all: get rid of error when creating memory database (ethereum#16716)

* all: get rid of error when create mdb

* core: clean up variables definition

* all: inline mdb definition

accounts/abi/bind/backends/simulated.go

@@ -66,7 +66,7 @@ type SimulatedBackend struct {
 // NewSimulatedBackend creates a new binding backend using a simulated blockchain
 // for testing purposes.
 func NewSimulatedBackend(alloc core.GenesisAlloc) *SimulatedBackend {
-	database, _ := ethdb.NewMemDatabase()
+	database := ethdb.NewMemDatabase()
 	genesis := core.Genesis{Config: params.AllEthashProtocolChanges, Alloc: alloc}
 	genesis.MustCommit(database)
 	blockchain, _ := core.NewBlockChain(database, nil, genesis.Config, ethash.NewFaker(), vm.Config{})

cmd/evm/runner.go

@@ -98,14 +98,13 @@ func runCmd(ctx *cli.Context) error {
 	}
 	if ctx.GlobalString(GenesisFlag.Name) != "" {
 		gen := readGenesis(ctx.GlobalString(GenesisFlag.Name))
-		db, _ := ethdb.NewMemDatabase()
+		db := ethdb.NewMemDatabase()
 		genesis := gen.ToBlock(db)
 		statedb, _ = state.New(genesis.Root(), state.NewDatabase(db))
 		chainConfig = gen.Config
 		blockNumber = gen.Number
 	} else {
-		db, _ := ethdb.NewMemDatabase()
-		statedb, _ = state.New(common.Hash{}, state.NewDatabase(db))
+		statedb, _ = state.New(common.Hash{}, state.NewDatabase(ethdb.NewMemDatabase()))
 	}
 	if ctx.GlobalString(SenderFlag.Name) != "" {
 		sender = common.HexToAddress(ctx.GlobalString(SenderFlag.Name))

consensus/clique/snapshot_test.go

@@ -352,7 +352,7 @@ func TestVoting(t *testing.T) {
 			copy(genesis.ExtraData[extraVanity+j*common.AddressLength:], signer[:])
 		}
 		// Create a pristine blockchain with the genesis injected
-		db, _ := ethdb.NewMemDatabase()
+		db := ethdb.NewMemDatabase()
 		genesis.Commit(db)
 
 		// Assemble a chain of headers from the cast votes

core/bench_test.go

@@ -149,7 +149,7 @@ func benchInsertChain(b *testing.B, disk bool, gen func(int, *BlockGen)) {
 	// Create the database in memory or in a temporary directory.
 	var db ethdb.Database
 	if !disk {
-		db, _ = ethdb.NewMemDatabase()
+		db = ethdb.NewMemDatabase()
 	} else {
 		dir, err := ioutil.TempDir("", "eth-core-bench")
 		if err != nil {

core/block_validator_test.go

@@ -32,7 +32,7 @@ import (
 func TestHeaderVerification(t *testing.T) {
 	// Create a simple chain to verify
 	var (
-		testdb, _ = ethdb.NewMemDatabase()
+		testdb    = ethdb.NewMemDatabase()
 		gspec     = &Genesis{Config: params.TestChainConfig}
 		genesis   = gspec.MustCommit(testdb)
 		blocks, _ = GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), testdb, 8, nil)
@@ -84,7 +84,7 @@ func TestHeaderConcurrentVerification32(t *testing.T) { testHeaderConcurrentVeri
 func testHeaderConcurrentVerification(t *testing.T, threads int) {
 	// Create a simple chain to verify
 	var (
-		testdb, _ = ethdb.NewMemDatabase()
+		testdb    = ethdb.NewMemDatabase()
 		gspec     = &Genesis{Config: params.TestChainConfig}
 		genesis   = gspec.MustCommit(testdb)
 		blocks, _ = GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), testdb, 8, nil)
@@ -156,7 +156,7 @@ func TestHeaderConcurrentAbortion32(t *testing.T) { testHeaderConcurrentAbortion
 func testHeaderConcurrentAbortion(t *testing.T, threads int) {
 	// Create a simple chain to verify
 	var (
-		testdb, _ = ethdb.NewMemDatabase()
+		testdb    = ethdb.NewMemDatabase()
 		gspec     = &Genesis{Config: params.TestChainConfig}
 		genesis   = gspec.MustCommit(testdb)
 		blocks, _ = GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), testdb, 1024, nil)

