aboutsummaryrefslogtreecommitdiffstats
path: root/accounts/abi/unpack.go
diff options
context:
space:
mode:
Diffstat (limited to 'accounts/abi/unpack.go')
-rw-r--r--accounts/abi/unpack.go279
1 files changed, 130 insertions, 149 deletions
diff --git a/accounts/abi/unpack.go b/accounts/abi/unpack.go
index fc41c88ac..ffa14ccd3 100644
--- a/accounts/abi/unpack.go
+++ b/accounts/abi/unpack.go
@@ -25,118 +25,16 @@ import (
"github.com/ethereum/go-ethereum/common"
)
-// toGoSliceType parses the input and casts it to the proper slice defined by the ABI
-// argument in T.
-func toGoSlice(i int, t Argument, output []byte) (interface{}, error) {
- index := i * 32
- // The slice must, at very least be large enough for the index+32 which is exactly the size required
- // for the [offset in output, size of offset].
- if index+32 > len(output) {
- return nil, fmt.Errorf("abi: cannot marshal in to go slice: insufficient size output %d require %d", len(output), index+32)
- }
- elem := t.Type.Elem
-
- // first we need to create a slice of the type
- var refSlice reflect.Value
- switch elem.T {
- case IntTy, UintTy, BoolTy:
- // create a new reference slice matching the element type
- switch t.Type.Kind {
- case reflect.Bool:
- refSlice = reflect.ValueOf([]bool(nil))
- case reflect.Uint8:
- refSlice = reflect.ValueOf([]uint8(nil))
- case reflect.Uint16:
- refSlice = reflect.ValueOf([]uint16(nil))
- case reflect.Uint32:
- refSlice = reflect.ValueOf([]uint32(nil))
- case reflect.Uint64:
- refSlice = reflect.ValueOf([]uint64(nil))
- case reflect.Int8:
- refSlice = reflect.ValueOf([]int8(nil))
- case reflect.Int16:
- refSlice = reflect.ValueOf([]int16(nil))
- case reflect.Int32:
- refSlice = reflect.ValueOf([]int32(nil))
- case reflect.Int64:
- refSlice = reflect.ValueOf([]int64(nil))
- default:
- refSlice = reflect.ValueOf([]*big.Int(nil))
- }
- case AddressTy: // address must be of slice Address
- refSlice = reflect.ValueOf([]common.Address(nil))
- case HashTy: // hash must be of slice hash
- refSlice = reflect.ValueOf([]common.Hash(nil))
- case FixedBytesTy:
- refSlice = reflect.ValueOf([][]byte(nil))
- default: // no other types are supported
- return nil, fmt.Errorf("abi: unsupported slice type %v", elem.T)
- }
-
- var slice []byte
- var size int
- var offset int
- if t.Type.IsSlice {
- // get the offset which determines the start of this array ...
- offset = int(binary.BigEndian.Uint64(output[index+24 : index+32]))
- if offset+32 > len(output) {
- return nil, fmt.Errorf("abi: cannot marshal in to go slice: offset %d would go over slice boundary (len=%d)", len(output), offset+32)
- }
-
- slice = output[offset:]
- // ... starting with the size of the array in elements ...
- size = int(binary.BigEndian.Uint64(slice[24:32]))
- slice = slice[32:]
- // ... and make sure that we've at the very least the amount of bytes
- // available in the buffer.
- if size*32 > len(slice) {
- return nil, fmt.Errorf("abi: cannot marshal in to go slice: insufficient size output %d require %d", len(output), offset+32+size*32)
- }
-
- // reslice to match the required size
- slice = slice[:size*32]
- } else if t.Type.IsArray {
- //get the number of elements in the array
- size = t.Type.SliceSize
-
- //check to make sure array size matches up
- if index+32*size > len(output) {
- return nil, fmt.Errorf("abi: cannot marshal in to go array: offset %d would go over slice boundary (len=%d)", len(output), index+32*size)
- }
- //slice is there for a fixed amount of times
- slice = output[index : index+size*32]
- }
-
- for i := 0; i < size; i++ {
- var (
- inter interface{} // interface type
- returnOutput = slice[i*32 : i*32+32] // the return output
- err error
- )
- // set inter to the correct type (cast)
- switch elem.T {
- case IntTy, UintTy:
- inter = readInteger(t.Type.Kind, returnOutput)
- case BoolTy:
- inter, err = readBool(returnOutput)
- if err != nil {
- return nil, err
- }
- case AddressTy:
- inter = common.BytesToAddress(returnOutput)
- case HashTy:
- inter = common.BytesToHash(returnOutput)
- case FixedBytesTy:
- inter = returnOutput
- }
- // append the item to our reflect slice
- refSlice = reflect.Append(refSlice, reflect.ValueOf(inter))
- }
-
- // return the interface
- return refSlice.Interface(), nil
+// unpacker is a utility interface that enables us to have
+// abstraction between events and methods and also to properly
+// "unpack" them; e.g. events use Inputs, methods use Outputs.
