path: root/core/vm/oracle.go

// Copyright 2019 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus 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 dexon-consensus 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 dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.

package vm

import (
    "strings"

    "github.com/dexon-foundation/dexon/accounts/abi"
    "github.com/dexon-foundation/dexon/common"
)

var GovernanceContractAddress = common.HexToAddress("63751838d6485578b23e8b051d40861ecc416794")

var GovernanceABI *OracleContractABI

func init() {
    GovernanceABI = NewOracleContractABI(GovernanceABIJSON)
}

// OracleContract represent special system contracts written in Go.
type OracleContract interface {
    Run(evm *EVM, input []byte, contract *Contract) (ret []byte, err error)
}

// A map representing available system oracle contracts.
var OracleContracts = map[common.Address]func() OracleContract{
    GovernanceContractAddress: func() OracleContract {
        return &GovernanceContract{
            coreDKGUtils: &defaultCoreDKGUtils{},
        }
    },
}

// Run oracle contract.
func RunOracleContract(oracle OracleContract, evm *EVM, input []byte, contract *Contract) (ret []byte, err error) {
    return oracle.Run(evm, input, contract)
}

// OracleContractABI represents ABI information for a given contract.
type OracleContractABI struct {
    ABI         abi.ABI
    Name2Method map[string]abi.Method
    Sig2Method  map[string]abi.Method
    Events      map[string]abi.Event
}

// NewOracleContractABI parse the ABI.
func NewOracleContractABI(abiDefinition string) *OracleContractABI {
    abiObject, err := abi.JSON(strings.NewReader(abiDefinition))
    if err != nil {
        panic(err)
    }

    sig2Method := make(map[string]abi.Method)
    name2Method := make(map[string]abi.Method)

    for _, method := range abiObject.Methods {
        sig2Method[string(method.Id())] = method
        name2Method[method.Name] = method
    }

    events := make(map[string]abi.Event)
    for _, event := range abiObject.Events {
        events[event.Name] = event
    }

    return &OracleContractABI{
        ABI:         abiObject,
        Name2Method: name2Method,
        Sig2Method:  sig2Method,
        Events:      events,
    }
}