Merge pull request #1933 from poanetwork/ab-eth-get-block-number

add eth_BlockNumber

CHANGELOG.md

@@ -22,6 +22,7 @@
 - [#1920](https://github.com/poanetwork/blockscout/pull/1920) - fix: remove source code fields from list endpoint
 - [#1876](https://github.com/poanetwork/blockscout/pull/1876) - async calculate a count of blocks
 - [#1941](https://github.com/poanetwork/blockscout/pull/1941) - feat: add on demand fetching and stale attr to rpc
+- [#1933](https://github.com/poanetwork/blockscout/pull/1933) - add eth_BlockNumber json rpc method
 - [#1952](https://github.com/poanetwork/blockscout/pull/1952) - feat: exclude empty contracts by default
 
 ### Fixes

apps/block_scout_web/lib/block_scout_web/controllers/api/rpc/block_controller.ex

@@ -3,6 +3,7 @@ defmodule BlockScoutWeb.API.RPC.BlockController do
 
   alias BlockScoutWeb.Chain, as: ChainWeb
   alias Explorer.Chain
+  alias Explorer.Chain.BlockNumberCache
 
   def getblockreward(conn, params) do
     with {:block_param, {:ok, unsafe_block_number}} <- {:block_param, Map.fetch(params, "blockno")},
@@ -23,4 +24,11 @@ defmodule BlockScoutWeb.API.RPC.BlockController do
         render(conn, :error, error: "Block does not exist")
     end
   end
+
+  def eth_block_number(conn, params) do
+    id = Map.get(params, "id", 1)
+    max_block_number = BlockNumberCache.max_number()
+
+    render(conn, :eth_block_number, number: max_block_number, id: id)
+  end
 end

apps/block_scout_web/lib/block_scout_web/etherscan.ex

@@ -279,6 +279,12 @@ defmodule BlockScoutWeb.Etherscan do
     "result" => nil
   }
 
+  @block_eth_block_number_example_value %{
+    "jsonrpc" => "2.0",
+    "result" => "767969",
+    "id" => 1
+  }
+
   @contract_listcontracts_example_value %{
     "status" => "1",
     "message" => "OK",
@@ -476,11 +482,26 @@ defmodule BlockScoutWeb.Etherscan do
     enum_interpretation: %{"0" => "error", "1" => "ok"}
   }
 
+  @jsonrpc_version_type %{
+    type: "string",
+    example: ~s("2.0")
+  }
+
   @message_type %{
     type: "string",
     example: ~s("OK")
   }
 
+  @hex_number_type %{
+    type: "string",
+    example: ~s("767969")
+  }
+
+  @id_type %{
+    type: "string",
+    example: ~s("1")
+  }
+
   @wei_type %{
     type: "wei",
     definition: &__MODULE__.wei_type_definition/1,
@@ -1737,6 +1758,35 @@ defmodule BlockScoutWeb.Etherscan do
     ]
   }
 
+  @block_eth_block_number_action %{
+    name: "eth_block_number",
+    description: "Mimics Ethereum JSON RPC's eth_blockNumber. Returns the lastest block number",
+    required_params: [],
+    optional_params: [
+      %{
+        key: "id",
+        placeholder: "request id",
+        type: "integer",
+        description: "A nonnegative integer that represents the json rpc request id."
+      }
+    ],
+    responses: [
+      %{
+        code: "200",
+        description: "successful request",
+        example_value: Jason.encode!(@block_eth_block_number_example_value),
+        model: %{
+          name: "Result",
+          fields: %{
+            jsonrpc: @jsonrpc_version_type,
+            id: @id_type,
+            result: @hex_number_type
+          }
+        }
+      }
+    ]
+  }
+
   @block_getblockreward_action %{
     name: "getblockreward",
     description: "Get block reward by block number.",
@@ -2171,7 +2221,7 @@ defmodule BlockScoutWeb.Etherscan do
 
   @block_module %{
     name: "block",
-    actions: [@block_getblockreward_action]
+    actions: [@block_getblockreward_action, @block_eth_block_number_action]
   }
 
