nimbus-eth2/beacon_chain/spec/forks.nim

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# beacon_chain
# Copyright (c) 2021-2022 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [Defect].}
import
stew/assign2,
chronicles,
../extras,
"."/[eth2_merkleization, eth2_ssz_serialization, presets],
./datatypes/[phase0, altair, bellatrix]
export
extras, phase0, altair, bellatrix, eth2_merkleization, eth2_ssz_serialization,
presets
# This file contains helpers for dealing with forks - we have two ways we can
# deal with forks:
# * generics - this means using the static typing and differentiating forks
# at compile time - this is preferred in fork-specific code where the fork
# is known up-front, for example spec functions.
# * variants - this means using a variant object and determining the fork at
# runtime - this carries the obvious risk and complexity of dealing with
# runtime checking, but is of course needed for external data that may be
# of any fork kind.
#
# For generics, we define `Forky*` type classes that cover "similar" objects
# across forks - for variants, they're called `Forked*` instead.
# See withXxx and `init` for convenient ways of moving between these two worlds.
# A clever programmer would use templates, macros and dark magic to create all
# these types and converters :)
type
BeaconStateFork* {.pure.} = enum
Phase0,
Altair,
Bellatrix
ForkyBeaconState* =
phase0.BeaconState |
altair.BeaconState |
bellatrix.BeaconState
ForkyHashedBeaconState* =
phase0.HashedBeaconState |
altair.HashedBeaconState |
bellatrix.HashedBeaconState
ForkedHashedBeaconState* = object
case kind*: BeaconStateFork
of BeaconStateFork.Phase0: phase0Data*: phase0.HashedBeaconState
of BeaconStateFork.Altair: altairData*: altair.HashedBeaconState
of BeaconStateFork.Bellatrix: mergeData*: bellatrix.HashedBeaconState
BeaconBlockFork* {.pure.} = enum
Phase0
Altair
Bellatrix
ForkyBeaconBlock* =
phase0.BeaconBlock |
altair.BeaconBlock |
bellatrix.BeaconBlock
ForkyTrustedBeaconBlock* =
phase0.TrustedBeaconBlock |
altair.TrustedBeaconBlock |
bellatrix.TrustedBeaconBlock
ForkedBeaconBlock* = object
case kind*: BeaconBlockFork
of BeaconBlockFork.Phase0: phase0Data*: phase0.BeaconBlock
of BeaconBlockFork.Altair: altairData*: altair.BeaconBlock
of BeaconBlockFork.Bellatrix: mergeData*: bellatrix.BeaconBlock
ForkedTrustedBeaconBlock* = object
case kind*: BeaconBlockFork
of BeaconBlockFork.Phase0: phase0Data*: phase0.TrustedBeaconBlock
of BeaconBlockFork.Altair: altairData*: altair.TrustedBeaconBlock
of BeaconBlockFork.Bellatrix: mergeData*: bellatrix.TrustedBeaconBlock
ForkySignedBeaconBlock* =
phase0.SignedBeaconBlock |
altair.SignedBeaconBlock |
bellatrix.SignedBeaconBlock
ForkedSignedBeaconBlock* = object
case kind*: BeaconBlockFork
of BeaconBlockFork.Phase0: phase0Data*: phase0.SignedBeaconBlock
of BeaconBlockFork.Altair: altairData*: altair.SignedBeaconBlock
of BeaconBlockFork.Bellatrix: mergeData*: bellatrix.SignedBeaconBlock
