github.com/FinTechToken/go-ethereum@v1.8.4-0.20190621030324-0b02bfba9171/consensus/ethash/consensus.go (about) 1 // Copyright 2017 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 package ethash 18 19 import ( 20 "bytes" 21 "errors" 22 "fmt" 23 "math/big" 24 "runtime" 25 "time" 26 27 "github.com/ethereum/go-ethereum/log" 28 29 mapset "github.com/deckarep/golang-set" 30 "github.com/ethereum/go-ethereum/common" 31 "github.com/ethereum/go-ethereum/common/math" 32 "github.com/ethereum/go-ethereum/consensus" 33 "github.com/ethereum/go-ethereum/consensus/misc" 34 "github.com/ethereum/go-ethereum/core/state" 35 "github.com/ethereum/go-ethereum/core/types" 36 "github.com/ethereum/go-ethereum/params" 37 "github.com/ethereum/go-ethereum/rlp" 38 "golang.org/x/crypto/sha3" 39 ) 40 41 // Ethash proof-of-work protocol constants. 42 var ( 43 FrontierBlockReward = big.NewInt(5e+18) // Block reward in wei for successfully mining a block 44 ByzantiumBlockReward = big.NewInt(0) // Block reward in wei for successfully mining a block upward from Byzantium 45 ConstantinopleBlockReward = big.NewInt(2e+18) // Block reward in wei for successfully mining a block upward from Constantinople 46 maxUncles = 2 // Maximum number of uncles allowed in a single block 47 allowedFutureBlockTime = 15 * time.Second // Max time from current time allowed for blocks, before they're considered future blocks 48 49 // calcDifficultyConstantinople is the difficulty adjustment algorithm for Constantinople. 50 // It returns the difficulty that a new block should have when created at time given the 51 // parent block's time and difficulty. The calculation uses the Byzantium rules, but with 52 // bomb offset 5M. 53 // Specification EIP-1234: https://eips.ethereum.org/EIPS/eip-1234 54 calcDifficultyConstantinople = makeDifficultyCalculator(big.NewInt(5000000)) 55 56 // calcDifficultyByzantium is the difficulty adjustment algorithm. It returns 57 // the difficulty that a new block should have when created at time given the 58 // parent block's time and difficulty. The calculation uses the Byzantium rules. 59 // Specification EIP-649: https://eips.ethereum.org/EIPS/eip-649 60 calcDifficultyByzantium = makeDifficultyCalculator(big.NewInt(3000000)) 61 ) 62 63 // Various error messages to mark blocks invalid. These should be private to 64 // prevent engine specific errors from being referenced in the remainder of the 65 // codebase, inherently breaking if the engine is swapped out. Please put common 66 // error types into the consensus package. 67 var ( 68 errZeroBlockTime = errors.New("timestamp equals parent's") 69 errTooManyUncles = errors.New("too many uncles") 70 errDuplicateUncle = errors.New("duplicate uncle") 71 errUncleIsAncestor = errors.New("uncle is ancestor") 72 errDanglingUncle = errors.New("uncle's parent is not ancestor") 73 errInvalidDifficulty = errors.New("non-positive difficulty") 74 errInvalidMixDigest = errors.New("invalid mix digest") 75 errInvalidPoW = errors.New("invalid proof-of-work") 76 ) 77 78 // Author implements consensus.Engine, returning the header's coinbase as the 79 // proof-of-work verified author of the block. 80 func (ethash *Ethash) Author(header *types.Header) (common.Address, error) { 81 return header.Coinbase, nil 82 } 83 84 // VerifyHeader checks whether a header conforms to the consensus rules of the 85 // stock Ethereum ethash engine. 86 func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error { 87 // If we're running a full engine faking, accept any input as valid 88 if ethash.config.PowMode == ModeFullFake { 89 return nil 90 } 91 // Short circuit if the header is known, or it's parent not 92 number := header.Number.Uint64() 93 if chain.GetHeader(header.Hash(), number) != nil { 94 return nil 95 } 96 parent := chain.GetHeader(header.ParentHash, number-1) 97 if parent == nil { 98 return consensus.ErrUnknownAncestor 99 } 100 // Sanity checks passed, do a proper verification 101 return ethash.verifyHeader(chain, header, parent, false, seal) 102 } 103 104 // VerifyHeaders is similar to VerifyHeader, but verifies a batch of headers 105 // concurrently. The method returns a quit channel to abort the operations and 106 // a results channel to retrieve the async verifications. 