Merge pull request #3470 from poanetwork/vb-address-tokens-sum

Display sum of tokens' USD value at tokens holder's address page

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Current
 
 ### Features
+- [#3470](https://github.com/poanetwork/blockscout/pull/3470) - Display sum of tokens' USD value at tokens holder's address page
 - [#3462](https://github.com/poanetwork/blockscout/pull/3462) - Display price for bridged tokens
 
 ### Fixes

apps/block_scout_web/lib/block_scout_web/controllers/address_token_balance_controller.ex

@@ -17,13 +17,13 @@ defmodule BlockScoutWeb.AddressTokenBalanceController do
           conn
           |> put_status(200)
           |> put_layout(false)
-          |> render("_token_balances.html", token_balances: token_balances)
+          |> render("_token_balances.html", address_hash: address_hash, token_balances: token_balances)
 
         _ ->
           conn
           |> put_status(200)
           |> put_layout(false)
-          |> render("_token_balances.html", token_balances: [])
+          |> render("_token_balances.html", address_hash: address_hash, token_balances: [])
       end
     else
       _ ->

apps/block_scout_web/lib/block_scout_web/controllers/tokens/holder_controller.ex

@@ -32,7 +32,11 @@ defmodule BlockScoutWeb.Tokens.HolderController do
 
       token_balances_json =
         Enum.map(token_balances_paginated, fn token_balance ->
-          View.render_to_string(HolderView, "_token_balances.html", token_balance: token_balance, token: token)
+          View.render_to_string(HolderView, "_token_balances.html",
+            address_hash: address_hash,
+            token_balance: token_balance,
+            token: token
+          )
         end)
 
       json(conn, %{items: token_balances_json, next_page_path: next_page_path})

apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex

@@ -11,6 +11,9 @@
 
      <i class="fas fa-chevron-down mr-2"></i>
      <span data-tokens-count><%= tokens_count_title(@token_balances) %></span>
+     <%= if @token_balances && Decimal.cmp(address_tokens_usd_sum_cache(@address_hash, @token_balances), Decimal.new(0)) == :gt do %>
+      (<span data-usd-value=<%= address_tokens_usd_sum_cache(@address_hash, @token_balances) %> ></span>)
+    <% end %>
   </a>
 <% else %>
    <span data-tokens-count><%= tokens_count_title(@token_balances) %></span>

apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex

@@ -18,7 +18,7 @@
           <p class="mb-0 col-md-6"><%= token_name(token_balance.token) %></p>
           <%= if token_balance.token.usd_value do %>
             <p class="mb-0 col-md-6 text-right">
-              <span data-selector="token-balance-usd" data-usd-value="<%= balance_in_usd(token_balance) %>"></span>
+              <span data-selector="token-balance-usd" data-usd-value="<%= Chain.balance_in_usd(token_balance) %>"></span>
             </p>
           <% end %>
         </div>

apps/block_scout_web/lib/block_scout_web/views/address_token_balance_view.ex

@@ -1,7 +1,8 @@
 defmodule BlockScoutWeb.AddressTokenBalanceView do
   use BlockScoutWeb, :view
 
-  alias BlockScoutWeb.CurrencyHelpers
+  alias Explorer.Chain
+  alias Explorer.Counters.AddressTokenUsdSum
 
   def tokens_count_title(token_balances) do
     ngettext("%{count} token", "%{count} tokens", Enum.count(token_balances))
@@ -57,7 +58,7 @@ defmodule BlockScoutWeb.AddressTokenBalanceView do
 
   defp sort_2_tokens_by_value_desc_and_name(token_balance1, token_balance2, usd_value1, usd_value2, sort_by_name)
        when not is_nil(usd_value1) and not is_nil(usd_value2) do
-    case Decimal.cmp(balance_in_usd(token_balance1), balance_in_usd(token_balance2)) do
+    case Decimal.cmp(Chain.balance_in_usd(token_balance1), Chain.balance_in_usd(token_balance2)) do
       :gt ->
         true
 
