def _process(cls, block, is_initial_sync=False):
"""Process a single block. Assumes a trx is open."""
#pylint: disable=too-many-branches
num = cls._push(block)
date = block['timestamp']
account_names = set()
json_ops = []
for tx_idx, tx in enumerate(block['transactions']):
for operation in tx['operations']:
op_type = operation['type']
op = operation['value']
# account ops
if op_type == 'pow_operation':
account_names.add(op['worker_account'])
elif op_type == 'pow2_operation':
account_names.add(
op['work']['value']['input']['worker_account'])
elif op_type == 'account_create_operation':
account_names.add(op['new_account_name'])
elif op_type == 'account_create_with_delegation_operation':
account_names.add(op['new_account_name'])
elif op_type == 'create_claimed_account_operation':
account_names.add(op['new_account_name'])
# account metadata updates
elif op_type == 'account_update_operation':
if not is_initial_sync:
Accounts.dirty(op['account']) # full
elif op_type == 'account_update2_operation':
if not is_initial_sync:
Accounts.dirty(op['account']) # full
# post ops
elif op_type == 'comment_operation':
Posts.comment_op(op, date)
if not is_initial_sync:
Accounts.dirty(op['author']) # lite - stats
elif op_type == 'delete_comment_operation':
Posts.delete_op(op)
elif op_type == 'vote_operation':
if not is_initial_sync:
Accounts.dirty(op['author']) # lite - rep
Accounts.dirty(op['voter']) # lite - stats
CachedPost.vote(op['author'], op['permlink'], None,
op['voter'])
# misc ops
elif op_type == 'transfer_operation':
Payments.op_transfer(op, tx_idx, num, date)
elif op_type == 'custom_json_operation':
json_ops.append(op)
Accounts.register(account_names, date) # register any new names
CustomOp.process_ops(json_ops, num,
date) # follow/reblog/community ops
return num
def _process(cls, block, is_initial_sync=False):
"""Process a single block. Assumes a trx is open."""
# pylint: disable=too-many-boolean-expressions,too-many-branches
num = cls._push(block)
date = block['timestamp']
account_names = set()
comment_ops = []
json_ops = []
delete_ops = []
voted_authors = set()
for tx_idx, tx in enumerate(block['transactions']):
for operation in tx['operations']:
if isinstance(operation, dict):
op_type = operation['type'].split('_operation')[0]
op = operation['value']
else: # pre-appbase-style. remove after deploy. #APPBASE
op_type, op = operation
# account ops
if op_type == 'pow':
account_names.add(op['worker_account'])
elif op_type == 'pow2':
# old style. remove after #APPBASE
#account_names.add(op['work'][1]['input']['worker_account'])
account_names.add(
op['work']['value']['input']['worker_account'])
elif op_type == 'account_create':
account_names.add(op['new_account_name'])
elif op_type == 'account_create_with_delegation':
account_names.add(op['new_account_name'])
# post ops
elif op_type == 'comment':
comment_ops.append(op)
elif op_type == 'delete_comment':
delete_ops.append(op)
elif op_type == 'vote':
if not is_initial_sync:
CachedPost.vote(op['author'], op['permlink'])
voted_authors.add(
op['author']) # TODO: move to cachedpost
# misc ops
elif op_type == 'transfer':
Payments.op_transfer(op, tx_idx, num, date)
elif op_type == 'custom_json':
json_ops.append(op)
Accounts.register(account_names, date) # register any new names
Accounts.dirty(voted_authors) # update rep of voted authors
Posts.comment_ops(comment_ops, date) # handle inserts, edits
Posts.delete_ops(delete_ops) # handle post deletion
CustomOp.process_ops(json_ops, num,
date) # follow/reblog/community ops
return num
def _process(cls, block, is_initial_sync=False):
"""Process a single block. Assumes a trx is open."""
