Merge pull request #61 from status-im/SUSP1

Spec update

beacon_chain/beacon_node.nim

@@ -197,7 +197,7 @@ proc proposeBlock(node: BeaconNode,
     slot: slot,
     parent_root: node.headBlockRoot,
     randao_reveal: randaoReveal,
-    candidate_pow_receipt_root: node.mainchainMonitor.getBeaconBlockRef(),
+    deposit_root: node.mainchainMonitor.getBeaconBlockRef(),
     signature: ValidatorSig(), # we need the rest of the block first!
     body: blockBody)
 

beacon_chain/spec/beaconstate.nim

@@ -187,7 +187,7 @@ func update_validator_status*(state: var BeaconState,
 func get_initial_beacon_state*(
     initial_validator_deposits: openArray[Deposit],
     genesis_time: uint64,
-    processed_pow_receipt_root: Eth2Digest,
+    latest_deposit_root: Eth2Digest,
     flags: UpdateFlags = {}): BeaconState =
   ## BeaconState constructor
   ##
@@ -207,25 +207,25 @@ func get_initial_beacon_state*(
 
   var state = BeaconState(
     # Misc
-    slot: INITIAL_SLOT_NUMBER,
+    slot: GENESIS_SLOT,
     genesis_time: genesis_time,
     fork_data: ForkData(
-        pre_fork_version: INITIAL_FORK_VERSION,
+        pre_fork_version: GENESIS_FORK_VERSION,
-        post_fork_version: INITIAL_FORK_VERSION,
+        post_fork_version: GENESIS_FORK_VERSION,
-        fork_slot: INITIAL_SLOT_NUMBER,
+        fork_slot: GENESIS_SLOT,
     ),
 
-    validator_registry_latest_change_slot: INITIAL_SLOT_NUMBER,
+    validator_registry_latest_change_slot: GENESIS_SLOT,
     validator_registry_exit_count: 0,
     validator_registry_delta_chain_tip: ZERO_HASH,
 
     # Finality
-    previous_justified_slot: INITIAL_SLOT_NUMBER,
+    previous_justified_slot: GENESIS_SLOT,
-    justified_slot: INITIAL_SLOT_NUMBER,
+    justified_slot: GENESIS_SLOT,
-    finalized_slot: INITIAL_SLOT_NUMBER,
+    finalized_slot: GENESIS_SLOT,
 
      # PoW receipt root
-    processed_pow_receipt_root: processed_pow_receipt_root,
+    latest_deposit_root: latest_deposit_root,
   )
 
   # handle initial deposits and activations
@@ -233,7 +233,7 @@ func get_initial_beacon_state*(
     let validator_index = process_deposit(
       state,
       deposit.deposit_data.deposit_input.pubkey,
-      deposit.deposit_data.value,
+      deposit.deposit_data.amount,
       deposit.deposit_data.deposit_input.proof_of_possession,
       deposit.deposit_data.deposit_input.withdrawal_credentials,
       deposit.deposit_data.deposit_input.randao_commitment,
@@ -245,7 +245,7 @@ func get_initial_beacon_state*(
   # set initial committee shuffling
   let
     initial_shuffling =
-      get_new_shuffling(Eth2Digest(), state.validator_registry, 0)
+      get_shuffling(Eth2Digest(), state.validator_registry, 0)
 
   # initial_shuffling + initial_shuffling in spec, but more ugly
   for i, n in initial_shuffling:
@@ -267,6 +267,13 @@ func get_block_root*(state: BeaconState,
   doAssert slot < state.slot
   state.latest_block_roots[slot mod LATEST_BLOCK_ROOTS_LENGTH]
 
+func get_randao_mix*(state: BeaconState,
+                    slot: uint64): Eth2Digest =
+    ## Returns the randao mix at a recent ``slot``.
+    assert state.slot < slot + LATEST_RANDAO_MIXES_LENGTH
+    assert slot <= state.slot
+    state.latest_randao_mixes[slot mod LATEST_RANDAO_MIXES_LENGTH]
+
 func get_attestation_participants*(state: BeaconState,
                                    attestation_data: AttestationData,
                                    participation_bitfield: seq[byte]): seq[Uint24] =
@@ -356,6 +363,18 @@ func update_validator_registry*(state: var BeaconState) =
         get_effective_balance(state, index.Uint24) *
           min(total_penalties * 3, total_balance) div total_balance
 