@@ -84,16 +85,7 @@ defmodule BlockScoutWeb.AddressTokenBalanceView do
     sort_by_name
   end
 
-  @doc """
-  Return the balance in usd corresponding to this token. Return nil if the usd_value of the token is not present.
-  """
-  def balance_in_usd(%{token: %{usd_value: nil}}) do
-    nil
-  end
-
-  def balance_in_usd(token_balance) do
-    tokens = CurrencyHelpers.divide_decimals(token_balance.value, token_balance.token.decimals)
-    price = token_balance.token.usd_value
-    Decimal.mult(tokens, price)
+  def address_tokens_usd_sum_cache(address, token_balances) do
+    AddressTokenUsdSum.fetch(address, token_balances)
   end
 end

apps/block_scout_web/priv/gettext/default.pot

@@ -1,5 +1,5 @@
 #, elixir-format
-#: lib/block_scout_web/views/address_token_balance_view.ex:7
+#: lib/block_scout_web/views/address_token_balance_view.ex:8
 msgid "%{count} token"
 msgid_plural "%{count} tokens"
 msgstr[0] ""
@@ -1262,7 +1262,7 @@ msgstr ""
 
 #, elixir-format
 #:
-#: lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex:30
+#: lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex:33
 msgid "Search tokens"
 msgstr ""
 

apps/block_scout_web/priv/gettext/en/LC_MESSAGES/default.po

@@ -1,5 +1,5 @@
 #, elixir-format
-#: lib/block_scout_web/views/address_token_balance_view.ex:7
+#: lib/block_scout_web/views/address_token_balance_view.ex:8
 msgid "%{count} token"
 msgid_plural "%{count} tokens"
 msgstr[0] ""
@@ -1262,7 +1262,7 @@ msgstr ""
 
 #, elixir-format
 #:
-#: lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex:30
+#: lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex:33
 msgid "Search tokens"
 msgstr ""
 

apps/block_scout_web/test/block_scout_web/views/address_token_balance_view_test.exs

@@ -2,6 +2,7 @@ defmodule BlockScoutWeb.AddressTokenBalanceViewTest do
   use BlockScoutWeb.ConnCase, async: true
 
   alias BlockScoutWeb.AddressTokenBalanceView
+  alias Explorer.Chain
 
   describe "tokens_count_title/1" do
     test "returns the title pluralized" do
@@ -146,7 +147,7 @@ defmodule BlockScoutWeb.AddressTokenBalanceViewTest do
 
       token_balance = build(:token_balance, value: Decimal.new(10), token: token)
 
-      result = AddressTokenBalanceView.balance_in_usd(token_balance)
+      result = Chain.balance_in_usd(token_balance)
 
       assert Decimal.cmp(result, 30) == :eq
     end
@@ -159,7 +160,7 @@ defmodule BlockScoutWeb.AddressTokenBalanceViewTest do
 
       token_balance = build(:token_balance, value: 10, token: token)
 
-      assert AddressTokenBalanceView.balance_in_usd(token_balance) == nil
+      assert Chain.balance_in_usd(token_balance) == nil
     end
 
     test "consider decimals when computing value" do
@@ -170,7 +171,7 @@ defmodule BlockScoutWeb.AddressTokenBalanceViewTest do
 
       token_balance = build(:token_balance, value: Decimal.new(10), token: token)
 
-      result = AddressTokenBalanceView.balance_in_usd(token_balance)
+      result = Chain.balance_in_usd(token_balance)
 
       assert Decimal.cmp(result, Decimal.from_float(0.3)) == :eq
     end

apps/explorer/config/config.exs

@@ -105,6 +105,28 @@ config :explorer, Explorer.Counters.AddressTransactionsGasUsageCounter,
   enable_consolidation: true,
   period: address_transactions_gas_usage_counter_cache_period
 