107 func (ethash *Ethash) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) { 108 // If we're running a full engine faking, accept any input as valid 109 if ethash.config.PowMode == ModeFullFake || len(headers) == 0 { 110 abort, results := make(chan struct{}), make(chan error, len(headers)) 111 for i := 0; i < len(headers); i++ { 112 results <- nil 113 } 114 return abort, results 115 } 116 117 // Spawn as many workers as allowed threads 118 workers := runtime.GOMAXPROCS(0) 119 if len(headers) < workers { 120 workers = len(headers) 121 } 122 123 // Create a task channel and spawn the verifiers 124 var ( 125 inputs = make(chan int) 126 done = make(chan int, workers) 127 errors = make([]error, len(headers)) 128 abort = make(chan struct{}) 129 ) 130 for i := 0; i < workers; i++ { 131 go func() { 132 for index := range inputs { 133 errors[index] = ethash.verifyHeaderWorker(chain, headers, seals, index) 134 done <- index 135 } 136 }() 137 } 138 139 errorsOut := make(chan error, len(headers)) 140 go func() { 141 defer close(inputs) 142 var ( 143 in, out = 0, 0 144 checked = make([]bool, len(headers)) 145 inputs = inputs 146 ) 147 for { 148 select { 149 case inputs <- in: 150 if in++; in == len(headers) { 151 // Reached end of headers. Stop sending to workers. 152 inputs = nil 153 } 154 case index := <-done: 155 for checked[index] = true; checked[out]; out++ { 156 errorsOut <- errors[out] 157 if out == len(headers)-1 { 158 return 159 } 160 } 161 case <-abort: 162 return 163 } 164 } 165 }() 166 return abort, errorsOut 167 } 168 169 func (ethash *Ethash) verifyHeaderWorker(chain consensus.ChainReader, headers []*types.Header, seals []bool, index int) error { 170 var parent *types.Header 171 if index == 0 { 172 parent = chain.GetHeader(headers[0].ParentHash, headers[0].Number.Uint64()-1) 173 } else if headers[index-1].Hash() == headers[index].ParentHash { 174 parent = headers[index-1] 175 } 176 if parent == nil { 177 return consensus.ErrUnknownAncestor 178 } 179 if chain.GetHeader(headers[index].Hash(), headers[index].Number.Uint64()) != nil { 180 return nil // known block 181 } 182 return ethash.verifyHeader(chain, headers[index], parent, false, seals[index]) 183 } 184 185 // VerifyUncles verifies that the given block's uncles conform to the consensus 186 // rules of the stock Ethereum ethash engine. 187 func (ethash *Ethash) VerifyUncles(chain consensus.ChainReader, block *types.Block) error { 188 // If we're running a full engine faking, accept any input as valid 189 if ethash.config.PowMode == ModeFullFake { 190 return nil 191 } 192 // Verify that there are at most 2 uncles included in this block 193 if len(block.Uncles()) > maxUncles { 194 return errTooManyUncles 195 } 196 // Gather the set of past uncles and ancestors 197 uncles, ancestors := mapset.NewSet(), make(map[common.Hash]*types.Header) 198 199 number, parent := block.NumberU64()-1, block.ParentHash() 200 for i := 0; i < 7; i++ { 201 ancestor := chain.GetBlock(parent, number) 202 if ancestor == nil { 203 break 204 } 205 ancestors[ancestor.Hash()] = ancestor.Header() 206 for _, uncle := range ancestor.Uncles() { 207 uncles.Add(uncle.Hash()) 208 } 209 parent, number = ancestor.ParentHash(), number-1 210 } 211 ancestors[block.Hash()] = block.Header() 212 uncles.Add(block.Hash()) 213 214 // Verify each of the uncles that it's recent, but not an ancestor 215 for _, uncle := range block.Uncles() { 216 // Make sure every uncle is rewarded only once 217 hash := uncle.Hash() 218 if uncles.Contains(hash) { 219 return errDuplicateUncle 220 } 221 uncles.Add(hash) 222 223 // Make sure the uncle has a valid ancestry 224 if ancestors[hash] != nil { 225 return errUncleIsAncestor 226 } 227 if ancestors[uncle.ParentHash] == nil || uncle.ParentHash == block.ParentHash() { 228 return errDanglingUncle 229 } 230 if err := ethash.verifyHeader(chain, uncle, ancestors[uncle.ParentHash], true, true); err != nil { 231 return err 232 } 233 } 234 return nil 235 } 236 237 // verifyHeader checks whether a header conforms to the consensus rules of the 238 // stock Ethereum ethash engine. 