refactor(ExTop, ExTop.View)

lib/ex_top.ex

@@ -1,7 +1,7 @@
 defmodule ExTop do
   use GenServer
 
-  defstruct [:node, :data, :prev_schedulers,
+  defstruct [:node, :data, :schedulers_snapshot,
              selected: 0, offset: 0, sort_by: 1, sort_order: :ascending]
 
   def start_link(opts \\ []) do
@@ -46,9 +46,9 @@ defmodule ExTop do
 
   def handle_info(:tick, state) do
     GenServer.cast self, :render
-    prev_schedulers = state.data && state.data.schedulers
+    schedulers_snapshot = state.data && state.data.schedulers
     data = :rpc.call state.node, ExTop.Collector, :collect, []
-    {:noreply, %{state | data: data, prev_schedulers: prev_schedulers}}
+    {:noreply, %{state | data: data, schedulers_snapshot: schedulers_snapshot}}
   end
 
   def handle_info({port, {:data, "\e[A" <> rest}}, state) do
@@ -150,7 +150,7 @@ defmodule ExTop do
       |> Enum.drop(state.offset)
       |> Enum.take(20)
     data = %{state.data | processes: processes}
-           |> Map.put(:prev_schedulers, state.prev_schedulers)
+           |> Map.put(:schedulers_snapshot, state.schedulers_snapshot)
     IO.write [IO.ANSI.home,
               ExTop.View.render(data, selected: state.selected)]
     {:noreply, state}

lib/ex_top/collector.ex

@@ -1,6 +1,7 @@
 defmodule ExTop.Collector do
   def collect do
     memory = :erlang.memory
+
     processes = for pid <- :erlang.processes do
       info = :erlang.process_info(pid, [:current_function,
                                         :initial_call,
@@ -19,23 +20,24 @@ defmodule ExTop.Collector do
       end
     end |> Enum.reject(&is_nil/1)
 
+    schedulers = :erlang.statistics(:scheduler_wall_time) |> Enum.sort
+
     {{:input, io_input}, {:output, io_output}} = :erlang.statistics(:io)
     run_queue = :erlang.statistics(:run_queue)
     process_count = :erlang.system_info(:process_count)
     process_limit = :erlang.system_info(:process_limit)
     uptime = :erlang.statistics(:wall_clock) |> elem(0) |> div(1000)
-    schedulers = :erlang.statistics(:scheduler_wall_time) |> Enum.sort
 
     %{memory: memory,
       processes: processes,
-      system: %{
+      schedulers: schedulers,
+      statistics: %{
         io_input: io_input,
         io_output: io_output,
         process_count: process_count,
         process_limit: process_limit,
         run_queue: run_queue,
         uptime: uptime
-      },
-      schedulers: schedulers}
+      }}
   end
 end

lib/ex_top/view.ex

@@ -1,25 +1,25 @@
 defmodule ExTop.View do
   def render(data, opts \\ []) do
-    [concat3(schedulers(data[:prev_schedulers], data[:schedulers]),
-             memory(data[:memory]),
-             statistics(data[:system])),
+    [concat3(schedulers(data.schedulers_snapshot, data.schedulers),
+             memory(data.memory),
+             statistics(data.statistics)),
      processes_separator,
      processes_heading,
      processes_separator,
-     processes_rows(data[:processes], opts),
+     processes_rows(data.processes, opts),
      processes_separator] |> Enum.intersperse("\n\r")
   end
 
-  defp statistics(system) do
+  defp statistics(statistics) do
     ["+-----------------+----------------+",
      "|             Statistics           |",
      "+-----------------+----------------+",
-     "| Uptime          | #{just(inspect(system[:uptime]), 13, :right)}s |",
-     "| Process Count   | #{just(inspect(system[:process_count]), 14, :right)} |",
-     "| Process Limit   | #{just(inspect(system[:process_limit]), 14, :right)} |",
-     "| Run Queue       | #{just(inspect(system[:run_queue]), 14, :right)} |",
-     "| IO Input        | #{just(inspect(system[:io_input]), 14, :right)} |",
-     "| IO Output       | #{just(inspect(system[:io_output]), 14, :right)} |"]
+     "| Uptime          | #{just(inspect(statistics.uptime), 13, :right)}s |",
+     "| Process Count   | #{just(inspect(statistics.process_count), 14, :right)} |",
+     "| Process Limit   | #{just(inspect(statistics.process_limit), 14, :right)} |",
+     "| Run Queue       | #{just(inspect(statistics.run_queue), 14, :right)} |",
+     "| IO Input        | #{just(inspect(statistics.io_input), 14, :right)} |",
+     "| IO Output       | #{just(inspect(statistics.io_output), 14, :right)} |"]
   end
 
   defp memory(memory) do
@@ -34,9 +34,9 @@ defmodule ExTop.View do
      "| ETS        | #{just(inspect(memory[:ets]), 13, :right)} "]
   end
 
-  defp schedulers(prev, now) do
-    usages = if prev do
-      for {{n, a1, t1}, {n, a2, t2}} <- Enum.zip(prev, now) |> Enum.take(8) do
+  defp schedulers(old, new) do
+    usages = if old do
+      for {{n, a1, t1}, {n, a2, t2}} <- Enum.zip(old, new) |> Enum.take(8) do
         {n, (a2 - a1) / (t2 - t1)}
       end
     else