ForkyTrustedSignedBeaconBlock* =
phase0.TrustedSignedBeaconBlock |
altair.TrustedSignedBeaconBlock |
bellatrix.TrustedSignedBeaconBlock
ForkedTrustedSignedBeaconBlock* = object
case kind*: BeaconBlockFork
of BeaconBlockFork.Phase0: phase0Data*: phase0.TrustedSignedBeaconBlock
of BeaconBlockFork.Altair: altairData*: altair.TrustedSignedBeaconBlock
of BeaconBlockFork.Bellatrix: mergeData*: bellatrix.TrustedSignedBeaconBlock
EpochInfoFork* {.pure.} = enum
Phase0
Altair
ForkedEpochInfo* = object
case kind*: EpochInfoFork
of EpochInfoFork.Phase0: phase0Data*: phase0.EpochInfo
of EpochInfoFork.Altair: altairData*: altair.EpochInfo
ForkyEpochInfo* = phase0.EpochInfo | altair.EpochInfo
ForkDigests* = object
phase0*: ForkDigest
altair*: ForkDigest
bellatrix*: ForkDigest
sharding*: ForkDigest
template toFork*[T: phase0.BeaconState | phase0.HashedBeaconState](
t: type T): BeaconStateFork =
BeaconStateFork.Phase0
template toFork*[T: altair.BeaconState | altair.HashedBeaconState](
t: type T): BeaconStateFork =
BeaconStateFork.Altair
template toFork*[T: bellatrix.BeaconState | bellatrix.HashedBeaconState](
t: type T): BeaconStateFork =
BeaconStateFork.Bellatrix
template init*(T: type ForkedHashedBeaconState, data: phase0.HashedBeaconState): T =
T(kind: BeaconStateFork.Phase0, phase0Data: data)
template init*(T: type ForkedHashedBeaconState, data: altair.HashedBeaconState): T =
T(kind: BeaconStateFork.Altair, altairData: data)
template init*(T: type ForkedHashedBeaconState, data: bellatrix.HashedBeaconState): T =
T(kind: BeaconStateFork.Bellatrix, mergeData: data)
template init*(T: type ForkedBeaconBlock, blck: phase0.BeaconBlock): T =
T(kind: BeaconBlockFork.Phase0, phase0Data: blck)
template init*(T: type ForkedBeaconBlock, blck: altair.BeaconBlock): T =
T(kind: BeaconBlockFork.Altair, altairData: blck)
template init*(T: type ForkedBeaconBlock, blck: bellatrix.BeaconBlock): T =
T(kind: BeaconBlockFork.Bellatrix, mergeData: blck)
template init*(T: type ForkedTrustedBeaconBlock, blck: phase0.TrustedBeaconBlock): T =
T(kind: BeaconBlockFork.Phase0, phase0Data: blck)
template init*(T: type ForkedTrustedBeaconBlock, blck: altair.TrustedBeaconBlock): T =
T(kind: BeaconBlockFork.Altair, altairData: blck)
template init*(T: type ForkedTrustedBeaconBlock, blck: bellatrix.TrustedBeaconBlock): T =
T(kind: BeaconBlockFork.Bellatrix, mergeData: blck)
template init*(T: type ForkedSignedBeaconBlock, blck: phase0.SignedBeaconBlock): T =
T(kind: BeaconBlockFork.Phase0, phase0Data: blck)
template init*(T: type ForkedSignedBeaconBlock, blck: altair.SignedBeaconBlock): T =
T(kind: BeaconBlockFork.Altair, altairData: blck)
template init*(T: type ForkedSignedBeaconBlock, blck: bellatrix.SignedBeaconBlock): T =
T(kind: BeaconBlockFork.Bellatrix, mergeData: blck)
template init*(T: type ForkedSignedBeaconBlock, forked: ForkedBeaconBlock,
blockRoot: Eth2Digest, signature: ValidatorSig): T =
case forked.kind
of BeaconBlockFork.Phase0:
T(kind: BeaconBlockFork.Phase0,
phase0Data: phase0.SignedBeaconBlock(message: forked.phase0Data,
root: blockRoot,
signature: signature))
of BeaconBlockFork.Altair:
T(kind: BeaconBlockFork.Altair,
altairData: altair.SignedBeaconBlock(message: forked.altairData,
root: blockRoot,
signature: signature))
of BeaconBlockFork.Bellatrix:
T(kind: BeaconBlockFork.Bellatrix,
mergeData: bellatrix.SignedBeaconBlock(message: forked.mergeData,
root: blockRoot,
signature: signature))
template init*(T: type ForkedTrustedSignedBeaconBlock, blck: phase0.TrustedSignedBeaconBlock): T =
T(kind: BeaconBlockFork.Phase0, phase0Data: blck)
template init*(T: type ForkedTrustedSignedBeaconBlock, blck: altair.TrustedSignedBeaconBlock): T =
T(kind: BeaconBlockFork.Altair, altairData: blck)
template init*(T: type ForkedTrustedSignedBeaconBlock, blck: bellatrix.TrustedSignedBeaconBlock): T =
T(kind: BeaconBlockFork.Bellatrix, mergeData: blck)
template toFork*[T: phase0.TrustedSignedBeaconBlock](
t: type T): BeaconBlockFork =
BeaconBlockFork.Phase0
template toFork*[T: altair.TrustedSignedBeaconBlock](
t: type T): BeaconBlockFork =
BeaconBlockFork.Altair
template toFork*[T: bellatrix.TrustedSignedBeaconBlock](
t: type T): BeaconBlockFork =
BeaconBlockFork.Bellatrix
template init*(T: type ForkedEpochInfo, info: phase0.EpochInfo): T =
T(kind: EpochInfoFork.Phase0, phase0Data: info)
template init*(T: type ForkedEpochInfo, info: altair.EpochInfo): T =
T(kind: EpochInfoFork.Altair, altairData: info)
template withState*(x: ForkedHashedBeaconState, body: untyped): untyped =
case x.kind
of BeaconStateFork.Bellatrix:
const stateFork {.inject, used.} = BeaconStateFork.Bellatrix
template state: untyped {.inject, used.} = x.mergeData
body
of BeaconStateFork.Altair:
const stateFork {.inject, used.} = BeaconStateFork.Altair
template state: untyped {.inject, used.} = x.altairData
body
of BeaconStateFork.Phase0:
const stateFork {.inject, used.} = BeaconStateFork.Phase0
template state: untyped {.inject, used.} = x.phase0Data
body
template withEpochInfo*(x: ForkedEpochInfo, body: untyped): untyped =
case x.kind
of EpochInfoFork.Phase0:
template info: untyped {.inject.} = x.phase0Data
body
of EpochInfoFork.Altair:
template info: untyped {.inject.} = x.altairData
body
template withEpochInfo*(
state: phase0.BeaconState, x: var ForkedEpochInfo, body: untyped): untyped =
x.kind = EpochInfoFork.Phase0
template info: untyped {.inject.} = x.phase0Data
body
template withEpochInfo*(
state: altair.BeaconState | bellatrix.BeaconState, x: var ForkedEpochInfo,
body: untyped): untyped =
x.kind = EpochInfoFork.Altair
template info: untyped {.inject.} = x.altairData
body
func assign*(tgt: var ForkedHashedBeaconState, src: ForkedHashedBeaconState) =
if tgt.kind == src.kind:
case tgt.kind
of BeaconStateFork.Bellatrix:
assign(tgt.mergeData, src.mergeData):
of BeaconStateFork.Altair:
assign(tgt.altairData, src.altairData):
of BeaconStateFork.Phase0:
assign(tgt.phase0Data, src.phase0Data):
else:
