go-ethereum/rlp/decode_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

931 lines
27 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"
"encoding/hex"
"errors"
"fmt"
"io"
"math/big"
"reflect"
"strings"
"testing"
)
func TestStreamKind(t *testing.T) {
tests := []struct {
input string
wantKind Kind
wantLen uint64
}{
{"00", Byte, 0},
{"01", Byte, 0},
{"7F", Byte, 0},
{"80", String, 0},
{"B7", String, 55},
{"B90400", String, 1024},
{"BFFFFFFFFFFFFFFFFF", String, ^uint64(0)},
{"C0", List, 0},
{"C8", List, 8},
{"F7", List, 55},
{"F90400", List, 1024},
{"FFFFFFFFFFFFFFFFFF", List, ^uint64(0)},
}
for i, test := range tests {
// using plainReader to inhibit input limit errors.
s := NewStream(newPlainReader(unhex(test.input)), 0)
kind, len, err := s.Kind()
if err != nil {
t.Errorf("test %d: Kind returned error: %v", i, err)
continue
}
if kind != test.wantKind {
t.Errorf("test %d: kind mismatch: got %d, want %d", i, kind, test.wantKind)
}
if len != test.wantLen {
t.Errorf("test %d: len mismatch: got %d, want %d", i, len, test.wantLen)
}
}
}
func TestNewListStream(t *testing.T) {
ls := NewListStream(bytes.NewReader(unhex("0101010101")), 3)
if k, size, err := ls.Kind(); k != List || size != 3 || err != nil {
t.Errorf("Kind() returned (%v, %d, %v), expected (List, 3, nil)", k, size, err)
}
if size, err := ls.List(); size != 3 || err != nil {
t.Errorf("List() returned (%d, %v), expected (3, nil)", size, err)
}
for i := 0; i < 3; i++ {
if val, err := ls.Uint(); val != 1 || err != nil {
t.Errorf("Uint() returned (%d, %v), expected (1, nil)", val, err)
}
}
if err := ls.ListEnd(); err != nil {
t.Errorf("ListEnd() returned %v, expected (3, nil)", err)
}
}
func TestStreamErrors(t *testing.T) {
withoutInputLimit := func(b []byte) *Stream {
return NewStream(newPlainReader(b), 0)
}
withCustomInputLimit := func(limit uint64) func([]byte) *Stream {
return func(b []byte) *Stream {
return NewStream(bytes.NewReader(b), limit)
}
}
type calls []string
tests := []struct {
string
calls
newStream func([]byte) *Stream // uses bytes.Reader if nil
error error
}{
{"C0", calls{"Bytes"}, nil, ErrExpectedString},
{"C0", calls{"Uint"}, nil, ErrExpectedString},
{"89000000000000000001", calls{"Uint"}, nil, errUintOverflow},
{"00", calls{"List"}, nil, ErrExpectedList},
{"80", calls{"List"}, nil, ErrExpectedList},
{"C0", calls{"List", "Uint"}, nil, EOL},
{"C8C9010101010101010101", calls{"List", "Kind"}, nil, ErrElemTooLarge},
{"C3C2010201", calls{"List", "List", "Uint", "Uint", "ListEnd", "Uint"}, nil, EOL},
{"00", calls{"ListEnd"}, nil, errNotInList},
{"C401020304", calls{"List", "Uint", "ListEnd"}, nil, errNotAtEOL},
// Non-canonical integers (e.g. leading zero bytes).
{"00", calls{"Uint"}, nil, ErrCanonInt},
{"820002", calls{"Uint"}, nil, ErrCanonInt},
{"8133", calls{"Uint"}, nil, ErrCanonSize},
{"817F", calls{"Uint"}, nil, ErrCanonSize},
{"8180", calls{"Uint"}, nil, nil},
// Non-valid boolean
{"02", calls{"Bool"}, nil, errors.New("rlp: invalid boolean value: 2")},
// Size tags must use the smallest possible encoding.
