go-ethereum/rlp/encode_test.go
Felix Lange 9b93564e21
rlp/rlpgen: RLP encoder code generator (#24251)
This change adds a code generator tool for creating EncodeRLP method
implementations. The generated methods will behave identically to the
reflect-based encoder, but run faster because there is no reflection overhead.

Package rlp now provides the EncoderBuffer type for incremental encoding. This
is used by generated code, but the new methods can also be useful for
hand-written encoders.

There is also experimental support for generating DecodeRLP, and some new
methods have been added to the existing Stream type to support this. Creating
decoders with rlpgen is not recommended at this time because the generated
methods create very poor error reporting.

More detail about package rlp changes:

* rlp: externalize struct field processing / validation

This adds a new package, rlp/internal/rlpstruct, in preparation for the
RLP encoder generator.

I think the struct field rules are subtle enough to warrant extracting
this into their own package, even though it means that a bunch of
adapter code is needed for converting to/from rlpstruct.Type.

* rlp: add more decoder methods (for rlpgen)

This adds new methods on rlp.Stream:

- Uint64, Uint32, Uint16, Uint8, BigInt
- ReadBytes for decoding into []byte
- MoreDataInList - useful for optional list elements

* rlp: expose encoder buffer (for rlpgen)

This exposes the internal encoder buffer type for use in EncodeRLP
implementations.

The new EncoderBuffer type is a sort-of 'opaque handle' for a pointer to
encBuffer. It is implemented this way to ensure the global encBuffer pool
is handled correctly.
2022-02-16 18:14:12 +01:00