+  # Perform additional updates
+  state.previous_epoch_calculation_slot = state.current_epoch_calculation_slot
+  state.previous_epoch_start_shard = state.current_epoch_start_shard
+  state.previous_epoch_randao_mix = state.current_epoch_randao_mix
+  state.current_epoch_calculation_slot = state.slot
+  state.current_epoch_start_shard = (state.current_epoch_start_shard + get_current_epoch_committee_count_per_slot(state) * EPOCH_LENGTH) mod SHARD_COUNT
+  state.current_epoch_randao_mix = get_randao_mix(state, state.current_epoch_calculation_slot - SEED_LOOKAHEAD)
+
+  # TODO "If a validator registry update does not happen do the following: ..."
+
+  #process_penalties_and_exits(state)
+
 proc checkAttestation*(
     state: BeaconState, attestation: Attestation, flags: UpdateFlags): bool =
   ## Check that an attestation follows the rules of being included in the state

beacon_chain/spec/datatypes.nim

@@ -46,6 +46,7 @@ import
 # TODO Many of these constants should go into a config object that can be used
 #      to run.. well.. a chain with different constants!
 const
+  # Misc
   SHARD_COUNT* = 1024 ##\
   ## Number of shards supported by the network - validators will jump around
   ## between these shards and provide attestations to their state.
@@ -73,12 +74,13 @@ const
 
   BEACON_CHAIN_SHARD_NUMBER* = not 0'u64 # 2^64 - 1 in spec
 
-  BLS_WITHDRAWAL_PREFIX_BYTE* = 0'u8
-
   MAX_CASPER_VOTES* = 2^10
   LATEST_BLOCK_ROOTS_LENGTH* = 2'u64^13
   LATEST_RANDAO_MIXES_LENGTH* = 2'u64^13
+  LATEST_PENALIZED_EXIT_LENGTH* = 8192 # epochs
+  MAX_WITHDRAWALS_PER_EPOCHS* = 4 # withdrawals
 
+  # Deposit contract
   DEPOSIT_CONTRACT_TREE_DEPTH* = 2^5
 
   MIN_DEPOSIT* = 2'u64^0 ##\
@@ -89,11 +91,15 @@ const
 
   # Initial values
 
-  INITIAL_FORK_VERSION* = 0'u64
+  GENESIS_FORK_VERSION* = 0'u64
-  INITIAL_SLOT_NUMBER* = 0'u64
+  GENESIS_SLOT* = 0'u64
+  GENESIS_START_SHARD* = 0'u64
+  FAR_FUTURE_SLOT* = not 0'u64 # 2^64 - 1 in spec
   ZERO_HASH* = Eth2Digest()
+  # TODO EMPTY_SIGNATURE* =
+  BLS_WITHDRAWAL_PREFIX_BYTE* = 0'u8
 
-  # Time constants
+  # Time parameters
   SLOT_DURATION* = 6'u64 ## \
   ## TODO consistent time unit across projects, similar to C++ chrono?
 
@@ -117,6 +123,9 @@ const
   POW_RECEIPT_ROOT_VOTING_PERIOD* = 2'u64^10 ##\
   ## slots (~1.7 hours)
 
+  SEED_LOOKAHEAD* = 64 ##\
+  ## slots (~6.4 minutes)
+
   SHARD_PERSISTENT_COMMITTEE_CHANGE_PERIOD* = 2'u64^17 ##\
   ## slots (~9 days)
 
@@ -126,6 +135,12 @@ const
   ZERO_BALANCE_VALIDATOR_TTL* = 2'u64^22 ##\
   ## slots (~291 days)
 
+  DEPOSIT_ROOT_VOTING_PERIOD* = 2'u64^10 ##\
+  ## slots (~1.7 hours)
+
+  MIN_VALIDATOR_WITHDRAWAL_TIME* = 2'u64^14 ##\
+  ## slots (~27 hours)
+
   # Quotients
   BASE_REWARD_QUOTIENT* = 2'u64^10 ##\
   ## The `BASE_REWARD_QUOTIENT` parameter dictates the per-epoch reward. It
@@ -135,6 +150,12 @@ const
   INCLUDER_REWARD_QUOTIENT* = 2'u64^3
   INACTIVITY_PENALTY_QUOTIENT* = 2'u64^24
 