// Leading zero bytes in the size tag are also rejected.
{"8100", calls{"Uint"}, nil, ErrCanonSize},
{"8100", calls{"Bytes"}, nil, ErrCanonSize},
{"8101", calls{"Bytes"}, nil, ErrCanonSize},
{"817F", calls{"Bytes"}, nil, ErrCanonSize},
{"8180", calls{"Bytes"}, nil, nil},
{"B800", calls{"Kind"}, withoutInputLimit, ErrCanonSize},
{"B90000", calls{"Kind"}, withoutInputLimit, ErrCanonSize},
{"B90055", calls{"Kind"}, withoutInputLimit, ErrCanonSize},
{"BA0002FFFF", calls{"Bytes"}, withoutInputLimit, ErrCanonSize},
{"F800", calls{"Kind"}, withoutInputLimit, ErrCanonSize},
{"F90000", calls{"Kind"}, withoutInputLimit, ErrCanonSize},
{"F90055", calls{"Kind"}, withoutInputLimit, ErrCanonSize},
{"FA0002FFFF", calls{"List"}, withoutInputLimit, ErrCanonSize},
// Expected EOF
{"", calls{"Kind"}, nil, io.EOF},
{"", calls{"Uint"}, nil, io.EOF},
{"", calls{"List"}, nil, io.EOF},
{"8180", calls{"Uint", "Uint"}, nil, io.EOF},
{"C0", calls{"List", "ListEnd", "List"}, nil, io.EOF},
{"", calls{"List"}, withoutInputLimit, io.EOF},
{"8180", calls{"Uint", "Uint"}, withoutInputLimit, io.EOF},
{"C0", calls{"List", "ListEnd", "List"}, withoutInputLimit, io.EOF},
// Input limit errors.
{"81", calls{"Bytes"}, nil, ErrValueTooLarge},
{"81", calls{"Uint"}, nil, ErrValueTooLarge},
{"81", calls{"Raw"}, nil, ErrValueTooLarge},
{"BFFFFFFFFFFFFFFFFFFF", calls{"Bytes"}, nil, ErrValueTooLarge},
{"C801", calls{"List"}, nil, ErrValueTooLarge},
// Test for list element size check overflow.
{"CD04040404FFFFFFFFFFFFFFFFFF0303", calls{"List", "Uint", "Uint", "Uint", "Uint", "List"}, nil, ErrElemTooLarge},
// Test for input limit overflow. Since we are counting the limit
// down toward zero in Stream.remaining, reading too far can overflow
// remaining to a large value, effectively disabling the limit.
{"C40102030401", calls{"Raw", "Uint"}, withCustomInputLimit(5), io.EOF},
{"C4010203048180", calls{"Raw", "Uint"}, withCustomInputLimit(6), ErrValueTooLarge},
// Check that the same calls are fine without a limit.
{"C40102030401", calls{"Raw", "Uint"}, withoutInputLimit, nil},
{"C4010203048180", calls{"Raw", "Uint"}, withoutInputLimit, nil},
// Unexpected EOF. This only happens when there is
// no input limit, so the reader needs to be 'dumbed down'.
{"81", calls{"Bytes"}, withoutInputLimit, io.ErrUnexpectedEOF},
{"81", calls{"Uint"}, withoutInputLimit, io.ErrUnexpectedEOF},
{"BFFFFFFFFFFFFFFF", calls{"Bytes"}, withoutInputLimit, io.ErrUnexpectedEOF},
{"C801", calls{"List", "Uint", "Uint"}, withoutInputLimit, io.ErrUnexpectedEOF},
// This test verifies that the input position is advanced
// correctly when calling Bytes for empty strings. Kind can be called
// any number of times in between and doesn't advance.