572 lines
19 KiB
Go

// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package rlp
import (
"bytes"
"errors"
"fmt"
"io"
"io/ioutil"
"math/big"
"runtime"
"sync"
"testing"
"github.com/ethereum/go-ethereum/common/math"
)
type testEncoder struct {
err error
}
func (e *testEncoder) EncodeRLP(w io.Writer) error {
if e == nil {
panic("EncodeRLP called on nil value")
}
if e.err != nil {
return e.err
}
w.Write([]byte{0, 1, 0, 1, 0, 1, 0, 1, 0, 1})
return nil
}
type testEncoderValueMethod struct{}
func (e testEncoderValueMethod) EncodeRLP(w io.Writer) error {
w.Write([]byte{0xFA, 0xFE, 0xF0})
return nil
}
type byteEncoder byte
func (e byteEncoder) EncodeRLP(w io.Writer) error {
w.Write(EmptyList)
return nil
}
type undecodableEncoder func()
func (f undecodableEncoder) EncodeRLP(w io.Writer) error {
w.Write([]byte{0xF5, 0xF5, 0xF5})
return nil
}
type encodableReader struct {
A, B uint
}
func (e *encodableReader) Read(b []byte) (int, error) {
panic("called")
}
type namedByteType byte
var (
_ = Encoder(&testEncoder{})
_ = Encoder(byteEncoder(0))
reader io.Reader = &encodableReader{1, 2}
)
type encTest struct {
val interface{}
output, error string
}
var encTests = []encTest{
// booleans
{val: true, output: "01"},
{val: false, output: "80"},
// integers
{val: uint32(0), output: "80"},
{val: uint32(127), output: "7F"},
{val: uint32(128), output: "8180"},
{val: uint32(256), output: "820100"},
{val: uint32(1024), output: "820400"},
{val: uint32(0xFFFFFF), output: "83FFFFFF"},
{val: uint32(0xFFFFFFFF), output: "84FFFFFFFF"},
{val: uint64(0xFFFFFFFF), output: "84FFFFFFFF"},
{val: uint64(0xFFFFFFFFFF), output: "85FFFFFFFFFF"},
{val: uint64(0xFFFFFFFFFFFF), output: "86FFFFFFFFFFFF"},
{val: uint64(0xFFFFFFFFFFFFFF), output: "87FFFFFFFFFFFFFF"},
{val: uint64(0xFFFFFFFFFFFFFFFF), output: "88FFFFFFFFFFFFFFFF"},
// big integers (should match uint for small values)
{val: big.NewInt(0), output: "80"},
{val: big.NewInt(1), output: "01"},
{val: big.NewInt(127), output: "7F"},
{val: big.NewInt(128), output: "8180"},
{val: big.NewInt(256), output: "820100"},
{val: big.NewInt(1024), output: "820400"},
{val: big.NewInt(0xFFFFFF), output: "83FFFFFF"},
{val: big.NewInt(0xFFFFFFFF), output: "84FFFFFFFF"},
{val: big.NewInt(0xFFFFFFFFFF), output: "85FFFFFFFFFF"},
{val: big.NewInt(0xFFFFFFFFFFFF), output: "86FFFFFFFFFFFF"},
{val: big.NewInt(0xFFFFFFFFFFFFFF), output: "87FFFFFFFFFFFFFF"},
{
val: big.NewInt(0).SetBytes(unhex("102030405060708090A0B0C0D0E0F2")),
output: "8F102030405060708090A0B0C0D0E0F2",
},
{
val: big.NewInt(0).SetBytes(unhex("0100020003000400050006000700080009000A000B000C000D000E01")),
output: "9C0100020003000400050006000700080009000A000B000C000D000E01",
},
{
val: big.NewInt(0).SetBytes(unhex("010000000000000000000000000000000000000000000000000000000000000000")),
output: "A1010000000000000000000000000000000000000000000000000000000000000000",
},
{
val: veryBigInt,
output: "89FFFFFFFFFFFFFFFFFF",
},
{
val: veryVeryBigInt,
output: "B848FFFFFFFFFFFFFFFFF800000000000000001BFFFFFFFFFFFFFFFFC8000000000000000045FFFFFFFFFFFFFFFFC800000000000000001BFFFFFFFFFFFFFFFFF8000000000000000001",
},
// non-pointer big.Int
{val: *big.NewInt(0), output: "80"},
{val: *big.NewInt(0xFFFFFF), output: "83FFFFFF"},
// negative ints are not supported
{val: big.NewInt(-1), error: "rlp: cannot encode negative big.Int"},
{val: *big.NewInt(-1), error: "rlp: cannot encode negative big.Int"},
// byte arrays
{val: [0]byte{}, output: "80"},
{val: [1]byte{0}, output: "00"},
{val: [1]byte{1}, output: "01"},
{val: [1]byte{0x7F}, output: "7F"},
{val: [1]byte{0x80}, output: "8180"},
{val: [1]byte{0xFF}, output: "81FF"},
