In the end, get_merkle_root is back

scripts/build_spec.py

@@ -11,7 +11,8 @@ from typing import (
 )
 
 
-PHASE0_IMPORTS = '''from typing import (
+PHASE0_IMPORTS = '''from math import log2
+from typing import (
     Any, Callable, Dict, Set, Sequence, Tuple,
 )
 
@@ -36,7 +37,8 @@ from eth2spec.utils.bls import (
 
 from eth2spec.utils.hash_function import hash
 '''
-PHASE1_IMPORTS = '''from typing import (
+PHASE1_IMPORTS = '''from math import log2
+from typing import (
     Any, Callable, Dict, Optional, Set, Sequence, MutableSequence, Tuple,
 )
 

specs/core/0_beacon-chain.md

@@ -51,6 +51,8 @@
         - [`hash`](#hash)
         - [`hash_tree_root`](#hash_tree_root)
         - [`signing_root`](#signing_root)
+        - [`calc_merkle_tree_from_leaves`](#calc_merkle_tree_from_leaves)
+        - [`get_merkle_root`](#get_merkle_root)
         - [`bls_domain`](#bls_domain)
         - [`slot_to_epoch`](#slot_to_epoch)
         - [`get_previous_epoch`](#get_previous_epoch)
@@ -558,6 +560,33 @@ The `hash` function is SHA256.
 
 `def signing_root(object: Container) -> Hash` is a function for computing signing messages, as defined in the [SimpleSerialize spec](../simple-serialize.md#self-signed-containers).
 
