rm min_empty_validator_index, ZERO_BALANCE_VALIDATOR_TTL, Validator.latest_status_change_slot; switch Fork.fork_slot to Fork.epoch; begin removing Validator.randao_layers; now that https://github.com/ethereum/eth2.0-specs/issues/352 is fixed, test out for more slots; get process_deposit consistent with current spec

beacon_chain/spec/beaconstate.nim

@@ -47,10 +47,10 @@ func validate_proof_of_possession(state: BeaconState,
 
 func process_deposit(state: var BeaconState,
                      pubkey: ValidatorPubKey,
-                     deposit: uint64,
+                     amount: uint64,
                      proof_of_possession: ValidatorSig,
                      withdrawal_credentials: Eth2Digest,
-                     randao_commitment: Eth2Digest) : ValidatorIndex =
+                     randao_commitment: Eth2Digest) =
   ## Process a deposit from Ethereum 1.0.
 
   if false:
@@ -77,16 +77,9 @@ func process_deposit(state: var BeaconState,
       status_flags: 0,
     )
 
-    let index = min_empty_validator_index(
+    # Note: In phase 2 registry indices that have been withdrawn for a long time will be recycled.
-      state.validator_registry, state.validator_balances, state.slot)
+    state.validator_registry.add(validator)
-    if index.isNone():
+    state.validator_balances.add(amount)
-      state.validator_registry.add(validator)
-      state.validator_balances.add(deposit)
-      (len(state.validator_registry) - 1).ValidatorIndex
-    else:
-      state.validator_registry[index.get()] = validator
-      state.validator_balances[index.get()] = deposit
-      index.get().ValidatorIndex
   else:
     # Increase balance by deposit amount
     let index = validator_pubkeys.find(pubkey)
@@ -94,8 +87,7 @@ func process_deposit(state: var BeaconState,
     assert state.validator_registry[index].withdrawal_credentials ==
       withdrawal_credentials
 
-    state.validator_balances[index] += deposit
+    state.validator_balances[index] += amount
-    index.ValidatorIndex
 
 func get_entry_exit_effect_epoch*(epoch: EpochNumber): EpochNumber =
   ## An entry or exit triggered in the ``epoch`` given by the input takes effect at
@@ -189,11 +181,10 @@ func get_initial_beacon_state*(
     # Misc
     slot: GENESIS_SLOT,
     genesis_time: genesis_time,
-    # rm fork_slot init in favor of epoch
     fork: Fork(
         previous_version: GENESIS_FORK_VERSION,
         current_version: GENESIS_FORK_VERSION,
-        fork_slot: GENESIS_SLOT,
+        epoch: GENESIS_EPOCH,
     ),
 
     validator_registry_update_epoch: GENESIS_EPOCH,
@@ -220,7 +211,7 @@ func get_initial_beacon_state*(
 
   # Process initial deposits
   for deposit in initial_validator_deposits:
-    let validator_index = process_deposit(
+    process_deposit(
       state,
       deposit.deposit_data.deposit_input.pubkey,
       deposit.deposit_data.amount,
@@ -229,13 +220,10 @@ func get_initial_beacon_state*(
       deposit.deposit_data.deposit_input.randao_commitment,
     )
 
-    if state.validator_balances[validator_index] >= MAX_DEPOSIT_AMOUNT:
-      activate_validator(state, validator_index, true)
-
   # Process initial activations
   for validator_index in 0 ..< state.validator_registry.len:
     let vi = validator_index.ValidatorIndex
-    if get_effective_balance(state, vi) > MAX_DEPOSIT_AMOUNT:
+    if get_effective_balance(state, vi) >= MAX_DEPOSIT_AMOUNT:
       activate_validator(state, vi, true)
 
   state

beacon_chain/spec/datatypes.nim

@@ -128,9 +128,6 @@ const
   ENTRY_EXIT_DELAY* = 256 ##\
   ## slots (~25.6 minutes)
 
-  ZERO_BALANCE_VALIDATOR_TTL* = 2'u64^22 ##\
-  ## slots (~291 days)
-
   DEPOSIT_ROOT_VOTING_PERIOD* = 2'u64^10 ##\
   ## slots (~1.7 hours)
 
@@ -347,7 +344,7 @@ type
     pubkey*: ValidatorPubKey
     withdrawal_credentials*: Eth2Digest
 
