Backport of cosmos#18959 (#538) (#540)

(cherry picked from commit c4a2b32)

Co-authored-by: Dev Ojha <[email protected]>

CHANGELOG.md

@@ -37,6 +37,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+* (slashing) [#18959](https://github.com/cosmos/cosmos-sdk/pull/18959) Slight speedup to Slashing Beginblock logic
+
 ## [v0.47.5](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.47.5) - 2023-09-01
 
 ### Features

x/slashing/abci.go

@@ -19,7 +19,8 @@ func BeginBlocker(ctx sdk.Context, req abci.RequestBeginBlock, k keeper.Keeper)
 	// Iterate over all the validators which *should* have signed this block
 	// store whether or not they have actually signed it and slash/unbond any
 	// which have missed too many blocks in a row (downtime slashing)
+	params := k.GetParams(ctx)
 	for _, voteInfo := range req.LastCommitInfo.GetVotes() {
-		k.HandleValidatorSignature(ctx, voteInfo.Validator.Address, voteInfo.Validator.Power, voteInfo.SignedLastBlock)
+		k.HandleValidatorSignatureWithParams(ctx, params, voteInfo.Validator.Address, voteInfo.Validator.Power, voteInfo.SignedLastBlock)
 	}
 }

x/slashing/keeper/infractions.go

@@ -11,6 +11,11 @@ import (
 
 // HandleValidatorSignature handles a validator signature, must be called once per validator per block.
 func (k Keeper) HandleValidatorSignature(ctx sdk.Context, addr cryptotypes.Address, power int64, signed bool) {
+	params := k.GetParams(ctx)
+	k.HandleValidatorSignatureWithParams(ctx, params, addr, power, signed)
+}
+
+func (k Keeper) HandleValidatorSignatureWithParams(ctx sdk.Context, params types.Params, addr cryptotypes.Address, power int64, signed bool) {
 	logger := k.Logger(ctx)
 	height := ctx.BlockHeight()
 
@@ -28,9 +33,14 @@ func (k Keeper) HandleValidatorSignature(ctx sdk.Context, addr cryptotypes.Addre
 		panic(fmt.Sprintf("Expected signing info for validator %s but not found", consAddr))
 	}
 
-	// this is a relative index, so it counts blocks the validator *should* have signed
-	// will use the 0-value default signing info if not present, except for start height
-	index := signInfo.IndexOffset % k.SignedBlocksWindow(ctx)
+	signedBlocksWindow := params.SignedBlocksWindow
+
+	// Compute the relative index, so we count the blocks the validator *should*
+	// have signed. We will use the 0-value default signing info if not present,
+	// except for start height. The index is in the range [0, SignedBlocksWindow)
+	// and is used to see if a validator signed a block at the given height, which
+	// is represented by a bit in the bitmap.
+	index := signInfo.IndexOffset % signedBlocksWindow
 	signInfo.IndexOffset++
 
 	// Update signed block bit array & counter
@@ -51,7 +61,7 @@ func (k Keeper) HandleValidatorSignature(ctx sdk.Context, addr cryptotypes.Addre
 		// Array value at this index has not changed, no need to update counter
 	}
 
-	minSignedPerWindow := k.MinSignedPerWindow(ctx)
+	minSignedPerWindow := params.MinSignedPerWindowInt()
 
 	if missed {
 		ctx.EventManager().EmitEvent(

x/slashing/keeper/params.go

@@ -15,11 +15,8 @@ func (k Keeper) SignedBlocksWindow(ctx sdk.Context) (res int64) {
 // MinSignedPerWindow - minimum blocks signed per window
 func (k Keeper) MinSignedPerWindow(ctx sdk.Context) int64 {
 	params := k.GetParams(ctx)
-	signedBlocksWindow := params.SignedBlocksWindow
 
-	// NOTE: RoundInt64 will never panic as minSignedPerWindow is
-	//       less than 1.
-	return params.MinSignedPerWindow.MulInt64(signedBlocksWindow).RoundInt64()
+	return params.MinSignedPerWindowInt()
 }
 
 // DowntimeJailDuration - Downtime unbond duration

x/slashing/types/params.go

@@ -148,3 +148,13 @@ func validateSlashFractionDowntime(i interface{}) error {
 
 	return nil
 }
+
+// return min signed per window as an integer (vs the decimal in the param)
+func (p *Params) MinSignedPerWindowInt() int64 {
+	signedBlocksWindow := p.SignedBlocksWindow
+	minSignedPerWindow := p.MinSignedPerWindow
+
+	// NOTE: RoundInt64 will never panic as minSignedPerWindow is
+	//       less than 1.
+	return minSignedPerWindow.MulInt64(signedBlocksWindow).RoundInt64()
+}