61 lines
1.5 KiB
Python
61 lines
1.5 KiB
Python
# standard imports
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import logging
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logg = logging.getLogger(__name__)
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class Backend:
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"""Base class for syncer state backend.
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:param flags_reversed: If set, filter flags are interpreted from left to right
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:type flags_reversed: bool
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"""
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def __init__(self, object_id, flags_reversed=False):
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self.object_id = object_id
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self.filter_count = 0
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self.flags_reversed = flags_reversed
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self.block_height_offset = 0
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self.tx_index_offset = 0
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self.block_height_cursor = 0
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self.tx_index_cursor = 0
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self.block_height_target = 0
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self.tx_index_target = 0
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def check_filter(self, n, flags):
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"""Check whether an individual filter flag is set.
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:param n: Bit index
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:type n: int
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:param flags: Bit field to check against
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:type flags: int
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:rtype: bool
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:returns: True if set
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"""
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if self.flags_reversed:
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try:
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v = 1 << flags.bit_length() - 1
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return (v >> n) & flags > 0
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except ValueError:
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pass
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return False
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return flags & (1 << n) > 0
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def chain(self):
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"""Returns chain spec for syncer.
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:returns: Chain spec
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:rtype chain_spec: cic_registry.chain.ChainSpec
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"""
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return self.chain_spec
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def __str__(self):
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return "syncerbackend {} chain {} start {} target {}".format(self.object_id, self.chain(), self.start(), self.target())
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