logos-blockchain-specs/cryptarchia/test_fork_choice.py
davidrusu dcdb419648
Cryptarchia/drop orphan proofs (#121)
* cryptarchia: introduce Hash class

* cryptarchia: Coin renamed to Note

* cryptarchia: simplify mock leader proof

* cryptarchia: remove orphan proofs from block headers

* cryptarchia: maintain a single commitment set in ledger state

* cryptarchia: drop note evolution

* cryptarchia: drop MOCK_LEADER_VRF

* cryptarchia fix nonce contribution derivation

* cryptarchia: mk_chain only returns list now

* fixup

* cryptarchia: shorten test cases using mk_chain
2025-03-21 20:49:04 +04:00

284 lines
7.9 KiB
Python

from unittest import TestCase
from copy import deepcopy
from cryptarchia.cryptarchia import (
maxvalid_bg,
Slot,
Note,
Follower,
common_prefix_depth,
LedgerState,
)
from .test_common import mk_chain, mk_config, mk_genesis_state, mk_block
class TestForkChoice(TestCase):
def test_common_prefix_depth(self):
# 6 - 7
# /
# 0 - 1 - 2 - 3
# \
# 4 - 5
note = Note(sk=1, value=100)
b0 = mk_genesis_state([]).block
b1, b2, b3 = mk_chain(b0, Note(sk=1, value=1), slots=[1, 2, 3])
b4, b5 = mk_chain(b0, Note(sk=2, value=1), slots=[1, 2])
b6, b7 = mk_chain(b2, Note(sk=3, value=1), slots=[3, 4])
states = {
b.id(): LedgerState(block=b) for b in [b0, b1, b2, b3, b4, b5, b6, b7]
}
assert (d := common_prefix_depth(b0.id(), b0.id(), states)) == (
0,
[b0],
0,
[b0],
), d
assert (d := common_prefix_depth(b1.id(), b0.id(), states)) == (
1,
[b0, b1],
0,
[b0],
), d
assert (d := common_prefix_depth(b0.id(), b1.id(), states)) == (
0,
[b0],
1,
[b0, b1],
), d
assert (d := common_prefix_depth(b1.id(), b1.id(), states)) == (
0,
[b1],
0,
[b1],
), d
assert (d := common_prefix_depth(b2.id(), b0.id(), states)) == (
2,
[b0, b1, b2],
0,
[b0],
), d
assert (d := common_prefix_depth(b0.id(), b2.id(), states)) == (
0,
[b0],
2,
[b0, b1, b2],
), d
assert (d := common_prefix_depth(b3.id(), b0.id(), states)) == (
3,
[b0, b1, b2, b3],
0,
[b0],
), d
assert (d := common_prefix_depth(b0.id(), b3.id(), states)) == (
0,
[b0],
3,
[b0, b1, b2, b3],
), d
assert (d := common_prefix_depth(b1.id(), b4.id(), states)) == (
1,
[b0, b1],
1,
[b0, b4],
), d
assert (d := common_prefix_depth(b4.id(), b1.id(), states)) == (
1,
[b0, b4],
1,
[b0, b1],
), d
assert (d := common_prefix_depth(b1.id(), b5.id(), states)) == (
1,
[b0, b1],
2,
[b0, b4, b5],
), d
assert (d := common_prefix_depth(b5.id(), b1.id(), states)) == (
2,
[b0, b4, b5],
1,
[b0, b1],
), d
assert (d := common_prefix_depth(b2.id(), b5.id(), states)) == (
2,
[b0, b1, b2],
2,
[b0, b4, b5],
), d
assert (d := common_prefix_depth(b5.id(), b2.id(), states)) == (
2,
[b0, b4, b5],
2,
[b0, b1, b2],
), d
assert (d := common_prefix_depth(b3.id(), b5.id(), states)) == (
3,
[b0, b1, b2, b3],
2,
[b0, b4, b5],
), d
assert (d := common_prefix_depth(b5.id(), b3.id(), states)) == (
2,
[b0, b4, b5],
3,
[b0, b1, b2, b3],
), d
assert (d := common_prefix_depth(b3.id(), b6.id(), states)) == (
1,
[b2, b3],
1,
[b2, b6],
), d
assert (d := common_prefix_depth(b6.id(), b3.id(), states)) == (
1,
[b2, b6],
1,
[b2, b3],
), d
assert (d := common_prefix_depth(b3.id(), b7.id(), states)) == (
1,
[b2, b3],
2,
[b2, b6, b7],
), d
