Merge branch 'master' into master

.gitignore

@@ -6,4 +6,5 @@ venv
 test-reports/
 notes.txt
 .mypy_cache
-.eggs/
+.eggs/
+*.egg-info/

README.md

@@ -3,7 +3,7 @@
 > Implements a proof of concept beacon chain for a sharded pos ethereum 2.0. Spec in progress can be found [here](https://notes.ethereum.org/s/Syj3QZSxm).
 
 ## Installation
-Using a python3 environment, run the following to install required libraries:
+Using a python3.6.* environment, run the following to install required libraries:
 ```
 pip install -e .[dev]
 ```
@@ -27,5 +27,5 @@ make deploy
 
 ---
 
-# Simple Serialization
-[here](https://github.com/ethereum/beacon_chain/tree/master/ssz)
+# Simple Serialize
+[here](https://github.com/ethereum/beacon_chain/tree/master/ssz)

beacon_chain/state/active_state.py

@@ -4,6 +4,7 @@
 )
 
 from .attestation_record import AttestationRecord
+from .chain import Chain
 
 
 class ActiveState():
@@ -31,6 +32,13 @@ def __init__(self, **kwargs):
         else:
             self.block_vote_cache = {}
 
+        # chain is not part of protocol state
+        # is used as helper class to aid in doing state transition
+        if 'chain' in kwargs:
+            self.chain = kwargs['chain']
+        else:
+            self.chain = Chain()
+
     def __setattr__(self, name: str, value: Any) -> None:
         super().__setattr__(name, value)
 

beacon_chain/state/block.py

@@ -8,6 +8,9 @@
 )
 
 from beacon_chain.utils.blake import blake
+from beacon_chain.state.constants import (
+    ZERO_HASH32,
+)
 
 from .attestation_record import AttestationRecord
 
@@ -31,13 +34,13 @@ class Block():
     }  # type: Dict[str, Any]
 
     defaults = {
-        'parent_hash': b'\x00'*32,
+        'parent_hash': ZERO_HASH32,
         'slot_number': 0,
-        'randao_reveal': b'\x00'*32,
+        'randao_reveal': ZERO_HASH32,
         'attestations': [],
-        'pow_chain_ref': b'\x00'*32,
-        'active_state_root': b'\x00'*32,
-        'crystallized_state_root': b'\x00'*32,
+        'pow_chain_ref': ZERO_HASH32,
+        'active_state_root': ZERO_HASH32,
+        'crystallized_state_root': ZERO_HASH32,
     }
 
     def __init__(self, **kwargs):

beacon_chain/state/chain.py

@@ -0,0 +1,49 @@
+from typing import (
+    List,
+    TYPE_CHECKING,
+)
+
+if TYPE_CHECKING:
+    from .block import Block  # noqa: F401
+
+
+class Chain():
+    # Note, this is not an object defined in the v2.1 spec
+    # this is a helper object to mask complexity in tracking
+    # blocks
+
+    def __init__(self, head: 'Block'=None, blocks: List['Block']=[]) -> None:
+        self.head = head
+        self.blocks = blocks
+        self.chain = []  # type: List['Block']
+
+        # temp helper
+        all_blocks_by_hash = {
+            block.hash: block
+            for block in self.blocks
+        }
+
+        if self.head:
+            tmp = self.head
+            self.chain.append(tmp)
+            while all_blocks_by_hash.get(tmp.parent_hash, None):
+                tmp = all_blocks_by_hash[tmp.parent_hash]
+                self.chain.append(tmp)
+
+        self.block_by_hash = {
+            block.hash: block
+            for block in self.chain
+        }
+        self.block_by_slot_number = {
+            block.slot_number: block
+            for block in self.chain
+        }
+
+    def __contains__(self, block: 'Block') -> bool:
+        return bool(self.get_block_by_hash(block.hash))
+
+    def get_block_by_slot_number(self, slot_number: int) -> 'Block':
+        return self.block_by_slot_number.get(slot_number, None)
+
+    def get_block_by_hash(self, block_hash: bytes) -> 'Block':
+        return self.block_by_hash.get(block_hash, None)

beacon_chain/state/config.py

@@ -1,31 +1,42 @@
+from beacon_chain.state.constants import (
+    WEI_PER_ETH,
+)
+
+
+BASE_REWARD_QUOTIENT = 2**15
 DEFAULT_END_DYNASTY = 9999999999999999999
-DEPOSIT_SIZE = 32  # ETH
+DEPOSIT_SIZE = 32 * WEI_PER_ETH  # WEI
 CYCLE_LENGTH = 64  # slots
 MAX_VALIDATOR_COUNT = 2**22  # validators
 MIN_COMMITTEE_SIZE = 128  # validators
 MIN_DYNASTY_LENGTH = 256  # slots
 SHARD_COUNT = 1024  # shards
 SLOT_DURATION = 8  # seconds
+SQRT_E_DROP_TIME = 2**20  # seconds
 
