Golang common.LeftPadBytes函數代碼示例

func TestLargeData(t *testing.T) {
	trie := NewEmpty()
	vals := make(map[string]*kv)

	for i := byte(0); i < 255; i++ {
		value := &kv{common.LeftPadBytes([]byte{i}, 32), []byte{i}, false}
		value2 := &kv{common.LeftPadBytes([]byte{10, i}, 32), []byte{i}, false}
		trie.Update(value.k, value.v)
		trie.Update(value2.k, value2.v)
		vals[string(value.k)] = value
		vals[string(value2.k)] = value2
	}

	it := trie.Iterator()
	for it.Next() {
		vals[string(it.Key)].t = true
	}

	var untouched []*kv
	for _, value := range vals {
		if !value.t {
			untouched = append(untouched, value)
		}
	}

	if len(untouched) > 0 {
		t.Errorf("Missed %d nodes", len(untouched))
		for _, value := range untouched {
			t.Error(value)
		}
	}
}

// packElement packs the given reflect value according to the abi specification in
// t.
func packElement(t Type, reflectValue reflect.Value) []byte {
	switch t.T {
	case IntTy, UintTy:
		return packNum(reflectValue, t.T)
	case StringTy:
		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
	case AddressTy:
		if reflectValue.Kind() == reflect.Array {
			reflectValue = mustArrayToByteSlice(reflectValue)
		}

		return common.LeftPadBytes(reflectValue.Bytes(), 32)
	case BoolTy:
		if reflectValue.Bool() {
			return common.LeftPadBytes(common.Big1.Bytes(), 32)
		} else {
			return common.LeftPadBytes(common.Big0.Bytes(), 32)
		}
	case BytesTy:
		if reflectValue.Kind() == reflect.Array {
			reflectValue = mustArrayToByteSlice(reflectValue)
		}
		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
	case FixedBytesTy:
		if reflectValue.Kind() == reflect.Array {
			reflectValue = mustArrayToByteSlice(reflectValue)
		}

		return common.RightPadBytes(reflectValue.Bytes(), 32)
	}
	panic("abi: fatal error")
}

// makeTestTrie create a sample test trie to test node-wise reconstruction.
func makeTestTrie() (ethdb.Database, *Trie, map[string][]byte) {
	// Create an empty trie
	db, _ := ethdb.NewMemDatabase()
	trie, _ := New(common.Hash{}, db)

	// Fill it with some arbitrary data
	content := make(map[string][]byte)
	for i := byte(0); i < 255; i++ {
		// Map the same data under multiple keys
		key, val := common.LeftPadBytes([]byte{1, i}, 32), []byte{i}
		content[string(key)] = val
		trie.Update(key, val)

		key, val = common.LeftPadBytes([]byte{2, i}, 32), []byte{i}
		content[string(key)] = val
		trie.Update(key, val)

		// Add some other data to inflate th trie
		for j := byte(3); j < 13; j++ {
			key, val = common.LeftPadBytes([]byte{j, i}, 32), []byte{j, i}
			content[string(key)] = val
			trie.Update(key, val)
		}
	}
	trie.Commit()

	// Remove any potentially cached data from the test trie creation
	globalCache.Clear()

	// Return the generated trie
	return db, trie, content
}

// XXX Could set directly. Testing requires resetting and setting of pre compiled contracts.
func PrecompiledContracts() map[string]*PrecompiledAccount {
	return map[string]*PrecompiledAccount{
		// ECRECOVER
		string(common.LeftPadBytes([]byte{1}, 20)): &PrecompiledAccount{func(l int) *big.Int {
			return params.EcrecoverGas
		}, ecrecoverFunc},

		// SHA256
		string(common.LeftPadBytes([]byte{2}, 20)): &PrecompiledAccount{func(l int) *big.Int {
			n := big.NewInt(int64(l+31) / 32)
			n.Mul(n, params.Sha256WordGas)
			return n.Add(n, params.Sha256Gas)
		}, sha256Func},

