rework trace_started? to use ETS table instead of GenServer

DockYard · Jan 31, 2023 · b0ac06d · b0ac06d
1 parent 55651c3
commit b0ac06d
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Showing 4 changed files with 8 additions and 5 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Next
 
+-   Rework trace_started? to not rely on Trace GenServer
 -   Run module/function validations on selected node (thanks @schrockwell)
 -   Upgrade LiveView to v0.18
 

diff --git a/lib/flame_on/capture/server.ex b/lib/flame_on/capture/server.ex
@@ -23,14 +23,18 @@ defmodule FlameOn.Capture.Server do
   singleton to track that it has started for a given capture
   """
   def trace_started? do
-    GenServer.call(__MODULE__, :trace_started?)
+    set = ETS.Set.wrap_existing!(__MODULE__)
+    {:started?, started?} = ETS.Set.get!(set, :started?, {:started?, false})
+    if !started?, do: ETS.Set.put!(set, {:started?, true})
+    started?
   end
 
   def stop_trace do
     GenServer.cast(__MODULE__, :stop_trace)
   end
 
   def init(%Config{} = config) do
+    ETS.Set.new!(name: __MODULE__, protection: :public)
     mock_function(config)
     starter_block = %Block{id: "starter", function: {config.module, config.function, config.arity}, absolute_start: 0}
     Process.send_after(self(), :timeout, config.timeout)
@@ -74,10 +78,6 @@ defmodule FlameOn.Capture.Server do
     {:stop, :normal, state}
   end
 
-  def handle_call(:trace_started?, _, %State{trace_started?: started?} = state) do
-    {:reply, started?, %State{state | trace_started?: true}}
-  end
-
   def handle_cast(:stop_trace, %State{} = state) do
     Process.send_after(self(), :do_stop_trace, 1000)
     {:noreply, state}

diff --git a/mix.exs b/mix.exs
@@ -54,6 +54,7 @@ defmodule FlameOn.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
+      {:ets, "~> 0.9.0"},
       {:dialyxir, "~> 1.2.0", only: [:dev, :test], runtime: false},
       {:mix_test_watch, "~> 1.1.0", only: :dev, runtime: false},
       {:ex_doc, "~> 0.28.0", only: :dev, runtime: false},

diff --git a/mix.lock b/mix.lock
@@ -5,6 +5,7 @@
   "earmark_parser": {:hex, :earmark_parser, "1.4.19", "de0d033d5ff9fc396a24eadc2fcf2afa3d120841eb3f1004d138cbf9273210e8", [:mix], [], "hexpm", "527ab6630b5c75c3a3960b75844c314ec305c76d9899bb30f71cb85952a9dc45"},
   "ecto": {:hex, :ecto, "3.7.1", "a20598862351b29f80f285b21ec5297da1181c0442687f9b8329f0445d228892", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "d36e5b39fc479e654cffd4dbe1865d9716e4a9b6311faff799b6f90ab81b8638"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
+  "ets": {:hex, :ets, "0.9.0", "79c6a6c205436780486f72d84230c6cba2f8a9920456750ddd1e47389107d5fd", [:mix], [], "hexpm", "2861fdfb04bcaeff370f1a5904eec864f0a56dcfebe5921ea9aadf2a481c822b"},
   "ex_doc": {:hex, :ex_doc, "0.28.0", "7eaf526dd8c80ae8c04d52ac8801594426ae322b52a6156cd038f30bafa8226f", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "e55cdadf69a5d1f4cfd8477122ebac5e1fadd433a8c1022dafc5025e48db0131"},
   "expo": {:hex, :expo, "0.1.0", "d4e932bdad052c374118e312e35280f1919ac13881cb3ac07a209a54d0c81dd8", [:mix], [], "hexpm", "c22c536021c56de058aaeedeabb4744eb5d48137bacf8c29f04d25b6c6bbbf45"},
   "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},