feat: distribute every 50 blocks (#527)

* distribute every 10 blocks

* total power logic in loop

* distribute on block height 2 as well

* set distribution to each block for tests

* remove special case for test

* add test displaying delayed logic

* add clarifying comments, change to 20

* remove block height 2 hack

* comment

* Update allocation_test.go

* test fixes, up to 50 blocks

tests/e2e/distribution/suite.go

@@ -19,6 +19,7 @@ import (
 	clitestutil "github.com/cosmos/cosmos-sdk/testutil/cli"
 	"github.com/cosmos/cosmos-sdk/testutil/network"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	distr "github.com/cosmos/cosmos-sdk/x/distribution"
 	"github.com/cosmos/cosmos-sdk/x/distribution/client/cli"
 	distrtypes "github.com/cosmos/cosmos-sdk/x/distribution/types"
 	minttypes "github.com/cosmos/cosmos-sdk/x/mint/types"
@@ -42,6 +43,10 @@ func NewE2ETestSuite(cfg network.Config) *E2ETestSuite {
 func (s *E2ETestSuite) SetupSuite() {
 	s.T().Log("setting up e2e test suite")
 
+	// We distribute rewards every block here since we test the delayed distribution
+	// in another test.
+	distr.BlockMultipleToDistributeRewards = 1
+
 	cfg := network.DefaultConfig(simapp.NewTestNetworkFixture)
 	cfg.NumValidators = 1
 	s.cfg = cfg

x/distribution/abci.go

@@ -7,20 +7,25 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/distribution/types"
 )
 
+var BlockMultipleToDistributeRewards = int64(50)
+
 // BeginBlocker sets the proposer for determining distribution during endblock
 // and distribute rewards for the previous block.
 func BeginBlocker(ctx sdk.Context, k keeper.Keeper) error {
 	defer telemetry.ModuleMeasureSince(types.ModuleName, telemetry.Now(), telemetry.MetricKeyBeginBlocker)
 
-	// determine the total power signing the block
-	var previousTotalPower int64
-	for _, voteInfo := range ctx.VoteInfos() {
-		previousTotalPower += voteInfo.Validator.Power
-	}
-
 	// TODO this is Tendermint-dependent
 	// ref https://github.com/cosmos/cosmos-sdk/issues/3095
-	if ctx.BlockHeight() > 1 {
+	blockHeight := ctx.BlockHeight()
+	// only allocate rewards if the block height is greater than 1
+	// and for every multiple of 50 blocks for performance reasons.
+	if blockHeight > 1 && blockHeight%BlockMultipleToDistributeRewards == 0 {
+		// determine the total power signing the block
+		var previousTotalPower int64
+		for _, voteInfo := range ctx.VoteInfos() {
+			previousTotalPower += voteInfo.Validator.Power
+		}
+
 		if err := k.AllocateTokens(ctx, previousTotalPower, ctx.VoteInfos()); err != nil {
 			return err
 		}