elixir_google_spreadsheets v0.1.10 GSS.Client.Limiter

Model of Limiter request subscribed to Client with partition :write or :read

This process is a ProducerConsumer for this GenStage pipeline.

Link to this section Summary

Functions

Check to reach limit

Gives events for the next stage to process when requested

Invoked on :producer_consumer and :consumer stages to handle events

Ask new events if needed

Invoked when the server is started

Starts an limiter manager linked to the current process

Link to this section Types

Link to this type options()
options() :: [name: atom, max_demand: pos_integer | nil, max_interval: timeout | nil, interval: timeout | nil, clients: [{atom, keyword} | atom]]
Link to this type state()
state() :: %GSS.Client.Limiter{interval: timeout, max_demand: pos_integer, max_interval: timeout, producer: GenStage.from, scheduled_at: pos_integer | nil, taked_events: pos_integer}

Link to this section Functions

Link to this function ask_and_schedule(state)

Check to reach limit.

If limit not reached ask again after :interval timeout, otherwise ask after :max_interval timeout.

Link to this function handle_demand(demand, state)

Gives events for the next stage to process when requested

Link to this function handle_events(events, from, state)

Invoked on :producer_consumer and :consumer stages to handle events.

Must always be explicitly implemented by such types.

Return values are the same as c:handle_cast/2.

Callback implementation for GenStage.handle_events/3.

Link to this function handle_info(msg, state)

Ask new events if needed

Invoked when the server is started.

start_link/3 (or start/3) will block until this callback returns. args is the argument term (second argument) passed to start_link/3 (or start/3).

In case of successful start, this callback must return a tuple where the first element is the stage type, which is one of:

  • :producer
  • :consumer
  • :producer_consumer (if the stage is acting as both)

For example:

def init(args) do
  {:producer, some_state}
end

The returned tuple may also contain 3 or 4 elements. The third element may be the :hibernate atom or a set of options defined below.

Returning :ignore will cause start_link/3 to return :ignore and the process will exit normally without entering the loop or calling terminate/2.

Returning {:stop, reason} will cause start_link/3 to return {:error, reason} and the process to exit with reason reason without entering the loop or calling terminate/2.

Options

This callback may return options. Some options are specific to the chosen stage type while others are shared across all types.

:producer options

  • :demand - when :forward, the demand is always forwarded to the c:handle_demand/2 callback. When :accumulate, demand is accumulated until its mode is set to :forward via demand/2. This is useful as a synchronization mechanism, where the demand is accumulated until all consumers are subscribed. Defaults to :forward.

:producer and :producer_consumer options

  • :buffer_size - the size of the buffer to store events without demand. Can be :infinity to signal no limit on the buffer size. Check the “Buffer events” section of the module documentation. Defaults to 10_000 for :producer, :infinity for :producer_consumer.

  • :buffer_keep - returns whether the :first or :last entries should be kept on the buffer in case the buffer size is exceeded. Defaults to :last.

  • :dispatcher - the dispatcher responsible for handling demands. Defaults to GenStage.DemandDispatch. May be either an atom representing a dispatcher module or a two-element tuple with the dispatcher module and the dispatcher options.

:consumer and :producer_consumer options

  • :subscribe_to - a list of producers to subscribe to. Each element represents either the producer module or a tuple with the producer module and the subscription options (as defined in sync_subscribe/2).

Callback implementation for GenStage.init/1.

Link to this function start_link(options \\ [])
start_link(options) :: GenServer.on_start

Starts an limiter manager linked to the current process.

If the event manager is successfully created and initialized, the function returns {:ok, pid}, where pid is the PID of the server. If a process with the specified server name already exists, the function returns {:error, {:already_started, pid}} with the PID of that process.

Options

  • :name - used for name registration as described in the “Name registration” section of the module documentation
  • :interval - ask new events from producer after :interval milliseconds.
  • :max_demand - count of maximum requests per :maximum_interval
  • :max_interval - maximum time that allowed in :max_demand requests
  • :clients - list of clients with partition options. For example [{GSS.Client, partition: :read}}].