{"C3808080", calls{
"List", // enter the list
"Bytes", // past first element
"Kind", "Kind", "Kind", // this shouldn't advance
"Bytes", // past second element
"Kind", "Kind", // can't hurt to try
"Bytes", // past final element
"Bytes", // this one should fail
}, nil, EOL},
}
testfor:
for i, test := range tests {
if test.newStream == nil {
test.newStream = func(b []byte) *Stream { return NewStream(bytes.NewReader(b), 0) }
}
s := test.newStream(unhex(test.string))
rs := reflect.ValueOf(s)
for j, call := range test.calls {
fval := rs.MethodByName(call)
ret := fval.Call(nil)
err := "<nil>"
if lastret := ret[len(ret)-1].Interface(); lastret != nil {
err = lastret.(error).Error()
}
if j == len(test.calls)-1 {
want := "<nil>"
if test.error != nil {
want = test.error.Error()
}
if err != want {
t.Log(test)
t.Errorf("test %d: last call (%s) error mismatch\ngot: %s\nwant: %s",
i, call, err, test.error)
}
} else if err != "<nil>" {
t.Log(test)
t.Errorf("test %d: call %d (%s) unexpected error: %q", i, j, call, err)
continue testfor
}
}
}
}
func TestStreamList(t *testing.T) {
s := NewStream(bytes.NewReader(unhex("C80102030405060708")), 0)
len, err := s.List()
if err != nil {
t.Fatalf("List error: %v", err)
}
if len != 8 {
t.Fatalf("List returned invalid length, got %d, want 8", len)
}
for i := uint64(1); i <= 8; i++ {
v, err := s.Uint()
if err != nil {
t.Fatalf("Uint error: %v", err)
}
if i != v {
t.Errorf("Uint returned wrong value, got %d, want %d", v, i)
}
}
if _, err := s.Uint(); err != EOL {
t.Errorf("Uint error mismatch, got %v, want %v", err, EOL)
}
if err = s.ListEnd(); err != nil {
t.Fatalf("ListEnd error: %v", err)
}
}
func TestStreamRaw(t *testing.T) {
tests := []struct {
input string
output string
}{
{
"C58401010101",
"8401010101",
},
{
"F842B84001010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101",
"B84001010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101",
},
}
for i, tt := range tests {
s := NewStream(bytes.NewReader(unhex(tt.input)), 0)
s.List()
want := unhex(tt.output)
raw, err := s.Raw()
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(want, raw) {
t.Errorf("test %d: raw mismatch: got %x, want %x", i, raw, want)
}
}
}
func TestDecodeErrors(t *testing.T) {
r := bytes.NewReader(nil)
if err := Decode(r, nil); err != errDecodeIntoNil {
t.Errorf("Decode(r, nil) error mismatch, got %q, want %q", err, errDecodeIntoNil)
}
var nilptr *struct{}
if err := Decode(r, nilptr); err != errDecodeIntoNil {
t.Errorf("Decode(r, nilptr) error mismatch, got %q, want %q", err, errDecodeIntoNil)
}
if err := Decode(r, struct{}{}); err != errNoPointer {
t.Errorf("Decode(r, struct{}{}) error mismatch, got %q, want %q", err, errNoPointer)
}
expectErr := "rlp: type chan bool is not RLP-serializable"
if err := Decode(r, new(chan bool)); err == nil || err.Error() != expectErr {
t.Errorf("Decode(r, new(chan bool)) error mismatch, got %q, want %q", err, expectErr)
}
if err := Decode(r, new(uint)); err != io.EOF {
t.Errorf("Decode(r, new(int)) error mismatch, got %q, want %q", err, io.EOF)
}
}
type decodeTest struct {
input string
ptr interface{}
value interface{}
error string
}
type simplestruct struct {
A uint
B string
}
type recstruct struct {
I uint
Child *recstruct `rlp:"nil"`
}
type invalidNilTag struct {
X []byte `rlp:"nil"`
}
type invalidTail1 struct {
A uint `rlp:"tail"`
B string
}
type invalidTail2 struct {
A uint
B string `rlp:"tail"`
}
type tailRaw struct {
A uint
Tail []RawValue `rlp:"tail"`
}