239 // See YP section 4.3.4. "Block Header Validity" 240 func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *types.Header, uncle bool, seal bool) error { 241 // Ensure that the header's extra-data section is of a reasonable size 242 if uint64(len(header.Extra)) > params.MaximumExtraDataSize { 243 return fmt.Errorf("extra-data too long: %d > %d", len(header.Extra), params.MaximumExtraDataSize) 244 } 245 // Verify the header's timestamp 246 if !uncle { 247 if header.Time > uint64(time.Now().Add(allowedFutureBlockTime).Unix()) { 248 return consensus.ErrFutureBlock 249 } 250 } 251 if header.Time <= parent.Time { 252 return errZeroBlockTime 253 } 254 // Verify the block's difficulty based in it's timestamp and parent's difficulty 255 expected := ethash.CalcDifficulty(chain, header.Time, parent) 256 257 if expected.Cmp(header.Difficulty) != 0 { 258 return fmt.Errorf("invalid difficulty: have %v, want %v", header.Difficulty, expected) 259 } 260 // Verify that the gas limit is <= 2^63-1 261 cap := uint64(0x7fffffffffffffff) 262 if header.GasLimit > cap { 263 return fmt.Errorf("invalid gasLimit: have %v, max %v", header.GasLimit, cap) 264 } 265 // Verify that the gasUsed is <= gasLimit 266 if header.GasUsed > header.GasLimit { 267 return fmt.Errorf("invalid gasUsed: have %d, gasLimit %d", header.GasUsed, header.GasLimit) 268 } 269 270 // Verify that the gas limit remains within allowed bounds 271 diff := int64(parent.GasLimit) - int64(header.GasLimit) 272 if diff < 0 { 273 diff *= -1 274 } 275 limit := parent.GasLimit / params.GasLimitBoundDivisor 276 277 if uint64(diff) >= limit || header.GasLimit < params.MinGasLimit { 278 return fmt.Errorf("invalid gas limit: have %d, want %d += %d", header.GasLimit, parent.GasLimit, limit) 279 } 280 // Verify that the block number is parent's +1 281 if diff := new(big.Int).Sub(header.Number, parent.Number); diff.Cmp(big.NewInt(1)) != 0 { 282 return consensus.ErrInvalidNumber 283 } 284 // Verify the engine specific seal securing the block 285 if seal { 286 if err := ethash.VerifySeal(chain, header); err != nil { 287 return err 288 } 289 } 290 // If all checks passed, validate any special fields for hard forks 291 if err := misc.VerifyDAOHeaderExtraData(chain.Config(), header); err != nil { 292 return err 293 } 294 if err := misc.VerifyForkHashes(chain.Config(), header, uncle); err != nil { 295 return err 296 } 297 return nil 298 } 299 300 // CalcDifficulty is the difficulty adjustment algorithm. It returns 301 // the difficulty that a new block should have when created at time 302 // given the parent block's time and difficulty. 303 func (ethash *Ethash) CalcDifficulty(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int { 304 return CalcDifficulty(chain.Config(), time, parent) 305 } 306 307 // CalcDifficulty is the difficulty adjustment algorithm. It returns 308 // the difficulty that a new block should have when created at time 309 // given the parent block's time and difficulty. 310 func CalcDifficulty(config *params.ChainConfig, time uint64, parent *types.Header) *big.Int { 311 next := new(big.Int).Add(parent.Number, big1) 312 return calcDifficultyByzantium(time, parent) 313 switch { 314 case config.IsConstantinople(next): 315 return calcDifficultyConstantinople(time, parent) 316 case config.IsByzantium(next): 317 return calcDifficultyByzantium(time, parent) 318 case config.IsHomestead(next): 319 return calcDifficultyHomestead(time, parent) 320 default: 321 return calcDifficultyFrontier(time, parent) 322 } 323 } 324 325 // Some weird constants to avoid constant memory allocs for them. 326 var ( 327 expDiffPeriod = big.NewInt(100000) 328 big0 = big.NewInt(0) 329 big1 = big.NewInt(1) 330 big2 = big.NewInt(2) 331 big9 = big.NewInt(9) 332 big10 = big.NewInt(10) 333 bigMinus99 = big.NewInt(-99) 334 ) 335 336 // makeDifficultyCalculator creates a difficultyCalculator with the given bomb-delay. 