diff options
Diffstat (limited to 'accounts/abi/type.go')
-rw-r--r-- | accounts/abi/type.go | 58 |
1 files changed, 49 insertions, 9 deletions
diff --git a/accounts/abi/type.go b/accounts/abi/type.go index dce89d2b4..6bfaabf5a 100644 --- a/accounts/abi/type.go +++ b/accounts/abi/type.go @@ -183,23 +183,39 @@ func (t Type) pack(v reflect.Value) ([]byte, error) { return nil, err } - if t.T == SliceTy || t.T == ArrayTy { - var packed []byte + switch t.T { + case SliceTy, ArrayTy: + var ret []byte + if t.requiresLengthPrefix() { + // append length + ret = append(ret, packNum(reflect.ValueOf(v.Len()))...) + } + + // calculate offset if any + offset := 0 + offsetReq := isDynamicType(*t.Elem) + if offsetReq { + offset = getDynamicTypeOffset(*t.Elem) * v.Len() + } + var tail []byte for i := 0; i < v.Len(); i++ { val, err := t.Elem.pack(v.Index(i)) if err != nil { return nil, err } - packed = append(packed, val...) - } - if t.T == SliceTy { - return packBytesSlice(packed, v.Len()), nil - } else if t.T == ArrayTy { - return packed, nil + if !offsetReq { + ret = append(ret, val...) + continue + } + ret = append(ret, packNum(reflect.ValueOf(offset))...) + offset += len(val) + tail = append(tail, val...) } + return append(ret, tail...), nil + default: + return packElement(t, v), nil } - return packElement(t, v), nil } // requireLengthPrefix returns whether the type requires any sort of length @@ -207,3 +223,27 @@ func (t Type) pack(v reflect.Value) ([]byte, error) { func (t Type) requiresLengthPrefix() bool { return t.T == StringTy || t.T == BytesTy || t.T == SliceTy } + +// 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. +func isDynamicType(t Type) bool { + // dynamic types + // array is also a dynamic type if the array type is dynamic + 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 + if t.T == ArrayTy && !isDynamicType(*t.Elem) { + return 32 * t.Size + } + return 32 +} |