199 lines
6.5 KiB
Nim
199 lines
6.5 KiB
Nim
# beacon_chain
|
|
# Copyright (c) 2018-2022 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
|
|
chronicles,
|
|
../spec/forks
|
|
|
|
export chronicles, forks
|
|
|
|
type
|
|
BlockRef* = ref object
|
|
## Node in object graph guaranteed to lead back to finalized head, and to
|
|
## have a corresponding entry in database.
|
|
##
|
|
## All blocks identified by a `BlockRef` are valid per the state transition
|
|
## rules and that at some point were candidates for head selection. The
|
|
## ChainDAG offers stronger guarantees: it only returns `BlockRef` instances
|
|
## that are rooted in the currently finalized chain - however, these
|
|
## guarantees are valid only until the next head update - in particular,
|
|
## they are not valid across `await` calls.
|
|
##
|
|
## Block graph forms a tree - in particular, there are no cycles.
|
|
|
|
bid*: BlockId ##\
|
|
## Root that can be used to retrieve block data from database
|
|
|
|
parent*: BlockRef ##\
|
|
## Not nil, except for the finalized head
|
|
|
|
BlockSlot* = object
|
|
## Unique identifier for a particular fork and time in the block chain -
|
|
## normally, there's a block for every slot, but in the case a block is not
|
|
## produced, the chain progresses anyway, producing a new state for every
|
|
## slot.
|
|
blck*: BlockRef
|
|
slot*: Slot ##\
|
|
## Slot time for this BlockSlot which may differ from blck.slot when time
|
|
## has advanced without blocks
|
|
|
|
template root*(blck: BlockRef): Eth2Digest = blck.bid.root
|
|
template slot*(blck: BlockRef): Slot = blck.bid.slot
|
|
|
|
func init*(T: type BlockRef, root: Eth2Digest, slot: Slot): BlockRef =
|
|
BlockRef(
|
|
bid: BlockId(root: root, slot: slot)
|
|
)
|
|
|
|
func init*(T: type BlockRef, root: Eth2Digest, blck: SomeForkyBeaconBlock):
|
|
BlockRef =
|
|
BlockRef.init(root, blck.slot)
|
|
|
|
func parent*(bs: BlockSlot): BlockSlot =
|
|
## Return a blockslot representing the previous slot, using the parent block
|
|
## if the current slot had a block
|
|
if bs.slot == Slot(0):
|
|
BlockSlot(blck: nil, slot: Slot(0))
|
|
else:
|
|
BlockSlot(
|
|
blck: if bs.slot > bs.blck.slot: bs.blck else: bs.blck.parent,
|
|
slot: bs.slot - 1
|
|
)
|
|
|
|
func parentOrSlot*(bs: BlockSlot): BlockSlot =
|
|
## Return a blockslot representing the previous slot, using the parent block
|
|
## with the current slot if the current had a block
|
|
if bs.blck.isNil():
|
|
BlockSlot(blck: nil, slot: Slot(0))
|
|
elif bs.slot == bs.blck.slot:
|
|
BlockSlot(blck: bs.blck.parent, slot: bs.slot)
|
|
else:
|
|
BlockSlot(blck: bs.blck, slot: bs.slot - 1)
|
|
|
|
func getDepth*(a, b: BlockRef): tuple[ancestor: bool, depth: int] =
|
|
var b = b
|
|
var depth = 0
|
|
const maxDepth = (100'i64 * 365 * 24 * 60 * 60 div SECONDS_PER_SLOT.int)
|
|
while true:
|
|
if a == b:
|
|
return (true, depth)
|
|
|
|
# for now, use an assert for block chain length since a chain this long
|
|
# indicates a circular reference here..
|
|
doAssert depth < maxDepth
|
|
depth += 1
|
|
|
|
if a.slot >= b.slot or b.parent.isNil:
|
|
return (false, depth)
|
|
|
|
doAssert b.slot > b.parent.slot
|
|
b = b.parent
|
|
|
|
func isAncestorOf*(a, b: BlockRef): bool =
|
|
let (isAncestor, _) = getDepth(a, b)
|
|
isAncestor
|
|
|
|
func link*(parent, child: BlockRef) =
|
|
doAssert (not (parent.root.isZero or child.root.isZero)),
|
|
"blocks missing root!"