+  # Status flags
+  # Could model this with enum, but following spec closely here
+  INITIATED_EXIT* = 1'u64
+  WITHDRAWABLE* = 2'u64
+
+  # Max operations per block
   MAX_PROPOSER_SLASHINGS* = 2^4
   MAX_CASPER_SLASHINGS* = 2^4
   MAX_ATTESTATIONS* = 2^7
@@ -203,24 +224,25 @@ type
     poc_bit: bool
 
   Deposit* = object
-    merkle_branch*: seq[Eth2Digest] ##\
+    branch*: seq[Eth2Digest] ##\
-    ## Receipt Merkle branch
+    ## Branch in the deposit tree
 
-    merkle_tree_index*: uint64
+    index*: uint64 ##\
+    ## Index in the deposit tree
 
-    ## Deposit data
+    deposit_data*: DepositData ##\
-    deposit_data*: DepositData
+    ## Data
 
   DepositData* = object
+    amount*: uint64 ## Value in Gwei
     deposit_input*: DepositInput
-    value*: uint64 ## Value in Gwei
     timestamp*: uint64 # Timestamp from deposit contract
 
   DepositInput* = object
     pubkey*: ValidatorPubKey
     withdrawal_credentials*: Eth2Digest
     randao_commitment*: Eth2Digest # Initial RANDAO commitment
-    poc_commitment*: Eth2Digest
+    custody_commitment*: Eth2Digest
     proof_of_possession*: ValidatorSig ##\
     ## BLS proof of possession (a BLS signature)
 
@@ -249,7 +271,7 @@ type
     randao_reveal*: Eth2Digest ##\
     ## Proposer RANDAO reveal
 
-    candidate_pow_receipt_root*: Eth2Digest
+    deposit_root*: Eth2Digest
 
     signature*: ValidatorSig ##\
     ## Proposer signature
@@ -261,14 +283,14 @@ type
     casper_slashings*: seq[CasperSlashing]
     attestations*: seq[Attestation]
     poc_seed_changes*: seq[ProofOfCustodySeedChange]
-    poc_challenges*: seq[ProofOfCustodyChallenge]
+    poc_challenges*: seq[CustodyChallenge]
     poc_responses*: seq[ProofOfCustodyResponse]
     deposits*: seq[Deposit]
     exits*: seq[Exit]
 
   # Phase1:
   ProofOfCustodySeedChange* = object
-  ProofOfCustodyChallenge* = object
+  CustodyChallenge* = object
   ProofOfCustodyResponse* = object
 
   ProposalSignedData* = object
@@ -302,10 +324,17 @@ type
     ## Committee members and their assigned shard, per slot, covers 2 cycles
     ## worth of assignments
 
+    previous_epoch_start_shard*: uint64
+    current_epoch_start_shard*: uint64
+    previous_epoch_calculation_slot*: uint64
+    current_epoch_calculation_slot*: uint64
+    previous_epoch_randao_mix*: Eth2Digest
+    current_epoch_randao_mix*: Eth2Digest
+
     persistent_committees*: seq[seq[Uint24]]
     persistent_committee_reassignments*: seq[ShardReassignmentRecord]
 
-    poc_challenges*: seq[ProofOfCustodyChallenge]
+    poc_challenges*: seq[CustodyChallenge]
 
     # Finality
     previous_justified_slot*: uint64
@@ -313,6 +342,7 @@ type
     justification_bitfield*: uint64
     finalized_slot*: uint64
 
+    # Recent state
     latest_crosslinks*: array[SHARD_COUNT, CrosslinkRecord]
     latest_block_roots*: array[LATEST_BLOCK_ROOTS_LENGTH.int, Eth2Digest] ##\
     ## Needed to process attestations, older to newer
@@ -323,8 +353,8 @@ type
     latest_attestations*: seq[PendingAttestationRecord]
     batched_block_roots*: seq[Eth2Digest]
 
-    processed_pow_receipt_root*: Eth2Digest
+    latest_deposit_root*: Eth2Digest
-    candidate_pow_receipt_roots*: seq[CandidatePoWReceiptRootRecord]
+    deposit_roots*: seq[DepositRootVote]
 
