87 lines
2.1 KiB
Python
87 lines
2.1 KiB
Python
# standard imports
|
||
import logging
|
||
import hashlib
|
||
|
||
# external imports
|
||
from sqlalchemy import Column, String, Integer, BLOB, ForeignKey
|
||
from sqlalchemy.ext.hybrid import hybrid_property, hybrid_method
|
||
|
||
# local imports
|
||
from .base import SessionBase
|
||
from .sync import BlockchainSync
|
||
|
||
zero_digest = bytearray(32)
|
||
logg = logging.getLogger(__name__)
|
||
|
||
|
||
class BlockchainSyncFilter(SessionBase):
|
||
|
||
__tablename__ = 'chain_sync_filter'
|
||
|
||
chain_sync_id = Column(Integer, ForeignKey('chain_sync.id'))
|
||
flags_start = Column(BLOB)
|
||
flags = Column(BLOB)
|
||
digest = Column(BLOB)
|
||
count = Column(Integer)
|
||
|
||
|
||
def __init__(self, chain_sync, count=0, flags=None, digest=zero_digest):
|
||
self.digest = digest
|
||
self.count = count
|
||
|
||
if flags == None:
|
||
flags = bytearray(0)
|
||
self.flags_start = flags
|
||
self.flags = flags
|
||
|
||
self.chain_sync_id = chain_sync.id
|
||
|
||
|
||
def add(self, name):
|
||
h = hashlib.new('sha256')
|
||
h.update(self.digest)
|
||
h.update(name.encode('utf-8'))
|
||
z = h.digest()
|
||
|
||
old_byte_count = int((self.count - 1) / 8 + 1)
|
||
new_byte_count = int((self.count) / 8 + 1)
|
||
|
||
logg.debug('old new {} {}'.format(old_byte_count, new_byte_count))
|
||
if old_byte_count != new_byte_count:
|
||
self.flags = bytearray(1) + self.flags
|
||
self.count += 1
|
||
self.digest = z
|
||
|
||
|
||
def start(self):
|
||
return int.from_bytes(self.flags_start, 'big')
|
||
|
||
|
||
def cursor(self):
|
||
return int.from_bytes(self.flags, 'big')
|
||
|
||
|
||
def clear(self):
|
||
self.flags = 0
|
||
|
||
|
||
def target(self):
|
||
n = 0
|
||
for i in range(self.count):
|
||
n |= (1 << self.count) - 1
|
||
return n
|
||
|
||
|
||
def set(self, n):
|
||
if n > self.count:
|
||
raise IndexError('bit flag out of range')
|
||
|
||
b = 1 << (n % 8)
|
||
i = int((n - 1) / 8 + 1)
|
||
if self.flags[i] & b > 0:
|
||
SessionBase.release_session(session)
|
||
raise AttributeError('Filter bit already set')
|
||
flags = bytearray(self.flags)
|
||
flags[i] |= b
|
||
self.flags = flags
|