num = cls._push(block)
date = block['timestamp']
account_names = set()
comment_ops = []
json_ops = []
delete_ops = []
for tx_idx, tx in enumerate(block['transactions']):
for operation in tx['operations']:
op_type = operation['type']
op = operation['value']
# account ops
if op_type == 'pow_operation':
account_names.add(op['worker_account'])
elif op_type == 'pow2_operation':
account_names.add(
op['work']['value']['input']['worker_account'])
elif op_type == 'account_create_operation':
account_names.add(op['new_account_name'])
elif op_type == 'account_create_with_delegation_operation':
account_names.add(op['new_account_name'])
elif op_type == 'create_claimed_account_operation':
account_names.add(op['new_account_name'])
# post ops
elif op_type == 'comment_operation':
comment_ops.append(op)
elif op_type == 'delete_comment_operation':
delete_ops.append(op)
elif op_type == 'vote_operation':
if not is_initial_sync:
CachedPost.vote(op['author'], op['permlink'])
# misc ops
elif op_type == 'transfer_operation':
Payments.op_transfer(op, tx_idx, num, date)
elif op_type == 'custom_json_operation':
json_ops.append(op)
Accounts.register(account_names, date) # register any new names
Posts.comment_ops(comment_ops, date) # handle inserts, edits
Posts.delete_ops(delete_ops) # handle post deletion
CustomOp.process_ops(json_ops, num,
date) # follow/reblog/community ops
return num
def _process(cls, block, is_initial_sync=False):
num = cls._push(block)
date = block['timestamp']
account_names = set()
comment_ops = []
json_ops = []
delete_ops = []
voted_authors = set()
for tx_idx, tx in enumerate(block['transactions']):
for operation in tx['operations']:
op_type, op = operation
# account ops
if op_type == 'pow':
account_names.add(op['worker_account'])
elif op_type == 'pow2':
account_names.add(op['work'][1]['input']['worker_account'])
elif op_type == 'account_create':
account_names.add(op['new_account_name'])
elif op_type == 'account_create_with_delegation':
account_names.add(op['new_account_name'])
# post ops
elif op_type == 'comment':
comment_ops.append(op)
elif op_type == 'delete_comment':
delete_ops.append(op)
elif op_type == 'vote':
if not is_initial_sync:
CachedPost.vote(op['author'], op['permlink'])
voted_authors.add(
op['author']) # TODO: move to cachedpost
# misc ops
elif op_type == 'transfer':
Payments.op_transfer(op, tx_idx, num, date)
elif op_type == 'custom_json':
json_ops.append(op)
Accounts.register(account_names, date) # register any new names
Accounts.dirty(voted_authors) # update rep of voted authors
Posts.comment_ops(comment_ops, date) # handle inserts, edits
Posts.delete_ops(delete_ops) # handle post deletion
CustomOp.process_ops(json_ops, num,
date) # follow/reblog/community ops
return num
def _check_migrations(cls):
"""Check current migration version and perform updates as needed."""
cls._ver = cls.db().query_one(
"SELECT db_version FROM hive_state LIMIT 1")
assert cls._ver is not None, 'could not load state record'
if cls._ver == 0:
raise Exception("dbv cannot be 0; reindex required")
if cls._ver == 1:
cls._set_ver(2)
if cls._ver == 2:
cls._set_ver(3)
if cls._ver == 3:
sql = """CREATE INDEX hive_accounts_ix3 ON hive_accounts
USING btree (vote_weight, name varchar_pattern_ops)"""
cls.db().query(sql)
cls._set_ver(4)
if cls._ver == 4:
sql = """CREATE INDEX hive_follows_ix4 ON public.hive_follows
USING btree (follower, following) WHERE state = 2;"""
cls.db().query(sql)
cls._set_ver(5)
if cls._ver == 5:
# recover acct names lost to issue #151
from hive.steem.client import SteemClient
from hive.indexer.accounts import Accounts
names = SteemClient().get_all_account_names()
Accounts.load_ids()
Accounts.register(names, '1970-01-01T00:00:00')
Accounts.clear_ids()
cls._set_ver(6)
assert cls._ver == DB_VERSION, "migration missing or invalid DB_VERSION"
def _check_migrations(cls):
"""Check current migration version and perform updates as needed."""
