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

Update 0_beacon-chain.md

This commit is contained in:
Justin 2019-02-16 21:11:48 +00:00 committed by GitHub
parent b92cd9be03
commit 1d95c1482c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 7 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
specs/core/0_beacon-chain.md
View File

@ -795,23 +795,16 @@ def get_shuffling(seed: Bytes32,
validators: List[Validator], validators: List[Validator],
epoch: Epoch) -> List[List[ValidatorIndex]] epoch: Epoch) -> List[List[ValidatorIndex]]
""" """
Shuffle ``validators`` into crosslink committees seeded by ``seed`` and ``epoch``. Shuffle (seeded by ``seed`` and ``epoch``) active validators and split into crosslink committees.
Return a list of ``committees_per_epoch`` committees where each Return a list of committees (each a list of validator indices).
committee is itself a list of validator indices.
""" """
# Shuffle active validator indices
active_validator_indices = get_active_validator_indices(validators, epoch) active_validator_indices = get_active_validator_indices(validators, epoch)
length = len(active_validator_indices)
shuffled_indices = [active_validator_indices[get_permuted_index(i, length, seed)] for i in range(length)]
committees_per_epoch = get_epoch_committee_count(len(active_validator_indices)) # Split the shuffled active validator indices
return split(shuffled_indices, get_epoch_committee_count(length))
# Shuffle
shuffled_active_validator_indices = [
active_validator_indices[get_permuted_index(i, len(active_validator_indices), seed)]
for i in range(len(active_validator_indices))
]
# Split the shuffled list into committees_per_epoch pieces
return split(shuffled_active_validator_indices, committees_per_epoch)
``` ```
**Invariant**: if `get_shuffling(seed, validators, epoch)` returns some value `x` for some `epoch <= get_current_epoch(state) + ACTIVATION_EXIT_DELAY`, it should return the same value `x` for the same `seed` and `epoch` and possible future modifications of `validators` forever in phase 0, and until the ~1 year deletion delay in phase 2 and in the future. **Invariant**: if `get_shuffling(seed, validators, epoch)` returns some value `x` for some `epoch <= get_current_epoch(state) + ACTIVATION_EXIT_DELAY`, it should return the same value `x` for the same `seed` and `epoch` and possible future modifications of `validators` forever in phase 0, and until the ~1 year deletion delay in phase 2 and in the future.