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stashed_pjson.py

ofrak.service.serialization.stashed_pjson

StashedPJSONSerializationService (SerializationServiceInterface)

Serialization service producing a more compact encoding than PJSONSerializationService, at the expense of time performance, by mapping each string in the PJSON to a shorter one, and including the mapping at the beginning of the serialized form.

_convert(self, pjson, string_mapping) private

Perform the string replacement according to string_mapping.

This method is used for both encoding and decoding, with opposite string_mapping dictionaries.

Source code in ofrak/service/serialization/stashed_pjson.py 
def _convert(
    self,
    pjson: PJSONType,
    string_mapping: Dict[str, str],
) -> PJSONType:
    """
    Perform the string replacement according to `string_mapping`.

    This method is used for both encoding and decoding, with opposite `string_mapping` dictionaries.
    """
    if isinstance(pjson, str):
        return string_mapping[pjson]
    elif isinstance(pjson, list):
        return [self._convert(item, string_mapping) for item in pjson]
    elif isinstance(pjson, tuple):
        return tuple(self._convert(item, string_mapping) for item in pjson)
    elif isinstance(pjson, dict):
        return {
            cast(str, self._convert(key, string_mapping)): self._convert(value, string_mapping)
            for key, value in pjson.items()
        }
    else:
        return pjson

_short_string_generator() private

Generator of short JSON-compatible strings of increasing size.

Source code in ofrak/service/serialization/stashed_pjson.py 
def _short_string_generator():
    """Generator of short JSON-compatible strings of increasing size."""
    disallowed_characters = [0x22, 0x5C, 0x2F, 0x62, 0x66, 0x6E, 0x72, 0x74, 0x75]
    alphabet = [chr(i) for i in range(0x20, 0x7E) if i not in disallowed_characters]
    size = 1
    while True:
        for letters in product(*([alphabet] * size)):
            yield "".join(letters)
        size += 1