		// RIPEMD160
		string(common.LeftPadBytes([]byte{3}, 20)): &PrecompiledAccount{func(l int) *big.Int {
			n := big.NewInt(int64(l+31) / 32)
			n.Mul(n, params.Ripemd160WordGas)
			return n.Add(n, params.Ripemd160Gas)
		}, ripemd160Func},

		string(common.LeftPadBytes([]byte{4}, 20)): &PrecompiledAccount{func(l int) *big.Int {
			n := big.NewInt(int64(l+31) / 32)
			n.Mul(n, params.IdentityWordGas)

			return n.Add(n, params.IdentityGas)
		}, memCpy},
	}
}

// Test the given input parameter `v` and checks if it matches certain
// criteria
// * Big integers are checks for ptr types and if the given value is
//   assignable
// * Integer are checked for size
// * Strings, addresses and bytes are checks for type and size
func (t Type) pack(v interface{}) ([]byte, error) {
	value := reflect.ValueOf(v)
	switch kind := value.Kind(); kind {
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		if t.Type != ubig_t {
			return nil, fmt.Errorf("type mismatch: %s for %T", t.Type, v)
		}
		return packNum(value, t.T), nil
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		if t.Type != ubig_t {
			return nil, fmt.Errorf("type mismatch: %s for %T", t.Type, v)
		}
		return packNum(value, t.T), nil
	case reflect.Ptr:
		// If the value is a ptr do a assign check (only used by
		// big.Int for now)
		if t.Type == ubig_t && value.Type() != ubig_t {
			return nil, fmt.Errorf("type mismatch: %s for %T", t.Type, v)
		}
		return packNum(value, t.T), nil
	case reflect.String:
		if t.Size > -1 && value.Len() > t.Size {
			return nil, fmt.Errorf("%v out of bound. %d for %d", value.Kind(), value.Len(), t.Size)
		}
		return []byte(common.LeftPadString(t.String(), 32)), nil
	case reflect.Slice:
		if t.Size > -1 && value.Len() > t.Size {
			return nil, fmt.Errorf("%v out of bound. %d for %d", value.Kind(), value.Len(), t.Size)
		}

		// Address is a special slice. The slice acts as one rather than a list of elements.
		if t.T == AddressTy {
			return common.LeftPadBytes(v.([]byte), 32), nil
		}

		// Signed / Unsigned check
		if (t.T != IntTy && isSigned(value)) || (t.T == UintTy && isSigned(value)) {
			return nil, fmt.Errorf("slice of incompatible types.")
		}

		var packed []byte
		for i := 0; i < value.Len(); i++ {
			packed = append(packed, packNum(value.Index(i), t.T)...)
		}
		return packed, nil
	case reflect.Bool:
		if value.Bool() {
			return common.LeftPadBytes(common.Big1.Bytes(), 32), nil
		} else {
			return common.LeftPadBytes(common.Big0.Bytes(), 32), nil
		}
	}

	panic("unreached")
}

// sha3 returns the canonical sha3 of the 32byte (padded) input
func sha3(in ...[]byte) []byte {
	out := make([]byte, len(in)*32)
	for i, input := range in {
		copy(out[i*32:i*32+32], common.LeftPadBytes(input, 32))
	}
	return crypto.Sha3(out)
}

func ecrecoverFunc(in []byte) []byte {
	in = common.RightPadBytes(in, 128)
	// "in" is (hash, v, r, s), each 32 bytes
	// but for ecrecover we want (r, s, v)

	r := common.BytesToBig(in[64:96])
	s := common.BytesToBig(in[96:128])
	// Treat V as a 256bit integer
	vbig := common.Bytes2Big(in[32:64])
	v := byte(vbig.Uint64())

	if !crypto.ValidateSignatureValues(v, r, s) {
		glog.V(logger.Error).Infof("EC RECOVER FAIL: v, r or s value invalid")
		return nil
	}

	// v needs to be at the end and normalized for libsecp256k1
	vbignormal := new(big.Int).Sub(vbig, big.NewInt(27))
	vnormal := byte(vbignormal.Uint64())
	rsv := append(in[64:128], vnormal)
	pubKey, err := crypto.Ecrecover(in[:32], rsv)
	// make sure the public key is a valid one
	if err != nil {
		glog.V(logger.Error).Infof("EC RECOVER FAIL: ", err)
		return nil
	}