+type unpacker interface {
+ tupleUnpack(v interface{}, output []byte) error
+ singleUnpack(v interface{}, output []byte) error
+ isTupleReturn() bool
}
+// reads the integer based on its kind
func readInteger(kind reflect.Kind, b []byte) interface{} {
switch kind {
case reflect.Uint8:
@@ -160,13 +58,10 @@ func readInteger(kind reflect.Kind, b []byte) interface{} {
}
}
+// reads a bool
func readBool(word []byte) (bool, error) {
- if len(word) != 32 {
- return false, fmt.Errorf("abi: fatal error: incorrect word length")
- }
-
- for i, b := range word {
- if b != 0 && i != 31 {
+ for _, b := range word[:31] {
+ if b != 0 {
return false, errBadBool
}
}
@@ -178,58 +73,144 @@ func readBool(word []byte) (bool, error) {
default:
return false, errBadBool
}
+}
+// A function type is simply the address with the function selection signature at the end.
+// This enforces that standard by always presenting it as a 24-array (address + sig = 24 bytes)
+func readFunctionType(t Type, word []byte) (funcTy [24]byte, err error) {
+ if t.T != FunctionTy {
+ return [24]byte{}, fmt.Errorf("abi: invalid type in call to make function type byte array.")
+ }
+ if garbage := binary.BigEndian.Uint64(word[24:32]); garbage != 0 {
+ err = fmt.Errorf("abi: got improperly encoded function type, got %v", word)
+ } else {
+ copy(funcTy[:], word[0:24])
+ }
+ return
}
-// toGoType parses the input and casts it to the proper type defined by the ABI
-// argument in T.
-func toGoType(i int, t Argument, output []byte) (interface{}, error) {
- // we need to treat slices differently
- if (t.Type.IsSlice || t.Type.IsArray) && t.Type.T != BytesTy && t.Type.T != StringTy && t.Type.T != FixedBytesTy && t.Type.T != FunctionTy {
- return toGoSlice(i, t, output)
+// through reflection, creates a fixed array to be read from
+func readFixedBytes(t Type, word []byte) (interface{}, error) {
+ if t.T != FixedBytesTy {
+ return nil, fmt.Errorf("abi: invalid type in call to make fixed byte array.")
