqueue(fn -> :bar end)
iex> {:ok, _ref, 2} = ThrottledQueue.enqueue(fn -> :yeee end)
iex> {:ok, ref, 3} = ThrottledQueue.enqueue(fn -> :yeee end)
iex> is_reference(ref)
true

Receiving messages

receive do
  {:position, ref, pos} -> do_something_with_position_in_line(ref, pos)
  {:dequeued, ref} -> do_something_when_dequeued(ref)
  {:result, ref, result} -> do_something_with_the_result(ref, result)
  {:error, ref} -> do_something_with_the_error(ref)
end

Link to this section Summary

Functions

clear(name \\ ThrottledQueue)

Clears the queue

enqueue(name \\ ThrottledQueue, action)

Enqueues an action in the queue

remove(name \\ ThrottledQueue, list)

Removes items the queue enqueued by from

start(opts \\ [])

Starts the queue process without linking it

start_link(opts \\ [])

Starts the queue process and links it

Link to this section Functions

clear(name \\ ThrottledQueue)

Clears the queue.

Parameters

name: Atom to identify the queue. Defaults to Elixir.ThrottledQueue (optional).

Examples

iex> ThrottledQueue.start_link(max_queue: 2)
iex> ThrottledQueue.enqueue(fn -> :foo end)
iex> ThrottledQueue.enqueue(fn -> :bar end)
iex> ThrottledQueue.clear
:ok

enqueue(name \\ ThrottledQueue, action)

Enqueues an action in the queue.

Parameters

name: Atom to identify the queue. Defaults to Elixir.ThrottledQueue (optional).
action: Function to enqueue.

Returns

{:ok, ref, position}: Returns a tuple with :ok, the message reference and the position in the queue.
:error: Returns :error if the queue is full.

Examples

iex> ThrottledQueue.start_link(max_queue: 2)
iex> {:ok, _ref, 0} = ThrottledQueue.enqueue(fn -> Process.sleep(3000) end)
iex> {:ok, _ref, 1} = ThrottledQueue.enqueue(fn -> :bar end)
iex> ThrottledQueue.enqueue(fn -> :hey end)
:error

remove(name \\ ThrottledQueue, list)

Removes items the queue enqueued by from.

Parameters

name: Atom to identify the queue. Defaults to Elixir.ThrottledQueue (optional).
from: Pid of the process that enqueued the items we want to remove. (required).

Examples

iex> ThrottledQueue.start_link(max_queue: 2)
iex> ThrottledQueue.enqueue(fn -> :foo end)
iex> ThrottledQueue.enqueue(fn -> :bar end)
iex> ThrottledQueue.remove(from: self())
:ok

start(opts \\ [])

Starts the queue process without linking it.

Parameters

name: Atom. Identifier for the queue. Defaults to ThrottledQueue (optional).
wait: Integer. The wait time between actions in milliseconds. Defaults to 500.
max_queue: Integer. The maximum number of items in the queue. Defaults to 10_000

start_link(opts \\ [])

Starts the queue process and links it.

Parameters

name: Atom. Identifier for the queue. Defaults to ThrottledQueue (optional).
wait: Integer. The wait time between actions in milliseconds. Defaults to 500.
max_queue: Integer. The maximum number of items in the queue. Defaults to 10_000

Examples

iex> {:ok, pid} = ThrottledQueue.start_link(
...> name: :my_queue,
...> max_queue: 100,
...> wait: 5000
...> )
iex> is_pid(pid)
true