   @contract_module %{

apps/block_scout_web/lib/block_scout_web/views/api/rpc/block_view.ex

@@ -1,7 +1,7 @@
 defmodule BlockScoutWeb.API.RPC.BlockView do
   use BlockScoutWeb, :view
 
-  alias BlockScoutWeb.API.RPC.RPCView
+  alias BlockScoutWeb.API.RPC.{EthRPCView, RPCView}
   alias Explorer.Chain.{Hash, Wei}
 
   def render("block_reward.json", %{block: block, reward: reward}) do
@@ -22,7 +22,33 @@ defmodule BlockScoutWeb.API.RPC.BlockView do
     RPCView.render("show.json", data: data)
   end
 
+  def render("eth_block_number.json", %{number: number, id: id}) do
+    result = encode_quantity(number)
+
+    EthRPCView.render("show.json", %{result: result, id: id})
+  end
+
   def render("error.json", %{error: error}) do
     RPCView.render("error.json", error: error)
   end
+
+  defp encode_quantity(binary) when is_binary(binary) do
+    hex_binary = Base.encode16(binary, case: :lower)
+
+    result = String.replace_leading(hex_binary, "0", "")
+
+    final_result = if result == "", do: "0", else: result
+
+    "0x#{final_result}"
+  end
+
+  defp encode_quantity(value) when is_integer(value) do
+    value
+    |> :binary.encode_unsigned()
+    |> encode_quantity()
+  end
+
+  defp encode_quantity(value) when is_nil(value) do
+    nil
+  end
 end

apps/block_scout_web/lib/block_scout_web/views/api/rpc/eth_rpc_view.ex

@@ -0,0 +1,33 @@
+defmodule BlockScoutWeb.API.RPC.EthRPCView do
+  use BlockScoutWeb, :view
+
+  defstruct [:result, :id, :error]
+
+  def render("show.json", %{result: result, id: id}) do
+    %__MODULE__{
+      result: result,
+      id: id
+    }
+  end
+
+  def render("error.json", %{error: message, id: id}) do
+    %__MODULE__{
+      error: message,
+      id: id
+    }
+  end
+
+  defimpl Poison.Encoder, for: BlockScoutWeb.API.RPC.EthRPCView do
+    def encode(%BlockScoutWeb.API.RPC.EthRPCView{result: result, id: id, error: error}, _options) when is_nil(error) do
+      """
+      {"jsonrpc":"2.0","result":"#{result}","id":#{id}}
+      """
+    end
+
+    def encode(%BlockScoutWeb.API.RPC.EthRPCView{id: id, error: error}, _options) do
+      """
+      {"jsonrpc":"2.0","error": #{error},"id": #{id}}
+      """
+    end
+  end
+end

apps/block_scout_web/test/block_scout_web/controllers/api/rpc/address_controller_test.exs

@@ -25,7 +25,6 @@ defmodule BlockScoutWeb.API.RPC.AddressControllerTest do
     start_supervised!(AddressesWithBalanceCounter)
 
     Application.put_env(:explorer, AverageBlockTime, enabled: true)
-    BlockNumberCache.setup(cache_period: 0)
 
     on_exit(fn ->
       Application.put_env(:explorer, AverageBlockTime, enabled: false)

apps/explorer/config/config.exs

@@ -13,6 +13,8 @@ config :explorer,
 
 config :explorer, Explorer.Counters.AverageBlockTime, enabled: true
 
+config :explorer, Explorer.Chain.BlockNumberCache, enabled: true
+
 config :explorer, Explorer.ExchangeRates.Source.CoinMarketCap,
   pages: String.to_integer(System.get_env("COINMARKETCAP_PAGES") || "10")
 

apps/explorer/config/test.exs

@@ -13,6 +13,8 @@ config :explorer, Explorer.Repo,
 
 config :explorer, Explorer.ExchangeRates, enabled: false, store: :ets
 
+config :explorer, Explorer.Chain.BlockNumberCache, enabled: false
+
 config :explorer, Explorer.KnownTokens, enabled: false, store: :ets
 
 config :explorer, Explorer.Counters.AverageBlockTime, enabled: false

apps/explorer/lib/explorer/chain/block_number_cache.ex

@@ -6,13 +6,10 @@ defmodule Explorer.Chain.BlockNumberCache do
   alias Explorer.Chain
 