	// the first byte of pubkey is bitcoin heritage
	return common.LeftPadBytes(crypto.Sha3(pubKey[1:])[12:], 32)
}

func ecrecoverFunc(in []byte) []byte {
	// "in" is (hash, v, r, s), each 32 bytes
	// but for ecrecover we want (r, s, v)
	if len(in) < ecRecoverInputLength {
		return nil
	}

	// Treat V as a 256bit integer
	v := new(big.Int).Sub(common.Bytes2Big(in[32:64]), big.NewInt(27))
	// Ethereum requires V to be either 0 or 1 => (27 || 28)
	if !(v.Cmp(Zero) == 0 || v.Cmp(One) == 0) {
		return nil
	}

	// v needs to be moved to the end
	rsv := append(in[64:128], byte(v.Uint64()))
	pubKey, err := crypto.Ecrecover(in[:32], rsv)
	// make sure the public key is a valid one
	if err != nil {
		glog.V(logger.Error).Infof("EC RECOVER FAIL: ", err)
		return nil
	}

	// the first byte of pubkey is bitcoin heritage
	return common.LeftPadBytes(crypto.Sha3(pubKey[1:])[12:], 32)
}

func checkLogs(tlog []Log, logs state.Logs) error {

	if len(tlog) != len(logs) {
		return fmt.Errorf("log length mismatch. Expected %d, got %d", len(tlog), len(logs))
	} else {
		for i, log := range tlog {
			if common.HexToAddress(log.AddressF) != logs[i].Address {
				return fmt.Errorf("log address expected %v got %x", log.AddressF, logs[i].Address)
			}

			if !bytes.Equal(logs[i].Data, common.FromHex(log.DataF)) {
				return fmt.Errorf("log data expected %v got %x", log.DataF, logs[i].Data)
			}

			if len(log.TopicsF) != len(logs[i].Topics) {
				return fmt.Errorf("log topics length expected %d got %d", len(log.TopicsF), logs[i].Topics)
			} else {
				for j, topic := range log.TopicsF {
					if common.HexToHash(topic) != logs[i].Topics[j] {
						return fmt.Errorf("log topic[%d] expected %v got %x", j, topic, logs[i].Topics[j])
					}
				}
			}
			genBloom := common.LeftPadBytes(types.LogsBloom(state.Logs{logs[i]}).Bytes(), 256)

			if !bytes.Equal(genBloom, common.Hex2Bytes(log.BloomF)) {
				return fmt.Errorf("bloom mismatch")
			}
		}
	}
	return nil
}

func Sign(hash []byte, prv *ecdsa.PrivateKey) (sig []byte, err error) {
	if len(hash) != 32 {
		return nil, fmt.Errorf("hash is required to be exactly 32 bytes (%d)", len(hash))
	}

	sig, err = secp256k1.Sign(hash, common.LeftPadBytes(prv.D.Bytes(), prv.Params().BitSize/8))
	return
}

func TestMarshalArrays(t *testing.T) {
	const definition = `[
	{ "name" : "bytes32", "constant" : false, "outputs": [ { "type": "bytes32" } ] },
	{ "name" : "bytes10", "constant" : false, "outputs": [ { "type": "bytes10" } ] }
	]`

	abi, err := JSON(strings.NewReader(definition))
	if err != nil {
		t.Fatal(err)
	}

	output := common.LeftPadBytes([]byte{1}, 32)

	var bytes10 [10]byte
	err = abi.Unpack(&bytes10, "bytes32", output)
	if err == nil || err.Error() != "abi: cannot unmarshal src (len=32) in to dst (len=10)" {
		t.Error("expected error or bytes32 not be assignable to bytes10:", err)
	}

	var bytes32 [32]byte
	err = abi.Unpack(&bytes32, "bytes32", output)
	if err != nil {
		t.Error("didn't expect error:", err)
	}
	if !bytes.Equal(bytes32[:], output) {
		t.Error("expected bytes32[31] to be 1 got", bytes32[31])
	}

	type (
		B10 [10]byte
		B32 [32]byte
	)

	var b10 B10
	err = abi.Unpack(&b10, "bytes32", output)
	if err == nil || err.Error() != "abi: cannot unmarshal src (len=32) in to dst (len=10)" {
		t.Error("expected error or bytes32 not be assignable to bytes10:", err)
	}

