From 26df98bf61b0d07d60263dbe339e80d93c3e6098 Mon Sep 17 00:00:00 2001 From: Vitalik Buterin Date: Sun, 13 Oct 2019 17:11:29 +0900 Subject: [PATCH] MAX_CATCHUP -> MAX_CATCHUP_RATIO --- specs/core/1_new_shards.md | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/specs/core/1_new_shards.md b/specs/core/1_new_shards.md index cf644b4c0..2d199a640 100644 --- a/specs/core/1_new_shards.md +++ b/specs/core/1_new_shards.md @@ -37,7 +37,7 @@ This document describes the shard transition function (data layer only) and the | `MAX_SHARDS` | `2**10` (= 1024) | | `ACTIVE_SHARDS` | `2**6` (= 64) | | `SHARD_ROOT_HISTORY_LENGTH` | `2**15` (= 32,768) | -| `MAX_CATCHUP` | `2**5` (= 32) | slots | 3.2 min | +| `MAX_CATCHUP_RATIO` | `2**2` (= 4) | | `ONLINE_PERIOD` | `2**3` (= 8) | epochs | ~51 min | | `LIGHT_CLIENT_COMMITTEE_SIZE` | `2**7` (= 128) | | `LIGHT_CLIENT_COMMITTEE_PERIOD` | `2**8` (= 256) | epochs | ~29 hours | @@ -56,9 +56,9 @@ class AttestationData(Container): source: Checkpoint target: Checkpoint # Shard data roots - shard_data_roots: List[Hash, MAX_CATCHUP] + shard_data_roots: List[Hash, MAX_CATCHUP_RATIO * MAX_SHARDS] # Intermediate state roots - shard_state_roots: List[Hash, MAX_CATCHUP] + shard_state_roots: List[Hash, MAX_CATCHUP_RATIO * MAX_SHARDS] # Index index: uint64 ``` @@ -69,7 +69,7 @@ class AttestationData(Container): class Attestation(Container): aggregation_bits: Bitlist[MAX_VALIDATORS_PER_COMMITTEE] data: AttestationData - custody_bits: List[Bitlist[MAX_VALIDATORS_PER_COMMITTEE], MAX_CATCHUP] + custody_bits: List[Bitlist[MAX_VALIDATORS_PER_COMMITTEE], MAX_CATCHUP_RATIO * MAX_SHARDS] signature: BLSSignature ``` @@ -141,7 +141,7 @@ def committee_to_compact_committee(state: BeaconState, committee: Sequence[Valid ### New state variables ``` - shard_state_roots: Vector[List[Hash, MAX_CATCHUP], MAX_SHARDS] + shard_state_roots: Vector[List[Hash, MAX_CATCHUP_RATIO * MAX_SHARDS], MAX_SHARDS] shard_next_slot: Vector[Slot, MAX_SHARDS] online_countdown: Bytes[VALIDATOR_REGISTRY_LIMIT] current_light_committee: CompactCommittee @@ -177,7 +177,8 @@ def process_attestation(state: BeaconState, attestation: Attestation) -> None: # Correct start slot assert data.slot == state.shard_next_slot[shard] # Correct data root count - assert len(data.shard_data_roots) == len(attestation.custody_bits) == len(data.shard_state_roots) == min(state.slot - data.slot, MAX_CATCHUP) + max_catchup = ACTIVE_SHARDS * MAX_CATCHUP_RATIO // get_committee_count(state, state.slot) + assert len(data.shard_data_roots) == len(attestation.custody_bits) == len(data.shard_state_roots) == min(state.slot - data.slot, max_catchup) # Correct parent block root assert data.beacon_block_root == get_block_root_at_slot(state, state.slot - 1) # Apply @@ -263,7 +264,7 @@ For phase 1, we will use a simple state transition function: Suppose you are a persistent committee member on shard `i` at slot `s`. Suppose `state.shard_next_slots[i] = s-1` ("the happy case"). In this case, you look for a valid proposal that satisfies the checks in the state transition function above, and if you see such a proposal `data` with post-state `post_state`, make an attestation with `shard_data_roots = [hash_tree_root(data)]` and `shard_state_roots = [post_state]`. If you do not find such a proposal, make an attestation using the "default empty proposal", `data = prev_state_root + b'\x00' * 96`. -Now suppose `state.shard_next_slots[i] = s-k` for `k>1`. Then, initialize `data = []`, `states = []`, `state = state.shard_state_roots[i]`. For `slot in (state.shard_next_slot, min(state.shard_next_slot + MAX_CATCHUP, s))`, do: +Now suppose `state.shard_next_slots[i] = s-k` for `k>1`. Then, initialize `data = []`, `states = []`, `state = state.shard_state_roots[i]`. For `slot in (state.shard_next_slot, min(state.shard_next_slot + max_catchup, s))`, do: * Look for all valid proposals for `slot` whose first 32 bytes equal to `state`. If there are none, add a default empty proposal to `data`. If there is one such proposal `p`, add `p` to `data`. If there is more than one, select the one with the largest number of total attestations supporting it or its descendants, and add it to `data`. * Set `state` to the state after processing the proposal just added to `data`; append it to `states`