}
+ // convert
+ array := reflect.New(t.Type).Elem()
- index := i * 32
- if index+32 > len(output) {
- return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), index+32)
+ reflect.Copy(array, reflect.ValueOf(word[0:t.Size]))
+ return array.Interface(), nil
+
+}
+
+// iteratively unpack elements
+func forEachUnpack(t Type, output []byte, start, size int) (interface{}, error) {
+ if start+32*size > len(output) {
+ return nil, fmt.Errorf("abi: cannot marshal in to go array: offset %d would go over slice boundary (len=%d)", len(output), start+32*size)
}
- // Parse the given index output and check whether we need to read
- // a different offset and length based on the type (i.e. string, bytes)
- var returnOutput []byte
- switch t.Type.T {
- case StringTy, BytesTy: // variable arrays are written at the end of the return bytes
- // parse offset from which we should start reading
- offset := int(binary.BigEndian.Uint64(output[index+24 : index+32]))
- if offset+32 > len(output) {
- return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), offset+32)
+ // this value will become our slice or our array, depending on the type
+ var refSlice reflect.Value
+ slice := output[start : start+size*32]
+
+ if t.T == SliceTy {
+ // declare our slice
+ refSlice = reflect.MakeSlice(t.Type, size, size)
+ } else if t.T == ArrayTy {
+ // declare our array
+ refSlice = reflect.New(t.Type).Elem()
+ } else {
+ return nil, fmt.Errorf("abi: invalid type in array/slice unpacking stage")
+ }
+
+ for i, j := start, 0; j*32 < len(slice); i, j = i+32, j+1 {
+ // this corrects the arrangement so that we get all the underlying array values
+ if t.Elem.T == ArrayTy && j != 0 {
+ i = start + t.Elem.Size*32*j
}
- // parse the size up until we should be reading
- size := int(binary.BigEndian.Uint64(output[offset+24 : offset+32]))
- if offset+32+size > len(output) {
- return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), offset+32+size)
+ inter, err := toGoType(i, *t.Elem, output)
+ if err != nil {
+ return nil, err
}
+ // append the item to our reflect slice
+ refSlice.Index(j).Set(reflect.ValueOf(inter))
+ }
- // get the bytes for this return value
- returnOutput = output[offset+32 : offset+32+size]
- default:
+ // return the interface
+ return refSlice.Interface(), nil
+}
+
+// toGoType parses the output bytes and recursively assigns the value of these bytes
+// into a go type with accordance with the ABI spec.
+func toGoType(index int, t Type, output []byte) (interface{}, error) {
+ if index+32 > len(output) {
+ return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), index+32)
+ }
+
+ var (
+ returnOutput []byte
+ begin, end int
+ err error
+ )
+
+ // if we require a length prefix, find the beginning word and size returned.
+ if t.requiresLengthPrefix() {
+ begin, end, err = lengthPrefixPointsTo(index, output)
+ if err != nil {
+ return nil, err
+ }
+ } else {
returnOutput = output[index : index+32]
}
- // convert the bytes to whatever is specified by the ABI.
- switch t.Type.T {
+ switch t.T {
+ case SliceTy:
+ return forEachUnpack(t, output, begin, end)
+ case ArrayTy:
+ return forEachUnpack(t, output, index, t.Size)
+ case StringTy: // variable arrays are written at the end of the return bytes
+ return string(output[begin : begin+end]), nil
case IntTy, UintTy:
- return readInteger(t.Type.Kind, returnOutput), nil
+ return readInteger(t.Kind, returnOutput), nil
case BoolTy:
return readBool(returnOutput)
case AddressTy:
return common.BytesToAddress(returnOutput), nil
case HashTy:
return common.BytesToHash(returnOutput), nil
- case BytesTy, FixedBytesTy, FunctionTy:
- return returnOutput, nil
- case StringTy:
- return string(returnOutput), nil
+ case BytesTy:
+ return output[begin : begin+end], nil
+ case FixedBytesTy:
+ return readFixedBytes(t, returnOutput)
+ case FunctionTy:
+ return readFunctionType(t, returnOutput)
+ default:
+ return nil, fmt.Errorf("abi: unknown type %v", t.T)
+ }
+}
+
+// interprets a 32 byte slice as an offset and then determines which indice to look to decode the type.
+func lengthPrefixPointsTo(index int, output []byte) (start int, length int, err error) {
+ offset := int(binary.BigEndian.Uint64(output[index+24 : index+32]))
+ if offset+32 > len(output) {
+ return 0, 0, fmt.Errorf("abi: cannot marshal in to go slice: offset %d would go over slice boundary (len=%d)", len(output), offset+32)
+ }
+ length = int(binary.BigEndian.Uint64(output[offset+24 : offset+32]))
+ if offset+32+length > len(output) {
+ return 0, 0, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), offset+32+length)
+ }
+ start = offset + 32
+
+ //fmt.Printf("LENGTH PREFIX INFO: \nsize: %v\noffset: %v\nstart: %v\n", length, offset, start)
+ return
+}
+
+// checks for proper formatting of byte output
+func bytesAreProper(output []byte) error {
+ if len(output) == 0 {
+ return fmt.Errorf("abi: unmarshalling empty output")
+ } else if len(output)%32 != 0 {
+ return fmt.Errorf("abi: improperly formatted output")
+ } else {
+ return nil
}
- return nil, fmt.Errorf("abi: unknown type %v", t.Type.T)
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 14:45:15 +0800