status-im
/
eth2.0-specs
mirror of https://github.com/status-im/eth2.0-specs.git
2
0
Fork 0
Code Issues Projects Releases Wiki Activity

Merge branch 'fork-choice-epoch' into checkpoints

This commit is contained in:
Danny Ryan 2019-06-24 21:26:28 -06:00
parent bb0a492fea d9b97578c0
commit bacd4b1e89
No known key found for this signature in database
GPG Key ID: 2765A792E42CE07A
6 changed files with 320 additions and 109 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Makefile
View File

@ -59,10 +59,9 @@ open_cov:
lint: $(PY_SPEC_ALL_TARGETS)
cd $(PY_SPEC_DIR); . venv/bin/activate; \
flake8 --ignore=E252,W504,W503 --max-line-length=120 ./eth2spec; \
cd ./eth2spec; \
mypy --follow-imports=silent --warn-unused-ignores --ignore-missing-imports --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs -p phase0; \
mypy --follow-imports=silent --warn-unused-ignores --ignore-missing-imports --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs -p phase1
flake8 --ignore=E252,W504,W503 --max-line-length=120 ./eth2spec \
&& cd ./eth2spec && mypy --follow-imports=silent --warn-unused-ignores --ignore-missing-imports --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs -p phase0 \
&& mypy --follow-imports=silent --warn-unused-ignores --ignore-missing-imports --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs -p phase1;
install_deposit_contract_test: $(PY_SPEC_ALL_TARGETS)
cd $(DEPOSIT_CONTRACT_DIR); python3 -m venv venv; . venv/bin/activate; pip3 install -r requirements-testing.txt