#pylint: disable=line-too-long
cls._ver = cls.db().query_one(
"SELECT db_version FROM hive_state LIMIT 1")
assert cls._ver is not None, 'could not load state record'
if cls._ver == 0:
raise Exception("dbv cannot be 0; reindex required")
if cls._ver == 1:
cls._set_ver(2)
if cls._ver == 2:
cls._set_ver(3)
if cls._ver == 3:
cls.db().query(
"CREATE INDEX hive_accounts_ix3 ON hive_accounts (vote_weight, name varchar_pattern_ops)"
)
cls._set_ver(4)
if cls._ver == 4:
cls.db().query(
"CREATE INDEX hive_follows_ix4 ON hive_follows (follower, following) WHERE state = 2"
)
cls._set_ver(5)
if cls._ver == 5:
# recover acct names lost to issue #151
from hive.steem.client import SteemClient
from hive.indexer.accounts import Accounts
names = SteemClient().get_all_account_names()
Accounts.load_ids()
Accounts.register(names, '1970-01-01T00:00:00')
Accounts.clear_ids()
cls._set_ver(6)
if cls._ver == 6:
cls.db().query("DROP INDEX hive_posts_cache_ix6")
cls.db().query(
"CREATE INDEX hive_posts_cache_ix6a ON hive_posts_cache (sc_trend, post_id) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix6b ON hive_posts_cache (post_id, sc_trend) WHERE is_paidout = '0'"
)
cls.db().query("DROP INDEX hive_posts_cache_ix7")
cls.db().query(
"CREATE INDEX hive_posts_cache_ix7a ON hive_posts_cache (sc_hot, post_id) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix7b ON hive_posts_cache (post_id, sc_hot) WHERE is_paidout = '0'"
)
cls._set_ver(7)
if cls._ver == 7:
cls.db().query(
"CREATE INDEX hive_accounts_ix4 ON hive_accounts (id, name)")
cls.db().query(
"CREATE INDEX hive_accounts_ix5 ON hive_accounts (cached_at, name)"
)
cls._set_ver(8)
if cls._ver == 8:
cls.db().query("DROP INDEX hive_follows_ix2")
cls.db().query("DROP INDEX hive_follows_ix3")
cls.db().query("DROP INDEX hive_follows_ix4")
cls.db().query(
"CREATE INDEX hive_follows_5a ON hive_follows (following, state, created_at, follower)"
)
cls.db().query(
"CREATE INDEX hive_follows_5b ON hive_follows (follower, state, created_at, following)"
)
cls._set_ver(9)
if cls._ver == 9:
from hive.indexer.follow import Follow
Follow.force_recount()
cls._set_ver(10)
if cls._ver == 10:
cls.db().query(
"CREATE INDEX hive_posts_cache_ix8 ON hive_posts_cache (category, payout, depth) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix9a ON hive_posts_cache (depth, payout, post_id) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix9b ON hive_posts_cache (category, depth, payout, post_id) WHERE is_paidout = '0'"
)
cls._set_ver(11)
if cls._ver == 11:
cls.db().query("DROP INDEX hive_posts_ix1")
cls.db().query("DROP INDEX hive_posts_ix2")
cls.db().query(
"CREATE INDEX hive_posts_ix3 ON hive_posts (author, depth, id) WHERE is_deleted = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_ix4 ON hive_posts (parent_id, id) WHERE is_deleted = '0'"
)
cls._set_ver(12)
reset_autovac(cls.db())
log.info("[HIVE] db version: %d", cls._ver)
assert cls._ver == DB_VERSION, "migration missing or invalid DB_VERSION"
def process_block(block, is_initial_sync=False):
date = block['timestamp']
block_id = block['block_id']
prev = block['previous']
block_num = int(block_id[:8], base=16)
txs = block['transactions']
query(
"INSERT INTO hive_blocks (num, hash, prev, txs, created_at) "
"VALUES (:num, :hash, :prev, :txs, :date)",
num=block_num,
hash=block_id,
prev=prev,
txs=len(txs),
date=date)
accounts = set()
comments = []
json_ops = []
deleted = []
dirty = set()
for tx in txs:
for operation in tx['operations']:
op_type, op = operation
if op_type == 'pow':
accounts.add(op['worker_account'])
elif op_type == 'pow2':
accounts.add(op['work'][1]['input']['worker_account'])
elif op_type in [
'account_create', 'account_create_with_delegation'
]:
accounts.add(op['new_account_name'])
elif op_type == 'comment':
comments.append(op)
dirty.add(op['author'] + '/' + op['permlink'])
Accounts.dirty(op['author'])
if op['parent_author']:
Accounts.dirty(op['parent_author'])
elif op_type == 'delete_comment':
deleted.append(op)
elif op_type == 'custom_json':
json_ops.append(op)
elif op_type == 'vote':
dirty.add(op['author'] + '/' + op['permlink'])
Accounts.dirty(op['author'])
Accounts.dirty(op['voter'])
Accounts.register(
accounts,
date) # if an account does not exist, mark it as created in this block
Posts.register(
comments, date
) # if this is a new post, add the entry and validate community param
Posts.delete(deleted) # mark hive_posts.is_deleted = 1
for op in json_ops:
if op['id'] not in ['follow', 'com.steemit.community']:
continue
# we are assuming `required_posting_auths` is always used and length 1.
# it may be that some ops will require `required_active_auths` instead
# (e.g. if we use that route for admin action of acct creation)
# if op['required_active_auths']:
# log.warning("unexpected active auths: %s" % op)
if len(op['required_posting_auths']) != 1:
log.warning("unexpected auths: %s" % op)
continue
account = op['required_posting_auths'][0]
op_json = load_json_key(op, 'json')
if op['id'] == 'follow':
if block_num < 6000000 and type(op_json) != list:
op_json = ['follow', op_json] # legacy compat
process_json_follow_op(account, op_json, date)
elif op['id'] == 'com.steemit.community':
if block_num > 13e6:
process_json_community_op(account, op_json, date)
# return all posts modified this block
return dirty
def _process(cls, block):
"""Process a single block. Assumes a trx is open."""
#pylint: disable=too-many-branches
assert issubclass(type(block), Block)
num = cls._push(block)
cls._current_block_date = block.get_date()
# head block date shall point to last imported block (not yet current one) to conform hived behavior.
# that's why operations processed by node are included in the block being currently produced, so its processing time is equal to last produced block.
# unfortunately it is not true to all operations, most likely in case of dates that used to come from
# FatNode where it supplemented it with its-current head block, since it was already past block processing,
# it saw later block (equal to _current_block_date here)
if cls._head_block_date is None:
cls._head_block_date = cls._current_block_date
ineffective_deleted_ops = Blocks.prepare_vops(
Posts.comment_payout_ops, block, cls._current_block_date, num,
num <= cls._last_safe_cashout_block)
json_ops = []
for transaction in block.get_next_transaction():
assert issubclass(type(transaction), Transaction)
for operation in transaction.get_next_operation():
assert issubclass(type(operation), Operation)
start = OPSM.start()
op_type = operation.get_type()
assert op_type, "Only supported types are expected"
op = operation.get_body()
assert 'block_num' not in op
op['block_num'] = num
account_name = None
op_details = None
potentially_new_account = False
# account ops
if op_type == OperationType.Pow:
account_name = op['worker_account']
potentially_new_account = True
elif op_type == OperationType.Pow2:
account_name = op['work']['value']['input'][
'worker_account']
potentially_new_account = True
elif op_type == OperationType.AccountCreate:
account_name = op['new_account_name']
op_details = op
potentially_new_account = True
elif op_type == OperationType.AccountCreateWithDelegation:
account_name = op['new_account_name']
op_details = op
potentially_new_account = True
elif op_type == OperationType.CreateClaimedAccount:
account_name = op['new_account_name']
op_details = op
potentially_new_account = True
if potentially_new_account and not Accounts.register(
account_name, op_details, cls._head_block_date, num):
log.error(
"Failed to register account {} from operation: {}".
