[squashed] shard chain updates wip

PR feedback from Danny and some refactor

1. Add stub `PHASE_1_GENESIS_SLOT`
2. Rename `get_updated_gasprice`  to `compute_updated_gasprice`
3. Rename `compute_shard_data_roots` to `compute_shard_body_roots`

Apply shard transition for the skipped slots

Refactor `shard_state_transition`

Get `beacon_parent_root` from offset slot

Add more test

Add `verify_shard_block_message`

Add `> 0`

Keep `beacon_parent_block` unchanged in `is_valid_fraud_proof`

Remove some lines

Fix type

Refactor + simplify skipped slot processing
This commit is contained in:
Hsiao-Wei Wang 2020-04-16 19:43:48 +08:00
parent 9724cb832d
commit 85d5a9abaf
No known key found for this signature in database
GPG Key ID: 95B070122902DEA4
7 changed files with 166 additions and 134 deletions

View File

@ -161,6 +161,8 @@ DOMAIN_CUSTODY_BIT_SLASHING: 0x83000000
# Phase 1: Upgrade from Phase 0
# ---------------------------------------------------------------
PHASE_1_FORK_VERSION: 0x01000000
# [STUB]
PHASE_1_GENESIS_SLOT: 32
INITIAL_ACTIVE_SHARDS: 64
# Phase 1: General

View File

@ -162,6 +162,8 @@ DOMAIN_CUSTODY_BIT_SLASHING: 0x83000000
# ---------------------------------------------------------------
# [customized] for testnet distinction
PHASE_1_FORK_VERSION: 0x01000001
# [customized] for testing
PHASE_1_GENESIS_SLOT: 8
# [customized] reduced for testing
INITIAL_ACTIVE_SHARDS: 4

