Packages

mongodb_driver

0.6.1
1.6.3 1.6.2 1.6.1 1.6.0 1.5.6 1.5.5 1.5.4 1.5.2 1.5.1 1.5.0 1.4.1 1.4.0 1.2.1 1.2.0 1.1.0 1.0.3 1.0.2 1.0.1 1.0.0 0.9.2 0.9.1 0.9.0 0.9.0-rc.1 0.9.0-rc.0 0.8.4 0.8.3 0.8.2 0.8.1 0.8.0 0.7.4 0.7.3 0.7.2 0.7.1 0.7.0 0.6.5 0.6.4 0.6.3 0.6.2 0.6.1 0.6.0 0.5.7 0.5.6 0.5.5 0.5.4 0.5.3 0.5.2 0.5.1 0.5.0

The MongoDB driver for Elixir

HexDocs

Current section

Files

Jump to
Readme
48 Versions
2 Dependencies
Dependants
Files
Activity
mongodb_driver lib mongo read_preference.ex
Raw

lib/mongo/read_preference.ex 

defmodule Mongo.ReadPreference do

  @moduledoc ~S"""

  Determines which servers are considered suitable for read operations

  """

  @type t :: %{

    mode: :primary | :secondary | :primary_preferred | :secondary_preferred |

          :nearest,

    tag_sets: [%{String.t => String.t}],

    max_staleness_ms: non_neg_integer

  }



  @default %{

    mode: :primary,

    tag_sets: [%{}],

    max_staleness_ms: 0

  }



  def defaults(map \\ nil)

  def defaults(map) when is_map(map) do

    Map.merge(@default, map)

  end

  def defaults(_), do: @default



  @doc """

  Add read preference to the cmd

  """

  def add_read_preference(cmd, opts) do



    read_preference = opts

                      |> Keyword.get(:read_preference)

                      |> Mongo.ReadPreference.defaults()

                      |> Map.update(:mode, :primary, fn mode -> map_mode(mode) end)



    cmd ++ ["$readPreference": read_preference]

  end



  defp map_mode(:primary_preferred), do: :primaryPreferred

  defp map_mode(:secondary_preferred), do: :secondaryPreferred

  defp map_mode(mode), do: mode



end