Add support for HIP15

include/blockchain_vars.hrl

@@ -179,6 +179,7 @@
 -define(poc_witnesses_percent, poc_witnesses_percent).
 -define(poc_challengers_percent, poc_challengers_percent).
 -define(dc_percent, dc_percent).
+-define(witness_redundancy, witness_redundancy).
 
 %%%
 %%% bundle txn vars

src/transactions/v1/blockchain_txn_rewards_v1.erl

@@ -291,6 +291,12 @@ get_reward_vars(Start, End, Ledger) ->
  {ok, R4} -> R4;
  _ -> 1
  end,
+
+ WitnessRedundancy = case blockchain:config(?witness_redundancy, Ledger) of
+ {ok, WR} -> WR;
+ _ -> 1
+ end,
+
  EpochReward = calculate_epoch_reward(Start, End, Ledger),
  #{
  monthly_reward => MonthlyReward,
@@ -300,6 +306,7 @@ get_reward_vars(Start, End, Ledger) ->
  poc_challengees_percent => PocChallengeesPercent,
  poc_challengers_percent => PocChallengersPercent,
  poc_witnesses_percent => PocWitnessesPercent,
+ witness_redundancy => WitnessRedundancy,
  consensus_percent => ConsensusPercent,
  consensus_members => ConsensusMembers,
  dc_percent => DCPercent,
@@ -578,7 +585,7 @@ poc_challengees_rewards_(Version, [Elem|Path], StaticPath, Txn, Chain, Ledger, _
  Ledger :: blockchain_ledger_v1:ledger(),
  WitnessRewards :: map()) -> #{{gateway, libp2p_crypto:pubkey_bin()} => non_neg_integer()}.
 poc_witnesses_rewards(Transactions,
- #{poc_version := POCVersion},
+ #{poc_version := POCVersion, witness_redundancy := WitnessRedundancy},
  Chain,
  Ledger,
  WitnessRewards) ->
@@ -604,11 +611,28 @@ poc_witnesses_rewards(Transactions,
  [] ->
  Acc1;
  ValidWitnesses ->
+ ToAdd = case WitnessRedundancy of
+ 1 ->
+ %% continue with the old thing
+ 1;
+ N ->
+ L = length(ValidWitnesses),
+ case L =< N of
+ true ->
+ %% Consider ideal redundant coverage when number of valid_witnesses is less than
+ %% or equal to configured witness_redundancy
+ 1;
+ false ->
+ %% Proportional reward_unit as there are more valid_witnesses than necessary
+ blockchain_utils:normalize_float(N/L)
+ end
+ end,
+
  lists:foldl(
  fun(WitnessRecord, Map) ->
  Witness = blockchain_poc_witness_v1:gateway(WitnessRecord),
  I = maps:get(Witness, Map, 0),
- maps:put(Witness, I+1, Map)
+ maps:put(Witness, I+ToAdd, Map)
  end,
  Acc1,
  ValidWitnesses

src/transactions/v1/blockchain_txn_vars_v1.erl

@@ -914,6 +914,8 @@ validate_var(?poc_challengers_percent, Value) ->
  validate_float(Value, "poc_challengers_percent", 0.0, 1.0);
 validate_var(?dc_percent, Value) ->
  validate_float(Value, "dc_percent", 0.0, 1.0);
+validate_var(?witness_redundancy, Value) ->
+ validate_int(Value, "witness_redundancy", 2, 100, false);
 validate_var(?reward_version, Value) ->
  case Value of
  N when is_integer(N), N >= 1, N =< 5 ->