core/blockchain_test.go

@@ -569,11 +569,11 @@ func testInsertNonceError(t *testing.T, full bool) {
 func TestFastVsFullChains(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		gendb, _ = ethdb.NewMemDatabase()
-		key, _   = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
-		address  = crypto.PubkeyToAddress(key.PublicKey)
-		funds    = big.NewInt(1000000000)
-		gspec    = &Genesis{
+		gendb   = ethdb.NewMemDatabase()
+		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+		address = crypto.PubkeyToAddress(key.PublicKey)
+		funds   = big.NewInt(1000000000)
+		gspec   = &Genesis{
 			Config: params.TestChainConfig,
 			Alloc:  GenesisAlloc{address: {Balance: funds}},
 		}
@@ -599,7 +599,7 @@ func TestFastVsFullChains(t *testing.T) {
 		}
 	})
 	// Import the chain as an archive node for the comparison baseline
-	archiveDb, _ := ethdb.NewMemDatabase()
+	archiveDb := ethdb.NewMemDatabase()
 	gspec.MustCommit(archiveDb)
 	archive, _ := NewBlockChain(archiveDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{})
 	defer archive.Stop()
@@ -608,7 +608,7 @@ func TestFastVsFullChains(t *testing.T) {
 		t.Fatalf("failed to process block %d: %v", n, err)
 	}
 	// Fast import the chain as a non-archive node to test
-	fastDb, _ := ethdb.NewMemDatabase()
+	fastDb := ethdb.NewMemDatabase()
 	gspec.MustCommit(fastDb)
 	fast, _ := NewBlockChain(fastDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{})
 	defer fast.Stop()
@@ -657,12 +657,12 @@ func TestFastVsFullChains(t *testing.T) {
 func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		gendb, _ = ethdb.NewMemDatabase()
-		key, _   = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
-		address  = crypto.PubkeyToAddress(key.PublicKey)
-		funds    = big.NewInt(1000000000)
-		gspec    = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{address: {Balance: funds}}}
-		genesis  = gspec.MustCommit(gendb)
+		gendb   = ethdb.NewMemDatabase()
+		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+		address = crypto.PubkeyToAddress(key.PublicKey)
+		funds   = big.NewInt(1000000000)
+		gspec   = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{address: {Balance: funds}}}
+		genesis = gspec.MustCommit(gendb)
 	)
 	height := uint64(1024)
 	blocks, receipts := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), gendb, int(height), nil)
@@ -685,7 +685,7 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 		}
 	}
 	// Import the chain as an archive node and ensure all pointers are updated
-	archiveDb, _ := ethdb.NewMemDatabase()
+	archiveDb := ethdb.NewMemDatabase()
 	gspec.MustCommit(archiveDb)
 
 	archive, _ := NewBlockChain(archiveDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{})
@@ -699,7 +699,7 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	assert(t, "archive", archive, height/2, height/2, height/2)
 
 	// Import the chain as a non-archive node and ensure all pointers are updated
-	fastDb, _ := ethdb.NewMemDatabase()
+	fastDb := ethdb.NewMemDatabase()
 	gspec.MustCommit(fastDb)
 	fast, _ := NewBlockChain(fastDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{})
 	defer fast.Stop()
@@ -719,7 +719,7 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	assert(t, "fast", fast, height/2, height/2, 0)
 
