async def reorg_chain(self, count):
'''Handle a chain reorganisation.
Count is the number of blocks to simulate a reorg, or None for a real reorg.
This is passed in as self.reorg_count may change asynchronously.
'''
if count < 0:
logger.info('chain reorg detected')
else:
logger.info(f'faking a reorg of {count:,d} blocks')
await self.flush(True)
start, hex_hashes = await self._reorg_hashes(count)
pairs = reversed(list(enumerate(hex_hashes, start=start)))
await OnDiskBlock.prefetch_many(self.daemon, pairs, 'reorg')
for hex_hash in reversed(hex_hashes):
if hex_hash != hash_to_hex_str(self.state.tip):
logger.error(f'block {hex_hash} is not tip; cannot back up')
return
block = await OnDiskBlock.streamed_block(hex_hash)
if not block:
break
await self.run_with_lock(run_in_thread(self.backup_block, block))
logger.info(f'backed up to height {self.state.height:,d}')
self.backed_up_event.set()
self.backed_up_event.clear()
async def run_in_thread_shielded(self, func, *args):
async with self.state_lock:
return await asyncio.shield(run_in_thread(func, *args))