go-ethereum/accounts/abi/event.go

78 lines
2.6 KiB
Go

// 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 (
"fmt"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
)
// Event is an event potentially triggered by the EVM's LOG mechanism. The Event
// holds type information (inputs) about the yielded output. Anonymous events
// don't get the signature canonical representation as the first LOG topic.
type Event struct {
// Name is the event name used for internal representation. It's derived from
// the raw name and a suffix will be added in the case of a event overload.
//
// e.g.
// There are two events have same name:
// * foo(int,int)
// * foo(uint,uint)
// The event name of the first one wll be resolved as foo while the second one
// will be resolved as foo0.
Name string
// RawName is the raw event name parsed from ABI.
RawName string
Anonymous bool
Inputs Arguments
}
func (e Event) String() string {
inputs := make([]string, len(e.Inputs))
for i, input := range e.Inputs {
inputs[i] = fmt.Sprintf("%v %v", input.Type, input.Name)
if input.Indexed {
inputs[i] = fmt.Sprintf("%v indexed %v", input.Type, input.Name)
}
}
return fmt.Sprintf("event %v(%v)", e.RawName, strings.Join(inputs, ", "))
}
// Sig returns the event string signature according to the ABI spec.
//
// Example
//
// event foo(uint32 a, int b) = "foo(uint32,int256)"
//
// Please note that "int" is substitute for its canonical representation "int256"
func (e Event) Sig() string {
types := make([]string, len(e.Inputs))
for i, input := range e.Inputs {
types[i] = input.Type.String()
}
return fmt.Sprintf("%v(%v)", e.RawName, strings.Join(types, ","))
}
// ID returns the canonical representation of the event's signature used by the
// abi definition to identify event names and types.
func (e Event) ID() common.Hash {
return common.BytesToHash(crypto.Keccak256([]byte(e.Sig())))
}