type tailUint struct {
A uint
Tail []uint `rlp:"tail"`
}
type tailPrivateFields struct {
A uint
Tail []uint `rlp:"tail"`
x, y bool
}
type nilListUint struct {
X *uint `rlp:"nilList"`
}
type nilStringSlice struct {
X *[]uint `rlp:"nilString"`
}
type intField struct {
X int
}
var (
veryBigInt = big.NewInt(0).Add(
big.NewInt(0).Lsh(big.NewInt(0xFFFFFFFFFFFFFF), 16),
big.NewInt(0xFFFF),
)
)
type hasIgnoredField struct {
A uint
B uint `rlp:"-"`
C uint
}
var decodeTests = []decodeTest{
// booleans
{input: "01", ptr: new(bool), value: true},
{input: "80", ptr: new(bool), value: false},
{input: "02", ptr: new(bool), error: "rlp: invalid boolean value: 2"},
// integers
{input: "05", ptr: new(uint32), value: uint32(5)},
{input: "80", ptr: new(uint32), value: uint32(0)},
{input: "820505", ptr: new(uint32), value: uint32(0x0505)},
{input: "83050505", ptr: new(uint32), value: uint32(0x050505)},
{input: "8405050505", ptr: new(uint32), value: uint32(0x05050505)},
{input: "850505050505", ptr: new(uint32), error: "rlp: input string too long for uint32"},
{input: "C0", ptr: new(uint32), error: "rlp: expected input string or byte for uint32"},
{input: "00", ptr: new(uint32), error: "rlp: non-canonical integer (leading zero bytes) for uint32"},
{input: "8105", ptr: new(uint32), error: "rlp: non-canonical size information for uint32"},
{input: "820004", ptr: new(uint32), error: "rlp: non-canonical integer (leading zero bytes) for uint32"},
{input: "B8020004", ptr: new(uint32), error: "rlp: non-canonical size information for uint32"},
// slices
{input: "C0", ptr: new([]uint), value: []uint{}},
{input: "C80102030405060708", ptr: new([]uint), value: []uint{1, 2, 3, 4, 5, 6, 7, 8}},
{input: "F8020004", ptr: new([]uint), error: "rlp: non-canonical size information for []uint"},
// arrays
{input: "C50102030405", ptr: new([5]uint), value: [5]uint{1, 2, 3, 4, 5}},
{input: "C0", ptr: new([5]uint), error: "rlp: input list has too few elements for [5]uint"},
{input: "C102", ptr: new([5]uint), error: "rlp: input list has too few elements for [5]uint"},
{input: "C6010203040506", ptr: new([5]uint), error: "rlp: input list has too many elements for [5]uint"},
{input: "F8020004", ptr: new([5]uint), error: "rlp: non-canonical size information for [5]uint"},
// zero sized arrays
{input: "C0", ptr: new([0]uint), value: [0]uint{}},
{input: "C101", ptr: new([0]uint), error: "rlp: input list has too many elements for [0]uint"},
// byte slices
{input: "01", ptr: new([]byte), value: []byte{1}},
{input: "80", ptr: new([]byte), value: []byte{}},
{input: "8D6162636465666768696A6B6C6D", ptr: new([]byte), value: []byte("abcdefghijklm")},
{input: "C0", ptr: new([]byte), error: "rlp: expected input string or byte for []uint8"},
{input: "8105", ptr: new([]byte), error: "rlp: non-canonical size information for []uint8"},
// byte arrays
{input: "02", ptr: new([1]byte), value: [1]byte{2}},
{input: "8180", ptr: new([1]byte), value: [1]byte{128}},
{input: "850102030405", ptr: new([5]byte), value: [5]byte{1, 2, 3, 4, 5}},
// byte array errors
{input: "02", ptr: new([5]byte), error: "rlp: input string too short for [5]uint8"},
{input: "80", ptr: new([5]byte), error: "rlp: input string too short for [5]uint8"},
{input: "820000", ptr: new([5]byte), error: "rlp: input string too short for [5]uint8"},
{input: "C0", ptr: new([5]byte), error: "rlp: expected input string or byte for [5]uint8"},
{input: "C3010203", ptr: new([5]byte), error: "rlp: expected input string or byte for [5]uint8"},