24
specs/core/0_beacon-chain.md
View File

@ -181,9 +181,7 @@ The following values are (non-configurable) constants used throughout the specif
## Configuration
*Note*: The default mainnet configuration values are included here for spec-design purposes.
The different configurations for mainnet, testnets, and YAML-based testing can be found in the `configs/constant_presets/` directory.
These configurations are updated for releases, but may be out of sync during `dev` changes.
*Note*: The default mainnet configuration values are included here for spec-design purposes. The different configurations for mainnet, testnets, and YAML-based testing can be found in the `configs/constant_presets/` directory. These configurations are updated for releases and may be out of sync during `dev` changes.
### Misc
@ -293,6 +291,8 @@ The following types are [SimpleSerialize (SSZ)](../simple-serialize.md) containe
*Note*: The definitions are ordered topologically to facilitate execution of the spec.
*Note*: Fields missing in container instantiations default to their zero value.
### Misc dependencies
#### `Fork`
@ -531,9 +531,9 @@ class BeaconState(Container):
# Shuffling
start_shard: Shard
randao_mixes: Vector[Hash, EPOCHS_PER_HISTORICAL_VECTOR]
active_index_roots: Vector[Hash, EPOCHS_PER_HISTORICAL_VECTOR] # Digests of the active registry, for light clients
active_index_roots: Vector[Hash, EPOCHS_PER_HISTORICAL_VECTOR] # Active registry digests for light clients
# Slashings
slashed_balances: Vector[Gwei, EPOCHS_PER_SLASHED_BALANCES_VECTOR] # Sums of the effective balances of slashed validators
slashed_balances: Vector[Gwei, EPOCHS_PER_SLASHED_BALANCES_VECTOR] # Sums of slashed effective balances
# Attestations
previous_epoch_attestations: List[PendingAttestation]
current_epoch_attestations: List[PendingAttestation]
@ -1500,16 +1500,16 @@ def process_registry_updates(state: BeaconState) -> None:
```python
def process_slashings(state: BeaconState) -> None:
current_epoch = get_current_epoch(state)
epoch = get_current_epoch(state)
total_balance = get_total_active_balance(state)
# Compute slashed balances in the current epoch
total_at_start = state.slashed_balances[(current_epoch + 1) % EPOCHS_PER_SLASHED_BALANCES_VECTOR]
total_at_end = state.slashed_balances[current_epoch % EPOCHS_PER_SLASHED_BALANCES_VECTOR]
total_at_start = state.slashed_balances[(epoch + 1) % EPOCHS_PER_SLASHED_BALANCES_VECTOR]
total_at_end = state.slashed_balances[epoch % EPOCHS_PER_SLASHED_BALANCES_VECTOR]
total_penalties = total_at_end - total_at_start
for index, validator in enumerate(state.validators):
if validator.slashed and current_epoch == validator.withdrawable_epoch - EPOCHS_PER_SLASHED_BALANCES_VECTOR // 2:
if validator.slashed and epoch + EPOCHS_PER_SLASHED_BALANCES_VECTOR // 2 == validator.withdrawable_epoch:
penalty = max(
validator.effective_balance * min(total_penalties * 3, total_balance) // total_balance,
validator.effective_balance // MIN_SLASHING_PENALTY_QUOTIENT
@ -1579,6 +1579,7 @@ def process_block_header(state: BeaconState, block: BeaconBlock) -> None:
state.latest_block_header = BeaconBlockHeader(
slot=block.slot,
parent_root=block.parent_root,
state_root=ZERO_HASH, # Overwritten in next `process_slot` call
body_root=hash_tree_root(block.body),
)
# Verify proposer is not slashed
@ -1800,10 +1801,13 @@ def process_transfer(state: BeaconState, transfer: Transfer) -> None:
assert state.balances[transfer.sender] >= max(transfer.amount, transfer.fee)
# A transfer is valid in only one slot
assert state.slot == transfer.slot
# Sender must be not yet eligible for activation, withdrawn, or transfer balance over MAX_EFFECTIVE_BALANCE
# Sender must satisfy at least one of the following conditions in the parenthesis:
assert (
# * Has not been activated
state.validators[transfer.sender].activation_eligibility_epoch == FAR_FUTURE_EPOCH or
# * Is withdrawable
get_current_epoch(state) >= state.validators[transfer.sender].withdrawable_epoch or
# * Balance after transfer is more than the effective balance threshold
transfer.amount + transfer.fee + MAX_EFFECTIVE_BALANCE <= state.balances[transfer.sender]
)
# Verify that the pubkey is valid

104
specs/core/0_fork-choice.md
View File

@ -12,7 +12,7 @@
- [Time parameters](#time-parameters)
- [Fork choice](#fork-choice)
- [Helpers](#helpers)
- [`Target`](#target)
- [`Checkpoint`](#checkpoint)
- [`Store`](#store)
- [`get_genesis_store`](#get_genesis_store)
- [`get_ancestor`](#get_ancestor)
@ -55,11 +55,11 @@ The head block root associated with a `store` is defined as `get_head(store)`. A
### Helpers
#### `Target`
#### `Checkpoint`
```python
@dataclass
class Target(object):
@dataclass(eq=True, frozen=True)
class Checkpoint(object):
epoch: Epoch
root: Hash
```
@ -69,12 +69,13 @@ class Target(object):
```python
@dataclass
class Store(object):
time: int
justified_checkpoint: Checkpoint
finalized_checkpoint: Checkpoint
blocks: Dict[Hash, BeaconBlock] = field(default_factory=dict)
states: Dict[Hash, BeaconState] = field(default_factory=dict)
time: int = 0
latest_targets: Dict[ValidatorIndex, Target] = field(default_factory=dict)
justified_root: Hash = ZERO_HASH
finalized_root: Hash = ZERO_HASH
block_states: Dict[Hash, BeaconState] = field(default_factory=dict)
checkpoint_states: Dict[Checkpoint, BeaconState] = field(default_factory=dict)
latest_targets: Dict[ValidatorIndex, Checkpoint] = field(default_factory=dict)
```
#### `get_genesis_store`
@ -83,12 +84,15 @@ class Store(object):
def get_genesis_store(genesis_state: BeaconState) -> Store:
genesis_block = BeaconBlock(state_root=hash_tree_root(genesis_state))