   ValidatorRecord* = object
     pubkey*: ValidatorPubKey
@@ -345,10 +375,22 @@ type
     latest_status_change_slot*: uint64 ##\
     ## Slot when validator last changed status (or 0)
 
+    activation_slot*: uint64 ##\
+    ## Slot when validator activated
+
+    exit_slot*: uint64 ##\
+    ## Slot when validator exited
+
+    withdrawal_slot*: uint64 ##\
+    ## Slot when validator withdrew
+
+    penalized_slot*: uint64 ##\
+    ## Slot when validator penalized
+
     exit_count*: uint64 ##\
     ## Exit counter when validator exited (or 0)
 
-    poc_commitment*: Eth2Digest
+    custody_commitment*: Eth2Digest
 
     last_poc_change_slot*: uint64
     second_last_poc_change_slot*: uint64
@@ -377,8 +419,8 @@ type
     slot*: uint64 ##\
     ## When
 
-  CandidatePoWReceiptRootRecord* = object
+  DepositRootVote* = object
-    candidate_pow_receipt_root*: Eth2Digest       # Candidate PoW receipt root
+    deposit_root*: Eth2Digest
     vote_count*: uint64                           # Vote count
 
   PendingAttestationRecord* = object

beacon_chain/spec/helpers.nim

@@ -180,3 +180,29 @@ proc is_surround_vote*(attestation_data_1: AttestationData,
     (attestation_data_1.justified_slot + 1 == attestation_data_2.slot) and
     (attestation_data_2.slot < attestation_data_1.slot)
   )
+
+#func is_active_validator*(validator: ValidatorRecord, slot: uint64): bool =
+#  ### Checks if validator is active
+#  validator.activation_slot <= slot and slot < validator.exit_slot
+
+func is_active_validator*(validator: ValidatorRecord): bool =
+  validator.status in {ACTIVE, ACTIVE_PENDING_EXIT}
+
+func get_active_validator_indices*(validators: openArray[ValidatorRecord], slot: uint64): seq[Uint24] =
+  ## Gets indices of active validators from validators
+  for idx, val in validators:
+    #if is_active_validator(val, slot):
+    if is_active_validator(val):
+      result.add idx.Uint24
+
+func get_committee_count_per_slot*(active_validator_count: int): uint64 =
+  clamp(
+    active_validator_count div EPOCH_LENGTH div TARGET_COMMITTEE_SIZE,
+    1, SHARD_COUNT div EPOCH_LENGTH).uint64
+
+func get_current_epoch_committee_count_per_slot*(state: BeaconState): uint64 =
+  let current_active_validators = get_active_validator_indices(
+    state.validator_registry,
+    state.current_epoch_calculation_slot,
+  )
+  return get_committee_count_per_slot(len(current_active_validators))

beacon_chain/spec/validator.nim

@@ -12,9 +12,6 @@ import
   ../ssz,
   ./crypto, ./datatypes, ./digest, ./helpers
 
-func is_active_validator*(validator: ValidatorRecord): bool =
-  validator.status in {ACTIVE, ACTIVE_PENDING_EXIT}
-
 func min_empty_validator_index*(
     validators: seq[ValidatorRecord],
     validator_balances: seq[uint64],
@@ -31,10 +28,10 @@ func get_active_validator_indices*(validators: openArray[ValidatorRecord]): seq[
     if is_active_validator(val):
       result.add idx.Uint24
 
-func get_new_shuffling*(seed: Eth2Digest,
+func get_shuffling*(seed: Eth2Digest,
-                        validators: openArray[ValidatorRecord],
+                    validators: openArray[ValidatorRecord],
-                        crosslinking_start_shard: uint64
+                    crosslinking_start_shard: uint64
-                        ): array[EPOCH_LENGTH, seq[ShardCommittee]] =
+                    ): array[EPOCH_LENGTH, seq[ShardCommittee]] =
   ## Split up validators into groups at the start of every epoch,
   ## determining at what height they can make attestations and what shard they are making crosslinks for
   ## Implementation should do the following: http://vitalik.ca/files/ShuffleAndAssign.png

beacon_chain/state_transition.nim

@@ -100,16 +100,16 @@ func processRandao(
 
   return true
 
-func processPoWReceiptRoot(state: var BeaconState, blck: BeaconBlock) =
+func processDepositRoot(state: var BeaconState, blck: BeaconBlock) =
   ## https://github.com/ethereum/eth2.0-specs/blob/master/specs/core/0_beacon-chain.md#pow-receipt-root
 
