prysm-pulse/beacon-chain/core/blocks/block.go
Raul Jordan 20803b4c9d
Revert Usage of ssz.TreeHash Across Repo (#1711)
* revert using ssz.TreeHash

* gazelle
2019-02-25 21:42:31 -06:00

102 lines
4.0 KiB
Go

// Package blocks contains block processing libraries. These libraries
// process and verify block specific messages such as PoW receipt root,
// RANDAO, validator deposits, exits and slashing proofs.
package blocks
import (
"bytes"
"fmt"
"github.com/prysmaticlabs/prysm/beacon-chain/utils"
pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
"github.com/prysmaticlabs/prysm/shared/hashutil"
"github.com/prysmaticlabs/prysm/shared/params"
)
var clock utils.Clock = &utils.RealClock{}
// NewGenesisBlock returns the canonical, genesis block for the beacon chain protocol.
func NewGenesisBlock(stateRoot []byte) *pb.BeaconBlock {
block := &pb.BeaconBlock{
Slot: params.BeaconConfig().GenesisSlot,
ParentRootHash32: params.BeaconConfig().ZeroHash[:],
StateRootHash32: stateRoot,
RandaoReveal: params.BeaconConfig().ZeroHash[:],
Signature: params.BeaconConfig().EmptySignature[:],
Eth1Data: &pb.Eth1Data{
DepositRootHash32: params.BeaconConfig().ZeroHash[:],
BlockHash32: params.BeaconConfig().ZeroHash[:],
},
Body: &pb.BeaconBlockBody{
ProposerSlashings: []*pb.ProposerSlashing{},
AttesterSlashings: []*pb.AttesterSlashing{},
Attestations: []*pb.Attestation{},
Deposits: []*pb.Deposit{},
VoluntaryExits: []*pb.VoluntaryExit{},
},
}
return block
}
// BlockRoot returns the block root stored in the BeaconState for a given slot.
// It returns an error if the requested block root is not within the BeaconState.
// Spec pseudocode definition:
// def get_block_root(state: BeaconState, slot: int) -> Hash32:
// """
// returns the block root at a recent ``slot``.
// """
// assert state.slot <= slot + LATEST_BLOCK_ROOTS_LENGTH
// assert slot < state.slot
// return state.latest_block_roots[slot % LATEST_BLOCK_ROOTS_LENGTH]
func BlockRoot(state *pb.BeaconState, slot uint64) ([]byte, error) {
earliestSlot := state.Slot - params.BeaconConfig().LatestBlockRootsLength
if slot < earliestSlot || slot >= state.Slot {
if earliestSlot < params.BeaconConfig().GenesisSlot {
earliestSlot = params.BeaconConfig().GenesisSlot
}
return []byte{}, fmt.Errorf("slot %d is not within expected range of %d to %d",
slot-params.BeaconConfig().GenesisSlot,
earliestSlot-params.BeaconConfig().GenesisSlot,
state.Slot-params.BeaconConfig().GenesisSlot,
)
}
return state.LatestBlockRootHash32S[slot%params.BeaconConfig().LatestBlockRootsLength], nil
}
// ProcessBlockRoots processes the previous block root into the state, by appending it
// to the most recent block roots.
// Spec:
// Let previous_block_root be the tree_hash_root of the previous beacon block processed in the chain.
// Set state.latest_block_roots[(state.slot - 1) % LATEST_BLOCK_ROOTS_LENGTH] = previous_block_root.
// If state.slot % LATEST_BLOCK_ROOTS_LENGTH == 0 append merkle_root(state.latest_block_roots) to state.batched_block_roots.
func ProcessBlockRoots(state *pb.BeaconState, prevBlockRoot [32]byte) *pb.BeaconState {
state.LatestBlockRootHash32S[(state.Slot-1)%params.BeaconConfig().LatestBlockRootsLength] = prevBlockRoot[:]
if state.Slot%params.BeaconConfig().LatestBlockRootsLength == 0 {
merkleRoot := hashutil.MerkleRoot(state.LatestBlockRootHash32S)
state.BatchedBlockRootHash32S = append(state.BatchedBlockRootHash32S, merkleRoot)
}
return state
}
// BlockChildren obtains the blocks in a list of observed blocks which have the current
// beacon block's hash as their parent root hash.
//
// Spec pseudocode definition:
// Let get_children(store: Store, block: BeaconBlock) ->
// List[BeaconBlock] returns the child blocks of the given block.
func BlockChildren(block *pb.BeaconBlock, observedBlocks []*pb.BeaconBlock) ([]*pb.BeaconBlock, error) {
var children []*pb.BeaconBlock
root, err := hashutil.HashBeaconBlock(block)
if err != nil {
return nil, fmt.Errorf("could not hash block: %v", err)
}
for _, observed := range observedBlocks {
if bytes.Equal(observed.ParentRootHash32, root[:]) {
children = append(children, observed)
}
}
return children, nil
}