root = signing_root(genesis_block)
justified_checkpoint = Checkpoint(GENESIS_EPOCH, root)
finalized_checkpoint = Checkpoint(GENESIS_EPOCH, root)
return Store(
blocks={root: genesis_block},
states={root: genesis_state},
time=genesis_state.genesis_time,
justified_root=root,
finalized_root=root,
justified_checkpoint=justified_checkpoint,
finalized_checkpoint=finalized_checkpoint,
blocks={root: genesis_block},
block_states={root: genesis_state},
checkpoint_states={justified_checkpoint: genesis_state.copy()},
)
```
@ -105,7 +109,7 @@ def get_ancestor(store: Store, root: Hash, slot: Slot) -> Hash:
```python
def get_latest_attesting_balance(store: Store, root: Hash) -> Gwei:
state = store.states[store.justified_root]
state = store.checkpoint_states[store.justified_checkpoint]
active_indices = get_active_validator_indices(state.validator_registry, get_current_epoch(state))
return Gwei(sum(
state.validator_registry[i].effective_balance for i in active_indices
@ -118,9 +122,13 @@ def get_latest_attesting_balance(store: Store, root: Hash) -> Gwei:
```python
def get_head(store: Store) -> Hash:
# Execute the LMD-GHOST fork choice
head = store.justified_root
head = store.justified_checkpoint.root
justified_slot = get_epoch_start_slot(store.justified_checkpoint.epoch)
while True:
children = [root for root in store.blocks.keys() if store.blocks[root].parent_root == head]
children = [
root for root in store.blocks.keys()
if store.blocks[root].parent_root == head and store.blocks[root].slot > justified_slot
]
if len(children) == 0:
return head
# Sort by latest attesting balance with ties broken lexicographically
@ -141,35 +149,65 @@ def on_tick(store: Store, time: int) -> None:
```python
def on_block(store: Store, block: BeaconBlock) -> None:
# Make a copy of the state to avoid mutability issues
pre_state = store.states[block.parent_root].copy()
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
# Add new block to the store
store.blocks[signing_root(block)] = block
# Check block is a descendant of the finalized block
assert get_ancestor(store, signing_root(block), store.blocks[store.finalized_root].slot) == store.finalized_root
assert (
get_ancestor(store, signing_root(block), store.blocks[store.finalized_checkpoint.root].slot) ==
store.finalized_checkpoint.root
)
# Check that block is later than the finalized epoch slot
assert block.slot > get_epoch_start_slot(store.finalized_checkpoint.epoch)
# Check the block is valid and compute the post-state
state = state_transition(pre_state, block)
# Add new state to the store
store.states[signing_root(block)] = state
# Update justified block root
if state.current_justified_epoch > slot_to_epoch(store.blocks[store.justified_root].slot):
store.justified_root = state.current_justified_root
elif state.previous_justified_epoch > slot_to_epoch(store.blocks[store.justified_root].slot):
store.justified_root = state.previous_justified_root
# Update finalized block root
if state.finalized_epoch > slot_to_epoch(store.blocks[store.finalized_root].slot):
store.finalized_root = state.finalized_root
# Add new state for this block to the store
store.block_states[signing_root(block)] = state
# Update justified checkpoint
if state.current_justified_epoch > store.justified_checkpoint.epoch:
store.justified_checkpoint = Checkpoint(state.current_justified_epoch, state.current_justified_root)
elif state.previous_justified_epoch > store.justified_checkpoint.epoch:
store.justified_checkpoint = Checkpoint(state.previous_justified_epoch, state.previous_justified_root)
# Update finalized checkpoint
if state.finalized_epoch > state.finalized_epoch:
store.finalized_checkpoint = Checkpoint(state.finalized_epoch, state.finalized_root)
```
#### `on_attestation`
```python
def on_attestation(store: Store, attestation: Attestation) -> None:
state = store.states[get_head(store)]
indexed_attestation = convert_to_indexed(state, attestation)
validate_indexed_attestation(state, indexed_attestation)
target = Checkpoint(attestation.data.target_epoch, attestation.data.target_root)
# Cannot calculate the current shuffling if have not seen the target
assert target.root in store.blocks
# Attestations cannot be from future epochs. If they are, delay consideration until the epoch arrivesr
base_state = store.block_states[target.root].copy()
assert store.time >= base_state.genesis_time + get_epoch_start_slot(target.epoch) * SECONDS_PER_SLOT
# Store target checkpoint state if not yet seen
if target not in store.checkpoint_states:
process_slots(base_state, get_epoch_start_slot(target.epoch))
store.checkpoint_states[target] = base_state
target_state = store.checkpoint_states[target]
# Attestations can only affect the fork choice of subsequent slots.
# Delay consideration in the fork choice until their slot is in the past.
attestation_slot = get_attestation_data_slot(target_state, attestation.data)
assert store.time >= (attestation_slot + 1) * SECONDS_PER_SLOT
# Get state at the `target` to validate attestation and calculate the committees
indexed_attestation = convert_to_indexed(target_state, attestation)
validate_indexed_attestation(target_state, indexed_attestation)
# Update latest targets
for i in indexed_attestation.custody_bit_0_indices + indexed_attestation.custody_bit_1_indices:
if i not in store.latest_targets or attestation.data.target_epoch > store.latest_targets[i].epoch:
store.latest_targets[i] = Target(attestation.data.target_epoch, attestation.data.target_root)
if i not in store.latest_targets or target.epoch > store.latest_targets[i].epoch:
store.latest_targets[i] = target
```