   @tab :block_number_cache
-  # 30 minutes
-  @cache_period 1_000 * 60 * 30
   @key "min_max"
-  @opts_key "opts"
 
-  @spec setup(Keyword.t()) :: :ok
-  def setup(opts \\ []) do
+  @spec setup() :: :ok
+  def setup do
     if :ets.whereis(@tab) == :undefined do
       :ets.new(@tab, [
         :set,
@@ -22,7 +19,6 @@ defmodule Explorer.Chain.BlockNumberCache do
       ])
     end
 
-    setup_opts(opts)
     update_cache()
 
     :ok
@@ -41,15 +37,11 @@ defmodule Explorer.Chain.BlockNumberCache do
   end
 
   defp value(type) do
-    initial_cache = {_min, _max, old_current_time} = cached_values()
-
-    {min, max, _current_time} =
-      if current_time() - old_current_time > cache_period() do
-        update_cache()
-
+    {min, max} =
+      if Application.get_env(:explorer, __MODULE__)[:enabled] do
         cached_values()
       else
-        initial_cache
+        min_and_max_from_db()
       end
 
     case type do
@@ -59,18 +51,29 @@ defmodule Explorer.Chain.BlockNumberCache do
     end
   end
 
-  defp update_cache do
-    current_time = current_time()
-    {min, max} = min_and_max_from_db()
-    tuple = {min, max, current_time}
+  @spec update(non_neg_integer()) :: boolean()
+  def update(number) do
+    {old_min, old_max} = cached_values()
 
-    :ets.insert(@tab, {@key, tuple})
+    cond do
+      number > old_max ->
+        tuple = {old_min, number}
+        :ets.insert(@tab, {@key, tuple})
+
+      number < old_min ->
+        tuple = {number, old_max}
+        :ets.insert(@tab, {@key, tuple})
+
+      true ->
+        false
+    end
   end
 
-  defp setup_opts(opts) do
-    cache_period = opts[:cache_period] || @cache_period
+  defp update_cache do
+    {min, max} = min_and_max_from_db()
+    tuple = {min, max}
 
-    :ets.insert(@tab, {@opts_key, cache_period})
+    :ets.insert(@tab, {@key, tuple})
   end
 
   defp cached_values do
@@ -79,22 +82,10 @@ defmodule Explorer.Chain.BlockNumberCache do
     cached_values
   end
 
-  defp cache_period do
-    [{_, cache_period}] = :ets.lookup(@tab, @opts_key)
-
-    cache_period
-  end
-
   defp min_and_max_from_db do
     Chain.fetch_min_and_max_block_numbers()
   rescue
     _e ->
       {0, 0}
   end
-
-  defp current_time do
-    utc_now = DateTime.utc_now()
-
-    DateTime.to_unix(utc_now, :millisecond)
-  end
 end

apps/explorer/test/explorer/chain/block_number_cache_test.exs

@@ -3,6 +3,14 @@ defmodule Explorer.Chain.BlockNumberCacheTest do
 
   alias Explorer.Chain.BlockNumberCache
 
+  setup do
+    Application.put_env(:explorer, Explorer.Chain.BlockNumberCache, enabled: true)
+
+    on_exit(fn ->
+      Application.put_env(:explorer, Explorer.Chain.BlockNumberCache, enabled: false)
+    end)
+  end
+
   describe "max_number/1" do
     test "returns max number" do
       insert(:block, number: 5)
@@ -11,33 +19,6 @@ defmodule Explorer.Chain.BlockNumberCacheTest do
 