 	// Import the chain as a light node and ensure all pointers are updated
-	lightDb, _ := ethdb.NewMemDatabase()
+	lightDb := ethdb.NewMemDatabase()
 	gspec.MustCommit(lightDb)
 
 	light, _ := NewBlockChain(lightDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{})
@@ -742,7 +742,7 @@ func TestChainTxReorgs(t *testing.T) {
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
 		addr2   = crypto.PubkeyToAddress(key2.PublicKey)
 		addr3   = crypto.PubkeyToAddress(key3.PublicKey)
-		db, _   = ethdb.NewMemDatabase()
+		db      = ethdb.NewMemDatabase()
 		gspec   = &Genesis{
 			Config:   params.TestChainConfig,
 			GasLimit: 3141592,
@@ -854,7 +854,7 @@ func TestLogReorgs(t *testing.T) {
 	var (
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
-		db, _   = ethdb.NewMemDatabase()
+		db      = ethdb.NewMemDatabase()
 		// this code generates a log
 		code    = common.Hex2Bytes("60606040525b7f24ec1d3ff24c2f6ff210738839dbc339cd45a5294d85c79361016243157aae7b60405180905060405180910390a15b600a8060416000396000f360606040526008565b00")
 		gspec   = &Genesis{Config: params.TestChainConfig, Alloc: GenesisAlloc{addr1: {Balance: big.NewInt(10000000000000)}}}
@@ -898,7 +898,7 @@ func TestLogReorgs(t *testing.T) {
 
 func TestReorgSideEvent(t *testing.T) {
 	var (
-		db, _   = ethdb.NewMemDatabase()
+		db      = ethdb.NewMemDatabase()
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
 		gspec   = &Genesis{
@@ -1026,7 +1026,7 @@ func TestCanonicalBlockRetrieval(t *testing.T) {
 func TestEIP155Transition(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		db, _      = ethdb.NewMemDatabase()
+		db         = ethdb.NewMemDatabase()
 		key, _     = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address    = crypto.PubkeyToAddress(key.PublicKey)
 		funds      = big.NewInt(1000000000)
@@ -1130,7 +1130,7 @@ func TestEIP155Transition(t *testing.T) {
 func TestEIP161AccountRemoval(t *testing.T) {
 	// Configure and generate a sample block chain
 	var (
-		db, _   = ethdb.NewMemDatabase()
+		db      = ethdb.NewMemDatabase()
 		key, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		address = crypto.PubkeyToAddress(key.PublicKey)
 		funds   = big.NewInt(1000000000)
@@ -1202,7 +1202,7 @@ func TestBlockchainHeaderchainReorgConsistency(t *testing.T) {
 	// Generate a canonical chain to act as the main dataset
 	engine := ethash.NewFaker()
 
-	db, _ := ethdb.NewMemDatabase()
+	db := ethdb.NewMemDatabase()
 	genesis := new(Genesis).MustCommit(db)
 	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 64, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 
@@ -1218,7 +1218,7 @@ func TestBlockchainHeaderchainReorgConsistency(t *testing.T) {
 	}
 	// Import the canonical and fork chain side by side, verifying the current block
 	// and current header consistency
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	new(Genesis).MustCommit(diskdb)
 
 	chain, err := NewBlockChain(diskdb, nil, params.TestChainConfig, engine, vm.Config{})
@@ -1247,7 +1247,7 @@ func TestTrieForkGC(t *testing.T) {
 	// Generate a canonical chain to act as the main dataset
 	engine := ethash.NewFaker()
 
-	db, _ := ethdb.NewMemDatabase()
+	db := ethdb.NewMemDatabase()
 	genesis := new(Genesis).MustCommit(db)
 	blocks, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 2*triesInMemory, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 
@@ -1262,7 +1262,7 @@ func TestTrieForkGC(t *testing.T) {
 		forks[i] = fork[0]
 	}
 	// Import the canonical and fork chain side by side, forcing the trie cache to cache both
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	new(Genesis).MustCommit(diskdb)
 
 	chain, err := NewBlockChain(diskdb, nil, params.TestChainConfig, engine, vm.Config{})
@@ -1293,15 +1293,15 @@ func TestLargeReorgTrieGC(t *testing.T) {
 	// Generate the original common chain segment and the two competing forks
 	engine := ethash.NewFaker()
 
