36 lines
1.3 KiB
Python
36 lines
1.3 KiB
Python
import base64
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from .exceptions import InvalidArgumentError
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def compose_new_shard_iterator(stream_name, shard, shard_iterator_type, starting_sequence_number,
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at_timestamp):
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if shard_iterator_type == "AT_SEQUENCE_NUMBER":
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last_sequence_id = int(starting_sequence_number) - 1
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elif shard_iterator_type == "AFTER_SEQUENCE_NUMBER":
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last_sequence_id = int(starting_sequence_number)
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elif shard_iterator_type == "TRIM_HORIZON":
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last_sequence_id = 0
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elif shard_iterator_type == "LATEST":
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last_sequence_id = shard.get_max_sequence_number()
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elif shard_iterator_type == "AT_TIMESTAMP":
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last_sequence_id = shard.get_sequence_number_at(at_timestamp)
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else:
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raise InvalidArgumentError(
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"Invalid ShardIteratorType: {0}".format(shard_iterator_type))
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return compose_shard_iterator(stream_name, shard, last_sequence_id)
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def compose_shard_iterator(stream_name, shard, last_sequence_id):
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return base64.encodestring(
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"{0}:{1}:{2}".format(
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stream_name,
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shard.shard_id,
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last_sequence_id,
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).encode("utf-8")
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).decode("utf-8")
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def decompose_shard_iterator(shard_iterator):
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return base64.decodestring(shard_iterator.encode("utf-8")).decode("utf-8").split(":")
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