View File

@ -39,6 +39,7 @@
- [`committee_to_compact_committee`](#committee_to_compact_committee)
- [`compute_shard_from_committee_index`](#compute_shard_from_committee_index)
- [`compute_offset_slots`](#compute_offset_slots)
- [`compute_updated_gasprice`](#compute_updated_gasprice)
- [Beacon state accessors](#beacon-state-accessors)
- [`get_active_shard_count`](#get_active_shard_count)
- [`get_online_validator_indices`](#get_online_validator_indices)
@ -46,7 +47,6 @@
- [`get_light_client_committee`](#get_light_client_committee)
- [`get_shard_proposer_index`](#get_shard_proposer_index)
- [`get_indexed_attestation`](#get_indexed_attestation)
- [`get_updated_gasprice`](#get_updated_gasprice)
- [`get_start_shard`](#get_start_shard)
- [`get_shard`](#get_shard)
- [`get_latest_slot_for_shard`](#get_latest_slot_for_shard)
@ -439,6 +439,20 @@ def compute_offset_slots(start_slot: Slot, end_slot: Slot) -> Sequence[Slot]:
return [Slot(start_slot + x) for x in SHARD_BLOCK_OFFSETS if start_slot + x < end_slot]
```
#### `compute_updated_gasprice`
```python
def compute_updated_gasprice(prev_gasprice: Gwei, length: uint8) -> Gwei:
if length > TARGET_SHARD_BLOCK_SIZE:
delta = (prev_gasprice * (length - TARGET_SHARD_BLOCK_SIZE)
// TARGET_SHARD_BLOCK_SIZE // GASPRICE_ADJUSTMENT_COEFFICIENT)
return min(prev_gasprice + delta, MAX_GASPRICE)
else:
delta = (prev_gasprice * (TARGET_SHARD_BLOCK_SIZE - length)
// TARGET_SHARD_BLOCK_SIZE // GASPRICE_ADJUSTMENT_COEFFICIENT)
return max(prev_gasprice, MIN_GASPRICE + delta) - delta
```
### Beacon state accessors
#### `get_active_shard_count`
@ -512,20 +526,6 @@ def get_indexed_attestation(beacon_state: BeaconState, attestation: Attestation)
)
```
#### `get_updated_gasprice`
```python
def get_updated_gasprice(prev_gasprice: Gwei, length: uint8) -> Gwei:
if length > TARGET_SHARD_BLOCK_SIZE:
delta = (prev_gasprice * (length - TARGET_SHARD_BLOCK_SIZE)
// TARGET_SHARD_BLOCK_SIZE // GASPRICE_ADJUSTMENT_COEFFICIENT)
return min(prev_gasprice + delta, MAX_GASPRICE)
else:
delta = (prev_gasprice * (TARGET_SHARD_BLOCK_SIZE - length)
// TARGET_SHARD_BLOCK_SIZE // GASPRICE_ADJUSTMENT_COEFFICIENT)
return max(prev_gasprice, MIN_GASPRICE + delta) - delta
```
#### `get_start_shard`
```python
@ -617,7 +617,6 @@ def is_valid_indexed_attestation(state: BeaconState, indexed_attestation: Indexe
return bls.AggregateVerify(zip(all_pubkeys, all_signing_roots), signature=attestation.signature)
```
### Block processing
```python
@ -630,7 +629,6 @@ def process_block(state: BeaconState, block: BeaconBlock) -> None:
process_operations(state, block.body)
```
#### Operations
```python
@ -714,32 +712,29 @@ def apply_shard_transition(state: BeaconState, shard: Shard, transition: ShardTr
assert transition.start_slot == offset_slots[0]
headers = []
header = ShardBlockHeader()
proposers = []
prev_gasprice = state.shard_states[shard].gasprice
shard_parent_root = state.shard_states[shard].latest_block_root
beacon_parent_root = get_block_root_at_slot(state, get_previous_slot(state.slot))
for i in range(len(offset_slots)):
shard_block_length = transition.shard_block_lengths[i]
is_empty_proposal = (shard_block_length == 0)
is_empty_proposal = shard_block_length == 0
shard_state = transition.shard_states[i]
if not is_empty_proposal:
proposal_index = get_shard_proposer_index(state, offset_slots[i], shard)
# Reconstruct shard headers
header = ShardBlockHeader(
shard_parent_root=shard_parent_root,
beacon_parent_root=beacon_parent_root,
beacon_parent_root=get_block_root_at_slot(state, offset_slots[i]),
proposer_index=proposal_index,
slot=offset_slots[i],
body_root=transition.shard_data_roots[i]
)
shard_parent_root = hash_tree_root(header)
if not is_empty_proposal:
# Only add non-empty signature
headers.append(header)
proposers.append(proposal_index)
# Verify correct calculation of gas prices and slots
assert shard_state.gasprice == get_updated_gasprice(prev_gasprice, shard_block_length)
assert shard_state.gasprice == compute_updated_gasprice(prev_gasprice, shard_block_length)
assert shard_state.slot == offset_slots[i]
prev_gasprice = shard_state.gasprice
@ -753,7 +748,6 @@ def apply_shard_transition(state: BeaconState, shard: Shard, transition: ShardTr
# Save updated state
state.shard_states[shard] = transition.shard_states[len(transition.shard_states) - 1]
assert state.slot > 0
state.shard_states[shard].slot = state.slot - 1
```