# Ensure case object and discriminator get updated simultaneously, even
# with nimOldCaseObjects. This is infrequent.
tgt = src
template getStateField*(x: ForkedHashedBeaconState, y: untyped): untyped =
# The use of `unsafeAddr` avoids excessive copying in certain situations, e.g.,
# ```
# for index, validator in getStateField(stateData.data, validators).pairs():
# ```
# Without `unsafeAddr`, the `validators` list would be copied to a temporary variable.
(case x.kind
of BeaconStateFork.Bellatrix: unsafeAddr x.mergeData.data.y
of BeaconStateFork.Altair: unsafeAddr x.altairData.data.y
of BeaconStateFork.Phase0: unsafeAddr x.phase0Data.data.y)[]
func getStateRoot*(x: ForkedHashedBeaconState): Eth2Digest =
withState(x): state.root
func setStateRoot*(x: var ForkedHashedBeaconState, root: Eth2Digest) =
withState(x): state.root = root
func stateForkAtEpoch*(cfg: RuntimeConfig, epoch: Epoch): BeaconStateFork =
## Return the current fork for the given epoch.
static:
doAssert BeaconStateFork.Bellatrix > BeaconStateFork.Altair
doAssert BeaconStateFork.Altair > BeaconStateFork.Phase0
doAssert GENESIS_EPOCH == 0
if epoch >= cfg.MERGE_FORK_EPOCH: BeaconStateFork.Bellatrix
elif epoch >= cfg.ALTAIR_FORK_EPOCH: BeaconStateFork.Altair
else: BeaconStateFork.Phase0
func blockForkAtEpoch*(cfg: RuntimeConfig, epoch: Epoch): BeaconBlockFork =
## Return the current fork for the given epoch.
if epoch >= cfg.MERGE_FORK_EPOCH: BeaconBlockFork.Bellatrix
elif epoch >= cfg.ALTAIR_FORK_EPOCH: BeaconBlockFork.Altair
else: BeaconBlockFork.Phase0
template asSigned*(x: ForkedTrustedSignedBeaconBlock): ForkedSignedBeaconBlock =
isomorphicCast[ForkedSignedBeaconBlock](x)
template asTrusted*(x: ForkedSignedBeaconBlock): ForkedTrustedSignedBeaconBlock =
isomorphicCast[ForkedTrustedSignedBeaconBlock](x)
template withBlck*(
x: ForkedBeaconBlock | ForkedSignedBeaconBlock |
ForkedTrustedSignedBeaconBlock,
body: untyped): untyped =
case x.kind
of BeaconBlockFork.Phase0:
const stateFork {.inject, used.} = BeaconStateFork.Phase0
template blck: untyped {.inject.} = x.phase0Data
body
of BeaconBlockFork.Altair:
const stateFork {.inject, used.} = BeaconStateFork.Altair
template blck: untyped {.inject.} = x.altairData
body
of BeaconBlockFork.Bellatrix:
const stateFork {.inject, used.} = BeaconStateFork.Bellatrix
template blck: untyped {.inject.} = x.mergeData
body
func proposer_index*(x: ForkedBeaconBlock): uint64 =
withBlck(x): blck.proposer_index
func hash_tree_root*(x: ForkedBeaconBlock): Eth2Digest =
withBlck(x): hash_tree_root(blck)
template getForkedBlockField*(x: ForkedSignedBeaconBlock | ForkedTrustedSignedBeaconBlock, y: untyped): untyped =
# unsafeAddr avoids a copy of the field in some cases
(case x.kind
of BeaconBlockFork.Phase0: unsafeAddr x.phase0Data.message.y
of BeaconBlockFork.Altair: unsafeAddr x.altairData.message.y