-	db, _ := ethdb.NewMemDatabase()
+	db := ethdb.NewMemDatabase()
 	genesis := new(Genesis).MustCommit(db)
 
 	shared, _ := GenerateChain(params.TestChainConfig, genesis, engine, db, 64, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{1}) })
 	original, _ := GenerateChain(params.TestChainConfig, shared[len(shared)-1], engine, db, 2*triesInMemory, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{2}) })
 	competitor, _ := GenerateChain(params.TestChainConfig, shared[len(shared)-1], engine, db, 2*triesInMemory+1, func(i int, b *BlockGen) { b.SetCoinbase(common.Address{3}) })
 
 	// Import the shared chain and the original canonical one
-	diskdb, _ := ethdb.NewMemDatabase()
+	diskdb := ethdb.NewMemDatabase()
 	new(Genesis).MustCommit(diskdb)
 
 	chain, err := NewBlockChain(diskdb, nil, params.TestChainConfig, engine, vm.Config{})
@@ -1361,7 +1361,7 @@ func benchmarkLargeNumberOfValueToNonexisting(b *testing.B, numTxs, numBlocks in
 	)
 	// Generate the original common chain segment and the two competing forks
 	engine := ethash.NewFaker()
-	db, _ := ethdb.NewMemDatabase()
+	db := ethdb.NewMemDatabase()
 	genesis := gspec.MustCommit(db)
 
 	blockGenerator := func(i int, block *BlockGen) {
@@ -1383,7 +1383,7 @@ func benchmarkLargeNumberOfValueToNonexisting(b *testing.B, numTxs, numBlocks in
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		// Import the shared chain and the original canonical one
-		diskdb, _ := ethdb.NewMemDatabase()
+		diskdb := ethdb.NewMemDatabase()
 		gspec.MustCommit(diskdb)
 
 		chain, err := NewBlockChain(diskdb, nil, params.TestChainConfig, engine, vm.Config{})

core/chain_indexer_test.go

@@ -48,7 +48,7 @@ func TestChainIndexerWithChildren(t *testing.T) {
 // multiple backends. The section size and required confirmation count parameters
 // are randomized.
 func testChainIndexer(t *testing.T, count int) {
-	db, _ := ethdb.NewMemDatabase()
+	db := ethdb.NewMemDatabase()
 	defer db.Close()
 
 	// Create a chain of indexers and ensure they all report empty

core/chain_makers.go

@@ -256,11 +256,12 @@ func makeHeader(chain consensus.ChainReader, parent *types.Block, state *state.S
 // chain. Depending on the full flag, if creates either a full block chain or a
 // header only chain.
 func newCanonical(engine consensus.Engine, n int, full bool) (ethdb.Database, *BlockChain, error) {
-	// Initialize a fresh chain with only a genesis block
-	gspec := new(Genesis)
-	db, _ := ethdb.NewMemDatabase()
-	genesis := gspec.MustCommit(db)
+	var (
+		db      = ethdb.NewMemDatabase()
+		genesis = new(Genesis).MustCommit(db)
+	)
 
+	// Initialize a fresh chain with only a genesis block
 	blockchain, _ := NewBlockChain(db, nil, params.AllEthashProtocolChanges, engine, vm.Config{})
 	// Create and inject the requested chain
 	if n == 0 {

core/chain_makers_test.go

@@ -36,7 +36,7 @@ func ExampleGenerateChain() {
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
 		addr2   = crypto.PubkeyToAddress(key2.PublicKey)
 		addr3   = crypto.PubkeyToAddress(key3.PublicKey)
-		db, _   = ethdb.NewMemDatabase()
+		db      = ethdb.NewMemDatabase()
 	)
 
