farmbot_os/farmbot_core/lib/asset_monitor.ex

81 lines
2.5 KiB
Elixir

defmodule Farmbot.AssetMonitor do
use GenServer
import Farmbot.TimeUtils, only: [compare_datetimes: 2]
alias Farmbot.Asset.{
Repo,
FarmEvent,
Peripheral,
PersistentRegimen,
PinBinding
}
require Logger
@checkup_time_ms Application.get_env(:farmbot_core, __MODULE__)[:checkup_time_ms]
@checkup_time_ms || Mix.raise("""
config :farmbot_core, #{__MODULE__}, checkup_time_ms: 30_000
""")
@doc false
def start_link(args) do
GenServer.start_link(__MODULE__, args, name: __MODULE__)
end
# This is helpful for tests, but should probably be avoided
@doc false
def force_checkup do
GenServer.call(__MODULE__, :force_checkup)
end
def init(_args) do
state = Map.new(order(), fn(module) -> {module, %{}} end)
state = Map.put(state, :order, order())
state = Map.put(state, :force_caller, nil)
{:ok, state, 0}
end
def handle_call(:force_checkup, caller, state) do
{:noreply, %{state | force_caller: caller}, 0}
end
def handle_info(:timeout, %{order: []} = state) do
if state.force_caller, do: GenServer.reply(state.force_caller, :ok)
{:noreply, %{state | order: order(), force_caller: nil}, @checkup_time_ms}
end
def handle_info(:timeout, state) do
[kind | rest] = state.order
results = handle_kind(kind, state[kind])
{:noreply, %{state | kind => results, order: rest}, 0}
end
def handle_kind(kind, sub_state) do
expected = Repo.all(kind)
expected_ids = Enum.map(expected, &Map.fetch!(&1, :local_id))
actual_ids = Enum.map(sub_state, fn({local_id, _}) -> local_id end)
deleted_ids = actual_ids -- expected_ids
sub_state = Map.drop(sub_state, deleted_ids)
Enum.each(deleted_ids, fn(local_id) ->
Logger.error "#{inspect kind} #{local_id} needs to be terminated"
Farmbot.AssetSupervisor.terminate_child(kind, local_id)
end)
Enum.reduce(expected, sub_state, fn(%{local_id: id, updated_at: updated_at} = asset, sub_state) ->
cond do
is_nil(sub_state[id]) ->
Logger.debug "#{inspect kind} #{id} needs to be started"
Farmbot.AssetSupervisor.start_child(asset)
Map.put(sub_state, id, updated_at)
compare_datetimes(updated_at, sub_state[id]) == :gt ->
Logger.warn "#{inspect kind} #{id} needs to be updated"
Farmbot.AssetSupervisor.update_child(asset)
Map.put(sub_state, id, updated_at)
true ->
sub_state
end
end)
end
def order, do: [FarmEvent, Peripheral, PersistentRegimen, PinBinding]
end