def build_uncle_chain_to_existing_db(write_db,
existing_db,
fork_at,
num_blocks=20):
# 1000pow_headers fixture uses byzantium and we don't want to upgrade the fixture to not bloat
# the git repository too much (see discussion: https://github.com/ethereum/trinity/pull/1777)
base_chain = load_mining_chain(existing_db, byzantium_at(0))
uncle_chain = load_mining_chain(write_db, byzantium_at(0))
assert uncle_chain.get_canonical_head(
) == base_chain.get_canonical_block_header_by_number(0)
for block_number in range(1, fork_at):
uncle_chain.import_block(
base_chain.get_canonical_block_by_number(block_number))
assert uncle_chain.get_canonical_head().block_number == fork_at - 1
for _ in range(num_blocks):
uncle_chain.mine_block()
# If `fork_at` is 500 it means that up to block 499 is shared history and 500 is the first uncle
tip_number = fork_at - 1 + num_blocks
assert uncle_chain.get_canonical_head().block_number == tip_number
assert uncle_chain.get_canonical_head(
) != base_chain.get_canonical_block_by_number(tip_number)
def load_mining_chain(db):
GENESIS_PARAMS = {
'coinbase': constants.ZERO_ADDRESS,
'difficulty': 5,
'gas_limit': 3141592,
'timestamp': 1514764800,
}
GENESIS_STATE = {
FUNDED_ACCT.public_key.to_canonical_address(): {
"balance": 100000000000000000,
}
}
return build(
FakeAsyncChain,
byzantium_at(0),
enable_pow_mining(),
genesis(db=db, params=GENESIS_PARAMS, state=GENESIS_STATE),
)