format(account_name, op))
# account metadata updates
if op_type == OperationType.AccountUpdate:
Accounts.update_op(op, False)
elif op_type == OperationType.AccountUpdate2:
Accounts.update_op(op, True)
# post ops
elif op_type == OperationType.Comment:
Posts.comment_op(op, cls._head_block_date)
elif op_type == OperationType.DeleteComment:
key = "{}/{}".format(op['author'], op['permlink'])
if key not in ineffective_deleted_ops:
Posts.delete_op(op, cls._head_block_date)
elif op_type == OperationType.CommentOption:
Posts.comment_options_op(op)
elif op_type == OperationType.Vote:
Votes.vote_op(op, cls._head_block_date)
# misc ops
elif op_type == OperationType.Transfer:
Payments.op_transfer(op, transaction.get_id(), num,
cls._head_block_date)
elif op_type == OperationType.CustomJson: # follow/reblog/community ops
CustomOp.process_op(op, num, cls._head_block_date)
OPSM.op_stats(str(op_type), OPSM.stop(start))
cls._head_block_date = cls._current_block_date
return num
def _check_migrations(cls):
"""Check current migration version and perform updates as needed."""
#pylint: disable=line-too-long,too-many-branches,too-many-statements
cls._ver = cls.db().query_one(
"SELECT db_version FROM hive_state LIMIT 1")
assert cls._ver is not None, 'could not load state record'
if cls._ver == 0:
raise Exception("dbv cannot be 0; reindex required")
if cls._ver == 1:
cls._set_ver(2)
if cls._ver == 2:
cls._set_ver(3)
if cls._ver == 3:
cls.db().query(
"CREATE INDEX hive_accounts_ix3 ON hive_accounts (vote_weight, name varchar_pattern_ops)"
)
cls._set_ver(4)
if cls._ver == 4:
cls.db().query(
"CREATE INDEX hive_follows_ix4 ON hive_follows (follower, following) WHERE state = 2"
)
cls._set_ver(5)
if cls._ver == 5:
# recover acct names lost to issue #151
from hive.steem.client import SteemClient
from hive.indexer.accounts import Accounts
names = SteemClient().get_all_account_names()
Accounts.load_ids()
Accounts.register(names, '1970-01-01T00:00:00')
Accounts.clear_ids()
cls._set_ver(6)
if cls._ver == 6:
cls.db().query("DROP INDEX hive_posts_cache_ix6")
cls.db().query(
"CREATE INDEX hive_posts_cache_ix6a ON hive_posts_cache (sc_trend, post_id) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix6b ON hive_posts_cache (post_id, sc_trend) WHERE is_paidout = '0'"
)
cls.db().query("DROP INDEX hive_posts_cache_ix7")
cls.db().query(
"CREATE INDEX hive_posts_cache_ix7a ON hive_posts_cache (sc_hot, post_id) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix7b ON hive_posts_cache (post_id, sc_hot) WHERE is_paidout = '0'"
)
cls._set_ver(7)
if cls._ver == 7:
cls.db().query(
"CREATE INDEX hive_accounts_ix4 ON hive_accounts (id, name)")
cls.db().query(
"CREATE INDEX hive_accounts_ix5 ON hive_accounts (cached_at, name)"
)
cls._set_ver(8)
if cls._ver == 8:
cls.db().query("DROP INDEX hive_follows_ix2")
cls.db().query("DROP INDEX hive_follows_ix3")
cls.db().query("DROP INDEX hive_follows_ix4")
cls.db().query(
"CREATE INDEX hive_follows_5a ON hive_follows (following, state, created_at, follower)"
)
cls.db().query(
"CREATE INDEX hive_follows_5b ON hive_follows (follower, state, created_at, following)"
)
cls._set_ver(9)
if cls._ver == 9:
from hive.indexer.follow import Follow
Follow.force_recount()
cls._set_ver(10)
if cls._ver == 10:
cls.db().query(
"CREATE INDEX hive_posts_cache_ix8 ON hive_posts_cache (category, payout, depth) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix9a ON hive_posts_cache (depth, payout, post_id) WHERE is_paidout = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix9b ON hive_posts_cache (category, depth, payout, post_id) WHERE is_paidout = '0'"