{input: "86010203040506", ptr: new([5]byte), error: "rlp: input string too long for [5]uint8"},
{input: "8105", ptr: new([1]byte), error: "rlp: non-canonical size information for [1]uint8"},
{input: "817F", ptr: new([1]byte), error: "rlp: non-canonical size information for [1]uint8"},
// zero sized byte arrays
{input: "80", ptr: new([0]byte), value: [0]byte{}},
{input: "01", ptr: new([0]byte), error: "rlp: input string too long for [0]uint8"},
{input: "8101", ptr: new([0]byte), error: "rlp: input string too long for [0]uint8"},
// strings
{input: "00", ptr: new(string), value: "\000"},
{input: "8D6162636465666768696A6B6C6D", ptr: new(string), value: "abcdefghijklm"},
{input: "C0", ptr: new(string), error: "rlp: expected input string or byte for string"},
// big ints
{input: "01", ptr: new(*big.Int), value: big.NewInt(1)},
{input: "89FFFFFFFFFFFFFFFFFF", ptr: new(*big.Int), value: veryBigInt},
{input: "10", ptr: new(big.Int), value: *big.NewInt(16)}, // non-pointer also works
{input: "C0", ptr: new(*big.Int), error: "rlp: expected input string or byte for *big.Int"},
{input: "820001", ptr: new(big.Int), error: "rlp: non-canonical integer (leading zero bytes) for *big.Int"},
{input: "8105", ptr: new(big.Int), error: "rlp: non-canonical size information for *big.Int"},
// structs
{
input: "C50583343434",
ptr: new(simplestruct),
value: simplestruct{5, "444"},
},
{
input: "C601C402C203C0",
ptr: new(recstruct),
value: recstruct{1, &recstruct{2, &recstruct{3, nil}}},
},
// struct errors
{
input: "C0",
ptr: new(simplestruct),
error: "rlp: too few elements for rlp.simplestruct",
},
{
input: "C105",
ptr: new(simplestruct),
error: "rlp: too few elements for rlp.simplestruct",
},
{
input: "C7C50583343434C0",
ptr: new([]*simplestruct),
error: "rlp: too few elements for rlp.simplestruct, decoding into ([]*rlp.simplestruct)[1]",
},
{
input: "83222222",
ptr: new(simplestruct),
error: "rlp: expected input list for rlp.simplestruct",
},
{
input: "C3010101",
ptr: new(simplestruct),
error: "rlp: input list has too many elements for rlp.simplestruct",
},
{
input: "C501C3C00000",
ptr: new(recstruct),
error: "rlp: expected input string or byte for uint, decoding into (rlp.recstruct).Child.I",
},
{
input: "C103",
ptr: new(intField),
error: "rlp: type int is not RLP-serializable (struct field rlp.intField.X)",
},
{
input: "C50102C20102",
ptr: new(tailUint),
error: "rlp: expected input string or byte for uint, decoding into (rlp.tailUint).Tail[1]",
},
{
input: "C0",
ptr: new(invalidNilTag),
error: `rlp: invalid struct tag "nil" for rlp.invalidNilTag.X (field is not a pointer)`,
},
// struct tag "tail"
{
input: "C3010203",
ptr: new(tailRaw),
value: tailRaw{A: 1, Tail: []RawValue{unhex("02"), unhex("03")}},
},
{
input: "C20102",
ptr: new(tailRaw),
value: tailRaw{A: 1, Tail: []RawValue{unhex("02")}},
},
{
input: "C101",
ptr: new(tailRaw),
value: tailRaw{A: 1, Tail: []RawValue{}},
},
{
input: "C3010203",
ptr: new(tailPrivateFields),
value: tailPrivateFields{A: 1, Tail: []uint{2, 3}},
},
{
input: "C0",
ptr: new(invalidTail1),
error: `rlp: invalid struct tag "tail" for rlp.invalidTail1.A (must be on last field)`,
},
{
input: "C0",
ptr: new(invalidTail2),
error: `rlp: invalid struct tag "tail" for rlp.invalidTail2.B (field type is not slice)`,
},
// struct tag "-"
{
input: "C20102",
ptr: new(hasIgnoredField),
value: hasIgnoredField{A: 1, C: 2},
},
// struct tag "nilList"
{
input: "C180",
ptr: new(nilListUint),