134
test_libs/pyspec/eth2spec/test/fork_choice/test_on_attestation.py Normal file
View File

@ -0,0 +1,134 @@
from eth2spec.utils.ssz.ssz_impl import hash_tree_root
from eth2spec.test.context import with_all_phases, with_state, bls_switch
from eth2spec.test.helpers.block import build_empty_block_for_next_slot
from eth2spec.test.helpers.attestations import get_valid_attestation
from eth2spec.test.helpers.state import next_slot
def run_on_attestation(spec, state, store, attestation, valid=True):
if not valid:
try:
spec.on_attestation(store, attestation)
except AssertionError:
return
else:
assert False
indexed_attestation = spec.convert_to_indexed(state, attestation)
spec.on_attestation(store, attestation)
assert (
store.latest_targets[indexed_attestation.custody_bit_0_indices[0]] ==
spec.Checkpoint(
epoch=attestation.data.target_epoch,
root=attestation.data.target_root,
)
)
@with_all_phases
@with_state
@bls_switch
def test_on_attestation(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
store = spec.get_genesis_store(state)
time = 100
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state, signed=True)
# store block in store
spec.on_block(store, block)
next_slot(spec, state)
attestation = get_valid_attestation(spec, state, slot=block.slot)
run_on_attestation(spec, state, store, attestation)
@with_all_phases
@with_state
@bls_switch
def test_on_attestation_target_not_in_store(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
store = spec.get_genesis_store(state)
time = 100
spec.on_tick(store, time)
# move to next epoch to make block new target
state.slot += spec.SLOTS_PER_EPOCH
block = build_empty_block_for_next_slot(spec, state, signed=True)
# do not add block to store
next_slot(spec, state)
attestation = get_valid_attestation(spec, state, slot=block.slot)
run_on_attestation(spec, state, store, attestation, False)
@with_all_phases
@with_state
@bls_switch
def test_on_attestation_future_epoch(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
store = spec.get_genesis_store(state)
time = 3 * spec.SECONDS_PER_SLOT
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state, signed=True)
# store block in store
spec.on_block(store, block)
next_slot(spec, state)
# move state forward but not store
attestation_slot = block.slot + spec.SLOTS_PER_EPOCH
state.slot = attestation_slot
attestation = get_valid_attestation(spec, state, slot=state.slot)
run_on_attestation(spec, state, store, attestation, False)
@with_all_phases
@with_state
@bls_switch
def test_on_attestation_same_slot(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
store = spec.get_genesis_store(state)
time = 1 * spec.SECONDS_PER_SLOT
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state, signed=True)
spec.on_block(store, block)
next_slot(spec, state)
attestation = get_valid_attestation(spec, state, slot=block.slot)
run_on_attestation(spec, state, store, attestation, False)
@with_all_phases
@with_state
@bls_switch
def test_on_attestation_invalid_attestation(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
store = spec.get_genesis_store(state)
time = 3 * spec.SECONDS_PER_SLOT
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state, signed=True)
spec.on_block(store, block)
next_slot(spec, state)
attestation = get_valid_attestation(spec, state, slot=block.slot)
# make attestation invalid
attestation.custody_bitfield = b'\xf0' + attestation.custody_bitfield[1:]
run_on_attestation(spec, state, store, attestation, False)