View File

@ -36,17 +36,48 @@ This document describes the shard transition function and fraud proofs as part o
```python
def shard_state_transition(beacon_state: BeaconState,
shard: Shard,
slot: Slot,
shard_state: ShardState,
beacon_parent_root: Root,
signed_block: SignedShardBlock) -> None:
# Update shard state
shard_state.data = hash(
hash_tree_root(shard_state) + hash_tree_root(beacon_parent_root) + hash_tree_root(signed_block.message.body)
prev_gasprice = shard_state.gasprice
if len(signed_block.message.body) == 0:
latest_block_root = shard_state.latest_block_root
else:
latest_block_root = hash_tree_root(signed_block.message)
shard_state.data = compute_shard_transition_data(
beacon_state,
shard_state,
signed_block.message.beacon_parent_root,
signed_block.message.body,
)
shard_state.slot = slot
shard_state.latest_block_root = hash_tree_root(signed_block.message)
shard_state.gasprice = compute_updated_gasprice(prev_gasprice, len(signed_block.message.body))
shard_state.slot = signed_block.message.slot
shard_state.latest_block_root = latest_block_root
```
```python
def compute_shard_transition_data(beacon_state: BeaconState,
shard_state: ShardState,
beacon_parent_root: Root,
shard_body_root: Root) -> Bytes32:
return hash(
hash_tree_root(shard_state) + beacon_parent_root + shard_body_root
)
```
```python
def verify_shard_block_message(beacon_state: BeaconState,
shard_state: ShardState,
block: ShardBlock,
slot: Slot,
shard: Shard) -> bool:
assert block.shard_parent_root == shard_state.latest_block_root
assert block.beacon_parent_root == get_block_root_at_slot(beacon_state, slot)
assert block.slot == slot
assert block.proposer_index == get_shard_proposer_index(beacon_state, slot, shard)
assert 0 < len(block.body) <= MAX_SHARD_BLOCK_SIZE
return True
```
```python
@ -67,11 +98,12 @@ TODO. The intent is to have a single universal fraud proof type, which contains
3. The `transition: ShardTransition` itself
4. The full body of the shard block `shard_block`
5. A Merkle proof to the `shard_states` in the parent block the attestation is referencing
6. The `subkey` to generate the custody bit
Call the following function to verify the proof:
```python
def verify_fraud_proof(beacon_state: BeaconState,
def is_valid_fraud_proof(beacon_state: BeaconState,
attestation: Attestation,
offset_index: uint64,
transition: ShardTransition,
@ -80,7 +112,6 @@ def verify_fraud_proof(beacon_state: BeaconState,
beacon_parent_block: BeaconBlock) -> bool:
# 1. Check if `custody_bits[offset_index][j] != generate_custody_bit(subkey, block_contents)` for any `j`.
shard = get_shard(beacon_state, attestation)
slot = attestation.data.slot
custody_bits = attestation.custody_bits_blocks
for j in range(custody_bits[offset_index]):
if custody_bits[offset_index][j] != generate_custody_bit(subkey, signed_block):
@ -89,19 +120,12 @@ def verify_fraud_proof(beacon_state: BeaconState,
# 2. Check if the shard state transition result is wrong between
# `transition.shard_states[offset_index - 1]` to `transition.shard_states[offset_index]`.
if offset_index == 0:
shard_state = beacon_parent_block.shard_transitions[shard].shard_states[-1]
shard_state = beacon_parent_block.shard_transitions[shard].shard_states[-1].copy()
else:
shard_state = transition.shard_states[offset_index - 1].copy() # Not doing the actual state updates here.
shard_state_transition(
beacon_state=beacon_state,
shard=shard,
slot=slot,
shard_state=shard_state,
beacon_parent_root=hash_tree_root(beacon_parent_block),
signed_block=signed_block,
)
if shard_state.latest_block_root != transition.shard_states[offset_index].data:
shard_state_transition(beacon_state, shard_state, signed_block)
if shard_state.data != transition.shard_states[offset_index].data:
return True
return False
@ -126,26 +150,7 @@ def get_winning_proposal(beacon_state: BeaconState, proposals: Sequence[SignedSh
```
```python
def get_empty_body_block(shard_parent_root: Root,
beacon_parent_root: Root,
slot: Slot,
proposer_index: ValidatorIndex) -> ShardBlock:
return ShardBlock(
shard_parent_root=shard_parent_root,
beacon_parent_root=beacon_parent_root,
slot=slot,
proposer_index=proposer_index,
)
```
```python
def is_empty_body(proposal: ShardBlock) -> bool:
# TODO
return len(proposal.body) == 0
```
```python
def compute_shard_data_roots(proposals: Sequence[SignedShardBlock]) -> Sequence[Root]:
def compute_shard_body_roots(proposals: Sequence[SignedShardBlock]) -> Sequence[Root]:
return [hash_tree_root(proposal.message.body) for proposal in proposals]
```
@ -155,28 +160,23 @@ def get_proposal_choices_at_slot(beacon_state: BeaconState,
slot: Slot,
shard: Shard,
shard_blocks: Sequence[SignedShardBlock],
validate_result: bool=True) -> Sequence[SignedShardBlock]:
validate_signature: bool=True) -> Sequence[SignedShardBlock]:
"""
Return the valid shard blocks at the given ``slot``.
Note that this function doesn't change the state.
"""
choices = []
beacon_parent_root = get_block_root_at_slot(beacon_state, get_previous_slot(beacon_state.slot))
proposer_index = get_shard_proposer_index(beacon_state, slot, shard)
shard_blocks_at_slot = [block for block in shard_blocks if block.message.slot == slot]
for block in shard_blocks_at_slot:
temp_shard_state = shard_state.copy() # Not doing the actual state updates here.
# Try to apply state transition to temp_shard_state.
try:
# Verify the proposer_index and signature
assert block.message.proposer_index == proposer_index
if validate_result:
# Verify block message and signature
assert verify_shard_block_message(beacon_state, temp_shard_state, block.message, slot, shard)
if validate_signature:
assert verify_shard_block_signature(beacon_state, block)
shard_state_transition(
beacon_state=beacon_state,
shard=shard,
slot=slot,
shard_state=temp_shard_state,
beacon_parent_root=beacon_parent_root,
signed_block=block,
)
shard_state_transition(beacon_state, temp_shard_state, block)
except Exception:
pass # TODO: throw error in the test helper
else:
@ -189,11 +189,12 @@ def get_proposal_at_slot(beacon_state: BeaconState,
shard_state: ShardState,
slot: Shard,
shard: Shard,
shard_parent_root: Root,
shard_blocks: Sequence[SignedShardBlock],
validate_result: bool=True) -> Tuple[SignedShardBlock, ShardState, Root]:
beacon_parent_root = get_block_root_at_slot(beacon_state, get_previous_slot(beacon_state.slot))
proposer_index = get_shard_proposer_index(beacon_state, slot, shard)
validate_signature: bool=True) -> Tuple[SignedShardBlock, ShardState]:
"""
Return ``proposal``, ``shard_state`` of the given ``slot``.
Note that this function doesn't change the state.
"""
shard_state = shard_state.copy() # Don't update the given shard_state
choices = get_proposal_choices_at_slot(
beacon_state=beacon_state,
@ -201,35 +202,20 @@ def get_proposal_at_slot(beacon_state: BeaconState,
slot=slot,
shard=shard,
shard_blocks=shard_blocks,
validate_result=validate_result,
validate_signature=validate_signature,
)
if len(choices) == 0:
block_header = get_empty_body_block(
shard_parent_root=shard_parent_root,
beacon_parent_root=beacon_parent_root,
slot=slot,
proposer_index=proposer_index,
)
proposal = SignedShardBlock(message=block_header)
block = ShardBlock(slot=slot)
proposal = SignedShardBlock(message=block)
elif len(choices) == 1:
proposal = choices[0]
else:
proposal = get_winning_proposal(beacon_state, choices)
shard_parent_root = hash_tree_root(proposal.message)
# Apply state transition
shard_state_transition(beacon_state, shard_state, proposal)
if not is_empty_body(proposal.message):
# Apply state transition to shard_state.
shard_state_transition(
beacon_state=beacon_state,
shard=shard,
slot=slot,
shard_state=shard_state,
beacon_parent_root=beacon_parent_root,
signed_block=proposal,
)
return proposal, shard_state, shard_parent_root
return proposal, shard_state
```
```python
@ -237,26 +223,24 @@ def get_shard_state_transition_result(
beacon_state: BeaconState,
shard: Shard,
shard_blocks: Sequence[SignedShardBlock],
validate_result: bool=True,
validate_signature: bool=True,
) -> Tuple[Sequence[SignedShardBlock], Sequence[ShardState], Sequence[Root]]:
proposals = []
shard_states = []
shard_state = beacon_state.shard_states[shard].copy()
shard_parent_root = beacon_state.shard_states[shard].latest_block_root
for slot in get_offset_slots(beacon_state, shard):
proposal, shard_state, shard_parent_root = get_proposal_at_slot(
proposal, shard_state = get_proposal_at_slot(
beacon_state=beacon_state,
shard_state=shard_state,
slot=slot,
shard=shard,
shard_parent_root=shard_parent_root,
shard_blocks=shard_blocks,
validate_result=validate_result,
validate_signature=validate_signature,
)
shard_states.append(shard_state)
proposals.append(proposal)
shard_data_roots = compute_shard_data_roots(proposals)
shard_data_roots = compute_shard_body_roots(proposals)
return proposals, shard_states, shard_data_roots
```

