go-pulse/rlp/encode_test.go
Felix Lange 96fb839133
rlp: improve nil pointer handling (#20064)
* rlp: improve nil pointer handling

In both encoder and decoder, the rules for encoding nil pointers were a
bit hard to understand, and didn't leave much choice. Since RLP allows
two empty values (empty list, empty string), any protocol built on RLP
must choose either of these values to represent the null value in a
certain context.

This change adds choice in the form of two new struct tags, "nilString"
and "nilList". These can be used to specify how a nil pointer value is
encoded. The "nil" tag still exists, but its implementation is now
explicit and defines exactly how nil pointers are handled in a single
place.

Another important change in this commit is how nil pointers and the
Encoder interface interact. The EncodeRLP method was previously called
even on nil values, which was supposed to give users a choice of how
their value would be handled when nil. It turns out this is a stupid
idea. If you create a network protocol containing an object defined in
another package, it's better to be able to say that the object should be
a list or string when nil in the definition of the protocol message
rather than defining the encoding of nil on the object itself.

As of this commit, the encoding rules for pointers now take precedence
over the Encoder interface rule. I think the "nil" tag will work fine
for most cases. For special kinds of objects which are a struct in Go
but strings in RLP, code using the object can specify the desired
encoding of nil using the "nilString" and "nilList" tags.

* rlp: propagate struct field type errors

If a struct contained fields of undecodable type, the encoder and
decoder would panic instead of returning an error. Fix this by
propagating type errors in makeStruct{Writer,Decoder} and add a test.
2019-09-13 11:10:57 +02:00

404 lines
15 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"
"sync"
"testing"
)
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
} else {
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",
},
// 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"},
// byte slices, strings
{val: []byte{}, output: "80"},
{val: []byte{0x7E}, output: "7E"},
{val: []byte{0x7F}, output: "7F"},
{val: []byte{0x80}, output: "8180"},
{val: []byte{1, 2, 3}, output: "83010203"},
{val: []namedByteType{1, 2, 3}, output: "83010203"},
{val: [...]namedByteType{1, 2, 3}, output: "83010203"},
{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: &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"},
{val: &hasIgnoredField{A: 1, B: 2, C: 3}, output: "C20103"},
{val: &intField{X: 3}, error: "rlp: type int is not RLP-serializable (struct field rlp.intField.X)"},
// 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()
}