 
 def generate_config(*,
+                    base_reward_quotient=BASE_REWARD_QUOTIENT,
                     default_end_dynasty=DEFAULT_END_DYNASTY,
                     deposit_size=DEPOSIT_SIZE,
                     cycle_length=CYCLE_LENGTH,
                     max_validator_count=MAX_VALIDATOR_COUNT,
                     min_committee_size=MIN_COMMITTEE_SIZE,
                     min_dynasty_length=MIN_DYNASTY_LENGTH,
                     shard_count=SHARD_COUNT,
-                    slot_duration=SLOT_DURATION):
+                    slot_duration=SLOT_DURATION,
+                    sqrt_e_drop_time=SQRT_E_DROP_TIME):
     return {
+        'base_reward_quotient': base_reward_quotient,
         'default_end_dynasty': default_end_dynasty,
         'deposit_size': deposit_size,
         'cycle_length': cycle_length,
         'max_validator_count': max_validator_count,
         'min_committee_size': min_committee_size,
         'min_dynasty_length': min_dynasty_length,
         'shard_count': shard_count,
-        'slot_duration': slot_duration
+        'slot_duration': slot_duration,
+        'sqrt_e_drop_time': sqrt_e_drop_time
     }
 
 

beacon_chain/state/constants.py

@@ -1,6 +1,9 @@
+from eth_utils import denoms
+
 from beacon_chain.beacon_typing.custom import (
     Hash32,
 )
 
 
+WEI_PER_ETH = denoms.ether
 ZERO_HASH32 = Hash32(32 * b'\x00')

beacon_chain/state/crystallized_state.py

@@ -1,12 +1,15 @@
 from typing import (  # noqa: F401
     Any,
     Dict,
+    List,
 )
 
 from .crosslink_record import CrosslinkRecord
 from .shard_and_committee import ShardAndCommittee
 from .validator_record import ValidatorRecord
 
+from .helpers import get_active_validator_indices
+
 
 class CrystallizedState():
     fields = {
@@ -44,7 +47,6 @@ class CrystallizedState():
         'last_finalized_slot': 0,
         'current_dynasty': 0,
         'crosslink_records': [],
-        'total_deposits': 0,
         'dynasty_seed': b'\x00'*32,
         'dynasty_start': 0,
     }  # type: Dict[str, Any]
@@ -60,6 +62,22 @@ def __setattr__(self, name: str, value: Any) -> None:
     def __getattribute__(self, name: str) -> Any:
         return super().__getattribute__(name)
 
+    @property
+    def active_validator_indices(self) -> List[int]:
+        return get_active_validator_indices(
+            self.current_dynasty,
+            self.validators
+        )
+
+    @property
+    def total_deposits(self) -> int:
+        return sum(
+            map(
+                lambda index: self.validators[index].balance,
+                self.active_validator_indices
+            )
+        )
+
     @property
     def num_validators(self) -> int:
         return len(self.validators)

beacon_chain/state/genesis_helpers.py

@@ -12,6 +12,7 @@
 
 from .active_state import ActiveState
 from .block import Block
+from .chain import Chain
 from .constants import (
     ZERO_HASH32,
 )
@@ -30,7 +31,8 @@ def get_genesis_active_state(config: Dict[str, Any]) -> ActiveState:
 
     return ActiveState(
         pending_attestations=[],
-        recent_block_hashes=recent_block_hashes
+        recent_block_hashes=recent_block_hashes,
+        chain=Chain()
     )
 
 
@@ -52,8 +54,6 @@ def get_genesis_crystallized_state(
     # concatenate with itself to span 2*CYCLE_LENGTH
     shard_and_committee_for_slots = shard_and_committee_for_slots + shard_and_committee_for_slots
 
-    total_deposits = config['deposit_size'] * len(validators)
-
     return CrystallizedState(
         validators=validators,
         last_state_recalc=0,
@@ -67,7 +67,6 @@ def get_genesis_crystallized_state(
             for i
             in range(config['shard_count'])
         ],
-        total_deposits=total_deposits,
         dynasty_seed=init_shuffling_seed,
         dynasty_start=0,
     )