Finish implementing LAID

lib/diamondtail/application.ex

@@ -2,6 +2,7 @@ defmodule Diamondtail.Application do
   # See https://hexdocs.pm/elixir/Application.html
   # for more information on OTP Applications
   @moduledoc false
+  alias Diamondtail.InternalLatencyManager
   alias Diamondtail.ExternalLatencyManager
   alias Diamondtail.Genometracker
   alias Diamondtail.Population
@@ -16,7 +17,7 @@ defmodule Diamondtail.Application do
       {Plug.Cowboy, scheme: :http, plug: Diamondtail.Router, options: [port: 4001]},
       {Task.Supervisor, name: Diamondtail.TaskSupervisor},
       {Population, 1..10 |> Enum.map(fn _ -> Population.Genome.random end) |> Enum.to_list},
-      Genometracker, ExternalLatencyManager
+      Genometracker, ExternalLatencyManager, InternalLatencyManager
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html

lib/diamondtail/brain.ex

@@ -1,5 +1,4 @@
 defmodule Diamondtail.Brain do
-  import Diamondtail.Operators.Implication
   alias Diamondtail.InternalLatencyManager
   alias Diamondtail.ExternalLatencyManager
   alias Diamondtail.Population.Genome
@@ -242,26 +241,32 @@ defmodule Diamondtail.Brain do
 
   @spec determine_move(Genome.t(), map(), map(), map()) :: %{move: :up | :down | :left | :right, shout: String.t()}
   def determine_move(genome, board, self, game) do
+    start_time = Time.utc_now()
     base_state = GameState.from(board, self)
     external_latency = ExternalLatencyManager.get_external_latency()
     max_latency = game["timeout"]
     target_latency = max_latency - external_latency - genome.latency_headroom
 
     depth = InternalLatencyManager.best_depth(map_size(base_state.snakes), target_latency)
+    Logger.debug("Using a depth of #{depth}")
 
     options = GameState.valid_actions(base_state) |>
       Task.async_stream(fn action ->
         qstate = GameState.apply_actions(base_state, action)
         {action, GameState.evaluate_state(genome, qstate, depth)}
-      end, ordered: false)
+      end, ordered: false, timeout: :infinity)
 
     if Enum.empty?(options) do
+      end_time = Time.utc_now()
+      InternalLatencyManager.register_latency(map_size(base_state.snakes), depth, Time.diff(end_time, start_time, :millisecond))
       %{
         move: :left,
         shout: "I'm dead, good game!"
       }
     else
       {:ok, {action, score}} = Enum.max_by(options, fn {:ok, {_, s}} -> s end)
+      end_time = Time.utc_now()
+      InternalLatencyManager.register_latency(map_size(base_state.snakes), depth, Time.diff(end_time, start_time, :millisecond))
 
       %{
         move: action,

lib/diamondtail/externallatencymanager.ex

@@ -22,12 +22,17 @@ defmodule Diamondtail.ExternalLatencyManager do
 
   def get_external_latency() do
     {tot, dp} = Agent.get(__MODULE__, fn {tot, dp, _} -> {tot, dp} end)
-    tot / dp
+    if dp == 0 do
+      # Some guesstimate
+      100
+    else
+      tot / dp
+    end
   end
 
   def clear_dangling_moves(predicate \\ fn -> true end) do
     Agent.update(__MODULE__, fn {tot_latency, tot_datapoints, dangling_moves} ->
-      {tot_latency, tot_datapoints, Map.filter(dangling_moves, fn {k, _} -> !predicate.(k) end)}
+      {tot_latency, tot_datapoints, Map.reject(dangling_moves, fn {k, _} -> predicate.(k) end)}
     end)
   end
 end

lib/diamondtail/internallatencymanager.ex

@@ -1,21 +1,46 @@
 defmodule Diamondtail.InternalLatencyManager do
   use Agent
+  require Logger
 
   def start_link(_) do
     Agent.start_link(fn -> %{} end, name: __MODULE__)
   end
 
   def best_depth(player_count, max_latency) do
-    Agent.get(__MODULE__, fn records ->
-      if Map.has_key?(records, player_count) do
+    Logger.debug("Looking for the best depth for #{player_count} players within #{max_latency}ms")
+    records = Agent.get(__MODULE__, &(&1))
+    if Map.has_key?(records, player_count) do
         # Find the highest depth value matching our max latency
-        # TODO
-        3
+        Enum.reduce_while(records[player_count], 1, fn {tot, reg}, acc ->
+          # TODO: "learning"
+          if (tot / reg) > max_latency do
+            {:halt, acc - 2}
+          else
+            {:cont, acc + 2}
+          end
+        end)
       else
         # We've never seen this player count before, we'll learn how fast we are on this player count after this is done
         # For now we'll return 1 so we don't die
         1
       end
+  end
+
+  def register_latency(player_count, depth, internal_latency) do
+    Logger.debug("Registering that a search of depth #{depth} with #{player_count} players took #{internal_latency}ms")
+    Agent.update(__MODULE__, fn records ->
+      Map.update(records, player_count, [], fn list ->
+        index = floor((depth - 1) / 2) # Floor should be avoidable but we do it anyway to be sure
+        if index >= length(list) do
+          list ++ [{internal_latency, 1}]
+        else
+          List.update_at(list, index, fn {tot, reg} -> {tot + internal_latency, reg + 1} end)
+        end
+      end)
     end)
   end
+
+  def get_latencies(player_count) do
+    Agent.get(__MODULE__, &(&1[player_count]))
+  end
 end

lib/diamondtail/population.ex

@@ -77,7 +77,7 @@ defmodule Diamondtail.Population do
 
         own_accessible_tiles_weight: random_between(0.7, 1),
 
-        latency_headroom: random_between(20.0, 50.0),
+        latency_headroom: random_between(80.0, 100.0),
         value_discount: random_between(1.0, 20.0) # as percentage
       }
     end

lib/diamondtail/router.ex

@@ -52,7 +52,9 @@ defmodule Diamondtail.Router do
     self = conn.params["you"]
     Logger.debug("Processing move #{game_id} as #{player_id} turn #{turn_number}")
     t_start = Time.utc_now()
-    move = Brain.determine_move(genome, board, self, game)
+    # nolink so internal latency is still reported
+    move_task = Task.Supervisor.async_nolink(Diamondtail.TaskSupervisor, fn -> Brain.determine_move(genome, board, self, game) end)
+    move = Task.await(move_task)
     internal_latency = Time.diff(t_start, Time.utc_now(), :millisecond)
     ExternalLatencyManager.report_internal_latency({game_id, player_id, turn_number}, internal_latency)
     Logger.debug("Our move: #{inspect(move)}")