[blockchain] Create fresh big int, remove more dead code from static … (#2749)

* [blockchain] Create fresh big int, remove more dead code from static analysis

* [measure] Remove IzZero/IsNil checks

core/blockchain.go

@@ -138,7 +138,6 @@ type BlockChain struct {
 	pendingCrossLinksMutex      sync.RWMutex // pending crosslinks lock
 	pendingSlashingCandidatesMU sync.RWMutex // pending slashing candidates
 
-	checkpoint       int          // checkpoint counts towards the new checkpoint
 	currentBlock     atomic.Value // Current head of the block chain
 	currentFastBlock atomic.Value // Current head of the fast-sync chain (may be above the block chain!)
 
@@ -1590,26 +1589,6 @@ func (bc *BlockChain) InsertHeaderChain(chain []*block.Header, checkFreq int) (i
 	return bc.hc.InsertHeaderChain(chain, whFunc, start)
 }
 
-// writeHeader writes a header into the local chain, given that its parent is
-// already known. If the total difficulty of the newly inserted header becomes
-// greater than the current known TD, the canonical chain is re-routed.
-//
-// Note: This method is not concurrent-safe with inserting blocks simultaneously
-// into the chain, as side effects caused by reorganisations cannot be emulated
-// without the real blocks. Hence, writing headers directly should only be done
-// in two scenarios: pure-header mode of operation (light clients), or properly
-// separated header/block phases (non-archive clients).
-func (bc *BlockChain) writeHeader(header *block.Header) error {
-	bc.wg.Add(1)
-	defer bc.wg.Done()
-
-	bc.mu.Lock()
-	defer bc.mu.Unlock()
-
-	_, err := bc.hc.WriteHeader(header)
-	return err
-}
-
 // CurrentHeader retrieves the current head header of the canonical chain. The
 // header is retrieved from the HeaderChain's internal cache.
 func (bc *BlockChain) CurrentHeader() *block.Header {
@@ -2180,10 +2159,7 @@ func (bc *BlockChain) IsSpent(cxp *types.CXReceiptsProof) bool {
 	shardID := cxp.MerkleProof.ShardID
 	blockNum := cxp.MerkleProof.BlockNum.Uint64()
 	by, _ := rawdb.ReadCXReceiptsProofSpent(bc.db, shardID, blockNum)
-	if by == rawdb.SpentByte {
-		return true
-	}
-	return false
+	return by == rawdb.SpentByte
 }
 
 // ReadTxLookupEntry returns where the given transaction resides in the chain,
@@ -2349,7 +2325,7 @@ func (bc *BlockChain) UpdateValidatorVotingPower(
 		for i := range value {
 			earningWrapping[i] = staking.VoteWithCurrentEpochEarning{
 				Vote:   value[i],
-				Earned: common.Big0,
+				Earned: big.NewInt(0),
 			}
 		}
 		stats.MetricsPerShard = earningWrapping
@@ -2714,7 +2690,7 @@ func (bc *BlockChain) addDelegationIndex(
 	// If there is an existing delegation, just return
 	validatorAddressBytes := validatorAddress.Bytes()
 	for _, delegation := range delegations {
-		if bytes.Compare(delegation.ValidatorAddress.Bytes(), validatorAddressBytes) == 0 {
+		if bytes.Equal(delegation.ValidatorAddress[:], validatorAddressBytes[:]) {
 			return delegations, nil
 		}
 	}
@@ -2726,7 +2702,9 @@ func (bc *BlockChain) addDelegationIndex(
 		return delegations, err
 	}
 	for i := range wrapper.Delegations {
-		if bytes.Compare(wrapper.Delegations[i].DelegatorAddress.Bytes(), delegatorAddress.Bytes()) == 0 {
+		if bytes.Equal(
+			wrapper.Delegations[i].DelegatorAddress[:], delegatorAddress[:],
+		) {
 			// TODO(audit): change the way of indexing if we allow delegation deletion.
 			delegations = append(delegations, staking.DelegationIndex{
 				validatorAddress,
@@ -2778,7 +2756,7 @@ func (bc *BlockChain) GetECDSAFromCoinbase(header *block.Header) (common.Address
 	}
 	for _, member := range committee.Slots {
 		// After staking the coinbase address will be the address of bls public key
-		if bytes.Compare(member.EcdsaAddress[:], coinbase[:]) == 0 {
+		if bytes.Equal(member.EcdsaAddress[:], coinbase[:]) {
 			return member.EcdsaAddress, nil
 		}
 

core/chain_makers.go

@@ -37,21 +37,18 @@ import (
 // BlockGen creates blocks for testing.
 // See GenerateChain for a detailed explanation.
 type BlockGen struct {
-	i       int
-	parent  *types.Block
-	chain   []*types.Block
-	factory blockfactory.Factory
-	header  *block.Header
-	statedb *state.DB
-
+	i        int
+	parent   *types.Block
+	chain    []*types.Block
+	factory  blockfactory.Factory
+	header   *block.Header
+	statedb  *state.DB
 	gasPool  *GasPool
 	txs      []*types.Transaction
-	stkTxs   staking.StakingTransactions
 	receipts []*types.Receipt
 	uncles   []*block.Header
-
-	config *params.ChainConfig
-	engine consensus_engine.Engine
+	config   *params.ChainConfig
+	engine   consensus_engine.Engine
 }
 
