def _get_latest_block(self, tx_context, orderer):
""" Get latest block from orderer.
Args:
tx_context (object): a tx_context instance
orderer (object): a orderer instance
"""
seek_info = ab_pb2.SeekInfo()
seek_info.start.newest = ab_pb2.SeekNewest()
seek_info.stop.newest = ab_pb2.SeekNewest()
seek_info.behavior = \
ab_pb2.SeekInfo.SeekBehavior.Value('BLOCK_UNTIL_READY')
seek_info_header = self._build_channel_header(
common_pb2.HeaderType.Value('DELIVER_SEEK_INFO'), tx_context.tx_id,
self._name, current_timestamp(), tx_context.epoch)
signature_header = common_pb2.SignatureHeader()
signature_header.creator = tx_context.identity
signature_header.nonce = tx_context.nonce
seek_payload = common_pb2.Payload()
seek_payload.header.signature_header = \
signature_header.SerializeToString()
seek_payload.header.channel_header = \
seek_info_header.SerializeToString()
seek_payload.data = seek_info.SerializeToString()
envelope = common_pb2.Envelope()
envelope.signature = tx_context.sign(seek_payload.SerializeToString())
envelope.payload = seek_payload.SerializeToString()
def create_seek_info(start=None, stop=None, behavior="BLOCK_UNTIL_READY"):
# build start
if start is not None:
seek_specified_start = ab_pb2.SeekSpecified()
seek_specified_start.number = start
seek_start = ab_pb2.SeekPosition()
seek_start.specified.CopyFrom(seek_specified_start)
else:
seek_start = ab_pb2.SeekPosition()
seek_start.newest.CopyFrom(ab_pb2.SeekNewest())
# build stop
if stop is not None:
seek_specified_stop = ab_pb2.SeekSpecified()
seek_specified_stop.number = stop
seek_stop = ab_pb2.SeekPosition()
seek_stop.specified.CopyFrom(seek_specified_stop)
else:
seek_stop = ab_pb2.SeekPosition()
seek_stop.newest.CopyFrom(ab_pb2.SeekNewest())
# seek info with all parts
seek_info = ab_pb2.SeekInfo()
seek_info.start.CopyFrom(seek_start)
seek_info.stop.CopyFrom(seek_stop)
seek_info.behavior = ab_pb2.SeekInfo.SeekBehavior.Value(behavior)
return seek_info
def _create_seek_info(self, start=None, stop=None):
behavior = 'BLOCK_UNTIL_READY'
# build start
seek_start = ab_pb2.SeekPosition()
if start is None or start == 'newest':
seek_start.newest.CopyFrom(ab_pb2.SeekNewest())
elif start == 'oldest':
seek_start.oldest.CopyFrom(ab_pb2.SeekOldest())
else:
seek_specified_start = ab_pb2.SeekSpecified()
seek_specified_start.number = start
seek_start.specified.CopyFrom(seek_specified_start)
# build stop
seek_stop = ab_pb2.SeekPosition()
if stop == 'newest':
self._ending_block_newest = True
seek_stop.newest.CopyFrom(ab_pb2.SeekNewest())
behavior = 'FAIL_IF_NOT_READY'
elif start == 'oldest':
seek_stop.oldest.CopyFrom(ab_pb2.SeekOldest())
behavior = 'FAIL_IF_NOT_READY'
else:
seek_specified_stop = ab_pb2.SeekSpecified()
if stop is not None:
seek_specified_stop.number = stop
behavior = 'FAIL_IF_NOT_READY'
else:
seek_specified_stop.number = sys.maxsize
seek_stop.specified.CopyFrom(seek_specified_stop)
# seek info with all parts
seek_info = ab_pb2.SeekInfo()
seek_info.start.CopyFrom(seek_start)
seek_info.stop.CopyFrom(seek_stop)
# BLOCK_UNTIL_READY will mean hold the stream open and keep sending
# as the blocks come in
# FAIL_IF_NOT_READY will mean if the block is not there throw an error
seek_info.behavior = ab_pb2.SeekInfo.SeekBehavior.Value(behavior)
return seek_info
def create_seek_info(start, stop, behavior="BLOCK_UNTIL_READY"):
# build start
seek_specified_start = ab_pb2.SeekSpecified()
seek_specified_start.number = start
seek_start = ab_pb2.SeekPosition()
seek_start.specified.CopyFrom(seek_specified_start)
# build stop
seek_specified_stop = ab_pb2.SeekSpecified()
seek_specified_stop.number = stop
seek_stop = ab_pb2.SeekPosition()
seek_stop.specified.CopyFrom(seek_specified_stop)
# seek info with all parts
seek_info = ab_pb2.SeekInfo()
seek_info.start.CopyFrom(seek_start)
seek_info.stop.CopyFrom(seek_stop)
seek_info.behavior = \
ab_pb2.SeekInfo.SeekBehavior.Value(behavior)
return seek_info