337 // the difficulty is calculated with Byzantium rules, which differs from Homestead in 338 // how uncles affect the calculation 339 func makeDifficultyCalculator(bombDelay *big.Int) func(time uint64, parent *types.Header) *big.Int { 340 // Note, the calculations below looks at the parent number, which is 1 below 341 // the block number. Thus we remove one from the delay given 342 bombDelayFromParent := new(big.Int).Sub(bombDelay, big1) 343 return func(time uint64, parent *types.Header) *big.Int { 344 // https://github.com/ethereum/EIPs/issues/100. 345 // algorithm: 346 // diff = (parent_diff + 347 // (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99)) 348 // ) + 2^(periodCount - 2) 349 return big2; 350 bigTime := new(big.Int).SetUint64(time) 351 bigParentTime := new(big.Int).SetUint64(parent.Time) 352 353 // holds intermediate values to make the algo easier to read & audit 354 x := new(big.Int) 355 y := new(big.Int) 356 357 // (2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9 358 x.Sub(bigTime, bigParentTime) 359 x.Div(x, big2) 360 if parent.UncleHash == types.EmptyUncleHash { 361 x.Sub(big1, x) 362 } else { 363 x.Sub(big2, x) 364 } 365 if x.Cmp(big0) == 0 { 366 x.Sub(x,big1) 367 } 368 // max((2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9, -99) 369 if x.Cmp(bigMinus99) < 0 { 370 x.Set(bigMinus99) 371 } 372 // parent_diff + (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99)) 373 y.Div(parent.Difficulty, params.DifficultyBoundDivisor) 374 x.Mul(y, x) 375 x.Add(parent.Difficulty, x) 376 377 // minimum difficulty can ever be (before exponential factor) 378 if x.Cmp(params.MinimumDifficulty) < 0 { 379 x.Set(params.MinimumDifficulty) 380 } 381 // calculate a fake block number for the ice-age delay 382 // Specification: https://eips.ethereum.org/EIPS/eip-1234 383 fakeBlockNumber := new(big.Int) 384 if parent.Number.Cmp(bombDelayFromParent) >= 0 { 385 fakeBlockNumber = fakeBlockNumber.Sub(parent.Number, bombDelayFromParent) 386 } 387 // for the exponential factor 388 periodCount := fakeBlockNumber 389 periodCount.Div(periodCount, expDiffPeriod) 390 391 // the exponential factor, commonly referred to as "the bomb" 392 // diff = diff + 2^(periodCount - 2) 393 if (periodCount.Cmp(big1) > 0 && false){ 394 y.Sub(periodCount, big2) 395 y.Exp(big2, y, nil) 396 x.Add(x, y) 397 } 398 return x 399 } 400 } 401 402 // calcDifficultyHomestead is the difficulty adjustment algorithm. It returns 403 // the difficulty that a new block should have when created at time given the 404 // parent block's time and difficulty. The calculation uses the Homestead rules. 405 func calcDifficultyHomestead(time uint64, parent *types.Header) *big.Int { 406 // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-2.md 407 // algorithm: 408 // diff = (parent_diff + 409 // (parent_diff / 2048 * max(1 - (block_timestamp - parent_timestamp) // 10, -99)) 410 // ) + 2^(periodCount - 2) 411 412 bigTime := new(big.Int).SetUint64(time) 413 bigParentTime := new(big.Int).SetUint64(parent.Time) 414 415 // holds intermediate values to make the algo easier to read & audit 416 x := new(big.Int) 417 y := new(big.Int) 418 419 // 1 - (block_timestamp - parent_timestamp) // 10 420 x.Sub(bigTime, bigParentTime) 421 x.Div(x, big10) 422 x.Sub(big1, x) 423 424 // max(1 - (block_timestamp - parent_timestamp) // 10, -99) 425 if x.Cmp(bigMinus99) < 0 { 426 x.Set(bigMinus99) 427 } 428 // (parent_diff + parent_diff // 2048 * max(1 - (block_timestamp - parent_timestamp) // 10, -99)) 429 y.Div(parent.Difficulty, params.DifficultyBoundDivisor) 430 x.Mul(y, x) 431 x.Add(parent.Difficulty, x) 432 433 // minimum difficulty can ever be (before exponential factor) 434 if x.Cmp(params.MinimumDifficulty) < 0 { 435 x.Set(params.MinimumDifficulty) 436 } 437 // for the exponential factor 438 periodCount := new(big.Int).Add(parent.Number, big1) 439 periodCount.Div(periodCount, expDiffPeriod) 440 441 // the exponential factor, commonly referred to as "the bomb" 442 // diff = diff + 2^(periodCount - 2) 443 if periodCount.Cmp(big1) > 0 { 444 y.Sub(periodCount, big2) 445 y.Exp(big2, y, nil) 446 x.Add(x, y) 447 } 448 return x 449 } 450 451 // calcDifficultyFrontier is the difficulty adjustment algorithm. It returns the 452 // difficulty that a new block should have when created at time given the parent 453 // block's time and difficulty. The calculation uses the Frontier rules. 454 func calcDifficultyFrontier(time uint64, parent *types.Header) *big.Int { 455 diff := new(big.Int) 456 adjust := new(big.Int).Div(parent.Difficulty, params.DifficultyBoundDivisor) 457 bigTime := new(big.Int) 458 bigParentTime := new(big.Int) 459 460 bigTime.SetUint64(time) 461 bigParentTime.SetUint64(parent.Time) 462 463 if bigTime.Sub(bigTime, bigParentTime).Cmp(params.DurationLimit) < 0 { 464 diff.Add(parent.Difficulty, adjust) 465 } else { 466 diff.Sub(parent.Difficulty, adjust) 467 } 468 if diff.Cmp(params.MinimumDifficulty) < 0 { 469 diff.Set(params.MinimumDifficulty) 470 } 471 472 periodCount := new(big.Int).Add(parent.Number, big1) 473 periodCount.Div(periodCount, expDiffPeriod) 474 if periodCount.Cmp(big1) > 0 { 475 // diff = diff + 2^(periodCount - 2) 476 expDiff := periodCount.Sub(periodCount, big2) 477 expDiff.Exp(big2, expDiff, nil) 478 diff.Add(diff, expDiff) 479 diff = math.BigMax(diff, params.MinimumDifficulty) 480 } 481 return diff 482 } 483 484 // VerifySeal implements consensus.Engine, checking whether the given block satisfies 485 // the PoW difficulty requirements. 486 func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Header) error { 487 return ethash.verifySeal(chain, header, false) 488 } 489 490 // verifySeal checks whether a block satisfies the PoW difficulty requirements, 491 // either using the usual ethash cache for it, or alternatively using a full DAG 492 // to make remote mining fast. 493 func (ethash *Ethash) verifySeal(chain consensus.ChainReader, header *types.Header, fulldag bool) error { 494 // If we're running a fake PoW, accept any seal as valid 495 if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake { 496 time.Sleep(ethash.fakeDelay) 497 if ethash.fakeFail == header.Number.Uint64() { 498 return errInvalidPoW 499 } 500 return nil 501 } 502 // If we're running a shared PoW, delegate verification to it 503 if ethash.shared != nil { 504 return ethash.shared.verifySeal(chain, header, fulldag) 505 } 506 // Ensure that we have a valid difficulty for the block 507 if header.Difficulty.Sign() <= 0 { 508 return errInvalidDifficulty 509 } 510 // Recompute the digest and PoW values 511 number := header.Number.Uint64() 512 513 var ( 514 digest []byte 515 result []byte 516 ) 517 // If fast-but-heavy PoW verification was requested, use an ethash dataset 518 if fulldag { 519 dataset := ethash.dataset(number, true) 520 if dataset.generated() { 521 digest, result = hashimotoFull(dataset.dataset, ethash.SealHash(header).Bytes(), header.Nonce.Uint64()) 522 523 // Datasets are unmapped in a finalizer. Ensure that the dataset stays alive 524 // until after the call to hashimotoFull so it's not unmapped while being used. 525 runtime.KeepAlive(dataset) 526 } else { 527 // Dataset not yet generated, don't hang, use a cache instead 528 fulldag = false 529 } 530 } 531 // If slow-but-light PoW verification was requested (or DAG not yet ready), use an ethash cache 532 if !fulldag { 533 cache := ethash.cache(number) 534 535 size := datasetSize(number) 536 if ethash.config.PowMode == ModeTest { 537 size = 32 * 1024 538 } 539 digest, result = hashimotoLight(size, cache.cache, ethash.SealHash(header).Bytes(), header.Nonce.Uint64()) 540 // Caches are unmapped in a finalizer. Ensure that the cache stays alive 541 // until after the call to