of BeaconBlockFork.Bellatrix: unsafeAddr x.mergeData.message.y)[]
template signature*(x: ForkedSignedBeaconBlock): ValidatorSig =
withBlck(x): blck.signature
template signature*(x: ForkedTrustedSignedBeaconBlock): TrustedSig =
withBlck(x): blck.signature
template root*(x: ForkedSignedBeaconBlock | ForkedTrustedSignedBeaconBlock): Eth2Digest =
withBlck(x): blck.root
template slot*(x: ForkedSignedBeaconBlock | ForkedTrustedSignedBeaconBlock): Slot =
withBlck(x): blck.message.slot
template shortLog*(x: ForkedBeaconBlock): auto =
withBlck(x): shortLog(blck)
template shortLog*(x: ForkedSignedBeaconBlock | ForkedTrustedSignedBeaconBlock): auto =
withBlck(x): shortLog(blck)
chronicles.formatIt ForkedBeaconBlock: it.shortLog
chronicles.formatIt ForkedSignedBeaconBlock: it.shortLog
chronicles.formatIt ForkedTrustedSignedBeaconBlock: it.shortLog
template withStateAndBlck*(
s: ForkedHashedBeaconState,
b: ForkedBeaconBlock | ForkedSignedBeaconBlock |
ForkedTrustedSignedBeaconBlock,
body: untyped): untyped =
case s.kind
of BeaconStateFork.Bellatrix:
const stateFork {.inject.} = BeaconStateFork.Bellatrix
template state: untyped {.inject.} = s.mergeData
template blck: untyped {.inject.} = b.mergeData
body
of BeaconStateFork.Altair:
const stateFork {.inject.} = BeaconStateFork.Altair
template state: untyped {.inject.} = s.altairData
template blck: untyped {.inject.} = b.altairData
body
of BeaconStateFork.Phase0:
const stateFork {.inject.} = BeaconStateFork.Phase0
template state: untyped {.inject.} = s.phase0Data
template blck: untyped {.inject.} = b.phase0Data
body
func genesisFork*(cfg: RuntimeConfig): Fork =
Fork(
previous_version: cfg.GENESIS_FORK_VERSION,
current_version: cfg.GENESIS_FORK_VERSION,
epoch: GENESIS_EPOCH)
func altairFork*(cfg: RuntimeConfig): Fork =
Fork(
previous_version: cfg.GENESIS_FORK_VERSION,
current_version: cfg.ALTAIR_FORK_VERSION,
epoch: cfg.ALTAIR_FORK_EPOCH)
func mergeFork*(cfg: RuntimeConfig): Fork =
# TODO in theory, the altair + merge forks could be in same epoch, so the
# previous fork version would be the GENESIS_FORK_VERSION
Fork(
previous_version: cfg.ALTAIR_FORK_VERSION,
current_version: cfg.MERGE_FORK_VERSION,
epoch: cfg.MERGE_FORK_EPOCH)
proc forkAtEpoch*(cfg: RuntimeConfig, epoch: Epoch): Fork =
case cfg.stateForkAtEpoch(epoch)
of BeaconStateFork.Bellatrix: cfg.mergeFork
of BeaconStateFork.Altair: cfg.altairFork
of BeaconStateFork.Phase0: cfg.genesisFork
proc forkVersionAtEpoch*(cfg: RuntimeConfig, epoch: Epoch): Version =
case cfg.stateForkAtEpoch(epoch)
of BeaconStateFork.Bellatrix: cfg.MERGE_FORK_VERSION
of BeaconStateFork.Altair: cfg.ALTAIR_FORK_VERSION
of BeaconStateFork.Phase0: cfg.GENESIS_FORK_VERSION
proc nextForkEpochAtEpoch*(cfg: RuntimeConfig, epoch: Epoch): Epoch =
case cfg.stateForkAtEpoch(epoch)