error: "rlp: wrong kind of empty value (got String, want List) for *uint, decoding into (rlp.nilListUint).X",
},
{
input: "C1C0",
ptr: new(nilListUint),
value: nilListUint{},
},
{
input: "C103",
ptr: new(nilListUint),
value: func() interface{} {
v := uint(3)
return nilListUint{X: &v}
}(),
},
// struct tag "nilString"
{
input: "C1C0",
ptr: new(nilStringSlice),
error: "rlp: wrong kind of empty value (got List, want String) for *[]uint, decoding into (rlp.nilStringSlice).X",
},
{
input: "C180",
ptr: new(nilStringSlice),
value: nilStringSlice{},
},
{
input: "C2C103",
ptr: new(nilStringSlice),
value: nilStringSlice{X: &[]uint{3}},
},
// RawValue
{input: "01", ptr: new(RawValue), value: RawValue(unhex("01"))},
{input: "82FFFF", ptr: new(RawValue), value: RawValue(unhex("82FFFF"))},
{input: "C20102", ptr: new([]RawValue), value: []RawValue{unhex("01"), unhex("02")}},
// pointers
{input: "00", ptr: new(*[]byte), value: &[]byte{0}},
{input: "80", ptr: new(*uint), value: uintp(0)},
{input: "C0", ptr: new(*uint), error: "rlp: expected input string or byte for uint"},
{input: "07", ptr: new(*uint), value: uintp(7)},
{input: "817F", ptr: new(*uint), error: "rlp: non-canonical size information for uint"},
{input: "8180", ptr: new(*uint), value: uintp(0x80)},
{input: "C109", ptr: new(*[]uint), value: &[]uint{9}},
{input: "C58403030303", ptr: new(*[][]byte), value: &[][]byte{{3, 3, 3, 3}}},
// check that input position is advanced also for empty values.
{input: "C3808005", ptr: new([]*uint), value: []*uint{uintp(0), uintp(0), uintp(5)}},
// interface{}
{input: "00", ptr: new(interface{}), value: []byte{0}},
{input: "01", ptr: new(interface{}), value: []byte{1}},
{input: "80", ptr: new(interface{}), value: []byte{}},
{input: "850505050505", ptr: new(interface{}), value: []byte{5, 5, 5, 5, 5}},
{input: "C0", ptr: new(interface{}), value: []interface{}{}},
{input: "C50183040404", ptr: new(interface{}), value: []interface{}{[]byte{1}, []byte{4, 4, 4}}},
{
input: "C3010203",
ptr: new([]io.Reader),
error: "rlp: type io.Reader is not RLP-serializable",
},
// fuzzer crashes
{
input: "c330f9c030f93030ce3030303030303030bd303030303030",
ptr: new(interface{}),
error: "rlp: element is larger than containing list",
},
}
func uintp(i uint) *uint { return &i }
func runTests(t *testing.T, decode func([]byte, interface{}) error) {
for i, test := range decodeTests {
input, err := hex.DecodeString(test.input)
if err != nil {
t.Errorf("test %d: invalid hex input %q", i, test.input)
continue
}
err = decode(input, test.ptr)
if err != nil && test.error == "" {
t.Errorf("test %d: unexpected Decode error: %v\ndecoding into %T\ninput %q",
i, err, test.ptr, test.input)
continue
}
if test.error != "" && fmt.Sprint(err) != test.error {
t.Errorf("test %d: Decode error mismatch\ngot %v\nwant %v\ndecoding into %T\ninput %q",
i, err, test.error, test.ptr, test.input)
continue
}
deref := reflect.ValueOf(test.ptr).Elem().Interface()
if err == nil && !reflect.DeepEqual(deref, test.value) {
t.Errorf("test %d: value mismatch\ngot %#v\nwant %#v\ndecoding into %T\ninput %q",
i, deref, test.value, test.ptr, test.input)
}
}
}
func TestDecodeWithByteReader(t *testing.T) {
runTests(t, func(input []byte, into interface{}) error {
return Decode(bytes.NewReader(input), into)
})
}
// plainReader reads from a byte slice but does not
// implement ReadByte. It is also not recognized by the
// size validation. This is useful to test how the decoder
// behaves on a non-buffered input stream.