-  for x in state.candidate_pow_receipt_roots.mitems():
+  for x in state.deposit_roots.mitems():
-    if blck.candidate_pow_receipt_root == x.candidate_pow_receipt_root:
+    if blck.deposit_root == x.deposit_root:
       x.vote_count += 1
       return
 
-  state.candidate_pow_receipt_roots.add CandidatePoWReceiptRootRecord(
+  state.deposit_roots.add DepositRootVote(
-    candidate_pow_receipt_root: blck.candidate_pow_receipt_root,
+    deposit_root: blck.deposit_root,
     vote_count: 1
   )
 
@@ -362,7 +362,7 @@ proc processBlock(
     warn("Randao reveal failed")
     return false
 
-  processPoWReceiptRoot(state, blck)
+  processDepositRoot(state, blck)
 
   if not processProposerSlashings(state, blck, flags):
     return false
@@ -565,11 +565,11 @@ func processEpoch(state: var BeaconState) =
 
   block: # Receipt roots
     if state.slot mod POW_RECEIPT_ROOT_VOTING_PERIOD == 0:
-      for x in state.candidate_pow_receipt_roots:
+      for x in state.deposit_roots:
         if x.vote_count * 2 >= POW_RECEIPT_ROOT_VOTING_PERIOD:
-          state.processed_pow_receipt_root = x.candidate_pow_receipt_root
+          state.latest_deposit_root = x.deposit_root
           break
-      state.candidate_pow_receipt_roots = @[]
+      state.deposit_roots = @[]
 
   block: # Justification
     state.previous_justified_slot = state.justified_slot
@@ -700,7 +700,7 @@ func processEpoch(state: var BeaconState) =
 
       let next_start_shard =
         (state.shard_committees_at_slots[^1][^1].shard + 1) mod SHARD_COUNT
-      for i, v in get_new_shuffling(
+      for i, v in get_shuffling(
           state.latest_randao_mixes[
             (state.slot - EPOCH_LENGTH) mod LATEST_RANDAO_MIXES_LENGTH],
           state.validator_registry, next_start_shard):
@@ -719,7 +719,7 @@ func processEpoch(state: var BeaconState) =
         start_shard = state.shard_committees_at_slots[0][0].shard
 
       if is_power_of_2(epochs_since_last_registry_change):
-        for i, v in get_new_shuffling(
+        for i, v in get_shuffling(
             state.latest_randao_mixes[
               (state.slot - EPOCH_LENGTH) mod LATEST_RANDAO_MIXES_LENGTH],
             state.validator_registry, start_shard):

tests/test_validator.nim

@@ -25,7 +25,7 @@ suite "Validators":
         ), 32*1024)
 
     # TODO the shuffling looks really odd, probably buggy
-    let s = get_new_shuffling(Eth2Digest(), validators, 0)
+    let s = get_shuffling(Eth2Digest(), validators, 0)
     check:
       s.len == EPOCH_LENGTH
        # 32k validators means 2 shards validated per slot - the aim is to get

tests/testutil.nim

@@ -67,7 +67,7 @@ func makeDeposit(i: int, flags: UpdateFlags): Deposit =
         withdrawal_credentials: withdrawal_credentials,
         randao_commitment: randao_commitment
       ),
-      value: MAX_DEPOSIT * GWEI_PER_ETH,
+      amount: MAX_DEPOSIT * GWEI_PER_ETH,
     )
   )
 
@@ -78,7 +78,7 @@ func makeInitialDeposits*(
 
 func makeGenesisBlock*(state: BeaconState): BeaconBlock =
   BeaconBlock(
-    slot: INITIAL_SLOT_NUMBER,
+    slot: GENESIS_SLOT,
     state_root: Eth2Digest(data: hash_tree_root(state))
   )
 
@@ -115,7 +115,7 @@ proc addBlock*(
       parent_root: previous_block_root,
       state_root: Eth2Digest(), # we need the new state first
       randao_reveal: hackReveal(proposer),
-      candidate_pow_receipt_root: Eth2Digest(), # TODO
+      deposit_root: Eth2Digest(), # TODO
       signature: ValidatorSig(), # we need the rest of the block first!
       body: body
     )