45 lines
1.3 KiB
Python
45 lines
1.3 KiB
Python
"""
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Utilities for working with python struct data.
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"""
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import logging
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logger = logging.getLogger(__name__)
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def pack_values(clazz, packers):
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"""
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Pack values for a given legacy class.
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:param class clazz: class that will provide a pack method
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:param list packers: a list of tuples that are used to pack values and transform them
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:return: packed data string of all values
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"""
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# iterate through tuples of values to pack
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logger.debug("packing: %s", packers)
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data = b""
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for packer in packers:
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# check if a transformer was provided for valid values
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transformer = None
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if len(packer) == 2:
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tlv_type, value = packer
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elif len(packer) == 3:
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tlv_type, value, transformer = packer
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else:
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raise RuntimeError("packer had more than 3 arguments")
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# only pack actual values and avoid packing empty strings
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# protobuf defaults to empty strings and does no imply a value to set
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if value is None or (isinstance(value, str) and not value):
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continue
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# transform values as needed
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if transformer:
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value = transformer(value)
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# pack and add to existing data
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logger.debug("packing: %s - %s type(%s)", tlv_type, value, type(value))
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data += clazz.pack(tlv_type.value, value)
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return data
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