{val: [3]byte{1, 2, 3}, output: "83010203"},
{val: [57]byte{1, 2, 3}, output: "B839010203000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"},
// named byte type arrays
{val: [0]namedByteType{}, output: "80"},
{val: [1]namedByteType{0}, output: "00"},
{val: [1]namedByteType{1}, output: "01"},
{val: [1]namedByteType{0x7F}, output: "7F"},
{val: [1]namedByteType{0x80}, output: "8180"},
{val: [1]namedByteType{0xFF}, output: "81FF"},
{val: [3]namedByteType{1, 2, 3}, output: "83010203"},
{val: [57]namedByteType{1, 2, 3}, output: "B839010203000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"},
// byte slices
{val: []byte{}, output: "80"},
{val: []byte{0}, output: "00"},
{val: []byte{0x7E}, output: "7E"},
{val: []byte{0x7F}, output: "7F"},
{val: []byte{0x80}, output: "8180"},
{val: []byte{1, 2, 3}, output: "83010203"},
// named byte type slices
{val: []namedByteType{}, output: "80"},
{val: []namedByteType{0}, output: "00"},
{val: []namedByteType{0x7E}, output: "7E"},
{val: []namedByteType{0x7F}, output: "7F"},
{val: []namedByteType{0x80}, output: "8180"},
{val: []namedByteType{1, 2, 3}, output: "83010203"},
// strings
{val: "", output: "80"},
{val: "\x7E", output: "7E"},
{val: "\x7F", output: "7F"},
{val: "\x80", output: "8180"},
{val: "dog", output: "83646F67"},
{
val: "Lorem ipsum dolor sit amet, consectetur adipisicing eli",
output: "B74C6F72656D20697073756D20646F6C6F722073697420616D65742C20636F6E7365637465747572206164697069736963696E6720656C69",
},
{
val: "Lorem ipsum dolor sit amet, consectetur adipisicing elit",
output: "B8384C6F72656D20697073756D20646F6C6F722073697420616D65742C20636F6E7365637465747572206164697069736963696E6720656C6974",
},
{
val: "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur mauris magna, suscipit sed vehicula non, iaculis faucibus tortor. Proin suscipit ultricies malesuada. Duis tortor elit, dictum quis tristique eu, ultrices at risus. Morbi a est imperdiet mi ullamcorper aliquet suscipit nec lorem. Aenean quis leo mollis, vulputate elit varius, consequat enim. Nulla ultrices turpis justo, et posuere urna consectetur nec. Proin non convallis metus. Donec tempor ipsum in mauris congue sollicitudin. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Suspendisse convallis sem vel massa faucibus, eget lacinia lacus tempor. Nulla quis ultricies purus. Proin auctor rhoncus nibh condimentum mollis. Aliquam consequat enim at metus luctus, a eleifend purus egestas. Curabitur at nibh metus. Nam bibendum, neque at auctor tristique, lorem libero aliquet arcu, non interdum tellus lectus sit amet eros. Cras rhoncus, metus ac ornare cursus, dolor justo ultrices metus, at ullamcorper volutpat",
output: "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",
},
// slices
{val: []uint{}, output: "C0"},
{val: []uint{1, 2, 3}, output: "C3010203"},
{
// [ [], [[]], [ [], [[]] ] ]
val: []interface{}{[]interface{}{}, [][]interface{}{{}}, []interface{}{[]interface{}{}, [][]interface{}{{}}}},
output: "C7C0C1C0C3C0C1C0",
},
{
val: []string{"aaa", "bbb", "ccc", "ddd", "eee", "fff", "ggg", "hhh", "iii", "jjj", "kkk", "lll", "mmm", "nnn", "ooo"},
output: "F83C836161618362626283636363836464648365656583666666836767678368686883696969836A6A6A836B6B6B836C6C6C836D6D6D836E6E6E836F6F6F",
},
{
val: []interface{}{uint(1), uint(0xFFFFFF), []interface{}{[]uint{4, 5, 5}}, "abc"},
output: "CE0183FFFFFFC4C304050583616263",
},
{
val: [][]string{
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
{"asdf", "qwer", "zxcv"},
},
output: "F90200CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376CF84617364668471776572847A786376",
},
// RawValue
