path: root/tests/difficulty_test_util.go

// Copyright 2017 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 tests

import (
    "fmt"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/common/math"
    "github.com/ethereum/go-ethereum/consensus/ethash"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/params"
)

//go:generate gencodec -type DifficultyTest -field-override difficultyTestMarshaling -out gen_difficultytest.go

type DifficultyTest struct {
    ParentTimestamp    *big.Int    `json:"parentTimestamp"`
    ParentDifficulty   *big.Int    `json:"parentDifficulty"`
    UncleHash          common.Hash `json:"parentUncles"`
    CurrentTimestamp   *big.Int    `json:"currentTimestamp"`
    CurrentBlockNumber uint64      `json:"currentBlockNumber"`
    CurrentDifficulty  *big.Int    `json:"currentDifficulty"`
}

type difficultyTestMarshaling struct {
    ParentTimestamp    *math.HexOrDecimal256
    ParentDifficulty   *math.HexOrDecimal256
    CurrentTimestamp   *math.HexOrDecimal256
    CurrentDifficulty  *math.HexOrDecimal256
    UncleHash          common.Hash
    CurrentBlockNumber math.HexOrDecimal64
}

func (test *DifficultyTest) Run(config *params.ChainConfig) error {
    parentNumber := big.NewInt(int64(test.CurrentBlockNumber - 1))
    parent := &types.Header{
        Difficulty: test.ParentDifficulty,
        Time:       test.ParentTimestamp,
        Number:     parentNumber,
        UncleHash:  test.UncleHash,
    }

    actual := ethash.CalcDifficulty(config, test.CurrentTimestamp.Uint64(), parent)
    exp := test.CurrentDifficulty

    if actual.Cmp(exp) != 0 {
        return fmt.Errorf("parent[time %v diff %v unclehash:%x] child[time %v number %v] diff %v != expected %v",
            test.ParentTimestamp, test.ParentDifficulty, test.UncleHash,
            test.CurrentTimestamp, test.CurrentBlockNumber, actual, exp)
    }
    return nil

}