of BeaconStateFork.Bellatrix: FAR_FUTURE_EPOCH
of BeaconStateFork.Altair: cfg.MERGE_FORK_EPOCH
of BeaconStateFork.Phase0: cfg.ALTAIR_FORK_EPOCH
func getForkSchedule*(cfg: RuntimeConfig): array[3, Fork] =
## This procedure returns list of known and/or scheduled forks.
##
## This procedure is used by HTTP REST framework and validator client.
##
## NOTE: Update this procedure when new fork will be scheduled.
[cfg.genesisFork(), cfg.altairFork(), cfg.mergeFork()]
type
# The first few fields of a state, shared across all forks
BeaconStateHeader = object
genesis_time: uint64
genesis_validators_root: Eth2Digest
slot: uint64
func readSszForkedHashedBeaconState*(cfg: RuntimeConfig, data: openArray[byte]):
ForkedHashedBeaconState {.raises: [Defect, SszError].} =
## Helper to read a header from bytes when it's not certain what kind of state
## it is - this happens for example when loading an SSZ state from command
## line
if data.len() < sizeof(BeaconStateHeader):
raise (ref MalformedSszError)(msg: "Not enough data for BeaconState header")
let header = SSZ.decode(
data.toOpenArray(0, sizeof(BeaconStateHeader) - 1),
BeaconStateHeader)
# careful - `result` is used, RVO didn't seem to work without
# TODO move time helpers somewhere to avoid circular imports
result = ForkedHashedBeaconState(
kind: cfg.stateForkAtEpoch(Epoch(header.slot div SLOTS_PER_EPOCH)))
withState(result):
readSszBytes(data, state.data)
state.root = hash_tree_root(state.data)
type
ForkedBeaconBlockHeader = object
message*: uint32 # message offset
signature*: ValidatorSig
slot: Slot # start of BeaconBlock
func readSszForkedSignedBeaconBlock*(
cfg: RuntimeConfig, data: openArray[byte]):
ForkedSignedBeaconBlock {.raises: [Defect, SszError].} =
## Helper to read a header from bytes when it's not certain what kind of block
## it is
if data.len() < sizeof(ForkedBeaconBlockHeader):
raise (ref MalformedSszError)(msg: "Not enough data for SignedBeaconBlock header")
let header = SSZ.decode(
data.toOpenArray(0, sizeof(ForkedBeaconBlockHeader) - 1),
ForkedBeaconBlockHeader)
# careful - `result` is used, RVO didn't seem to work without
# TODO move time helpers somewhere to avoid circular imports
result = ForkedSignedBeaconBlock(
kind: cfg.blockForkAtEpoch(Epoch(header.slot div SLOTS_PER_EPOCH)))
withBlck(result):
readSszBytes(data, blck)
func toBeaconBlockFork*(fork: BeaconStateFork): BeaconBlockFork =
case fork
of BeaconStateFork.Phase0: BeaconBlockFork.Phase0
of BeaconStateFork.Altair: BeaconBlockFork.Altair
of BeaconStateFork.Bellatrix: BeaconBlockFork.Bellatrix
# https://github.com/ethereum/consensus-specs/blob/v1.1.8/specs/phase0/beacon-chain.md#compute_fork_data_root
func compute_fork_data_root*(current_version: Version,
genesis_validators_root: Eth2Digest): Eth2Digest =
## Return the 32-byte fork data root for the ``current_version`` and
## ``genesis_validators_root``.
## This is used primarily in signature domains to avoid collisions across
## forks/chains.
hash_tree_root(ForkData(
current_version: current_version,
genesis_validators_root: genesis_validators_root
))
# https://github.com/ethereum/consensus-specs/blob/v1.1.8/specs/phase0/beacon-chain.md#compute_fork_digest
func compute_fork_digest*(current_version: Version,
genesis_validators_root: Eth2Digest): ForkDigest =
## Return the 4-byte fork digest for the ``current_version`` and
## ``genesis_validators_root``.
## This is a digest primarily used for domain separation on the p2p layer.
## 4-bytes suffices for practical separation of forks/chains.
array[4, byte](result)[0..3] =
compute_fork_data_root(
current_version, genesis_validators_root).data.toOpenArray(0, 3)
func init*(T: type ForkDigests,
cfg: RuntimeConfig,
genesisValidatorsRoot: Eth2Digest): T =
T(
phase0:
compute_fork_digest(cfg.GENESIS_FORK_VERSION, genesisValidatorsRoot),
altair:
compute_fork_digest(cfg.ALTAIR_FORK_VERSION, genesisValidatorsRoot),
bellatrix:
compute_fork_digest(cfg.MERGE_FORK_VERSION, genesisValidatorsRoot),
sharding:
compute_fork_digest(cfg.SHARDING_FORK_VERSION, genesisValidatorsRoot),
)