       assert BlockNumberCache.max_number() == 5
     end
-
-    test "invalidates cache if period did pass" do
-      insert(:block, number: 5)
-
-      BlockNumberCache.setup(cache_period: 2_000)
-
-      assert BlockNumberCache.max_number() == 5
-
-      insert(:block, number: 10)
-
-      Process.sleep(2_000)
-
-      assert BlockNumberCache.max_number() == 10
-      assert BlockNumberCache.min_number() == 5
-    end
-
-    test "does not invalidate cache if period time did not pass" do
-      insert(:block, number: 5)
-
-      BlockNumberCache.setup(cache_period: 10_000)
-
-      assert BlockNumberCache.max_number() == 5
-
-      insert(:block, number: 10)
-
-      assert BlockNumberCache.max_number() == 5
-    end
   end
 
   describe "min_number/1" do
@@ -48,32 +29,31 @@ defmodule Explorer.Chain.BlockNumberCacheTest do
 
       assert BlockNumberCache.max_number() == 2
     end
+  end
 
-    test "invalidates cache" do
-      insert(:block, number: 5)
-
-      BlockNumberCache.setup(cache_period: 2_000)
+  describe "update/1" do
+    test "updates max number" do
+      insert(:block, number: 2)
 
-      assert BlockNumberCache.min_number() == 5
+      BlockNumberCache.setup()
 
-      insert(:block, number: 2)
+      assert BlockNumberCache.max_number() == 2
 
-      Process.sleep(2_000)
+      assert BlockNumberCache.update(3)
 
-      assert BlockNumberCache.min_number() == 2
-      assert BlockNumberCache.max_number() == 5
+      assert BlockNumberCache.max_number() == 3
     end
 
-    test "does not invalidate cache if period time did not pass" do
-      insert(:block, number: 5)
+    test "updates min number" do
+      insert(:block, number: 2)
 
-      BlockNumberCache.setup(cache_period: 10_000)
+      BlockNumberCache.setup()
 
-      assert BlockNumberCache.max_number() == 5
+      assert BlockNumberCache.min_number() == 2
 
-      insert(:block, number: 2)
+      assert BlockNumberCache.update(1)
 
-      assert BlockNumberCache.max_number() == 5
+      assert BlockNumberCache.min_number() == 1
     end
   end
 end

apps/explorer/test/support/data_case.ex

@@ -39,7 +39,7 @@ defmodule Explorer.DataCase do
       Ecto.Adapters.SQL.Sandbox.mode(Explorer.Repo, {:shared, self()})
     end
 
-    Explorer.Chain.BlockNumberCache.setup(cache_period: 0)
+    Explorer.Chain.BlockNumberCache.setup()
 
     :ok
   end

apps/indexer/lib/indexer/block/fetcher.ex

@@ -11,7 +11,7 @@ defmodule Indexer.Block.Fetcher do
 
   alias EthereumJSONRPC.{Blocks, FetchedBeneficiaries}
   alias Explorer.Chain
-  alias Explorer.Chain.{Address, Block, Hash, Import, Transaction}
+  alias Explorer.Chain.{Address, Block, BlockNumberCache, Hash, Import, Transaction}
   alias Indexer.Block.Fetcher.Receipts
 
   alias Indexer.Fetcher.{
@@ -171,13 +171,23 @@ defmodule Indexer.Block.Fetcher do
                transactions: %{params: transactions_with_receipts}
              }
            ) do
-      {:ok, %{inserted: inserted, errors: blocks_errors}}
+      result = {:ok, %{inserted: inserted, errors: blocks_errors}}
+      update_block_cache(inserted[:blocks])
+      result
     else
       {step, {:error, reason}} -> {:error, {step, reason}}
       {:import, {:error, step, failed_value, changes_so_far}} -> {:error, {step, failed_value, changes_so_far}}
     end
   end
 
+  defp update_block_cache(blocks) do
+    max_block = Enum.max_by(blocks, fn block -> block.number end)
+    min_block = Enum.min_by(blocks, fn block -> block.number end)
+
+    BlockNumberCache.update(max_block.number)
+    BlockNumberCache.update(min_block.number)
+  end
+
   def import(
         %__MODULE__{broadcast: broadcast, callback_module: callback_module} = state,
         options