 	// Ensure that key1 has some funds in the genesis block.

core/dao_test.go

@@ -32,13 +32,13 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	forkBlock := big.NewInt(32)
 
 	// Generate a common prefix for both pro-forkers and non-forkers
-	db, _ := ethdb.NewMemDatabase()
+	db := ethdb.NewMemDatabase()
 	gspec := new(Genesis)
 	genesis := gspec.MustCommit(db)
 	prefix, _ := GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, int(forkBlock.Int64()-1), func(i int, gen *BlockGen) {})
 
 	// Create the concurrent, conflicting two nodes
-	proDb, _ := ethdb.NewMemDatabase()
+	proDb := ethdb.NewMemDatabase()
 	gspec.MustCommit(proDb)
 
 	proConf := *params.TestChainConfig
@@ -48,7 +48,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	proBc, _ := NewBlockChain(proDb, nil, &proConf, ethash.NewFaker(), vm.Config{})
 	defer proBc.Stop()
 
-	conDb, _ := ethdb.NewMemDatabase()
+	conDb := ethdb.NewMemDatabase()
 	gspec.MustCommit(conDb)
 
 	conConf := *params.TestChainConfig
@@ -67,7 +67,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	// Try to expand both pro-fork and non-fork chains iteratively with other camp's blocks
 	for i := int64(0); i < params.DAOForkExtraRange.Int64(); i++ {
 		// Create a pro-fork block, and try to feed into the no-fork chain
-		db, _ = ethdb.NewMemDatabase()
+		db = ethdb.NewMemDatabase()
 		gspec.MustCommit(db)
 		bc, _ := NewBlockChain(db, nil, &conConf, ethash.NewFaker(), vm.Config{})
 		defer bc.Stop()
@@ -92,7 +92,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 			t.Fatalf("contra-fork chain didn't accepted no-fork block: %v", err)
 		}
 		// Create a no-fork block, and try to feed into the pro-fork chain
-		db, _ = ethdb.NewMemDatabase()
+		db = ethdb.NewMemDatabase()
 		gspec.MustCommit(db)
 		bc, _ = NewBlockChain(db, nil, &proConf, ethash.NewFaker(), vm.Config{})
 		defer bc.Stop()
@@ -118,7 +118,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		}
 	}
 	// Verify that contra-forkers accept pro-fork extra-datas after forking finishes
-	db, _ = ethdb.NewMemDatabase()
+	db = ethdb.NewMemDatabase()
 	gspec.MustCommit(db)
 	bc, _ := NewBlockChain(db, nil, &conConf, ethash.NewFaker(), vm.Config{})
 	defer bc.Stop()
@@ -138,7 +138,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		t.Fatalf("contra-fork chain didn't accept pro-fork block post-fork: %v", err)
 	}
 	// Verify that pro-forkers accept contra-fork extra-datas after forking finishes
-	db, _ = ethdb.NewMemDatabase()
+	db = ethdb.NewMemDatabase()
 	gspec.MustCommit(db)
 	bc, _ = NewBlockChain(db, nil, &proConf, ethash.NewFaker(), vm.Config{})
 	defer bc.Stop()

core/genesis.go

@@ -222,7 +222,7 @@ func (g *Genesis) configOrDefault(ghash common.Hash) *params.ChainConfig {
 // to the given database (or discards it if nil).
 func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 	if db == nil {
-		db, _ = ethdb.NewMemDatabase()
+		db = ethdb.NewMemDatabase()
 	}
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 	for addr, account := range g.Alloc {

core/genesis_test.go

@@ -141,7 +141,7 @@ func TestSetupGenesis(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		db, _ := ethdb.NewMemDatabase()
+		db := ethdb.NewMemDatabase()
 		config, hash, err := test.fn(db)
 		// Check the return values.
 		if !reflect.DeepEqual(err, test.wantErr) {