eth2.0-specs/specs/phase1/phase1-fork.md
Hsiao-Wei Wang 524ba166d1
[squashed] shard chain updates wip
Fix wrong field names

Fix `build_attestation_data` and other PR feedback from Danny and
Terence

1. Rename `get_previous_slot` to `compute_previous_slot`
2. Break down `build_empty_block` into
`get_state_and_beacon_parent_root_at_slot`, use it in
`build_shard_block`
3. Set defult `slot` to `shard_state.slot + 1` in `build_shard_block`

Update `verify_shard_block_message`: check beacon_parent_root at fork
choice rule stage instead of state transition

Fix  `beacon-chain.md`

1. Fix typo `attestation.slot == state.slot` -> `attestation.data.slot == state.slot` in `is_winning_attestation`
2. Check `verify_shard_transition_false_positives` **after** `process_operations`
3. Fix `shard_attestations` filter in `process_crosslinks`: since attestations come from block, should use `attestation.data.slot + MIN_ATTESTATION_INCLUSION_DELAY == state.slot`
4. [TBD] Allow empty `light_client_signature` to make the tests pass
5. [TBD] Add `is_shard_attestation`, filter out empty `ShardTransition()`

Rework `test_process_crosslink`

Add basic phase 1 `test_blocks`

Add more test cases

Revert `is_shard_attestation` and fix test cases backward compatibility.

Remove `test_process_beacon_block_no_shard_transition` and consider it as invalid case.
2020-05-02 02:32:31 +08:00

122 lines
5.0 KiB
Markdown

<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
**Table of Contents** *generated with [DocToc](https://github.com/thlorenz/doctoc)*
- [Ethereum 2.0 Phase 1 -- From Phase 0 to Phase 1](#ethereum-20-phase-1----from-phase-0-to-phase-1)
- [Table of contents](#table-of-contents)
- [Introduction](#introduction)
- [Configuration](#configuration)
- [Fork to Phase 1](#fork-to-phase-1)
- [Fork trigger](#fork-trigger)
- [Upgrading the state](#upgrading-the-state)
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
# Ethereum 2.0 Phase 1 -- From Phase 0 to Phase 1
**Notice**: This document is a work-in-progress for researchers and implementers.
## Table of contents
<!-- TOC -->
TODO
<!-- /TOC -->
## Introduction
This document describes the process of moving from Phase 0 to Phase 1 of Ethereum 2.0.
## Configuration
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
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, 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:
epoch = get_current_epoch(pre)
post = BeaconState(
genesis_time=pre.genesis_time,
slot=pre.slot,
fork=Fork(
previous_version=pre.fork.current_version,
current_version=PHASE_1_FORK_VERSION,
epoch=epoch,
),
# History
latest_block_header=pre.latest_block_header,
block_roots=pre.block_roots,
state_roots=pre.state_roots,
historical_roots=pre.historical_roots,
# Eth1
eth1_data=pre.eth1_data,
eth1_data_votes=pre.eth1_data_votes,
eth1_deposit_index=pre.eth1_deposit_index,
# Registry
validators=List[Validator, VALIDATOR_REGISTRY_LIMIT](
Validator(
pubkey=phase0_validator.pubkey,
withdrawal_credentials=phase0_validator.withdrawal_credentials,
effective_balance=phase0_validator.effective_balance,
slashed=phase0_validator.slashed,
activation_eligibility_epoch=phase0_validator.activation_eligibility_epoch,
activation_epoch=phase0_validator.activation_eligibility_epoch,
exit_epoch=phase0_validator.exit_epoch,
withdrawable_epoch=phase0_validator.withdrawable_epoch,
next_custody_secret_to_reveal=get_custody_period_for_validator(ValidatorIndex(i), epoch),
max_reveal_lateness=0, # TODO custody refactor. Outdated?
) for i, phase0_validator in enumerate(pre.validators)
),
balances=pre.balances,
# Randomness
randao_mixes=pre.randao_mixes,
# Slashings
slashings=pre.slashings,
# Attestations
# previous_epoch_attestations is cleared on upgrade.
previous_epoch_attestations=List[PendingAttestation, MAX_ATTESTATIONS * SLOTS_PER_EPOCH](),
# empty in pre state, since the upgrade is performed just after an epoch boundary.
current_epoch_attestations=List[PendingAttestation, MAX_ATTESTATIONS * SLOTS_PER_EPOCH](),
# Finality
justification_bits=pre.justification_bits,
previous_justified_checkpoint=pre.previous_justified_checkpoint,
current_justified_checkpoint=pre.current_justified_checkpoint,
finalized_checkpoint=pre.finalized_checkpoint,
# Phase 1
shard_states=List[ShardState, MAX_SHARDS](
ShardState(
slot=pre.slot,
gasprice=MIN_GASPRICE,
transition_digest=Root(),
latest_block_root=Root(),
) for i in range(INITIAL_ACTIVE_SHARDS)
),
online_countdown=[ONLINE_PERIOD] * len(pre.validators), # all online
current_light_committee=CompactCommittee(), # computed after state creation
next_light_committee=CompactCommittee(),
# Custody game
exposed_derived_secrets=[] * EARLY_DERIVED_SECRET_PENALTY_MAX_FUTURE_EPOCHS,
# exposed_derived_secrets will fully default to zeroes
)
next_epoch = Epoch(epoch + 1)
post.current_light_committee = committee_to_compact_committee(post, get_light_client_committee(post, epoch))
post.next_light_committee = committee_to_compact_committee(post, get_light_client_committee(post, next_epoch))
return post
```