Merge pull request #2505 from poanetwork/ab-poa-block-emission-rewards

add POA emission rewards importer

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Current
 
 ### Features
+- [#2505](https://github.com/poanetwork/blockscout/pull/2505) - support POA Network emission rewards
 - [#2636](https://github.com/poanetwork/blockscout/pull/2636) - Execute all address' transactions page queries in parallel
 - [#2596](https://github.com/poanetwork/blockscout/pull/2596) - support AuRa's empty step reward type
 - [#2581](https://github.com/poanetwork/blockscout/pull/2581) - Add generic Map-like Cache behaviour and implementation

apps/explorer/config/config.exs

@@ -27,7 +27,11 @@ config :explorer, Explorer.Counters.AverageBlockTime,
   enabled: true,
   period: average_block_period
 
-config :explorer, Explorer.ChainSpec.GenesisData, enabled: false, chain_spec_path: System.get_env("CHAIN_SPEC_PATH")
+config :explorer, Explorer.ChainSpec.GenesisData,
+  enabled: true,
+  chain_spec_path: System.get_env("CHAIN_SPEC_PATH"),
+  emission_format: System.get_env("EMISSION_FORMAT", "DEFAULT"),
+  rewards_contract_address: System.get_env("REWARDS_CONTRACT_ADDRESS", "0xeca443e8e1ab29971a45a9c57a6a9875701698a5")
 
 config :explorer, Explorer.Chain.Cache.BlockNumber, enabled: true
 

apps/explorer/lib/explorer/chain_spec/parity/importer.ex

@@ -3,18 +3,23 @@ defmodule Explorer.ChainSpec.Parity.Importer do
   Imports data from parity chain spec.
   """
 
+  require Logger
+
   alias Explorer.{Chain, Repo}
   alias Explorer.Chain.Block.{EmissionReward, Range}
   alias Explorer.Chain.Hash.Address, as: AddressHash
   alias Explorer.Chain.Wei
+  alias Explorer.ChainSpec.GenesisData
+  alias Explorer.ChainSpec.POA.Importer, as: PoaEmissionImporter
 
   @max_block_number :infinity
 
   def import_emission_rewards(chain_spec) do
-    rewards = emission_rewards(chain_spec)
-
-    {_, nil} = Repo.delete_all(EmissionReward)
-    {_, nil} = Repo.insert_all(EmissionReward, rewards)
+    if Application.get_env(:explorer, GenesisData)[:emission_format] == "POA" do
+      PoaEmissionImporter.import_emission_rewards()
+    else
+      import_rewards_from_chain_spec(chain_spec)
+    end
   end
 
   def import_genesis_coin_balances(chain_spec) do
@@ -38,18 +43,37 @@ defmodule Explorer.ChainSpec.Parity.Importer do
     Chain.import(params)
   end
 
+  defp import_rewards_from_chain_spec(chain_spec) do
+    rewards = emission_rewards(chain_spec)
+
+    {_, nil} = Repo.delete_all(EmissionReward)
+    {_, nil} = Repo.insert_all(EmissionReward, rewards)
+  end
+
   def genesis_coin_balances(chain_spec) do
     accounts = chain_spec["accounts"]
 
-    parse_accounts(accounts)
+    if accounts do
+      parse_accounts(accounts)
+    else
+      Logger.warn(fn -> "No accounts are defined in chain spec" end)
+
+      []
+    end
   end
 
   def emission_rewards(chain_spec) do
     rewards = chain_spec["engine"]["Ethash"]["params"]["blockReward"]
 
-    rewards
-    |> parse_hex_numbers()
-    |> format_ranges()
+    if rewards do
+      rewards
+      |> parse_hex_numbers()
+      |> format_ranges()
+    else
+      Logger.warn(fn -> "No rewards are defined in chain spec" end)
+
+      []
+    end
   end
 
   defp parse_accounts(accounts) do
@@ -59,7 +83,7 @@ defmodule Explorer.ChainSpec.Parity.Importer do
     end)
     |> Stream.map(fn {address, %{"balance" => value}} ->
       {:ok, address_hash} = AddressHash.cast(address)
-      balance = parse_hex_number(value)
+      balance = parse_number(value)
 
       %{address_hash: address_hash, value: balance}
     end)
@@ -92,16 +116,22 @@ defmodule Explorer.ChainSpec.Parity.Importer do
 
   defp parse_hex_numbers(rewards) do
     Enum.map(rewards, fn {hex_block_number, hex_reward} ->
-      block_number = parse_hex_number(hex_block_number)
-      {:ok, reward} = hex_reward |> parse_hex_number() |> Wei.cast()
+      block_number = parse_number(hex_block_number)
+      {:ok, reward} = hex_reward |> parse_number() |> Wei.cast()
 