98
test_libs/pyspec/eth2spec/test/fork_choice/test_on_block.py Normal file
View File

@ -0,0 +1,98 @@
from eth2spec.utils.ssz.ssz_impl import signing_root, hash_tree_root
from eth2spec.test.context import with_all_phases, with_state, bls_switch
from eth2spec.test.helpers.block import build_empty_block_for_next_slot
def run_on_block(spec, state, store, block, valid=True):
if not valid:
try:
spec.on_block(store, block)
except AssertionError:
return
else:
assert False
spec.on_block(store, block)
assert store.blocks[signing_root(block)] == block
@with_all_phases
@with_state
@bls_switch
def test_basic(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
# Initialization
store = spec.get_genesis_store(state)
time = 100
spec.on_tick(store, time)
assert store.time == time
# On receiving a block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, state)
run_on_block(spec, state, store, block)
# On receiving a block of next epoch
store.time = time + spec.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH
block = build_empty_block_for_next_slot(spec, state)
block.slot += spec.SLOTS_PER_EPOCH
run_on_block(spec, state, store, block)
# TODO: add tests for justified_root and finalized_root
@with_all_phases
@with_state
@bls_switch
def test_on_block_future_block(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
# Initialization
store = spec.get_genesis_store(state)
# do not tick time
# Fail receiving block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, state)
run_on_block(spec, state, store, block, False)
@with_all_phases
@with_state
@bls_switch
def test_on_block_bad_parent_root(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
# Initialization
store = spec.get_genesis_store(state)
time = 100
spec.on_tick(store, time)
# Fail receiving block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, state)
block.parent_root = b'\x45' * 32
run_on_block(spec, state, store, block, False)
@with_all_phases
@with_state
@bls_switch
def test_on_block_before_finalized(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
# Initialization
store = spec.get_genesis_store(state)
time = 100
spec.on_tick(store, time)
store.finalized_checkpoint = spec.Checkpoint(
epoch=store.finalized_checkpoint.epoch + 2,
root=store.finalized_checkpoint.root
)
# Fail receiving block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, state)
run_on_block(spec, state, store, block, False)

62
test_libs/pyspec/eth2spec/test/test_fork_choice.py
View File

@ -1,62 +0,0 @@
from typing import List
from eth2spec.utils.ssz.ssz_impl import signing_root, hash_tree_root
from eth2spec.test.context import with_all_phases, with_state, bls_switch
from eth2spec.test.helpers.block import build_empty_block_for_next_slot
from eth2spec.test.helpers.attestations import get_valid_attestation
from eth2spec.test.helpers.state import next_slot
@with_all_phases
@with_state
@bls_switch
def test_basic(spec, state):
state.latest_block_header = spec.BeaconBlockHeader(body_root=hash_tree_root(spec.BeaconBlockBody()))
# Initialization
store = spec.get_genesis_store(state)
blocks = []
time = 100
spec.on_tick(store, time)
assert store.time == time
# On receiving a block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, state)
blocks.append(block)
spec.on_block(store, block)
assert store.blocks[signing_root(block)] == block
# On receiving a block of next epoch
store.time = time + spec.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH
block = build_empty_block_for_next_slot(spec, state)
block.slot += spec.SLOTS_PER_EPOCH
blocks.append(block)
spec.on_block(store, block)
assert store.blocks[signing_root(block)] == block
# TODO: add tests for justified_root and finalized_root
@with_all_phases
@with_state
@bls_switch
def test_on_attestation(spec, state):
store = spec.get_genesis_store(state)
time = 100
spec.on_tick(store, time)
next_slot(spec, state)
attestation = get_valid_attestation(spec, state, slot=1)
indexed_attestation = spec.convert_to_indexed(state, attestation)
spec.on_attestation(store, attestation)
assert (
store.latest_targets[indexed_attestation.custody_bit_0_indices[0]] ==
spec.Target(
epoch=attestation.data.target_epoch,
root=attestation.data.target_root,
)
)