+address_tokens_usd_sum_cache_period =
+  case Integer.parse(System.get_env("ADDRESS_TOKENS_USD_SUM_CACHE_PERIOD", "")) do
+    {secs, ""} -> :timer.seconds(secs)
+    _ -> :timer.hours(1)
+  end
+
+config :explorer, Explorer.Counters.AddressTokenUsdSum,
+  enabled: true,
+  enable_consolidation: true,
+  period: address_tokens_usd_sum_cache_period
+
+token_exchange_rate_cache_period =
+  case Integer.parse(System.get_env("TOKEN_EXCHANGE_RATE_CACHE_PERIOD", "")) do
+    {secs, ""} -> :timer.seconds(secs)
+    _ -> :timer.hours(1)
+  end
+
+config :explorer, Explorer.Chain.Cache.TokenExchangeRate,
+  enabled: true,
+  enable_consolidation: true,
+  period: token_exchange_rate_cache_period
+
 token_holders_counter_cache_period =
   case Integer.parse(System.get_env("TOKEN_HOLDERS_COUNTER_CACHE_PERIOD", "")) do
     {secs, ""} -> :timer.seconds(secs)

apps/explorer/lib/explorer/application.ex

@@ -76,12 +76,14 @@ defmodule Explorer.Application do
       configure(Explorer.ChainSpec.GenesisData),
       configure(Explorer.KnownTokens),
       configure(Explorer.Market.History.Cataloger),
+      configure(Explorer.Chain.Cache.TokenExchangeRate),
       configure(Explorer.Chain.Transaction.History.Historian),
       configure(Explorer.Chain.Events.Listener),
       configure(Explorer.Counters.AddressesWithBalanceCounter),
       configure(Explorer.Counters.AddressesCounter),
       configure(Explorer.Counters.AddressTransactionsCounter),
       configure(Explorer.Counters.AddressTransactionsGasUsageCounter),
+      configure(Explorer.Counters.AddressTokenUsdSum),
       configure(Explorer.Counters.TokenHoldersCounter),
       configure(Explorer.Counters.TokenTransfersCounter),
       configure(Explorer.Counters.AverageBlockTime),

apps/explorer/lib/explorer/chain.ex

@@ -44,6 +44,7 @@ defmodule Explorer.Chain do
     Address.TokenBalance,
     Block,
     BridgedToken,
+    CurrencyHelpers,
     Data,
     DecompiledSmartContract,
     Hash,
@@ -2012,6 +2013,30 @@ defmodule Explorer.Chain do
     end
   end
 
+  @doc """
+  Return the balance in usd corresponding to this token. Return nil if the usd_value of the token is not present.
+  """
+  def balance_in_usd(%{token: %{usd_value: nil}}) do
+    nil
+  end
+
+  def balance_in_usd(token_balance) do
+    tokens = CurrencyHelpers.divide_decimals(token_balance.value, token_balance.token.decimals)
+    price = token_balance.token.usd_value
+    Decimal.mult(tokens, price)
+  end
+
+  def address_tokens_usd_sum(token_balances) do
+    token_balances
+    |> Enum.reduce(Decimal.new(0), fn token_balance, acc ->
+      if token_balance.value && token_balance.token.usd_value do
+        Decimal.add(acc, balance_in_usd(token_balance))
+      else
+        acc
+      end
+    end)
+  end
+
   defp contract?(%{contract_code: nil}), do: false
 
