Optimize JSON encoding of int, float, str, and None

XMLWordPrintableJSON

    • Type: Improvement
    • Resolution: Fixed
    • Priority: Unknown
    • 4.7
    • Affects Version/s: None
    • Component/s: JSON, Performance
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      Context

      When encoding ints, floats, str, or None (depending on the JSONOptions set) our encoder will raise a TypeError and then catch the error and suppress it:

          elif json_options.json_mode == JSONMode.CANONICAL and isinstance(obj, int):
        if -(2**31) <= obj < 2**31:
            return {"$numberInt": str(obj)}
        return {"$numberLong": str(obj)}
    elif json_options.json_mode != JSONMode.LEGACY and isinstance(obj, float):
        if math.isnan(obj):
            return {"$numberDouble": "NaN"}
        elif math.isinf(obj):
            representation = "Infinity" if obj > 0 else "-Infinity"
            return {"$numberDouble": representation}
        elif json_options.json_mode == JSONMode.CANONICAL:
            # repr() will return the shortest string guaranteed to produce the
            # original value, when float() is called on it.
            return {"$numberDouble": str(repr(obj))}
    raise TypeError("%r is not JSON serializable" % obj) # <---- Will be used for ints/floats

      This results in very poor performance. Instead we can skip the TypeError and directly return the int/float:

            Assignee:
            Shane Harvey
            Reporter:
            Shane Harvey
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              Created:
              Updated:
              Resolved: