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accounts/abi: tuple support (#18406)

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This commit is contained in:
gary rong
2019-01-10 16:59:37 +08:00
committed by Guillaume Ballet
parent 6df3e4eeb0
commit 7ca40306af
9 changed files with 1003 additions and 393 deletions
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141
accounts/abi/type.go
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@ -17,6 +17,7 @@
package abi
import (
"errors"
"fmt"
"reflect"
"regexp"
@ -32,6 +33,7 @@ const (
StringTy
SliceTy
ArrayTy
TupleTy
AddressTy
FixedBytesTy
BytesTy
@ -43,13 +45,16 @@ const (
// Type is the reflection of the supported argument type
type Type struct {
Elem *Type
Kind reflect.Kind
Type reflect.Type
Size int
T byte // Our own type checking
stringKind string // holds the unparsed string for deriving signatures
// Tuple relative fields
TupleElems []*Type // Type information of all tuple fields
TupleRawNames []string // Raw field name of all tuple fields
}
var (
@ -58,7 +63,7 @@ var (
)
// NewType creates a new reflection type of abi type given in t.
func NewType(t string) (typ Type, err error) {
func NewType(t string, components []ArgumentMarshaling) (typ Type, err error) {
// check that array brackets are equal if they exist
if strings.Count(t, "[") != strings.Count(t, "]") {
return Type{}, fmt.Errorf("invalid arg type in abi")
@ -71,7 +76,7 @@ func NewType(t string) (typ Type, err error) {
if strings.Count(t, "[") != 0 {
i := strings.LastIndex(t, "[")
// recursively embed the type
embeddedType, err := NewType(t[:i])
embeddedType, err := NewType(t[:i], components)
if err != nil {
return Type{}, err
}
@ -87,6 +92,9 @@ func NewType(t string) (typ Type, err error) {
typ.Kind = reflect.Slice
typ.Elem = &embeddedType
typ.Type = reflect.SliceOf(embeddedType.Type)
if embeddedType.T == TupleTy {
typ.stringKind = embeddedType.stringKind + sliced
}
} else if len(intz) == 1 {
// is a array
typ.T = ArrayTy
@ -97,6 +105,9 @@ func NewType(t string) (typ Type, err error) {
return Type{}, fmt.Errorf("abi: error parsing variable size: %v", err)
}
typ.Type = reflect.ArrayOf(typ.Size, embeddedType.Type)
if embeddedType.T == TupleTy {
typ.stringKind = embeddedType.stringKind + sliced
}
} else {
return Type{}, fmt.Errorf("invalid formatting of array type")
}
@ -158,6 +169,40 @@ func NewType(t string) (typ Type, err error) {
typ.Size = varSize
typ.Type = reflect.ArrayOf(varSize, reflect.TypeOf(byte(0)))
}
case "tuple":
var (
fields []reflect.StructField
elems []*Type
names []string
expression string // canonical parameter expression
)
expression += "("
for idx, c := range components {
cType, err := NewType(c.Type, c.Components)
if err != nil {
return Type{}, err
}
if ToCamelCase(c.Name) == "" {
return Type{}, errors.New("abi: purely anonymous or underscored field is not supported")
}
fields = append(fields, reflect.StructField{
Name: ToCamelCase(c.Name), // reflect.StructOf will panic for any exported field.
Type: cType.Type,
})
elems = append(elems, &cType)
names = append(names, c.Name)
expression += cType.stringKind
if idx != len(components)-1 {
expression += ","
}
}
expression += ")"
typ.Kind = reflect.Struct
typ.Type = reflect.StructOf(fields)
typ.TupleElems = elems
typ.TupleRawNames = names
typ.T = TupleTy
typ.stringKind = expression
case "function":
typ.Kind = reflect.Array
typ.T = FunctionTy
@ -178,7 +223,6 @@ func (t Type) String() (out string) {
func (t Type) pack(v reflect.Value) ([]byte, error) {
// dereference pointer first if it's a pointer
v = indirect(v)
if err := typeCheck(t, v); err != nil {
return nil, err
}
@ -196,7 +240,7 @@ func (t Type) pack(v reflect.Value) ([]byte, error) {
offset := 0
offsetReq := isDynamicType(*t.Elem)
if offsetReq {
offset = getDynamicTypeOffset(*t.Elem) * v.Len()
offset = getTypeSize(*t.Elem) * v.Len()
}
var tail []byte
for i := 0; i < v.Len(); i++ {
@ -213,6 +257,45 @@ func (t Type) pack(v reflect.Value) ([]byte, error) {
tail = append(tail, val...)
}
return append(ret, tail...), nil
case TupleTy:
// (T1,...,Tk) for k >= 0 and any types T1, …, Tk
// enc(X) = head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(k))
// where X = (X(1), ..., X(k)) and head and tail are defined for Ti being a static
// type as
// head(X(i)) = enc(X(i)) and tail(X(i)) = "" (the empty string)
// and as
// head(X(i)) = enc(len(head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(i-1))))
// tail(X(i)) = enc(X(i))
// otherwise, i.e. if Ti is a dynamic type.
fieldmap, err := mapArgNamesToStructFields(t.TupleRawNames, v)
if err != nil {
return nil, err
}
// Calculate prefix occupied size.
offset := 0
for _, elem := range t.TupleElems {
offset += getTypeSize(*elem)
}
var ret, tail []byte
for i, elem := range t.TupleElems {
field := v.FieldByName(fieldmap[t.TupleRawNames[i]])
if !field.IsValid() {
return nil, fmt.Errorf("field %s for tuple not found in the given struct", t.TupleRawNames[i])
}
val, err := elem.pack(field)
if err != nil {
return nil, err
}
if isDynamicType(*elem) {
ret = append(ret, packNum(reflect.ValueOf(offset))...)
tail = append(tail, val...)
offset += len(val)
} else {
ret = append(ret, val...)
}
}
return append(ret, tail...), nil
default:
return packElement(t, v), nil
}
@ -225,25 +308,45 @@ func (t Type) requiresLengthPrefix() bool {
}
// isDynamicType returns true if the type is dynamic.
// StringTy, BytesTy, and SliceTy(irrespective of slice element type) are dynamic types
// ArrayTy is considered dynamic if and only if the Array element is a dynamic type.
// This function recursively checks the type for slice and array elements.
// The following types are called “dynamic”:
// * bytes
// * string
// * T[] for any T
// * T[k] for any dynamic T and any k >= 0
// * (T1,...,Tk) if Ti is dynamic for some 1 <= i <= k
func isDynamicType(t Type) bool {
// dynamic types
// array is also a dynamic type if the array type is dynamic
if t.T == TupleTy {
for _, elem := range t.TupleElems {
if isDynamicType(*elem) {
return true
}
}
return false
}
return t.T == StringTy || t.T == BytesTy || t.T == SliceTy || (t.T == ArrayTy && isDynamicType(*t.Elem))
}
// getDynamicTypeOffset returns the offset for the type.
// See `isDynamicType` to know which types are considered dynamic.
// If the type t is an array and element type is not a dynamic type, then we consider it a static type and
// return 32 * size of array since length prefix is not required.
// If t is a dynamic type or element type(for slices and arrays) is dynamic, then we simply return 32 as offset.
func getDynamicTypeOffset(t Type) int {
// if it is an array and there are no dynamic types
// then the array is static type
// getTypeSize returns the size that this type needs to occupy.
// We distinguish static and dynamic types. Static types are encoded in-place
// and dynamic types are encoded at a separately allocated location after the
// current block.
// So for a static variable, the size returned represents the size that the
// variable actually occupies.
// For a dynamic variable, the returned size is fixed 32 bytes, which is used
// to store the location reference for actual value storage.
func getTypeSize(t Type) int {
if t.T == ArrayTy && !isDynamicType(*t.Elem) {
return 32 * t.Size
// Recursively calculate type size if it is a nested array
if t.Elem.T == ArrayTy {
return t.Size * getTypeSize(*t.Elem)
}
return t.Size * 32
} else if t.T == TupleTy && !isDynamicType(t) {
total := 0
for _, elem := range t.TupleElems {
total += getTypeSize(*elem)
}
return total
}
return 32
}