)
cls._set_ver(11)
if cls._ver == 11:
cls.db().query("DROP INDEX hive_posts_ix1")
cls.db().query("DROP INDEX hive_posts_ix2")
cls.db().query(
"CREATE INDEX hive_posts_ix3 ON hive_posts (author, depth, id) WHERE is_deleted = '0'"
)
cls.db().query(
"CREATE INDEX hive_posts_ix4 ON hive_posts (parent_id, id) WHERE is_deleted = '0'"
)
cls._set_ver(12)
if cls._ver == 12: # community schema
assert False, 'not finalized'
for table in [
'hive_members', 'hive_flags', 'hive_modlog',
'hive_communities', 'hive_subscriptions', 'hive_roles',
'hive_notifs'
]:
cls.db().query("DROP TABLE IF EXISTS %s" % table)
build_metadata_community().create_all(cls.db().engine())
cls.db().query(
"ALTER TABLE hive_accounts ADD COLUMN lr_notif_id integer")
cls.db().query(
"ALTER TABLE hive_posts DROP CONSTRAINT hive_posts_fk2")
cls.db().query("ALTER TABLE hive_posts DROP COLUMN community")
cls.db().query(
"ALTER TABLE hive_posts ADD COLUMN community_id integer")
cls.db().query(
"ALTER TABLE hive_posts_cache ADD COLUMN community_id integer")
cls._set_ver(13)
if cls._ver == 13:
sqls = (
"CREATE INDEX hive_posts_ix5 ON hive_posts (id) WHERE is_pinned = '1' AND is_deleted = '0'",
"CREATE INDEX hive_posts_ix6 ON hive_posts (community_id, id) WHERE community_id IS NOT NULL AND is_pinned = '1' AND is_deleted = '0'",
"CREATE INDEX hive_posts_cache_ix10 ON hive_posts_cache (post_id, payout) WHERE is_grayed = '1' AND payout > 0",
"CREATE INDEX hive_posts_cache_ix30 ON hive_posts_cache (community_id, sc_trend, post_id) WHERE community_id IS NOT NULL AND is_grayed = '0' AND depth = 0",
"CREATE INDEX hive_posts_cache_ix31 ON hive_posts_cache (community_id, sc_hot, post_id) WHERE community_id IS NOT NULL AND is_grayed = '0' AND depth = 0",
"CREATE INDEX hive_posts_cache_ix32 ON hive_posts_cache (community_id, created_at, post_id) WHERE community_id IS NOT NULL AND is_grayed = '0' AND depth = 0",
"CREATE INDEX hive_posts_cache_ix33 ON hive_posts_cache (community_id, payout, post_id) WHERE community_id IS NOT NULL AND is_grayed = '0' AND is_paidout = '0'",
"CREATE INDEX hive_posts_cache_ix34 ON hive_posts_cache (community_id, payout, post_id) WHERE community_id IS NOT NULL AND is_grayed = '1' AND is_paidout = '0'"
)
for sql in sqls:
cls.db().query(sql)
cls._set_ver(14)
if cls._ver == 14:
cls.db().query(
"ALTER TABLE hive_communities ADD COLUMN primary_tag VARCHAR(32) NOT NULL DEFAULT ''"
)
cls.db().query(
"ALTER TABLE hive_communities ADD COLUMN category VARCHAR(32) NOT NULL DEFAULT ''"
)
cls.db().query(
"ALTER TABLE hive_communities ADD COLUMN avatar_url VARCHAR(1024) NOT NULL DEFAULT ''"
)
cls.db().query(
"ALTER TABLE hive_communities ADD COLUMN num_authors INTEGER NOT NULL DEFAULT 0"
)
cls.db().query(
"CREATE INDEX hive_posts_cache_ix20 ON hive_posts_cache (community_id, author, payout, post_id) WHERE is_paidout = '0'"
)
cls._set_ver(15)
if cls._ver == 15:
cls.db().query("ALTER TABLE hive_accounts DROP COLUMN lr_notif_id")
cls.db().query(
"ALTER TABLE hive_accounts ADD COLUMN lastread_at TIMESTAMP WITHOUT TIME ZONE DEFAULT '1970-01-01 00:00:00' NOT NULL"
)
cls.db().query(
"CREATE INDEX hive_notifs_ix6 ON hive_notifs (dst_id, created_at, score, id) WHERE dst_id IS NOT NULL"
)
cls._set_ver(16)
reset_autovac(cls.db())
log.info("[HIVE] db version: %d", cls._ver)
assert cls._ver == DB_VERSION, "migration missing or invalid DB_VERSION"