[Elixir/phoenix] Implementing suggestions from @josevalim

frameworks/Elixir/phoenix/lib/hello/world_cache.ex

@@ -23,9 +23,9 @@ defmodule Hello.WorldCache do
         world = Repo.get(World, id)
         :ok = __MODULE__.put(id, world)
         world
+
       world ->
         world
     end
   end
-
 end

frameworks/Elixir/phoenix/lib/hello_web.ex

@@ -95,8 +95,8 @@ defmodule HelloWeb do
   end
 
   @doc """
-    When used, dispatch to the appropriate controller/view/etc.
-    """
+  When used, dispatch to the appropriate controller/view/etc.
+  """
   defmacro __using__(which) when is_atom(which) do
     apply(__MODULE__, which, [])
   end

frameworks/Elixir/phoenix/lib/hello_web/controllers/page_controller.ex

@@ -8,6 +8,8 @@ defmodule HelloWeb.PageController do
 
   @random_max 10_000
 
+  plug :accepts, ~w(html json) when action == :fortunes
+
   def index(conn, _params) do
     json(conn, %{"TE Benchmarks\n" => "Started"})
   end
@@ -24,17 +26,11 @@ defmodule HelloWeb.PageController do
   end
 
   def queries(conn, params) do
-    {:ok, worlds} =
-      Repo.transaction(fn ->
-        :rand.seed(:exsp)
-
-        worlds =
-          Stream.repeatedly(&random_id/0)
-          |> Stream.uniq()
-          |> Stream.map(&Repo.get(World, &1))
-          |> Enum.take(size(params["queries"]))
-
-        worlds
+    worlds =
+      Repo.checkout(fn ->
+        params["queries"]
+        |> random_ids_sample()
+        |> Enum.map(&Repo.get(World, &1))
       end)
 
     json(conn, worlds)
@@ -48,54 +44,51 @@ defmodule HelloWeb.PageController do
 
     fortunes =
       [additional_fortune | Repo.all(Fortune)]
-      |> Enum.sort_by(& &1.message)
+      |> Enum.sort(fn a, b -> a.message < b.message end)
 
     render(conn, :fortunes, fortunes: fortunes)
   end
 
   def updates(conn, params) do
-    {:ok, worlds} =
-      Repo.transaction(fn ->
-        :rand.seed(:exsp)
-
-        worlds =
-          Stream.repeatedly(&random_id/0)
-          |> Stream.uniq()
-          |> Stream.map(&Repo.get(World, &1))
-          |> Stream.map(fn world -> %{id: world.id, randomnumber: :rand.uniform(@random_max)} end)
-          |> Enum.take(size(params["queries"]))
-          # If this is not sorted it sometimes generates
-          #  FAIL for http://tfb-server:8080/updates/20
-          #  Only 20470 executed queries in the database out of roughly 20480 expected.
-          |> Enum.sort_by(& &1.id)
-
-        Repo.insert_all(
-          World,
-          worlds,
-          on_conflict: {:replace_all_except, [:id]},
-          conflict_target: [:id],
-          returning: false
-        )
-
-        worlds
+    world_updates =
+      Repo.checkout(fn ->
+        params["queries"]
+        |> random_ids_sample()
+        |> Enum.sort()
+        #
+        # If this is not sorted it will intermittently generate:
+        #
+        #   FAIL for http://tfb-server:8080/updates/20
+        #   Only 20470 executed queries in the database out of roughly 20480 expected.
+        #
+        |> Enum.map(fn id ->
+          world = Repo.get(World, id)
+          %{id: world.id, randomnumber: :rand.uniform(@random_max)}
+        end)
       end)
 
-    json(conn, worlds)
+    Repo.insert_all(
+      World,
+      world_updates,
+      on_conflict: {:replace_all_except, [:id]},
+      conflict_target: [:id],
+      returning: false
+    )
+
+    json(conn, world_updates)
   end
 
   def plaintext(conn, _params) do
     text(conn, "Hello, World!")
   end
 
   def cached(conn, params) do
-    :rand.seed(:exsp)
     WorldCache.seed()
 
     worlds =
-      Stream.repeatedly(&random_id/0)
-      |> Stream.uniq()
-      |> Stream.map(&WorldCache.fetch(&1))
-      |> Enum.take(size(params["count"]))
+      params["count"]
+      |> random_ids_sample()
+      |> Enum.map(&WorldCache.fetch(&1))
 
     json(conn, worlds)
   end
@@ -104,11 +97,17 @@ defmodule HelloWeb.PageController do
     :rand.uniform(@random_max)
   end
 
-  defp size(nil), do: 1
-  defp size(""), do: 1
+  defp random_ids_sample(count) do
+    # Use the fastest rand algorithm
+    :rand.seed(:exsp)
+
+    Stream.repeatedly(&random_id/0)
+    |> Stream.uniq()
+    |> Enum.take(size(count))
+  end
 
-  defp size(queries) when is_bitstring(queries) do
-    case Integer.parse(queries) do
+  defp size(param_count) when is_bitstring(param_count) do
+    case Integer.parse(param_count) do
       {count, _} -> max(1, min(500, count))
       _ -> 1
     end

frameworks/Elixir/phoenix/lib/hello_web/endpoint.ex

@@ -20,4 +20,3 @@ defmodule HelloWeb.Endpoint do
   plug HelloWeb.HeadersPlug
   plug HelloWeb.Router
 end
-

frameworks/Elixir/phoenix/lib/hello_web/router.ex

@@ -1,13 +1,7 @@
 defmodule HelloWeb.Router do
   use HelloWeb, :router
 
-  pipeline :browser do
-    plug :accepts, ~w(html json)
-  end
-
   scope "/", HelloWeb do
-    pipe_through [:browser]
-
     get "/json", PageController, :_json
     get "/db", PageController, :db
     get "/queries", PageController, :queries