 // SetCoinbase sets the coinbase of the generated block.
@@ -248,27 +245,8 @@ func makeHeader(chain consensus_engine.ChainReader, parent *types.Block, state *
 		Header()
 }
 
-// makeHeaderChain creates a deterministic chain of headers rooted at parent.
-func makeHeaderChain(parent *block.Header, n int, engine consensus_engine.Engine, db ethdb.Database, seed int) []*block.Header {
-	blocks := makeBlockChain(types.NewBlockWithHeader(parent), n, engine, db, seed)
-	headers := make([]*block.Header, len(blocks))
-	for i, block := range blocks {
-		headers[i] = block.Header()
-	}
-	return headers
-}
-
-// makeBlockChain creates a deterministic chain of blocks rooted at parent.
-func makeBlockChain(parent *types.Block, n int, engine consensus_engine.Engine, db ethdb.Database, seed int) []*types.Block {
-	blocks, _ := GenerateChain(params.TestChainConfig, parent, engine, db, n, func(i int, b *BlockGen) {
-		b.SetCoinbase(common.Address{0: byte(seed), 19: byte(i)})
-	})
-	return blocks
-}
-
 type fakeChainReader struct {
-	config  *params.ChainConfig
-	genesis *types.Block
+	config *params.ChainConfig
 }
 
 // Config returns the chain configuration.

core/tx_cacher.go

@@ -17,14 +17,9 @@
 package core
 
 import (
-	"runtime"
-
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
-// senderCacher is a concurrent transaction sender recoverer anc cacher.
-var senderCacher = newTxSenderCacher(runtime.NumCPU())
-
 // txSenderCacherRequest is a request for recovering transaction senders with a
 // specific signature scheme and caching it into the transactions themselves.
 //
@@ -66,40 +61,3 @@ func (cacher *txSenderCacher) cache() {
 		}
 	}
 }
-
-// recover recovers the senders from a batch of transactions and caches them
-// back into the same data structures. There is no validation being done, nor
-// any reaction to invalid signatures. That is up to calling code later.
-func (cacher *txSenderCacher) recover(signer types.Signer, txs []*types.Transaction) {
-	// If there's nothing to recover, abort
-	if len(txs) == 0 {
-		return
-	}
-	// Ensure we have meaningful task sizes and schedule the recoveries
-	tasks := cacher.threads
-	if len(txs) < tasks*4 {
-		tasks = (len(txs) + 3) / 4
-	}
-	for i := 0; i < tasks; i++ {
-		cacher.tasks <- &txSenderCacherRequest{
-			signer: signer,
-			txs:    txs[i:],
-			inc:    tasks,
-		}
-	}
-}
-
-// recoverFromBlocks recovers the senders from a batch of blocks and caches them
-// back into the same data structures. There is no validation being done, nor
-// any reaction to invalid signatures. That is up to calling code later.
-func (cacher *txSenderCacher) recoverFromBlocks(signer types.Signer, blocks []*types.Block) {
-	count := 0
-	for _, block := range blocks {
-		count += len(block.Transactions())
-	}
-	txs := make([]*types.Transaction, 0, count)
-	for _, block := range blocks {
-		txs = append(txs, block.Transactions()...)
-	}
-	cacher.recover(signer, txs)
-}

core/tx_pool_test.go

@@ -176,34 +176,6 @@ func validateTxPoolInternals(pool *TxPool) error {
 	return nil
 }
 
-// validateEvents checks that the correct number of transaction addition events
-// were fired on the pool's event feed.
-func validateEvents(events chan NewTxsEvent, count int) error {
-	var received []*types.Transaction
-
-	for len(received) < count {
-		select {
-		case ev := <-events:
-			received = append(received, ev.Txs...)
-		case <-time.After(time.Second):
-			return fmt.Errorf("event #%d not fired", len(received))
-		}
-	}
-	if len(received) > count {
-		return fmt.Errorf("more than %d events fired: %v", count, received[count:])
-	}
-	select {
-	case ev := <-events:
-		return fmt.Errorf("more than %d events fired: %v", count, ev.Txs)
-
-	case <-time.After(50 * time.Millisecond):
-		// This branch should be "default", but it's a data race between goroutines,
-		// reading the event channel and pushing into it, so better wait a bit ensuring
-		// really nothing gets injected.
-	}
-	return nil
-}
-
 func deriveSender(tx types.PoolTransaction) (common.Address, error) {
 	return types.PoolTransactionSender(types.HomesteadSigner{}, tx)
 }

staking/availability/measure.go

@@ -185,11 +185,6 @@ func ComputeCurrentSigning(
 	}
 
 	s1, s2 := numeric.NewDecFromBigInt(signed), numeric.NewDecFromBigInt(toSign)
-	if s2.IsZero() || s2.IsNil() {
-		utils.Logger().Debug().Interface("s2", s2).
-			Msg("s2 is 0 or nil")
-		return computed
-	}
 	computed.Percentage = s1.Quo(s2)
 	computed.IsBelowThreshold = IsBelowSigningThreshold(computed.Percentage)
 	return computed