{val: RawValue(unhex("01")), output: "01"},
{val: RawValue(unhex("82FFFF")), output: "82FFFF"},
{val: []RawValue{unhex("01"), unhex("02")}, output: "C20102"},
// structs
{val: simplestruct{}, output: "C28080"},
{val: simplestruct{A: 3, B: "foo"}, output: "C50383666F6F"},
{val: &recstruct{5, nil}, output: "C205C0"},
{val: &recstruct{5, &recstruct{4, &recstruct{3, nil}}}, output: "C605C404C203C0"},
{val: &intField{X: 3}, error: "rlp: type int is not RLP-serializable (struct field rlp.intField.X)"},
// struct tag "-"
{val: &ignoredField{A: 1, B: 2, C: 3}, output: "C20103"},
// struct tag "tail"
{val: &tailRaw{A: 1, Tail: []RawValue{unhex("02"), unhex("03")}}, output: "C3010203"},
{val: &tailRaw{A: 1, Tail: []RawValue{unhex("02")}}, output: "C20102"},
{val: &tailRaw{A: 1, Tail: []RawValue{}}, output: "C101"},
{val: &tailRaw{A: 1, Tail: nil}, output: "C101"},
// struct tag "optional"
{val: &optionalFields{}, output: "C180"},
{val: &optionalFields{A: 1}, output: "C101"},
{val: &optionalFields{A: 1, B: 2}, output: "C20102"},
{val: &optionalFields{A: 1, B: 2, C: 3}, output: "C3010203"},
{val: &optionalFields{A: 1, B: 0, C: 3}, output: "C3018003"},
{val: &optionalAndTailField{A: 1}, output: "C101"},
{val: &optionalAndTailField{A: 1, B: 2}, output: "C20102"},
{val: &optionalAndTailField{A: 1, Tail: []uint{5, 6}}, output: "C401800506"},
{val: &optionalAndTailField{A: 1, Tail: []uint{5, 6}}, output: "C401800506"},
{val: &optionalBigIntField{A: 1}, output: "C101"},
{val: &optionalPtrField{A: 1}, output: "C101"},
{val: &optionalPtrFieldNil{A: 1}, output: "C101"},
// nil
{val: (*uint)(nil), output: "80"},
{val: (*string)(nil), output: "80"},
{val: (*[]byte)(nil), output: "80"},
{val: (*[10]byte)(nil), output: "80"},
{val: (*big.Int)(nil), output: "80"},
{val: (*[]string)(nil), output: "C0"},
{val: (*[10]string)(nil), output: "C0"},
{val: (*[]interface{})(nil), output: "C0"},
{val: (*[]struct{ uint })(nil), output: "C0"},
{val: (*interface{})(nil), output: "C0"},
// nil struct fields
{
val: struct {
X *[]byte
}{},
output: "C180",
},
{
val: struct {
X *[2]byte
}{},
output: "C180",
},
{
val: struct {
X *uint64
}{},
output: "C180",
},
{
val: struct {
X *uint64 `rlp:"nilList"`
}{},
output: "C1C0",
},
{
val: struct {
X *[]uint64
}{},
output: "C1C0",
},
{
val: struct {
X *[]uint64 `rlp:"nilString"`
}{},
output: "C180",
},
// interfaces
{val: []io.Reader{reader}, output: "C3C20102"}, // the contained value is a struct
// Encoder
{val: (*testEncoder)(nil), output: "C0"},
{val: &testEncoder{}, output: "00010001000100010001"},
{val: &testEncoder{errors.New("test error")}, error: "test error"},
{val: struct{ E testEncoderValueMethod }{}, output: "C3FAFEF0"},
{val: struct{ E *testEncoderValueMethod }{}, output: "C1C0"},
// Verify that the Encoder interface works for unsupported types like func().
{val: undecodableEncoder(func() {}), output: "F5F5F5"},
// Verify that pointer method testEncoder.EncodeRLP is called for
// addressable non-pointer values.
{val: &struct{ TE testEncoder }{testEncoder{}}, output: "CA00010001000100010001"},
{val: &struct{ TE testEncoder }{testEncoder{errors.New("test error")}}, error: "test error"},
// Verify the error for non-addressable non-pointer Encoder.
{val: testEncoder{}, error: "rlp: unadressable value of type rlp.testEncoder, EncodeRLP is pointer method"},
// Verify Encoder takes precedence over []byte.
{val: []byteEncoder{0, 1, 2, 3, 4}, output: "C5C0C0C0C0C0"},
}
func runEncTests(t *testing.T, f func(val interface{}) ([]byte, error)) {
for i, test := range encTests {
output, err := f(test.val)
if err != nil && test.error == "" {
