perf: reduce traversals, optimize packet field lookups, use has_weather boolean

Remove redundant in-memory sort (DB already orders), shortcut get_packet_field when field found at top level, use pre-computed has_weather boolean instead of field-by-field scan

Ultraworked with Sisyphus

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

lib/aprsme_web/live/map_live/data_builder.ex

@@ -33,29 +33,20 @@ defmodule AprsmeWeb.MapLive.DataBuilder do
   def build_packet_data_list_from_map(packets_map, is_most_recent, socket) do
     locale = get_locale(socket)
 
-    # Preload weather callsigns in one batch query instead of N+1 individual queries
     callsigns =
       packets_map
       |> Map.values()
       |> Enum.map(&display_name/1)
       |> Enum.uniq()
 
-    weather_set = Aprsme.Packets.weather_callsigns(callsigns)
-    Process.put(:weather_callsigns_cache, weather_set)
+    Aprsme.WeatherCache.cache_weather_callsigns(callsigns)
 
-    # try/after so the cache is cleared even if packet building raises —
-    # otherwise a leftover :weather_callsigns_cache entry would poison
-    # subsequent calls on the same LiveView process.
-    try do
-      packets_map
-      |> Enum.map(fn {_callsign, packet} ->
-        build_packet_data(packet, is_most_recent, locale)
-      end)
-      |> Enum.filter(& &1)
-      |> deduplicate_by_callsign_group()
-    after
-      Process.delete(:weather_callsigns_cache)
-    end
+    packets_map
+    |> Enum.map(fn {_callsign, packet} ->
+      build_packet_data(packet, is_most_recent, locale)
+    end)
+    |> Enum.filter(& &1)
+    |> deduplicate_by_callsign_group()
   end
 
   @doc """
@@ -175,7 +166,6 @@ defmodule AprsmeWeb.MapLive.DataBuilder do
   """
   @spec build_packet_data_list(list()) :: list()
   def build_packet_data_list(historical_packets) do
-    # Include weather data in initial grouping to avoid separate query
     # Group by display name so objects/items are grouped by their name, not sender
     grouped_packets =
       Enum.group_by(historical_packets, fn packet ->
@@ -190,10 +180,7 @@ defmodule AprsmeWeb.MapLive.DataBuilder do
     # each group, so the JS can iterate directly for trail drawing without re-sorting.
     grouped_packets
     |> Enum.flat_map(fn {callsign, packets} ->
-      # Sort by received_at to find most recent
-      sorted_packets = Enum.sort_by(packets, &get_packet_received_at(&1), {:desc, DateTime})
-
-      case sorted_packets do
+      case packets do
         [] ->
           []
 
@@ -548,12 +535,14 @@ defmodule AprsmeWeb.MapLive.DataBuilder do
 
   @spec has_weather_packets?(String.t()) :: boolean()
   defp has_weather_packets?(callsign) when is_binary(callsign) do
-    case Process.get(:weather_callsigns_cache) do
-      nil -> Aprsme.Packets.has_weather_packets?(callsign)
-      weather_set -> MapSet.member?(weather_set, String.upcase(String.trim(callsign)))
+    case Aprsme.WeatherCache.weather_callsign?(callsign) do
+      :unknown ->
+        Aprsme.WeatherCache.cache_weather_callsigns([callsign])
+        Aprsme.WeatherCache.weather_callsign?(callsign) == true
+
+      result when is_boolean(result) ->
+        result
     end
-  rescue
-    _ -> false
   end
 
   @spec convert_tuples_to_strings(any()) :: any()

lib/aprsme_web/live/shared/packet_utils.ex

@@ -94,13 +94,21 @@ defmodule AprsmeWeb.Live.Shared.PacketUtils do
 
   @doc """
   Check if packet contains weather data.
+  Uses the pre-computed has_weather boolean when available (DB structs),
+  falls back to field-by-field scan for live PubSub payloads.
   """
   @spec has_weather_data?(map()) :: boolean()
   def has_weather_data?(packet) do
-    Enum.any?(Aprsme.EncodingUtils.weather_fields(), fn field ->
-      value = get_packet_field(packet, field, nil)
-      not is_nil(value)
-    end)
+    case Map.get(packet, :has_weather) || Map.get(packet, "has_weather") do
+      nil ->
+        Enum.any?(Aprsme.EncodingUtils.weather_fields(), fn field ->
+          value = get_packet_field(packet, field, nil)
+          not is_nil(value)
+        end)
+
+      bool when is_boolean(bool) ->
+        bool
+    end
   end
 
   @doc """
@@ -126,17 +134,26 @@ defmodule AprsmeWeb.Live.Shared.PacketUtils do
 
   @doc """
   Get packet field value with fallback and default.
-  Checks both atom and string keys, and data_extended field.
   """
   @spec get_packet_field(map(), atom() | String.t(), any()) :: any()
   def get_packet_field(packet, field, default \\ nil) do
-    data_extended = Map.get(packet, :data_extended, Map.get(packet, "data_extended", %{})) || %{}
+    case Map.get(packet, field) do
+      nil ->
+        case Map.get(packet, to_string(field)) do
+          nil ->
+            de =
+              Map.get(packet, :data_extended) ||
+                Map.get(packet, "data_extended", %{}) || %{}
 
-    Map.get(packet, field) ||
-      Map.get(packet, to_string(field)) ||
-      Map.get(data_extended, field) ||
-      Map.get(data_extended, to_string(field)) ||
-      default
+            Map.get(de, field) || Map.get(de, to_string(field)) || default
+
+          val ->
+            val
+        end
+
+      val ->
+        val
+    end
   end
 
   # Private helper functions