AEIP-14 State UTXO

lib/archethic/account.ex

@@ -3,6 +3,7 @@ defmodule Archethic.Account do
 
   alias __MODULE__.MemTables.TokenLedger
   alias __MODULE__.MemTables.UCOLedger
+  alias __MODULE__.MemTables.StateLedger
   alias __MODULE__.MemTablesLoader
 
   alias Archethic.Crypto
@@ -38,6 +39,9 @@ defmodule Archethic.Account do
       },
       acc ->
         update_in(acc, [:token, Access.key({token_address, token_id}, 0)], &(&1 + amount))
+
+      _, acc ->
+        acc
     end)
   end
 
@@ -46,7 +50,16 @@ defmodule Archethic.Account do
   """
   @spec get_unspent_outputs(binary()) :: list(VersionedUnspentOutput.t())
   def get_unspent_outputs(address) when is_binary(address) do
-    UCOLedger.get_unspent_outputs(address) ++ TokenLedger.get_unspent_outputs(address)
+    uco_tokens_utxos =
+      UCOLedger.get_unspent_outputs(address) ++ TokenLedger.get_unspent_outputs(address)
+
+    case StateLedger.get_unspent_output(address) do
+      nil ->
+        uco_tokens_utxos
+
+      state_utxo ->
+        [state_utxo | uco_tokens_utxos]
+    end
   end
 
   @doc """

lib/archethic/account/mem_tables/state_ledger.ex

@@ -0,0 +1,88 @@
+defmodule Archethic.Account.MemTables.StateLedger do
+  @moduledoc """
+  A bit different than the token & uco ledgers.
+  This one can contain only 1 value by chain (instead of N values per transaction)
+  """
+
+  alias Archethic.Crypto
+  alias Archethic.TransactionChain.Transaction.ValidationStamp.LedgerOperations.UnspentOutput
+
+  alias Archethic.TransactionChain.Transaction.ValidationStamp.LedgerOperations.VersionedUnspentOutput
+
+  use GenServer
+  @vsn Mix.Project.config()[:version]
+
+  require Logger
+
+  @ledger_table :archethic_state_ledger
+
+  @doc """
+  Starts the GenServer that owns the ETS table
+  """
+  @spec start_link(args :: list()) :: GenServer.on_start()
+  def start_link([]) do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  @doc """
+  Get the state of given contract or nil
+  """
+  # @spec get_unspent_output(Crypto.prepended_hash()) :: nil | VersionedUnspentOutput.t()
+  def get_unspent_output(address) when is_binary(address) do
+    case :ets.lookup(@ledger_table, address) do
+      [] ->
+        nil
+
+      [{^address, encoded_payload, protocol_version}] ->
+        %VersionedUnspentOutput{
+          protocol_version: protocol_version,
+          unspent_output: %UnspentOutput{
+            type: :state,
+            encoded_payload: encoded_payload
+          }
+        }
+    end
+  end
+
+  @doc """
+  Set the state for given contract's address
+  """
+  @spec add_unspent_output(Crypto.prepended_hash(), VersionedUnspentOutput.t()) :: :ok
+  def add_unspent_output(address, %VersionedUnspentOutput{
+        unspent_output: %UnspentOutput{
+          type: :state,
+          encoded_payload: encoded_payload
+        },
+        protocol_version: protocol_version
+      })
+      when is_binary(address) do
+    true = Crypto.valid_address?(address)
+
+    true =
+      :ets.insert(
+        @ledger_table,
+        {address, encoded_payload, protocol_version}
+      )
+
+    :ok
+  end
+
+  @doc """
+  Spend the state (deletes it)
+  """
+  @spec spend_all_unspent_outputs(Crypto.prepended_hash()) :: :ok
+  def spend_all_unspent_outputs(address) when is_binary(address) do
+    :ets.delete(@ledger_table, address)
+    :ok
+  end
+
+  ###############
+  # CALLBACKS
+  ###############
+  @spec init(args :: list()) :: {:ok, :no_state}
+  def init([]) do
+    Logger.info("Initialize InMemory State Ledger...")
+    :ets.new(@ledger_table, [:set, :named_table, :public, read_concurrency: true])
+    {:ok, :no_state}
+  end
+end

lib/archethic/account/mem_tables_loader.ex

@@ -6,6 +6,7 @@ defmodule Archethic.Account.MemTablesLoader do
 
   alias Archethic.Account.MemTables.TokenLedger
   alias Archethic.Account.MemTables.UCOLedger
+  alias Archethic.Account.MemTables.StateLedger
 
   alias Archethic.Crypto
 
@@ -87,6 +88,7 @@ defmodule Archethic.Account.MemTablesLoader do
 
       UCOLedger.spend_all_unspent_outputs(previous_address)
       TokenLedger.spend_all_unspent_outputs(previous_address)
+      StateLedger.spend_all_unspent_outputs(previous_address)
     end
 
     :ok =
@@ -126,6 +128,9 @@ defmodule Archethic.Account.MemTablesLoader do
       } ->
         TokenLedger.add_unspent_output(address, unspent_output)
 
+      unspent_output = %VersionedUnspentOutput{unspent_output: %UnspentOutput{type: :state}} ->
+        StateLedger.add_unspent_output(address, unspent_output)
+
       _ ->
         # Ignore smart contract calls
         :ignore

lib/archethic/account/supervisor.ex

@@ -5,6 +5,7 @@ defmodule Archethic.Account.Supervisor do
 
   alias Archethic.Account.MemTables.TokenLedger
   alias Archethic.Account.MemTables.UCOLedger
+  alias Archethic.Account.MemTables.StateLedger
   alias Archethic.Account.MemTablesLoader
 
   alias Archethic.Utils
@@ -17,6 +18,7 @@ defmodule Archethic.Account.Supervisor do
     children = [
       TokenLedger,
       UCOLedger,
+      StateLedger,
       MemTablesLoader
     ]