-    # TODO remove randao_commitment, randao_layers, latest_status_change_slot
+    # TODO remove randao_commitment, randao_layers
     randao_commitment*: Eth2Digest ##\
     ## RANDAO commitment created by repeatedly taking the hash of a secret value
     ## so as to create "onion layers" around it. For every block that a
@@ -360,9 +357,6 @@ type
     ## Number of proposals the proposer missed, and thus the number of times to
     ## apply hash function to randao reveal
 
-    latest_status_change_slot*: uint64 ##\
-    ## Slot when validator last changed status (or 0)
-
     activation_epoch*: EpochNumber ##\
     ## Slot when validator activated
 
@@ -413,8 +407,8 @@ type
 
   Fork* = object
     previous_version*: uint64                     # Previous fork version
-    current_version*: uint64                    # Current fork version
+    current_version*: uint64                      # Current fork version
-    fork_slot*: uint64                            # Fork slot number TODO should be epoch
+    epoch*: uint64                                # Fork epoch number
 
   ValidatorRegistryDeltaBlock* = object
     latest_registry_delta_root*: Eth2Digest

beacon_chain/spec/helpers.nim

@@ -119,9 +119,11 @@ func integer_squareroot*(n: SomeInteger): SomeInteger =
     y = (x + n div x) div 2
   x
 
-func get_fork_version*(fork: Fork, slot: uint64): uint64 =
+func get_fork_version*(fork: Fork, epoch: EpochNumber): uint64 =
-  if slot < fork.fork_slot: fork.previous_version
+  if epoch < fork.epoch:
-  else: fork.current_version
+    fork.previous_version
+  else:
+    fork.current_version
 
 func get_domain*(
     fork: Fork, slot: uint64, domain_type: SignatureDomain): uint64 =

beacon_chain/spec/validator.nim

@@ -12,16 +12,6 @@ import
   ../ssz,
   ./crypto, ./datatypes, ./digest, ./helpers
 
-func min_empty_validator_index*(
-    validators: seq[Validator],
-    validator_balances: seq[uint64],
-    current_slot: uint64): Option[int] =
-  for i, v in validators:
-    if validator_balances[i] == 0 and
-        v.latest_status_change_slot +
-          ZERO_BALANCE_VALIDATOR_TTL.uint64 <= current_slot:
-      return some(i)
-
 func xorSeed(seed: Eth2Digest, x: uint64): Eth2Digest =
   ## Integers are all encoded as bigendian
   ## Helper for get_shuffling in lieu of generally better bitwise handling
@@ -154,5 +144,5 @@ func get_beacon_proposer_index*(state: BeaconState, slot: uint64): ValidatorInde
   # TODO this index is invalid outside of the block state transition function
   #      because presently, `state.slot += 1` happens before this function
   #      is called - see also testutil.getNextBeaconProposerIndex
-  let first_committee = get_crosslink_committees_at_slot(state, slot)[0][0]
+  let (first_committee, _) = get_crosslink_committees_at_slot(state, slot)[0]
   first_committee[slot.int mod len(first_committee)]

tests/test_state_transition.nim

@@ -34,10 +34,6 @@ suite "Block processing":
 
       state.slot == genesisState.slot + 1
 
-      # When proposer skips their proposal, randao layer is still peeled!
-      state.validator_registry[proposer_index].randao_layers ==
-        genesisState.validator_registry[proposer_index].randao_layers + 1
-
   test "Passes from genesis state, empty block":
     var
       state = genesisState
@@ -53,10 +49,6 @@ suite "Block processing":
 
       state.slot == genesisState.slot + 1
 
-      # Proposer proposed, no need for additional peeling
-      state.validator_registry[proposer_index].randao_layers ==
-        genesisState.validator_registry[proposer_index].randao_layers
-
   test "Passes through epoch update, no block":
     var
       state = genesisState
@@ -122,9 +114,7 @@ suite "Block processing":
     check:
       state.latest_attestations.len == 1
 
-    # TODO Can't run more than 127 for now:
+    while state.slot < 191:
-    # https://github.com/ethereum/eth2.0-specs/issues/352
-    while state.slot < 127:
       discard updateState(
         state, previous_block_root, none(BeaconBlock), {})