Ori Newman 5dbb1da84b
Implement pruning point proof (#1832)
* Calculate GHOSTDAG, reachability etc for each level

* Don't preallocate cache for dag stores except level 0 and reduce the number of connections in the integration test to 32

* Reduce the number of connections in the integration test to 16

* Increase page file

* BuildPruningPointProof

* BuildPruningPointProof

* Add PruningProofManager

* Implement ApplyPruningPointProof

* Add prefix and fix blockAtDepth and fill headersByLevel

* Some bug fixes

* Include all relevant blocks for each level in the proof

* Fix syncAndValidatePruningPointProof to return the right block hash

* Fix block window

* Fix isAncestorOfPruningPoint

* Ban for rule errors on pruning proof

* Find common ancestor for blockAtDepthMAtNextLevel

* Use pruning proof in TestValidateAndInsertImportedPruningPoint

* stage status and finality point for proof blocks

* Uncomment golint

* Change test timeouts

* Calculate merge set for ApplyPruningPointProof

* Increase test timeout

* Add better caching for daa window store

* Return to default timeout

* Add ErrPruningProofMissesBlocksBelowPruningPoint

* Add errDAAWindowBlockNotFound

* Force connection loop next iteration on connection manager stop

* Revert to Test64IncomingConnections

* Remove BlockAtDepth from DAGTraversalManager

* numBullies->16

* Set page file size to 8gb

* Increase p2p max message size

* Test64IncomingConnections->Test16IncomingConnections

* Add comment for PruningProofM

* Add comment in `func (c *ConnectionManager) Stop()`

* Rename isAncestorOfPruningPoint->isAncestorOfSelectedTip

* Revert page file to 16gb

* Improve ExpectedHeaderPruningPoint perf

* Fix comment

* Revert "Improve ExpectedHeaderPruningPoint perf"

This reverts commit bca1080e7140c78d510f51bbea858ae280c2f38e.

* Don't test windows
2021-10-26 09:48:27 +03:00

79 lines
3.0 KiB
Go

package pow
import (
"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
"github.com/kaspanet/kaspad/domain/consensus/utils/consensushashing"
"github.com/kaspanet/kaspad/domain/consensus/utils/constants"
"github.com/kaspanet/kaspad/domain/consensus/utils/hashes"
"github.com/kaspanet/kaspad/domain/consensus/utils/serialization"
"github.com/kaspanet/kaspad/util/difficulty"
"github.com/pkg/errors"
"math/big"
)
// CheckProofOfWorkWithTarget check's if the block has a valid PoW according to the provided target
// it does not check if the difficulty itself is valid or less than the maximum for the appropriate network
func CheckProofOfWorkWithTarget(header externalapi.MutableBlockHeader, target *big.Int) bool {
// The block pow must be less than the claimed target
powNum := CalculateProofOfWorkValue(header)
// The block hash must be less or equal than the claimed target.
return powNum.Cmp(target) <= 0
}
// CheckProofOfWorkByBits check's if the block has a valid PoW according to its Bits field
// it does not check if the difficulty itself is valid or less than the maximum for the appropriate network
func CheckProofOfWorkByBits(header externalapi.MutableBlockHeader) bool {
return CheckProofOfWorkWithTarget(header, difficulty.CompactToBig(header.Bits()))
}
// CalculateProofOfWorkValue hashes the given header and returns its big.Int value
func CalculateProofOfWorkValue(header externalapi.MutableBlockHeader) *big.Int {
// Zero out the time and nonce.
timestamp, nonce := header.TimeInMilliseconds(), header.Nonce()
header.SetTimeInMilliseconds(0)
header.SetNonce(0)
prePowHash := consensushashing.HeaderHash(header)
header.SetTimeInMilliseconds(timestamp)
header.SetNonce(nonce)
// PRE_POW_HASH || TIME || 32 zero byte padding || NONCE
writer := hashes.NewPoWHashWriter()
writer.InfallibleWrite(prePowHash.ByteSlice())
err := serialization.WriteElement(writer, timestamp)
if err != nil {
panic(errors.Wrap(err, "this should never happen. Hash digest should never return an error"))
}
zeroes := [32]byte{}
writer.InfallibleWrite(zeroes[:])
err = serialization.WriteElement(writer, nonce)
if err != nil {
panic(errors.Wrap(err, "this should never happen. Hash digest should never return an error"))
}
return toBig(writer.Finalize())
}
// ToBig converts a externalapi.DomainHash into a big.Int treated as a little endian string.
func toBig(hash *externalapi.DomainHash) *big.Int {
// We treat the Hash as little-endian for PoW purposes, but the big package wants the bytes in big-endian, so reverse them.
buf := hash.ByteSlice()
blen := len(buf)
for i := 0; i < blen/2; i++ {
buf[i], buf[blen-1-i] = buf[blen-1-i], buf[i]
}
return new(big.Int).SetBytes(buf)
}
// BlockLevel returns the block level of the given header.
func BlockLevel(header externalapi.BlockHeader) int {
proofOfWorkValue := CalculateProofOfWorkValue(header.ToMutable())
for blockLevel := 0; ; blockLevel++ {
if blockLevel == constants.MaxBlockLevel || proofOfWorkValue.Bit(blockLevel+1) != 0 {
return blockLevel
}
}
}