	var b32 B32
	err = abi.Unpack(&b32, "bytes32", output)
	if err != nil {
		t.Error("didn't expect error:", err)
	}
	if !bytes.Equal(b32[:], output) {
		t.Error("expected bytes32[31] to be 1 got", bytes32[31])
	}

	output[10] = 1
	var shortAssignLong [32]byte
	err = abi.Unpack(&shortAssignLong, "bytes10", output)
	if err != nil {
		t.Error("didn't expect error:", err)
	}
	if !bytes.Equal(output, shortAssignLong[:]) {
		t.Errorf("expected %x to be %x", shortAssignLong, output)
	}
}

func randomTrie(n int) (*Trie, map[string]*kv) {
	trie := new(Trie)
	vals := make(map[string]*kv)
	for i := byte(0); i < 100; i++ {
		value := &kv{common.LeftPadBytes([]byte{i}, 32), []byte{i}, false}
		value2 := &kv{common.LeftPadBytes([]byte{i + 10}, 32), []byte{i}, false}
		trie.Update(value.k, value.v)
		trie.Update(value2.k, value2.v)
		vals[string(value.k)] = value
		vals[string(value2.k)] = value2
	}
	for i := 0; i < n; i++ {
		value := &kv{randBytes(32), randBytes(20), false}
		trie.Update(value.k, value.v)
		vals[string(value.k)] = value
	}
	return trie, vals
}

func opByte(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
	th, val := stack.pop(), stack.pop()
	if th.Cmp(big.NewInt(32)) < 0 {
		byte := big.NewInt(int64(common.LeftPadBytes(val.Bytes(), 32)[th.Int64()]))
		stack.push(byte)
	} else {
		stack.push(new(big.Int))
	}
}

func StdErrFormat(logs []StructLog) {
	fmt.Fprintf(os.Stderr, "VM STAT %d OPs\n", len(logs))
	for _, log := range logs {
		fmt.Fprintf(os.Stderr, "PC %08d: %s GAS: %v COST: %v", log.Pc, log.Op, log.Gas, log.GasCost)
		if log.Err != nil {
			fmt.Fprintf(os.Stderr, " ERROR: %v", log.Err)
		}
		fmt.Fprintf(os.Stderr, "\n")

		fmt.Fprintln(os.Stderr, "STACK =", len(log.Stack))

		for i := len(log.Stack) - 1; i >= 0; i-- {
			fmt.Fprintf(os.Stderr, "%04d: %x\n", len(log.Stack)-i-1, common.LeftPadBytes(log.Stack[i].Bytes(), 32))
		}

		const maxMem = 10
		addr := 0
		fmt.Fprintln(os.Stderr, "MEM =", len(log.Memory))
		for i := 0; i+16 <= len(log.Memory) && addr < maxMem; i += 16 {
			data := log.Memory[i : i+16]
			str := fmt.Sprintf("%04d: % x  ", addr*16, data)
			for _, r := range data {
				if r == 0 {
					str += "."
				} else if unicode.IsPrint(rune(r)) {
					str += fmt.Sprintf("%s", string(r))
				} else {
					str += "?"
				}
			}
			addr++
			fmt.Fprintln(os.Stderr, str)
		}

		fmt.Fprintln(os.Stderr, "STORAGE =", len(log.Storage))
		for h, item := range log.Storage {
			fmt.Fprintf(os.Stderr, "%x: %x\n", h, common.LeftPadBytes(item, 32))
		}
		fmt.Fprintln(os.Stderr)
	}
}

// makeTestTrie create a sample test trie to test node-wise reconstruction.
func makeTestTrie() (ethdb.Database, *Trie, map[string][]byte) {
	// Create an empty trie
	db, _ := ethdb.NewMemDatabase()
	trie, _ := New(common.Hash{}, db)

	// Fill it with some arbitrary data
	content := make(map[string][]byte)
	for i := byte(0); i < 255; i++ {
		key, val := common.LeftPadBytes([]byte{1, i}, 32), []byte{i}
		content[string(key)] = val
		trie.Update(key, val)

		key, val = common.LeftPadBytes([]byte{2, i}, 32), []byte{i}
		content[string(key)] = val
		trie.Update(key, val)
	}
	trie.Commit()

	// Return the generated trie
	return db, trie, content
}