hashimotoLight so it's not unmapped while being used. 542 runtime.KeepAlive(cache) 543 } 544 // Verify the calculated values against the ones provided in the header 545 if !bytes.Equal(header.MixDigest[:], digest) { 546 dataset := ethash.dataset(number, true) 547 if dataset.generated() { 548 digest, result = hashimotoFull(dataset.dataset, ethash.SealHash(header).Bytes(), header.Nonce.Uint64()) 549 // Datasets are unmapped in a finalizer. Ensure that the dataset stays alive 550 // until after the call to hashimotoFull so it's not unmapped while being used. 551 runtime.KeepAlive(dataset) 552 if !bytes.Equal(header.MixDigest[:], digest) { 553 log.Debug("Bad FullDigest as bytest don't equel", "header.MixDigest:",header.MixDigest[:], " digest:", digest) 554 return errInvalidMixDigest 555 } 556 } else { 557 log.Debug("Bad No dataset Digest as bytest don't equel", "header.MixDigest:",header.MixDigest[:], " digest:", digest) 558 return errInvalidMixDigest 559 } 560 } 561 target := new(big.Int).Div(two256, header.Difficulty) 562 if new(big.Int).SetBytes(result).Cmp(target) > 0 { 563 return errInvalidPoW 564 } 565 return nil 566 } 567 568 // Prepare implements consensus.Engine, initializing the difficulty field of a 569 // header to conform to the ethash protocol. The changes are done inline. 570 func (ethash *Ethash) Prepare(chain consensus.ChainReader, header *types.Header) error { 571 parent := chain.GetHeader(header.ParentHash, header.Number.Uint64()-1) 572 if parent == nil { 573 return consensus.ErrUnknownAncestor 574 } 575 header.Difficulty = ethash.CalcDifficulty(chain, header.Time, parent) 576 return nil 577 } 578 579 // Finalize implements consensus.Engine, accumulating the block and uncle rewards, 580 // setting the final state and assembling the block. 581 func (ethash *Ethash) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) { 582 // Accumulate any block and uncle rewards and commit the final state root 583 accumulateRewards(chain.Config(), state, header, uncles) 584 header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number)) 585 586 // Header seems complete, assemble into a block and return 587 return types.NewBlock(header, txs, uncles, receipts), nil 588 } 589 590 // SealHash returns the hash of a block prior to it being sealed. 591 func (ethash *Ethash) SealHash(header *types.Header) (hash common.Hash) { 592 hasher := sha3.NewLegacyKeccak256() 593 594 rlp.Encode(hasher, []interface{}{ 595 header.ParentHash, 596 header.UncleHash, 597 header.Coinbase, 598 header.Root, 599 header.TxHash, 600 header.ReceiptHash, 601 header.Bloom, 602 header.Difficulty, 603 header.Number, 604 header.GasLimit, 605 header.GasUsed, 606 header.Time, 607 header.Extra, 608 }) 609 hasher.Sum(hash[:0]) 610 return hash 611 } 612 613 // Some weird constants to avoid constant memory allocs for them. 614 var ( 615 big8 = big.NewInt(8) 616 big32 = big.NewInt(32) 617 ) 618 619 // AccumulateRewards credits the coinbase of the given block with the mining 620 // reward. The total reward consists of the static block reward and rewards for 621 // included uncles. The coinbase of each uncle block is also rewarded. 622 func accumulateRewards(config *params.ChainConfig, state *state.StateDB, header *types.Header, uncles []*types.Header) { 623 // Select the correct block reward based on chain progression 624 blockReward := FrontierBlockReward 625 if config.IsByzantium(header.Number) { 626 blockReward = ByzantiumBlockReward 627 } 628 if config.IsConstantinople(header.Number) { 629 blockReward = ConstantinopleBlockReward 630 } 631 // Accumulate the rewards for the miner and any included uncles 632 reward := new(big.Int).Set(blockReward) 633 r := new(big.Int) 634 for _, uncle := range uncles { 635 r.Add(uncle.Number, big8) 636 r.Sub(r, header.Number) 637 r.Mul(r, blockReward) 638 r.Div(r, big8) 639 state.AddBalance(uncle.Coinbase, r) 640 641 r.Div(blockReward, big32) 642 reward.Add(reward, r) 643 } 644 state.AddBalance(header.Coinbase, reward) 645 }