From 6462e18954512be2ae2a9e2856f9afa96b85abe9 Mon Sep 17 00:00:00 2001
From: Neylix <julien.leclerc05@protonmail.com>
Date: Tue, 16 May 2023 14:18:30 +0200
Subject: [PATCH] Use PartitionSupervisor for ChainWriter

---
 .../db/embedded_impl/chain_writer.ex          | 16 +++---------
 lib/archethic/db/embedded_impl/supervisor.ex  | 25 +++++++------------
 .../db/embedded_impl/chain_index_test.exs     |  1 -
 3 files changed, 13 insertions(+), 29 deletions(-)

diff --git a/lib/archethic/db/embedded_impl/chain_writer.ex b/lib/archethic/db/embedded_impl/chain_writer.ex
index 8ee44d522..adba1e8f4 100644
--- a/lib/archethic/db/embedded_impl/chain_writer.ex
+++ b/lib/archethic/db/embedded_impl/chain_writer.ex
@@ -11,6 +11,7 @@ defmodule Archethic.DB.EmbeddedImpl.ChainWriter do
 
   alias Archethic.DB.EmbeddedImpl.Encoding
   alias Archethic.DB.EmbeddedImpl.ChainIndex
+  alias Archethic.DB.EmbeddedImpl.ChainWriterSupervisor
 
   alias Archethic.TransactionChain.Transaction
   alias Archethic.TransactionChain.Transaction.ValidationStamp
@@ -26,9 +27,8 @@ defmodule Archethic.DB.EmbeddedImpl.ChainWriter do
   """
   @spec append_transaction(binary(), Transaction.t()) :: :ok
   def append_transaction(genesis_address, tx = %Transaction{}) do
-    partition = :erlang.phash2(genesis_address, 20)
-    [{_, pid}] = :ets.lookup(:archethic_db_chain_writers, partition)
-    GenServer.call(pid, {:append_tx, genesis_address, tx})
+    via_tuple = {:via, PartitionSupervisor, {ChainWriterSupervisor, genesis_address}}
+    GenServer.call(via_tuple, {:append_tx, genesis_address, tx})
   end
 
   @doc """
@@ -107,13 +107,10 @@ defmodule Archethic.DB.EmbeddedImpl.ChainWriter do
 
   def init(arg) do
     db_path = Keyword.get(arg, :path)
-    partition = Keyword.get(arg, :partition)
-
-    :ets.insert(:archethic_db_chain_writers, {partition, self()})
 
     setup_folders(db_path)
 
-    {:ok, %{db_path: db_path, partition: partition}}
+    {:ok, %{db_path: db_path}}
   end
 
   defp setup_folders(path) do
@@ -152,11 +149,6 @@ defmodule Archethic.DB.EmbeddedImpl.ChainWriter do
     {:reply, :ok, state}
   end
 
-  def terminate(_reason, _state = %{partition: partition}) do
-    :ets.delete(:archethic_db_chain_writers, partition)
-    :ignore
-  end
-
   defp write_transaction(genesis_address, tx, db_path) do
     start = System.monotonic_time()
 
diff --git a/lib/archethic/db/embedded_impl/supervisor.ex b/lib/archethic/db/embedded_impl/supervisor.ex
index 3d7cfc912..ca535121e 100644
--- a/lib/archethic/db/embedded_impl/supervisor.ex
+++ b/lib/archethic/db/embedded_impl/supervisor.ex
@@ -5,6 +5,7 @@ defmodule Archethic.DB.EmbeddedImpl.Supervisor do
 
   alias Archethic.DB.EmbeddedImpl.BootstrapInfo
   alias Archethic.DB.EmbeddedImpl.ChainWriter
+  alias Archethic.DB.EmbeddedImpl.ChainWriterSupervisor
   alias Archethic.DB.EmbeddedImpl.ChainIndex
   alias Archethic.DB.EmbeddedImpl.P2PView
   alias Archethic.DB.EmbeddedImpl.StatsInfo
@@ -21,16 +22,17 @@ defmodule Archethic.DB.EmbeddedImpl.Supervisor do
     path = Archethic.DB.EmbeddedImpl.db_path()
     Logger.info("Load database at #{path}")
     File.mkdir_p!(path)
-    :ets.new(:archethic_db_chain_writers, [:named_table, :public])
 
-    DynamicSupervisor.start_link(
-      strategy: :one_for_one,
-      name: Archethic.DB.EmbeddedImpl.ChainWriterSupervisor
-    )
-
-    initialize_chain_writers(path)
+    # Remove old things while in hot reload
+    # TODO remove after version 1.1.0
+    if :ets.whereis(:archethic_db_chain_writers) != :undefined do
+      :ets.delete(:archethic_db_chain_writers)
+      DynamicSupervisor.stop(ChainWriterSupervisor)
+    end
 
     children = [
+      {PartitionSupervisor,
+       child_spec: {ChainWriter, path: path}, name: ChainWriterSupervisor, partitions: 20},
       chain_index_cache(),
       {ChainIndex, path: path},
       {BootstrapInfo, path: path},
@@ -54,13 +56,4 @@ defmodule Archethic.DB.EmbeddedImpl.Supervisor do
          ]}
     }
   end
-
-  defp initialize_chain_writers(path) do
-    Enum.each(0..19, fn i ->
-      DynamicSupervisor.start_child(
-        Archethic.DB.EmbeddedImpl.ChainWriterSupervisor,
-        {ChainWriter, path: path, partition: i}
-      )
-    end)
-  end
 end
diff --git a/test/archethic/db/embedded_impl/chain_index_test.exs b/test/archethic/db/embedded_impl/chain_index_test.exs
index 38a0a919f..35bbf405a 100644
--- a/test/archethic/db/embedded_impl/chain_index_test.exs
+++ b/test/archethic/db/embedded_impl/chain_index_test.exs
@@ -9,7 +9,6 @@ defmodule Archethic.DB.EmbeddedImpl.ChainIndexTest do
     db_path = Application.app_dir(:archethic, "data_test")
     File.mkdir_p!(db_path)
 
-    :ets.new(:archethic_db_chain_writers, [:named_table, :public])
     {:ok, _} = ChainWriter.start_link(path: db_path)
 
     on_exit(fn ->