type plainReader []byte
func newPlainReader(b []byte) io.Reader {
return (*plainReader)(&b)
}
func (r *plainReader) Read(buf []byte) (n int, err error) {
if len(*r) == 0 {
return 0, io.EOF
}
n = copy(buf, *r)
*r = (*r)[n:]
return n, nil
}
func TestDecodeWithNonByteReader(t *testing.T) {
runTests(t, func(input []byte, into interface{}) error {
return Decode(newPlainReader(input), into)
})
}
func TestDecodeStreamReset(t *testing.T) {
s := NewStream(nil, 0)
runTests(t, func(input []byte, into interface{}) error {
s.Reset(bytes.NewReader(input), 0)
return s.Decode(into)
})
}
type testDecoder struct{ called bool }
func (t *testDecoder) DecodeRLP(s *Stream) error {
if _, err := s.Uint(); err != nil {
return err
}
t.called = true
return nil
}
func TestDecodeDecoder(t *testing.T) {
var s struct {
T1 testDecoder
T2 *testDecoder
T3 **testDecoder
}
if err := Decode(bytes.NewReader(unhex("C3010203")), &s); err != nil {
t.Fatalf("Decode error: %v", err)
}
if !s.T1.called {
t.Errorf("DecodeRLP was not called for (non-pointer) testDecoder")
}
if s.T2 == nil {
t.Errorf("*testDecoder has not been allocated")
} else if !s.T2.called {
t.Errorf("DecodeRLP was not called for *testDecoder")
}
if s.T3 == nil || *s.T3 == nil {
t.Errorf("**testDecoder has not been allocated")
} else if !(*s.T3).called {
t.Errorf("DecodeRLP was not called for **testDecoder")
}
}
func TestDecodeDecoderNilPointer(t *testing.T) {
var s struct {
T1 *testDecoder `rlp:"nil"`
T2 *testDecoder
}
if err := Decode(bytes.NewReader(unhex("C2C002")), &s); err != nil {
t.Fatalf("Decode error: %v", err)
}
if s.T1 != nil {
t.Errorf("decoder T1 allocated for empty input (called: %v)", s.T1.called)
}
if s.T2 == nil || !s.T2.called {
t.Errorf("decoder T2 not allocated/called")
}
}
type byteDecoder byte
func (bd *byteDecoder) DecodeRLP(s *Stream) error {
_, err := s.Uint()
*bd = 255
return err
}
func (bd byteDecoder) called() bool {
return bd == 255
}
// This test verifies that the byte slice/byte array logic
// does not kick in for element types implementing Decoder.