assert (d := common_prefix_depth(b7.id(), b3.id(), states)) == (
2,
[b2, b6, b7],
1,
[b2, b3],
), d
assert (d := common_prefix_depth(b5.id(), b7.id(), states)) == (
2,
[b0, b4, b5],
4,
[b0, b1, b2, b6, b7],
), d
assert (d := common_prefix_depth(b7.id(), b5.id(), states)) == (
4,
[b0, b1, b2, b6, b7],
2,
[b0, b4, b5],
), d
def test_fork_choice_long_sparse_chain(self):
# The longest chain is not dense after the fork
genesis = mk_genesis_state([]).block
short_note, long_note = Note(sk=0, value=100), Note(sk=1, value=100)
common = mk_chain(parent=genesis, note=long_note, slots=range(50))
long_chain_sparse_ext = mk_chain(
parent=common[-1], note=long_note, slots=range(50, 100, 2)
)
short_chain_dense_ext = mk_chain(
parent=common[-1], note=short_note, slots=range(50, 100)
)
# add more blocks to the long chain to ensure the long chain is indeed longer
long_chain_further_ext = mk_chain(
parent=long_chain_sparse_ext[-1], note=long_note, slots=range(100, 126)
)
long_chain = deepcopy(common) + long_chain_sparse_ext + long_chain_further_ext
short_chain = deepcopy(common) + short_chain_dense_ext
assert len(long_chain) > len(short_chain)
# by setting a low k we trigger the density choice rule
k = 1
s = 50
states = {b.id(): LedgerState(block=b) for b in short_chain + long_chain}
assert (
maxvalid_bg(short_chain[-1].id(), [long_chain[-1].id()], k, s, states)
== short_chain[-1].id()
)
# However, if we set k to the fork length, it will be accepted
k = len(long_chain)
assert (
maxvalid_bg(short_chain[-1].id(), [long_chain[-1].id()], k, s, states)
== long_chain[-1].id()
)
def test_fork_choice_long_dense_chain(self):
# The longest chain is also the densest after the fork
short_note, long_note = Note(sk=0, value=100), Note(sk=1, value=100)
common = mk_chain(
parent=mk_genesis_state([]).block,
note=long_note,
slots=range(1, 50),
)
long_chain_dense_ext = mk_chain(
parent=common[-1], note=long_note, slots=range(50, 100)
)
short_chain_sparse_ext = mk_chain(
parent=common[-1], note=short_note, slots=range(50, 100, 2)
)
long_chain = deepcopy(common) + long_chain_dense_ext
short_chain = deepcopy(common) + short_chain_sparse_ext
k = 1
s = 50
states = {b.id(): LedgerState(block=b) for b in short_chain + long_chain}
assert (
maxvalid_bg(short_chain[-1].id(), [long_chain[-1].id()], k, s, states)
== long_chain[-1].id()
)
def test_fork_choice_integration(self):
n_a, n_b = Note(sk=0, value=10), Note(sk=1, value=10)
notes = [n_a, n_b]
config = mk_config(notes)
genesis = mk_genesis_state(notes)
follower = Follower(genesis, config)
b1 = mk_block(genesis.block, 1, n_a)
follower.on_block(b1)
assert follower.tip_id() == b1.id()
assert follower.forks == [], follower.forks
# -- then we fork --
#
# b2 == tip
# /
# b1
# \
# b3
#
b2 = mk_block(b1, 2, n_a)
b3 = mk_block(b1, 2, n_b)
follower.on_block(b2)
follower.on_block(b3)
assert follower.tip_id() == b2.id()
assert len(follower.forks) == 1 and follower.forks[0] == b3.id()
# -- extend the fork causing a re-org --
#
# b2
# /
# b1
# \
# b3 - b4 == tip
#
b4 = mk_block(b3, 3, n_b)
follower.on_block(b4)
assert follower.tip_id() == b4.id()
assert len(follower.forks) == 1 and follower.forks[0] == b2.id(), follower.forks