1 files changed, 76 insertions, 0 deletions
diff --git a/accounts/abi/method.go b/accounts/abi/method.go
new file mode 100644
index 000000000..63194e788
--- /dev/null
+++ b/accounts/abi/method.go
@@ -0,0 +1,76 @@
+// 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 (
+	"fmt"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+// Callable method given a `Name` and whether the method is a constant.
+// If the method is `Const` no transaction needs to be created for this
+// particular Method call. It can easily be simulated using a local VM.
+// For example a `Balance()` method only needs to retrieve something
+// from the storage and therefor requires no Tx to be send to the
+// network. A method such as `Transact` does require a Tx and thus will
+// be flagged `true`.
+// Input specifies the required input parameters for this gives method.
+type Method struct {
+	Name    string
+	Const   bool
+	Inputs  []Argument
+	Outputs []Argument
+}
+
+// Sig returns the methods string signature according to the ABI spec.
+//
+// Example
+//
+//     function foo(uint32 a, int b)    =    "foo(uint32,int256)"
+//
+// Please note that "int" is substitute for its canonical representation "int256"
+func (m Method) Sig() string {
+	types := make([]string, len(m.Inputs))
+	i := 0
+	for _, input := range m.Inputs {
+		types[i] = input.Type.String()
+		i++
+	}
+	return fmt.Sprintf("%v(%v)", m.Name, strings.Join(types, ","))
+}
+
+func (m Method) String() string {
+	inputs := make([]string, len(m.Inputs))
+	for i, input := range m.Inputs {
+		inputs[i] = fmt.Sprintf("%v %v", input.Name, input.Type)
+	}
+	outputs := make([]string, len(m.Outputs))
+	for i, output := range m.Outputs {
+		if len(output.Name) > 0 {
+			outputs[i] = fmt.Sprintf("%v ", output.Name)
+		}
+		outputs[i] += output.Type.String()
+	}
+
+	return fmt.Sprintf("function %v(%v) returns(%v)", m.Name, strings.Join(inputs, ", "), strings.Join(outputs, ", "))
+}
+
+func (m Method) Id() []byte {
+	return crypto.Sha3([]byte(m.Sig()))[:4]
+}