pydataclass

#!/usr/bin/env python3
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

import dataclasses
import io
import json
import os
from timeit import timeit
from typing import List

from tabulate import tabulate

import orjson

os.sched_setaffinity(os.getpid(), {0, 1})


@dataclasses.dataclass
class Member:
    id: int
    active: bool


@dataclasses.dataclass
class Object:
    id: int
    name: str
    members: List[Member]


objects_as_dataclass = [
    Object(i, str(i) * 3, [Member(j, True) for j in range(0, 10)])
    for i in range(100000, 102000)
]

objects_as_dict = [dataclasses.asdict(each) for each in objects_as_dataclass]

output_in_kib = len(orjson.dumps(objects_as_dict)) / 1024

print(f"{output_in_kib:,.0f}KiB output (orjson)")


def default(__obj):
    if dataclasses.is_dataclass(__obj):
        return dataclasses.asdict(__obj)


headers = ("Library", "dict (ms)", "dataclass (ms)", "vs. orjson")

LIBRARIES = ("orjson", "json")

ITERATIONS = 100


def per_iter_latency(val):
    if val is None:
        return None
    return (val * 1000) / ITERATIONS


table = []
for lib_name in LIBRARIES:
    if lib_name == "json":
        as_dict = timeit(
            lambda: json.dumps(objects_as_dict).encode("utf-8"),
            number=ITERATIONS,
        )
        as_dataclass = timeit(
            lambda: json.dumps(objects_as_dataclass, default=default).encode("utf-8"),
            number=ITERATIONS,
        )
    elif lib_name == "orjson":
        as_dict = timeit(lambda: orjson.dumps(objects_as_dict), number=ITERATIONS)
        as_dataclass = timeit(
            lambda: orjson.dumps(
                objects_as_dataclass, None, orjson.OPT_SERIALIZE_DATACLASS
            ),
            number=ITERATIONS,
        )
        orjson_as_dataclass = per_iter_latency(as_dataclass)
    else:
        raise NotImplementedError

    as_dict = per_iter_latency(as_dict)
    as_dataclass = per_iter_latency(as_dataclass)

    if lib_name == "orjson":
        compared_to_orjson = 1
    elif as_dataclass:
        compared_to_orjson = int(as_dataclass / orjson_as_dataclass)
    else:
        compared_to_orjson = None

    table.append(
        (
            lib_name,
            f"{as_dict:,.2f}" if as_dict else "",
            f"{as_dataclass:,.2f}" if as_dataclass else "",
            f"{compared_to_orjson:d}" if compared_to_orjson else "",
        )
    )

buf = io.StringIO()
buf.write(tabulate(table, headers, tablefmt="github"))
buf.write("\n")

print(buf.getvalue())