func TestDecoderInByteSlice(t *testing.T) {
var slice []byteDecoder
if err := Decode(bytes.NewReader(unhex("C101")), &slice); err != nil {
t.Errorf("unexpected Decode error %v", err)
} else if !slice[0].called() {
t.Errorf("DecodeRLP not called for slice element")
}
var array [1]byteDecoder
if err := Decode(bytes.NewReader(unhex("C101")), &array); err != nil {
t.Errorf("unexpected Decode error %v", err)
} else if !array[0].called() {
t.Errorf("DecodeRLP not called for array element")
}
}
type unencodableDecoder func()
func (f *unencodableDecoder) DecodeRLP(s *Stream) error {
if _, err := s.List(); err != nil {
return err
}
if err := s.ListEnd(); err != nil {
return err
}
*f = func() {}
return nil
}
func TestDecoderFunc(t *testing.T) {
var x func()
if err := DecodeBytes([]byte{0xC0}, (*unencodableDecoder)(&x)); err != nil {
t.Fatal(err)
}
x()
}
func ExampleDecode() {
input, _ := hex.DecodeString("C90A1486666F6F626172")
type example struct {
A, B uint
private uint // private fields are ignored
String string
}
var s example
err := Decode(bytes.NewReader(input), &s)
if err != nil {
fmt.Printf("Error: %v\n", err)
} else {
fmt.Printf("Decoded value: %#v\n", s)
}
// Output:
// Decoded value: rlp.example{A:0xa, B:0x14, private:0x0, String:"foobar"}
}
func ExampleDecode_structTagNil() {
// In this example, we'll use the "nil" struct tag to change
// how a pointer-typed field is decoded. The input contains an RLP
// list of one element, an empty string.
input := []byte{0xC1, 0x80}
// This type uses the normal rules.
// The empty input string is decoded as a pointer to an empty Go string.
var normalRules struct {
String *string
}
Decode(bytes.NewReader(input), &normalRules)
fmt.Printf("normal: String = %q\n", *normalRules.String)
// This type uses the struct tag.
// The empty input string is decoded as a nil pointer.
var withEmptyOK struct {
String *string `rlp:"nil"`
}
Decode(bytes.NewReader(input), &withEmptyOK)
fmt.Printf("with nil tag: String = %v\n", withEmptyOK.String)
// Output:
// normal: String = ""
// with nil tag: String = <nil>
}
func ExampleStream() {
input, _ := hex.DecodeString("C90A1486666F6F626172")
s := NewStream(bytes.NewReader(input), 0)
// Check what kind of value lies ahead
kind, size, _ := s.Kind()
fmt.Printf("Kind: %v size:%d\n", kind, size)
// Enter the list
if _, err := s.List(); err != nil {
fmt.Printf("List error: %v\n", err)
return
}
// Decode elements
fmt.Println(s.Uint())
fmt.Println(s.Uint())
fmt.Println(s.Bytes())
// Acknowledge end of list
if err := s.ListEnd(); err != nil {
fmt.Printf("ListEnd error: %v\n", err)
}
// Output:
// Kind: List size:9
// 10 <nil>
// 20 <nil>
// [102 111 111 98 97 114] <nil>
}
func BenchmarkDecode(b *testing.B) {
enc := encodeTestSlice(90000)
b.SetBytes(int64(len(enc)))
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
var s []uint
r := bytes.NewReader(enc)
if err := Decode(r, &s); err != nil {
b.Fatalf("Decode error: %v", err)
}
}
}
func BenchmarkDecodeIntSliceReuse(b *testing.B) {
enc := encodeTestSlice(100000)
b.SetBytes(int64(len(enc)))
b.ReportAllocs()
b.ResetTimer()
var s []uint
for i := 0; i < b.N; i++ {
r := bytes.NewReader(enc)
if err := Decode(r, &s); err != nil {
b.Fatalf("Decode error: %v", err)
}
}
}
func encodeTestSlice(n uint) []byte {
s := make([]uint, n)
for i := uint(0); i < n; i++ {
s[i] = i
}
b, err := EncodeToBytes(s)
if err != nil {
panic(fmt.Sprintf("encode error: %v", err))
}
return b
}
func unhex(str string) []byte {
b, err := hex.DecodeString(strings.Replace(str, " ", "", -1))
if err != nil {
panic(fmt.Sprintf("invalid hex string: %q", str))
}
return b
}