Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

explicit use of GENESIS_SLOT in fork choice #1510

Merged
merged 2 commits into from
Dec 10, 2019
Merged

explicit use of GENESIS_SLOT in fork choice #1510

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9989f3e
ensure fork choice functions when GENESIS_SLOT != 0
djrtwo Dec 10, 2019
2c5c9cb
feedback from mikhail
djrtwo Dec 10, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
21 changes: 17 additions & 4 deletions specs/core/0_fork-choice.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,9 +13,15 @@
- [`LatestMessage`](#latestmessage)
- [`Store`](#store)
- [`get_genesis_store`](#get_genesis_store)
- [`get_slots_since_genesis`](#get_slots_since_genesis)
- [`get_current_slot`](#get_current_slot)
- [`compute_slots_since_epoch_start`](#compute_slots_since_epoch_start)
- [`get_ancestor`](#get_ancestor)
- [`get_latest_attesting_balance`](#get_latest_attesting_balance)
- [`filter_block_tree`](#filter_block_tree)
- [`get_filtered_block_tree`](#get_filtered_block_tree)
- [`get_head`](#get_head)
- [`should_update_justified_checkpoint`](#should_update_justified_checkpoint)
- [Handlers](#handlers)
- [`on_tick`](#on_tick)
- [`on_block`](#on_block)
Expand Down Expand Up @@ -96,11 +102,18 @@ def get_genesis_store(genesis_state: BeaconState) -> Store:
)
```

#### `get_slots_since_genesis`

```python
def get_slots_since_genesis(store: Store) -> int:
return (store.time - store.genesis_time) // SECONDS_PER_SLOT
```

#### `get_current_slot`

```python
def get_current_slot(store: Store) -> Slot:
return Slot((store.time - store.genesis_time) // SECONDS_PER_SLOT)
return Slot(GENESIS_SLOT + get_slots_since_genesis(store))
```

#### `compute_slots_since_epoch_start`
Expand Down Expand Up @@ -264,7 +277,7 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
assert block.parent_root in store.block_states
pre_state = store.block_states[block.parent_root].copy()
# Blocks cannot be in the future. If they are, their consideration must be delayed until the are in the past.
assert store.time >= pre_state.genesis_time + block.slot * SECONDS_PER_SLOT
assert get_current_slot(store) >= block.slot
# Add new block to the store
store.blocks[hash_tree_root(block)] = block
# Check block is a descendant of the finalized block
Expand Down Expand Up @@ -312,7 +325,7 @@ def on_attestation(store: Store, attestation: Attestation) -> None:
assert target.root in store.blocks
# Attestations cannot be from future epochs. If they are, delay consideration until the epoch arrives
base_state = store.block_states[target.root].copy()
assert store.time >= base_state.genesis_time + compute_start_slot_at_epoch(target.epoch) * SECONDS_PER_SLOT
assert get_current_slot(store) >= compute_start_slot_at_epoch(target.epoch)

# Attestations must be for a known block. If block is unknown, delay consideration until the block is found
assert attestation.data.beacon_block_root in store.blocks
Expand All @@ -327,7 +340,7 @@ def on_attestation(store: Store, attestation: Attestation) -> None:

# Attestations can only affect the fork choice of subsequent slots.
# Delay consideration in the fork choice until their slot is in the past.
assert store.time >= (attestation.data.slot + 1) * SECONDS_PER_SLOT
assert get_current_slot(store) >= attestation.data.slot + 1

# Get state at the `target` to validate attestation and calculate the committees
indexed_attestation = get_indexed_attestation(target_state, attestation)
Expand Down