+### `calc_merkle_tree_from_leaves`
+
+```python
+zerohashes = [ZERO_HASH]
+for layer in range(1, 100):
+    zerohashes.append(hash(zerohashes[layer - 1] + zerohashes[layer - 1]))
+def calc_merkle_tree_from_leaves(values: Sequence[Hash], layer_count: int=32) -> Sequence[Sequence[Hash]]:
+    values = list(values)
+    tree = [values[::]]
+    for h in range(layer_count):
+        if len(values) % 2 == 1:
+            values.append(zerohashes[h])
+        values = [hash(values[i] + values[i + 1]) for i in range(0, len(values), 2)]
+        tree.append(values[::])
+    return tree
+```
+
+### `get_merkle_root`
+
+```python
+def get_merkle_root(values: Sequence[Hash], pad_to: int=1) -> Hash:
+    layer_count = int(log2(pad_to))
+    if len(values) == 0:
+        return zerohashes[layer_count]
+    return calc_merkle_tree_from_leaves(values, layer_count)[-1][0]
+```
+
 ### `bls_domain`
 
 ```python
@@ -1144,10 +1173,10 @@ def is_genesis_trigger(deposits: List[Deposit, 2**DEPOSIT_CONTRACT_TREE_DEPTH],
 
     # Process deposits
     state = BeaconState()
-    for i, deposit in enumerate(deposits):
-        state.eth1_data.deposit_root = hash_tree_root(
-            Vector[DepositData, len(deposits)](list(map(lambda deposit: deposit.data, deposits[:i])))
-        )
+    for deposit_index, deposit in enumerate(deposits):
+        leaves = [hash_tree_root(d.data) for d in deposits[:deposit_index + 1]]
+        state.eth1_data.deposit_root = get_merkle_root(leaves, 2**DEPOSIT_CONTRACT_TREE_DEPTH)
+        state.eth1_deposit_index = deposit_index
         process_deposit(state, deposit)
 
     # Count active validators at genesis
@@ -1173,9 +1202,14 @@ def get_genesis_beacon_state(deposits: Sequence[Deposit], genesis_time: int, eth
     )
 
     # Process genesis deposits
-    for deposit in deposits:
+    for deposit_index, deposit in enumerate(deposits):
+        leaves = [hash_tree_root(d.data) for d in deposits[:deposit_index + 1]]
+        state.eth1_data.deposit_root = get_merkle_root(leaves, 2**DEPOSIT_CONTRACT_TREE_DEPTH)
+        state.eth1_deposit_index = deposit_index
         process_deposit(state, deposit)
 
+    assert state.eth1_data.deposit_root == eth1_data.deposit_root
+
     # Process genesis activations
     for validator in state.validators:
         if validator.effective_balance == MAX_EFFECTIVE_BALANCE:

test_libs/pyspec/eth2spec/test/genesis/test_genesis_trigger.py

@@ -8,12 +8,11 @@ from eth2spec.test.helpers.deposits import (
 @spectest_with_bls_switch
 def test_is_genesis_trigger_false(spec):
     deposit_count = 2
-    genesis_deposits, deposit_root = prepare_genesis_deposits(spec, deposit_count, spec.MAX_EFFECTIVE_BALANCE)
+    genesis_deposits, _ = prepare_genesis_deposits(spec, deposit_count, spec.MAX_EFFECTIVE_BALANCE)
     genesis_time = 1546300800
 
     yield "deposits", genesis_deposits
     yield "time", genesis_time
-    yield "deposit_root", deposit_root
 
     is_triggered = spec.is_genesis_trigger(genesis_deposits, genesis_time)
     assert is_triggered is False
@@ -25,13 +24,12 @@ def test_is_genesis_trigger_false(spec):
 @spectest_with_bls_switch
 def test_is_genesis_trigger_true(spec):
     deposit_count = spec.GENESIS_ACTIVE_VALIDATOR_COUNT
-    genesis_deposits, deposit_root = prepare_genesis_deposits(spec, deposit_count, spec.MAX_EFFECTIVE_BALANCE)
+    genesis_deposits, _ = prepare_genesis_deposits(spec, deposit_count, spec.MAX_EFFECTIVE_BALANCE)
     SECONDS_PER_DAY = 86400
     genesis_time = 1578009600 - 2 * SECONDS_PER_DAY
 
     yield "deposits", genesis_deposits
     yield "time", genesis_time
-    yield "deposit_root", deposit_root
 
     is_triggered = spec.is_genesis_trigger(genesis_deposits, genesis_time)
     assert is_triggered is True
@@ -43,11 +41,10 @@ def test_is_genesis_trigger_true(spec):
 @spectest_with_bls_switch
 def test_is_genesis_trigger_not_enough_balance(spec):
     deposit_count = spec.GENESIS_ACTIVE_VALIDATOR_COUNT
-    genesis_deposits, deposit_root = prepare_genesis_deposits(spec, deposit_count, spec.MAX_EFFECTIVE_BALANCE - 1)
+    genesis_deposits, _ = prepare_genesis_deposits(spec, deposit_count, spec.MAX_EFFECTIVE_BALANCE - 1)
     genesis_time = 1546300800
     yield "deposits", genesis_deposits
     yield "time", genesis_time
-    yield "deposit_root", deposit_root
 
     is_triggered = spec.is_genesis_trigger(genesis_deposits, genesis_time)
     assert is_triggered is False

test_libs/pyspec/eth2spec/test/helpers/deposits.py

@@ -41,7 +41,9 @@ def build_deposit(spec,
                   amount,
                   withdrawal_credentials,
                   signed):
-    deposit_data = build_deposit_data(spec, pubkey, privkey, amount, withdrawal_credentials, state=state, signed=signed)
+    deposit_data = build_deposit_data(
+        spec, pubkey, privkey, amount, withdrawal_credentials, state=state, signed=signed,
+    )
 
     item = deposit_data.hash_tree_root()
     index = len(deposit_data_leaves)
@@ -63,6 +65,7 @@ def build_deposit(spec,
 def prepare_genesis_deposits(spec, genesis_validator_count, amount, signed=False):
     genesis_deposit_data_list = []
     deposit_data_leaves = []
+    genesis_deposits = []
     for validator_index in range(genesis_validator_count):
         pubkey = pubkeys[validator_index]
         privkey = privkeys[validator_index]
@@ -79,13 +82,11 @@ def prepare_genesis_deposits(spec, genesis_validator_count, amount, signed=False
         deposit_data_leaves.append(item)
         genesis_deposit_data_list.append(deposit_data)
 
-    tree = calc_merkle_tree_from_leaves(tuple(deposit_data_leaves))
-    root = get_merkle_root((tuple(deposit_data_leaves)))
-
-    genesis_deposits = list(
-        spec.Deposit(proof=list(get_merkle_proof(tree, item_index=index)), data=deposit_data)
-        for index, deposit_data in enumerate(genesis_deposit_data_list)
-    )
+        tree = calc_merkle_tree_from_leaves(tuple(deposit_data_leaves))
+        root = get_merkle_root((tuple(deposit_data_leaves)), 2**32)
+        genesis_deposits.append(
+            spec.Deposit(proof=list(get_merkle_proof(tree, item_index=validator_index)), data=deposit_data)
+        )
 
     return genesis_deposits, root
 

test_libs/pyspec/eth2spec/utils/merkle_minimal.py

@@ -1,5 +1,5 @@
 from .hash_function import hash
-from math import log2 
+from math import log2
 
 
 ZERO_BYTES32 = b'\x00' * 32

test_libs/pyspec/eth2spec/utils/test_merkle_minimal.py

@@ -1,5 +1,5 @@
 import pytest
-from .merkle_minimal import zerohashes, merkleize_chunks
+from .merkle_minimal import zerohashes, merkleize_chunks, get_merkle_root
 from .hash_function import hash
 
 
@@ -53,6 +53,7 @@ cases = [
     'depth,count,pow2,value',
     cases,
 )
-def test_merkleize_chunks(depth, count, pow2, value):
+def test_merkleize_chunks_and_get_merkle_root(depth, count, pow2, value):
     chunks = [e(i) for i in range(count)]
     assert merkleize_chunks(chunks, pad_to=pow2) == value
+    assert get_merkle_root(chunks, pad_to=pow2) == value