t.Errorf("test %d: unexpected error: %v\nvalue %#v\ntype %T",
i, err, test.val, test.val)
continue
}
if test.error != "" && fmt.Sprint(err) != test.error {
t.Errorf("test %d: error mismatch\ngot %v\nwant %v\nvalue %#v\ntype %T",
i, err, test.error, test.val, test.val)
continue
}
if err == nil && !bytes.Equal(output, unhex(test.output)) {
t.Errorf("test %d: output mismatch:\ngot %X\nwant %s\nvalue %#v\ntype %T",
i, output, test.output, test.val, test.val)
}
}
}
func TestEncode(t *testing.T) {
runEncTests(t, func(val interface{}) ([]byte, error) {
b := new(bytes.Buffer)
err := Encode(b, val)
return b.Bytes(), err
})
}
func TestEncodeToBytes(t *testing.T) {
runEncTests(t, EncodeToBytes)
}
func TestEncodeToReader(t *testing.T) {
runEncTests(t, func(val interface{}) ([]byte, error) {
_, r, err := EncodeToReader(val)
if err != nil {
return nil, err
}
return ioutil.ReadAll(r)
})
}
func TestEncodeToReaderPiecewise(t *testing.T) {
runEncTests(t, func(val interface{}) ([]byte, error) {
size, r, err := EncodeToReader(val)
if err != nil {
return nil, err
}
// read output piecewise
output := make([]byte, size)
for start, end := 0, 0; start < size; start = end {
if remaining := size - start; remaining < 3 {
end += remaining
} else {
end = start + 3
}
n, err := r.Read(output[start:end])
end = start + n
if err == io.EOF {
break
} else if err != nil {
return nil, err
}
}
return output, nil
})
}
// This is a regression test verifying that encReader
// returns its encbuf to the pool only once.
func TestEncodeToReaderReturnToPool(t *testing.T) {
buf := make([]byte, 50)
wg := new(sync.WaitGroup)
for i := 0; i < 5; i++ {
wg.Add(1)
go func() {
for i := 0; i < 1000; i++ {
_, r, _ := EncodeToReader("foo")
ioutil.ReadAll(r)
r.Read(buf)
r.Read(buf)
r.Read(buf)
r.Read(buf)
}
wg.Done()
}()
}
wg.Wait()
}
var sink interface{}
func BenchmarkIntsize(b *testing.B) {
for i := 0; i < b.N; i++ {
sink = intsize(0x12345678)
}
}
func BenchmarkPutint(b *testing.B) {
buf := make([]byte, 8)
for i := 0; i < b.N; i++ {
putint(buf, 0x12345678)
sink = buf
}
}
func BenchmarkEncodeBigInts(b *testing.B) {
ints := make([]*big.Int, 200)
for i := range ints {
ints[i] = math.BigPow(2, int64(i))
}
out := bytes.NewBuffer(make([]byte, 0, 4096))
b.ResetTimer()
b.ReportAllocs()
for i := 0; i < b.N; i++ {
out.Reset()
if err := Encode(out, ints); err != nil {
b.Fatal(err)
}
}
}
func BenchmarkEncodeConcurrentInterface(b *testing.B) {
type struct1 struct {
A string
B *big.Int
C [20]byte
}
value := []interface{}{
uint(999),
&struct1{A: "hello", B: big.NewInt(0xFFFFFFFF)},
[10]byte{1, 2, 3, 4, 5, 6},
[]string{"yeah", "yeah", "yeah"},
}
var wg sync.WaitGroup
for cpu := 0; cpu < runtime.NumCPU(); cpu++ {
wg.Add(1)
go func() {
defer wg.Done()
var buffer bytes.Buffer
for i := 0; i < b.N; i++ {
buffer.Reset()
err := Encode(&buffer, value)
if err != nil {
panic(err)
}
}
}()
}
wg.Wait()
}
type byteArrayStruct struct {
A [20]byte
B [32]byte
C [32]byte
}
func BenchmarkEncodeByteArrayStruct(b *testing.B) {
var out bytes.Buffer
var value byteArrayStruct
b.ReportAllocs()
for i := 0; i < b.N; i++ {
out.Reset()
if err := Encode(&out, &value); err != nil {
b.Fatal(err)
}
}
}
type structSliceElem struct {
X uint64
Y uint64
Z uint64
}
type structPtrSlice []*structSliceElem
func BenchmarkEncodeStructPtrSlice(b *testing.B) {
var out bytes.Buffer
var value = structPtrSlice{
&structSliceElem{1, 1, 1},
&structSliceElem{2, 2, 2},
&structSliceElem{3, 3, 3},
&structSliceElem{5, 5, 5},
&structSliceElem{6, 6, 6},
&structSliceElem{7, 7, 7},
}
b.ReportAllocs()
for i := 0; i < b.N; i++ {
out.Reset()
if err := Encode(&out, &value); err != nil {
b.Fatal(err)
}
}
}