github.com/theQRL/go-zond@v0.1.1/beacon/types/header.go (about)

     1  // Copyright 2022 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 types implements a few types of the beacon chain for light client usage.
    18  package types
    19  
    20  import (
    21  	"crypto/sha256"
    22  	"encoding/binary"
    23  
    24  	"github.com/theQRL/go-zond/beacon/merkle"
    25  	"github.com/theQRL/go-zond/beacon/params"
    26  	"github.com/theQRL/go-zond/common"
    27  )
    28  
    29  //go:generate go run github.com/fjl/gencodec -type Header -field-override headerMarshaling -out gen_header_json.go
    30  
    31  const (
    32  	headerIndexSlot          = 8
    33  	headerIndexProposerIndex = 9
    34  	headerIndexParentRoot    = 10
    35  	headerIndexStateRoot     = 11
    36  	headerIndexBodyRoot      = 12
    37  )
    38  
    39  // Header defines a beacon header.
    40  //
    41  // See data structure definition here:
    42  // https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/beacon-chain.md#beaconblockheader
    43  type Header struct {
    44  	// Monotonically increasing slot number for the beacon block (may be gapped)
    45  	Slot uint64 `gencodec:"required" json:"slot"`
    46  
    47  	// Index into the validator table who created the beacon block
    48  	ProposerIndex uint64 `gencodec:"required" json:"proposer_index"`
    49  
    50  	// SSZ hash of the parent beacon header
    51  	ParentRoot common.Hash `gencodec:"required" json:"parent_root"`
    52  
    53  	// SSZ hash of the beacon state (https://github.com/ethereum/consensus-specs/blob/dev/specs/bellatrix/beacon-chain.md#beacon-state)
    54  	StateRoot common.Hash `gencodec:"required" json:"state_root"`
    55  
    56  	// SSZ hash of the beacon block body (https://github.com/ethereum/consensus-specs/blob/dev/specs/bellatrix/beacon-chain.md#beaconblockbody)
    57  	BodyRoot common.Hash `gencodec:"required" json:"body_root"`
    58  }
    59  
    60  // headerMarshaling is a field type overrides for gencodec.
    61  type headerMarshaling struct {
    62  	Slot          common.Decimal
    63  	ProposerIndex common.Decimal
    64  }
    65  
    66  // Hash calculates the block root of the header.
    67  //
    68  // TODO(zsfelfoldi): Remove this when an SSZ encoder lands.
    69  func (h *Header) Hash() common.Hash {
    70  	var values [16]merkle.Value // values corresponding to indices 8 to 15 of the beacon header tree
    71  	binary.LittleEndian.PutUint64(values[headerIndexSlot][:8], h.Slot)
    72  	binary.LittleEndian.PutUint64(values[headerIndexProposerIndex][:8], h.ProposerIndex)
    73  	values[headerIndexParentRoot] = merkle.Value(h.ParentRoot)
    74  	values[headerIndexStateRoot] = merkle.Value(h.StateRoot)
    75  	values[headerIndexBodyRoot] = merkle.Value(h.BodyRoot)
    76  	hasher := sha256.New()
    77  	for i := 7; i > 0; i-- {
    78  		hasher.Reset()
    79  		hasher.Write(values[i*2][:])
    80  		hasher.Write(values[i*2+1][:])
    81  		hasher.Sum(values[i][:0])
    82  	}
    83  	return common.Hash(values[1])
    84  }
    85  
    86  // Epoch returns the epoch the header belongs to.
    87  func (h *Header) Epoch() uint64 {
    88  	return h.Slot / params.EpochLength
    89  }
    90  
    91  // SyncPeriod returns the sync period the header belongs to.
    92  func (h *Header) SyncPeriod() uint64 {
    93  	return SyncPeriod(h.Slot)
    94  }
    95  
    96  // SyncPeriodStart returns the first slot of the given period.
    97  func SyncPeriodStart(period uint64) uint64 {
    98  	return period * params.SyncPeriodLength
    99  }
   100  
   101  // SyncPeriod returns the sync period that the given slot belongs to.
   102  func SyncPeriod(slot uint64) uint64 {
   103  	return slot / params.SyncPeriodLength
   104  }
   105  
   106  // SignedHeader represents a beacon header signed by a sync committee.
   107  //
   108  // This structure is created from either an optimistic update or an instant update:
   109  //   - https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#lightclientoptimisticupdate
   110  //   - https://github.com/zsfelfoldi/beacon-APIs/blob/instant_update/apis/beacon/light_client/instant_update.yaml
   111  type SignedHeader struct {
   112  	// Beacon header being signed
   113  	Header Header
   114  
   115  	// Sync committee BLS signature aggregate
   116  	Signature SyncAggregate
   117  
   118  	// Slot in which the signature has been created (newer than Header.Slot,
   119  	// determines the signing sync committee)
   120  	SignatureSlot uint64
   121  }