   defp contract?(%{contract_code: _}), do: true

apps/explorer/lib/explorer/chain/cache/token_exchange_rate.ex

@@ -0,0 +1,132 @@
+defmodule Explorer.Chain.Cache.TokenExchangeRate do
+  @moduledoc """
+  Caches Token USD exchange_rate.
+  """
+  use GenServer
+
+  alias Explorer.ExchangeRates.Source
+
+  @cache_name :token_exchange_rate
+  @last_update_key "last_update"
+  @cache_period Application.get_env(:explorer, __MODULE__)[:period]
+
+  @ets_opts [
+    :set,
+    :named_table,
+    :public,
+    read_concurrency: true
+  ]
+
+  config = Application.get_env(:explorer, Explorer.Chain.Cache.TokenExchangeRate)
+  @enable_consolidation Keyword.get(config, :enable_consolidation)
+
+  @spec start_link(term()) :: GenServer.on_start()
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, :ok, name: __MODULE__)
+  end
+
+  @impl true
+  def init(_args) do
+    create_cache_table()
+
+    {:ok, %{consolidate?: enable_consolidation?()}, {:continue, :ok}}
+  end
+
+  @impl true
+  def handle_continue(:ok, %{consolidate?: true} = state) do
+    {:noreply, state}
+  end
+
+  @impl true
+  def handle_continue(:ok, state) do
+    {:noreply, state}
+  end
+
+  @impl true
+  def handle_info(:consolidate, state) do
+    {:noreply, state}
+  end
+
+  def cache_key(symbol) do
+    "token_symbol_exchange_rate_#{symbol}"
+  end
+
+  def fetch(symbol) do
+    if cache_expired?(symbol) || value_is_empty?(symbol) do
+      Task.start_link(fn ->
+        update_cache(symbol)
+      end)
+    end
+
+    fetch_from_cache(cache_key(symbol))
+  end
+
+  def cache_name, do: @cache_name
+
+  defp cache_expired?(symbol) do
+    updated_at = fetch_from_cache("#{cache_key(symbol)}_#{@last_update_key}")
+
+    cond do
+      is_nil(updated_at) -> true
+      current_time() - updated_at > @cache_period -> true
+      true -> false
+    end
+  end
+
+  defp value_is_empty?(symbol) do
+    value = fetch_from_cache(cache_key(symbol))
+    is_nil(value) || value == 0
+  end
+
+  defp update_cache(symbol) do
+    put_into_cache("#{cache_key(symbol)}_#{@last_update_key}", current_time())
+
+    exchange_rate = fetch_token_exchange_rate(symbol)
+
+    put_into_cache(cache_key(symbol), exchange_rate)
+  end
+
+  def fetch_token_exchange_rate(symbol) do
+    case Source.fetch_exchange_rates_for_token(symbol) do
+      {:ok, [rates]} ->
+        rates.usd_value
+
+      _ ->
+        nil
+    end
+  end
+
+  defp fetch_from_cache(key) do
+    case :ets.lookup(@cache_name, key) do
+      [{_, value}] ->
+        value
+
+      [] ->
+        0
+    end
+  end
+
+  def put_into_cache(key, value) do
+    if cache_table_exists?() do
+      :ets.insert(@cache_name, {key, value})
+    end
+  end
+
+  defp current_time do
+    utc_now = DateTime.utc_now()
+
+    DateTime.to_unix(utc_now, :millisecond)
+  end
+
+  def cache_table_exists? do
+    :ets.whereis(@cache_name) !== :undefined
+  end
+
+  def create_cache_table do
+    unless cache_table_exists?() do
+      :ets.new(@cache_name, @ets_opts)
+    end
+  end
+
+  def enable_consolidation?, do: @enable_consolidation
+end

apps/explorer/lib/explorer/chain/currency_helpers.ex

@@ -0,0 +1,12 @@
+defmodule Explorer.Chain.CurrencyHelpers do
+  @moduledoc """
+  Helper functions for interacting with `t:BlockScoutWeb.ExchangeRates.USD.t/0` values.
+  """
+
+  @spec divide_decimals(Decimal.t(), Decimal.t()) :: Decimal.t()
+  def divide_decimals(%{sign: sign, coef: coef, exp: exp}, decimals) do
+    sign
+    |> Decimal.new(coef, exp - Decimal.to_integer(decimals))
+    |> Decimal.normalize()
+  end
+end