       {block_number, reward}
     end)
   end
 
-  defp parse_hex_number("0x" <> hex_number) do
+  defp parse_number("0x" <> hex_number) do
     {number, ""} = Integer.parse(hex_number, 16)
 
     number
   end
+
+  defp parse_number(string_number) do
+    {number, ""} = Integer.parse(string_number, 10)
+
+    number
+  end
 end

apps/explorer/lib/explorer/chain_spec/poa/importer.ex

@@ -0,0 +1,89 @@
+defmodule Explorer.ChainSpec.POA.Importer do
+  @moduledoc """
+  Imports emission reward range for POA chain.
+  """
+
+  require Logger
+
+  alias Explorer.Chain.Wei
+  alias Explorer.Repo
+  alias Explorer.SmartContract.Reader
+  alias Explorer.Chain.Block.{EmissionReward, Range}
+  alias Explorer.ChainSpec.GenesisData
+
+  @block_reward_amount_abi %{
+    "type" => "function",
+    "stateMutability" => "view",
+    "payable" => false,
+    "outputs" => [%{"type" => "uint256", "name" => ""}],
+    "name" => "blockRewardAmount",
+    "inputs" => [],
+    "constant" => true
+  }
+  @block_reward_amount_params %{"blockRewardAmount" => []}
+  @emission_funds_amount_abi %{
+    "type" => "function",
+    "stateMutability" => "view",
+    "payable" => false,
+    "outputs" => [%{"type" => "uint256", "name" => ""}],
+    "name" => "emissionFundsAmount",
+    "inputs" => [],
+    "constant" => true
+  }
+  @emission_funds_amount_params %{"emissionFundsAmount" => []}
+  @emission_funds_block_start 5_098_087
+
+  def import_emission_rewards do
+    if is_nil(rewards_contract_address()) do
+      Logger.warn(fn -> "No rewards contract address is defined" end)
+    else
+      block_reward = block_reward_amount()
+      emission_funds = emission_funds_amount()
+
+      rewards = [
+        %{
+          block_range: %Range{from: 0, to: @emission_funds_block_start},
+          reward: %Wei{value: block_reward}
+        },
+        %{
+          block_range: %Range{from: @emission_funds_block_start + 1, to: :infinity},
+          reward: %Wei{value: Decimal.add(block_reward, emission_funds)}
+        }
+      ]
+
+      {_, nil} = Repo.delete_all(EmissionReward)
+      {_, nil} = Repo.insert_all(EmissionReward, rewards)
+    end
+  end
+
+  def block_reward_amount do
+    call_contract(rewards_contract_address(), @block_reward_amount_abi, @block_reward_amount_params)
+  end
+
+  def emission_funds_amount do
+    call_contract(rewards_contract_address(), @emission_funds_amount_abi, @emission_funds_amount_params)
+  end
+
+  defp rewards_contract_address do
+    Application.get_env(:explorer, GenesisData)[:rewards_contract_address]
+  end
+
+  defp call_contract(address, abi, params) do
+    abi = [abi]
+
+    method_name =
+      params
+      |> Enum.map(fn {key, _value} -> key end)
+      |> List.first()
+
+    Reader.query_contract(address, abi, params)
+
+    value =
+      case Reader.query_contract(address, abi, params) do
+        %{^method_name => {:ok, [result]}} -> result
+        _ -> 0
+      end
+
+    Decimal.new(value)
+  end
+end

docs/env-variables.md

@@ -66,3 +66,5 @@ $ export NETWORK=POA
 | `API_URL` | | Link to API instance, e.g. `http://host/path` | (empty) | v2.0.3+ | | |
 | `CHAIN_SPEC_PATH` | | Chain specification path (absolute file system path or url) to import block emission reward ranges and genesis account balances from | (empty) | master | | |
 | `COIN_GECKO_ID` | | CoinGecko coin id required for fetching an exchange rate | poa-network | master | | |
+| `EMISSION_FORMAT` | | Should be set to `POA` if you have block emission indentical to POA Network. This env var is used only if `CHAIN_SPEC_PATH` is set | `STANDARD` | master | | |
+| `REWARDS_CONTRACT_ADDRESS` | | Emission rewards contract address. This env var is used only if `EMISSION_FORMAT` is set to `POA` | `0xeca443e8e1ab29971a45a9c57a6a9875701698a5` | master | | |