|
|
doAssert parent.root != child.root, "self-references not allowed"
|
|
|
|
child.parent = parent
|
|
|
|
func get_ancestor*(blck: BlockRef, slot: Slot,
|
|
maxDepth = 100'i64 * 365 * 24 * 60 * 60 div SECONDS_PER_SLOT.int):
|
|
BlockRef =
|
|
## https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/phase0/fork-choice.md#get_ancestor
|
|
## Return the most recent block as of the time at `slot` that not more recent
|
|
## than `blck` itself
|
|
if isNil(blck): return nil
|
|
|
|
var blck = blck
|
|
|
|
var depth = 0
|
|
|
|
while true:
|
|
if blck.slot <= slot:
|
|
return blck
|
|
|
|
if isNil(blck.parent):
|
|
return nil
|
|
|
|
doAssert depth < maxDepth
|
|
depth += 1
|
|
|
|
blck = blck.parent
|
|
|
|
func atSlot*(blck: BlockRef, slot: Slot): BlockSlot =
|
|
## Return a BlockSlot at a given slot, with the block set to the closest block
|
|
## available. If slot comes from before the block, a suitable block ancestor
|
|
## will be used, else blck is returned as if all slots after it were empty.
|
|
## This helper is useful when imagining what the chain looked like at a
|
|
## particular moment in time, or when imagining what it will look like in the
|
|
## near future if nothing happens (such as when looking ahead for the next
|
|
## block proposal)
|
|
BlockSlot(blck: blck.get_ancestor(slot), slot: slot)
|
|
|
|
func atSlot*(blck: BlockRef): BlockSlot =
|
|
blck.atSlot(blck.slot)
|
|
|
|
func atEpochStart*(blck: BlockRef, epoch: Epoch): BlockSlot =
|
|
## Return the BlockSlot corresponding to the first slot in the given epoch
|
|
atSlot(blck, epoch.start_slot())
|
|
|
|
func atSlotEpoch*(blck: BlockRef, epoch: Epoch): BlockSlot =
|
|
## Return the last block that was included in the chain leading
|
|
## up to the given epoch - this amounts to the state at the time
|
|
## when epoch processing for `epoch` has been done, but no block
|
|
## has yet been applied
|
|
if epoch == GENESIS_EPOCH:
|
|
blck.atEpochStart(epoch)
|
|
else:
|
|
let
|
|
start = epoch.start_slot()
|
|
tmp = blck.atSlot(start - 1)
|
|
if isNil(tmp.blck):
|
|
BlockSlot()
|
|
else:
|
|
tmp.blck.atSlot(start)
|
|
|
|
func toBlockSlotId*(bs: BlockSlot): Opt[BlockSlotId] =
|
|
if isNil(bs.blck):
|
|
err()
|
|
else:
|
|
ok BlockSlotId.init(bs.blck.bid, bs.slot)
|
|
|
|
func isProposed*(blck: BlockRef, slot: Slot): bool =
|
|
## Return true if `blck` was proposed in the given slot
|
|
not isNil(blck) and blck.bid.isProposed(slot)
|
|
|
|
func isProposed*(bs: BlockSlot): bool =
|
|
## Return true if `bs` represents the proposed block (as opposed to an empty
|
|
## slot)
|
|
bs.blck.isProposed(bs.slot)
|
|
|
|
func shortLog*(v: BlockRef): string =
|
|
# epoch:root when logging epoch, root:slot when logging slot!
|
|
if v.isNil():
|
|
"nil:0"
|
|
else:
|
|
shortLog(v.bid)
|
|
|
|
func shortLog*(v: BlockSlot): string =
|
|
# epoch:root when logging epoch, root:slot when logging slot!
|
|
if isNil(v.blck):
|
|
"nil:0@" & $v.slot
|
|
elif v.blck.slot == v.slot:
|
|
shortLog(v.blck)
|
|
else: # There was a gap - log it
|
|
shortLog(v.blck) & "@" & $v.slot
|
|
|
|
chronicles.formatIt BlockSlot: shortLog(it)
|
|
chronicles.formatIt BlockRef: shortLog(it)
|