cosmos-sdk/x/slashing/tick.go

package slashing

import (
	"encoding/binary"
	"fmt"

	sdk "github.com/cosmos/cosmos-sdk/types"
	abci "github.com/tendermint/abci/types"
	crypto "github.com/tendermint/go-crypto"
	tmtypes "github.com/tendermint/tendermint/types"
)

// slash begin blocker functionality
func BeginBlocker(ctx sdk.Context, req abci.RequestBeginBlock, sk Keeper) (tags sdk.Tags) {

	// Tag the height
	heightBytes := make([]byte, 8)
	binary.LittleEndian.PutUint64(heightBytes, uint64(req.Header.Height))

	// TODO Add some more tags so clients can track slashing events
	tags = sdk.NewTags("height", heightBytes)

	// Deal with any equivocation evidence
	for _, evidence := range req.ByzantineValidators {
		var pk crypto.PubKey
		sk.cdc.MustUnmarshalBinaryBare(evidence.PubKey, &pk)
		switch string(evidence.Type) {
		case tmtypes.DUPLICATE_VOTE:
			sk.handleDoubleSign(ctx, evidence.Height, evidence.Time, pk)
		default:
			ctx.Logger().With("module", "x/slashing").Error(fmt.Sprintf("Ignored unknown evidence type: %s", string(evidence.Type)))
		}
	}

	// Figure out which validators were absent
	absent := make(map[crypto.PubKey]struct{})
	for _, pubkey := range req.AbsentValidators {
		var pk crypto.PubKey
		sk.cdc.MustUnmarshalBinaryBare(pubkey, &pk)
		absent[pk] = struct{}{}
	}

	// Iterate over all the validators which *should* have signed this block
	sk.validatorSet.IterateValidatorsBonded(ctx, func(_ int64, validator sdk.Validator) (stop bool) {
		pubkey := validator.GetPubKey()
		present := true
		if _, ok := absent[pubkey]; ok {
			present = false
		}
		sk.handleValidatorSignature(ctx, pubkey, present)
		return false
	})
	return
}