View File

@ -7,7 +7,7 @@
- [Introduction](#introduction)
- [Configuration](#configuration)
- [Fork to Phase 1](#fork-to-phase-1)
- [Fork trigger.](#fork-trigger)
- [Fork trigger](#fork-trigger)
- [Upgrading the state](#upgrading-the-state)
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
@ -35,17 +35,18 @@ Warning: this configuration is not definitive.
| Name | Value |
| - | - |
| `PHASE_1_FORK_VERSION` | `Version('0x01000000')` |
| `PHASE_1_GENESIS_SLOT` | `2**5` **TBD** |
| `INITIAL_ACTIVE_SHARDS` | `2**6` (= 64) |
## Fork to Phase 1
### Fork trigger.
### Fork trigger
TBD. Social consensus, along with state conditions such as epoch boundary, finality, deposits, active validator count, etc. may be part of the decision process to trigger the fork.
TBD. Social consensus, along with state conditions such as epoch boundary, finality, deposits, active validator count, etc. may be part of the decision process to trigger the fork. For now we assume the condition will be triggered at slot `PHASE_1_GENESIS_SLOT`, where `PHASE_1_GENESIS_SLOT % SLOTS_PER_EPOCH == 0`.
### Upgrading the state
After `process_slots` of Phase 0 finishes, but before the first Phase 1 block is processed, an irregular state change is made to upgrade to Phase 1.
After `process_slots` of Phase 0 finishes, if `state.slot == PHASE_1_GENESIS_SLOT`, an irregular state change is made to upgrade to Phase 1.
```python
def upgrade_to_phase1(pre: phase0.BeaconState) -> BeaconState:

View File

@ -32,7 +32,7 @@ def build_shard_block(spec,
block = spec.ShardBlock(
shard_parent_root=shard_state.latest_block_root,
beacon_parent_root=spec.get_block_root_at_slot(beacon_state, spec.get_previous_slot(beacon_state.slot)),
beacon_parent_root=spec.get_block_root_at_slot(beacon_state, spec.get_previous_slot(slot)),
slot=slot,
proposer_index=proposer_index,
body=body,

View File

@ -10,7 +10,7 @@ from eth2spec.test.helpers.crosslinks import (
run_crosslinks_processing,
)
from eth2spec.test.helpers.shard_block import build_shard_block
from eth2spec.test.helpers.state import next_epoch, next_slot
from eth2spec.test.helpers.state import next_epoch, next_slot, next_slots
@with_all_phases_except(['phase0'])
@ -24,7 +24,8 @@ def test_basic_crosslinks(spec, state):
committee_index = spec.CommitteeIndex(0)
shard = spec.compute_shard_from_committee_index(state, committee_index, state.slot)
shard_block = build_shard_block(spec, state, shard, body=b'\x12' * 10, slot=state.slot, signed=True)
body = b'1' * spec.MAX_SHARD_BLOCK_SIZE
shard_block = build_shard_block(spec, state, shard, body=body, slot=state.slot, signed=True)
shard_blocks = [shard_block]
next_slot(spec, state)
@ -43,10 +44,58 @@ def test_basic_crosslinks(spec, state):
)
attestations = [attestation]
pre_gasprice = state.shard_states[shard].gasprice
offset_slots = spec.get_offset_slots(state, shard)
assert len(offset_slots) == 1
yield from run_crosslinks_processing(spec, state, shard_transitions, attestations)
shard_state = state.shard_states[shard]
assert shard_state.slot == offset_slots[-1]
assert shard_state.latest_block_root == shard_block.message.hash_tree_root()
assert shard_state == shard_transition.shard_states[len(shard_transition.shard_states) - 1]
assert shard_state.gasprice > pre_gasprice
@with_all_phases_except(['phase0'])
@spec_state_test
@always_bls
def test_multiple_offset_slots(spec, state):
next_epoch(spec, state)
next_epoch(spec, state)
state = spec.upgrade_to_phase1(state)
next_slot(spec, state)
committee_index = spec.CommitteeIndex(0)
shard = spec.compute_shard_from_committee_index(state, committee_index, state.slot)
body = b'1' * spec.MAX_SHARD_BLOCK_SIZE
shard_block = build_shard_block(spec, state, shard, body=body, slot=state.slot, signed=True)
shard_blocks = [shard_block]
next_slots(spec, state, 3)
shard_transition = spec.get_shard_transition(state, shard, shard_blocks)
shard_transitions = [spec.ShardTransition()] * len(state.shard_states)
shard_transitions[shard] = shard_transition
attestation = get_valid_on_time_attestation(
spec,
state,
slot=state.slot,
index=committee_index,
shard_transition=shard_transition,
signed=True,
)
attestations = [attestation]
pre_gasprice = state.shard_states[shard].gasprice
offset_slots = spec.get_offset_slots(state, shard)
assert len(offset_slots) == 3
yield from run_crosslinks_processing(spec, state, shard_transitions, attestations)
shard_state = state.shard_states[shard]
assert shard_state.slot == offset_slots[-1]
assert shard_state.latest_block_root == shard_block.message.hash_tree_root()
assert shard_state == shard_transition.shard_states[len(shard_transition.shard_states) - 1]
assert shard_state.gasprice > pre_gasprice