accounts/abi: reorganizing package with small fixes (#14610)

* accounts/abi: reorganizing package and some notes and a quick correction of name.

Signed-off-by: RJ Catalano <rj@monax.io>

get rid of some imports

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: move file names

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: fix boolean decode function

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: fix for the array set and for creating a bool

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: be very very very correct

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: fix up error message and variable names

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: take out unnecessary argument in pack method

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: add bool unpack test and add a panic to readBool function

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: fix panic message

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: change from panic to basic error

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: fix nil to false

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: fill out type regex tests and fill with the correct type for integers

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: move packNumbers into pack.go.

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: separation of the testing suite into appropriately named files.

Signed-off-by: RJ Catalano <rj@monax.io>

* account/abi: change to hex string tests.

Signed-off-by: RJ Catalano <rj@monax.io>

* account/abi: fix up rest of tests to hex

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: declare bool at the package level

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: use errors package in the error file.

Signed-off-by: RJ Catalano <rj@monax.io>

* accounts/abi: fix ugly hack and fix error type declaration.

Signed-off-by: RJ Catalano <rj@monax.io>

1 files changed, 235 insertions, 0 deletions

diff --git a/accounts/abi/unpack.go b/accounts/abi/unpack.go
new file mode 100644
index 000000000..fc41c88ac
--- /dev/null
+++ b/accounts/abi/unpack.go
@@ -0,0 +1,235 @@
+// Copyright 2015 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 abi
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math/big"
+	"reflect"
+
+	"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
+}
+
+func readInteger(kind reflect.Kind, b []byte) interface{} {
+	switch kind {
+	case reflect.Uint8:
+		return uint8(b[len(b)-1])
+	case reflect.Uint16:
+		return binary.BigEndian.Uint16(b[len(b)-2:])
+	case reflect.Uint32:
+		return binary.BigEndian.Uint32(b[len(b)-4:])
+	case reflect.Uint64:
+		return binary.BigEndian.Uint64(b[len(b)-8:])
+	case reflect.Int8:
+		return int8(b[len(b)-1])
+	case reflect.Int16:
+		return int16(binary.BigEndian.Uint16(b[len(b)-2:]))
+	case reflect.Int32:
+		return int32(binary.BigEndian.Uint32(b[len(b)-4:]))
+	case reflect.Int64:
+		return int64(binary.BigEndian.Uint64(b[len(b)-8:]))
+	default:
+		return new(big.Int).SetBytes(b)
+	}
+}
+
+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 {
+			return false, errBadBool
+		}
+	}
+	switch word[31] {
+	case 0:
+		return false, nil
+	case 1:
+		return true, nil
+	default:
+		return false, errBadBool
+	}
+
+}
+
+// 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)
+	}
+
+	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)
+	}
+
+	// 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)
+		}
+		// 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)
+		}
+
+		// get the bytes for this return value
+		returnOutput = output[offset+32 : offset+32+size]
+	default:
+		returnOutput = output[index : index+32]
+	}
+
+	// convert the bytes to whatever is specified by the ABI.
+	switch t.Type.T {
+	case IntTy, UintTy:
+		return readInteger(t.Type.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
+	}
+	return nil, fmt.Errorf("abi: unknown type %v", t.Type.T)
+}