// Copyright 2018 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 downloader
import (
"fmt"
"math/big"
"sync"
"github.com/dexon-foundation/dexon/common"
"github.com/dexon-foundation/dexon/consensus/ethash"
"github.com/dexon-foundation/dexon/core"
"github.com/dexon-foundation/dexon/core/types"
"github.com/dexon-foundation/dexon/crypto"
"github.com/dexon-foundation/dexon/ethdb"
"github.com/dexon-foundation/dexon/params"
)
// Test chain parameters.
var (
testKey, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
testAddress = crypto.PubkeyToAddress(testKey.PublicKey)
testDB = ethdb.NewMemDatabase()
testGenesis = core.GenesisBlockForTesting(testDB, testAddress, big.NewInt(1000000000))
)
// The common prefix of all test chains:
var testChainBase = newTestChain(blockCacheItems+200, testGenesis)
// Different forks on top of the base chain:
var testChainForkLightA, testChainForkLightB, testChainForkHeavy *testChain
func init() {
var forkLen = int(MaxForkAncestry + 50)
var wg sync.WaitGroup
wg.Add(3)
go func() { testChainForkLightA = testChainBase.makeFork(forkLen, false, 1); wg.Done() }()
go func() { testChainForkLightB = testChainBase.makeFork(forkLen, false, 2); wg.Done() }()
go func() { testChainForkHeavy = testChainBase.makeFork(forkLen, true, 3); wg.Done() }()
wg.Wait()
}
type testChain struct {
genesis *types.Block
chain []common.Hash
headerm map[common.Hash]*types.Header
blockm map[common.Hash]*types.Block
receiptm map[common.Hash][]*types.Receipt
tdm map[common.Hash]*big.Int
}
// newTestChain creates a blockchain of the given length.
func newTestChain(length int, genesis *types.Block) *testChain {
tc := new(testChain).copy(length)
tc.genesis = genesis
tc.chain = append(tc.chain, genesis.Hash())
tc.headerm[tc.genesis.Hash()] = tc.genesis.Header()
tc.tdm[tc.genesis.Hash()] = tc.genesis.Difficulty()
tc.blockm[tc.genesis.Hash()] = tc.genesis
tc.generate(length-1, 0, genesis, false)
return tc
}
// makeFork creates a fork on top of the test chain.
func (tc *testChain) makeFork(length int, heavy bool, seed byte) *testChain {
fork := tc.copy(tc.len() + length)
fork.generate(length, seed, tc.headBlock(), heavy)
return fork
}
// shorten creates a copy of the chain with the given length. It panics if the
// length is longer than the number of available blocks.
func (tc *testChain) shorten(length int) *testChain {
if length > tc.len() {
panic(fmt.Errorf("can't shorten test chain to %d blocks, it's only %d blocks long", length, tc.len()))
}
return tc.copy(length)
}
func (tc *testChain) copy(newlen int) *testChain {
cpy := &testChain{
genesis: tc.genesis,
headerm: make(map[common.Hash]*types.Header, newlen),
blockm: make(map[common.Hash]*types.Block, newlen),
receiptm: make(map[common.Hash][]*types.Receipt, newlen),
tdm: make(map[common.Hash]*big.Int, newlen),
}
for i := 0; i < len(tc.chain) && i < newlen; i++ {
hash := tc.chain[i]
cpy.chain = append(cpy.chain, tc.chain[i])
cpy.tdm[hash] = tc.tdm[hash]
cpy.blockm[hash] = tc.blockm[hash]
cpy.headerm[hash] = tc.headerm[hash]
cpy.receiptm[hash] = tc.receiptm[hash]
}
return cpy
}
// generate creates a chain of n blocks starting at and including parent.
// the returned hash chain is ordered head->parent. In addition, every 22th block
// contains a transaction and every 5th an uncle to allow testing correct block
// reassembly.
func (tc *testChain) generate(n int, seed byte, parent *types.Block, heavy bool) {
// start := time.Now()
// defer func() { fmt.Printf("test chain generated in %v\n", time.Since(start)) }()
blocks, receipts := core.GenerateChain(params.TestChainConfig, parent, ethash.NewFaker(), testDB, n, func(i int, block *core.BlockGen) {
block.SetCoinbase(common.Address{seed})
// If a heavy chain is requested, delay blocks to raise difficulty
if heavy {
block.OffsetTime(-1)
}
// Include transactions to the miner to make blocks more interesting.
if parent == tc.genesis && i%22 == 0 {
signer := types.MakeSigner(params.TestChainConfig, block.Number())
tx, err := types.SignTx(types.NewTransaction(block.TxNonce(testAddress), common.Address{seed}, big.NewInt(1000), params.TxGas, nil, nil), signer, testKey)
if err != nil {
panic(err)
}
block.AddTx(tx)
}
// if the block number is a multiple of 5, add a bonus uncle to the block
if i > 0 && i%5 == 0 {
block.AddUncle(&types.Header{
ParentHash: block.PrevBlock(i - 1).Hash(),
Number: big.NewInt(block.Number().Int64() - 1),
})
}
})
// Convert the block-chain into a hash-chain and header/block maps
td := new(big.Int).Set(tc.td(parent.Hash()))
for i, b := range blocks {
td := td.Add(td, b.Difficulty())
hash := b.Hash()
tc.chain = append(tc.chain, hash)
tc.blockm[hash] = b
tc.headerm[hash] = b.Header()
tc.receiptm[hash] = receipts[i]
tc.tdm[hash] = new(big.Int).Set(td)
}
}
// len returns the total number of blocks in the chain.
func (tc *testChain) len() int {
return len(tc.chain)
}
// headBlock returns the head of the chain.
func (tc *testChain) headBlock() *types.Block {
return tc.blockm[tc.chain[len(tc.chain)-1]]
}
// td returns the total difficulty of the given block.
func (tc *testChain) td(hash common.Hash) *big.Int {
return tc.tdm[hash]
}
// headersByHash returns headers in ascending order from the given hash.
func (tc *testChain) headersByHash(origin common.Hash, amount int, skip int) []*types.Header {
num, _ := tc.hashToNumber(origin)
return tc.headersByNumber(num, amount, skip)
}
// headersByNumber returns headers in ascending order from the given number.
func (tc *testChain) headersByNumber(origin uint64, amount int, skip int) []*types.Header {
result := make([]*types.Header, 0, amount)
for num := origin; num < uint64(len(tc.chain)) && len(result) < amount; num += uint64(skip) + 1 {
if header, ok := tc.headerm[tc.chain[int(num)]]; ok {
result = append(result, header)
}
}
return result
}
// receipts returns the receipts of the given block hashes.
func (tc *testChain) receipts(hashes []common.Hash) [][]*types.Receipt {
results := make([][]*types.Receipt, 0, len(hashes))
for _, hash := range hashes {
if receipt, ok := tc.receiptm[hash]; ok {
results = append(results, receipt)
}
}
return results
}
// bodies returns the block bodies of the given block hashes.
func (tc *testChain) bodies(hashes []common.Hash) ([][]*types.Transaction, [][]*types.Header) {
transactions := make([][]*types.Transaction, 0, len(hashes))
uncles := make([][]*types.Header, 0, len(hashes))
for _, hash := range hashes {
if block, ok := tc.blockm[hash]; ok {
transactions = append(transactions, block.Transactions())
uncles = append(uncles, block.Uncles())
}
}
return transactions, uncles
}
func (tc *testChain) hashToNumber(target common.Hash) (uint64, bool) {
for num, hash := range tc.chain {
if hash == target {
return uint64(num), true
}
}
return 0, false
}
