1 files changed, 79 insertions, 0 deletions
diff --git a/accounts/abi/pack.go b/accounts/abi/pack.go
new file mode 100644
index 000000000..4d8a3f031
--- /dev/null
+++ b/accounts/abi/pack.go
@@ -0,0 +1,79 @@
+// Copyright 2016 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 (
+	"math/big"
+	"reflect"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+)
+
+// packBytesSlice packs the given bytes as [L, V] as the canonical representation
+// bytes slice
+func packBytesSlice(bytes []byte, l int) []byte {
+	len := packNum(reflect.ValueOf(l))
+	return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
+}
+
+// packElement packs the given reflect value according to the abi specification in
+// t.
+func packElement(t Type, reflectValue reflect.Value) []byte {
+	switch t.T {
+	case IntTy, UintTy:
+		return packNum(reflectValue)
+	case StringTy:
+		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
+	case AddressTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+
+		return common.LeftPadBytes(reflectValue.Bytes(), 32)
+	case BoolTy:
+		if reflectValue.Bool() {
+			return math.PaddedBigBytes(common.Big1, 32)
+		} else {
+			return math.PaddedBigBytes(common.Big0, 32)
+		}
+	case BytesTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
+	case FixedBytesTy, FunctionTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+		return common.RightPadBytes(reflectValue.Bytes(), 32)
+	}
+	panic("abi: fatal error")
+}
+
+// packNum packs the given number (using the reflect value) and will cast it to appropriate number representation
+func packNum(value reflect.Value) []byte {
+	switch kind := value.Kind(); kind {
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return U256(new(big.Int).SetUint64(value.Uint()))
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return U256(big.NewInt(value.Int()))
+	case reflect.Ptr:
+		return U256(value.Interface().(*big.Int))
+	}
+	return nil
+}