方法：アップロード（リアルタイム）

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import math
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from typing import Callable
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# Constants
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MINIMUM_PART_SIZE = 5_242_880
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MAXIMUM_PART_COUNT = 10_000
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MAXIMUM_FILE_SIZE = 5_497_558_138_880
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# Maximum uniform data rate that allows for 10,000 parts
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MAXIMUM_DATA_RATE = MAXIMUM_FILE_SIZE // MAXIMUM_PART_COUNT
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def part_size(part_number: int, format_bytes_per_second: int) -> int:
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    """
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    Returns the payload size for a specific part number given the file's
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    expected data rate.
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    """
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    if part_number < 1:
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        raise ValueError("part_number must be greater than 0")
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    if part_number > 10_000:
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        raise ValueError("part_number must be less than 10,000")
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    # Make sure we never go above the maximum data rate or fall below the
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    # minimum part size, even if the data rate is lower.
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    data_rate = min(format_bytes_per_second, MAXIMUM_DATA_RATE)
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    data_rate = max(data_rate, MINIMUM_PART_SIZE)
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    # Calculate a scalar given our data rate. We will explain this step
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    # futher on in the guides.
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    scalar = -(2 * (125 * data_rate - 68_719_476_736)) / 8_334_583_375
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    part_size = math.floor(scalar * pow(part_number, 2)) + data_rate
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    return part_size

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def create_part_size_calculator(format_bytes_per_second: int) -> Callable[[int], int]:
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    """
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    Returns a function that takes in a `part_number` and returns a
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    `part_size` based on `data_rate`.
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    """
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    # Make sure we never go above the maximum data rate or fall below the
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    # minimum part size, even if the data rate is lower.
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    data_rate = min(format_bytes_per_second, MAXIMUM_DATA_RATE)
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    data_rate = max(data_rate, MINIMUM_PART_SIZE)
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    static_scalar = -(2 * (125 * data_rate - 68_719_476_736)) / 8_334_583_375
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    def part_size_calculator(part_number: int) -> int:
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        """Calculates size in bytes of upload for `part_number`."""
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        if part_number < 1:
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            raise ValueError("part_number must be greater than 0")
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        if part_number > 10_000:
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            raise ValueError("part_number must be less than 10,000")
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        return math.floor(static_scalar * pow(part_number, 2) + data_rate)
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    return part_size_calculator

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math.floor(16.33293799427617 * pow(part_number, 2)) + 5_242_880

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import math
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from datetime import datetime, timezone
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from typing import Callable
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# The minimum size, in bytes, for a single, non-final part upload.
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MINIMUM_PART_SIZE = 5_242_880
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# The maximum filesize in
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MAXIMUM_PART_COUNT = 10_000
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# The maximum size, in bytes, for an AWS upload.
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MAXIMUM_FILE_SIZE = 5_497_558_138_880
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# The data rate at which every part is an equal size, and could not
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# be any uniformly larger without violating the maximum total file
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# size if 10_000 parts were to be uploaded. it works out to
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# ~549.8 MB per payload. By enforcing this we actually never need
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# to check if a part exceeds the maximum allowed part size, as our
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# parts will never exceed ~549.8 MB.
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MAXIMUM_DATA_RATE = MAXIMUM_FILE_SIZE // MAXIMUM_PART_COUNT
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def create_part_size_calculator(format_bytes_per_second: int) -> Callable[[int], int]:
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    """
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    Returns a function that takes in a `part_number` and returns a
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    `part_size` based on `data_rate`.
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    """
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    ...
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def upload_render(data_stream: DataStream, channel: int = 0) -> None:
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    """
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    Uploads an asset for data_stream, which is a custom IO class that pulls remaining
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    upload data from an internal buffer or file, depending on how well the upload is
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    keeping pace with the render.
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    Uploads to `channel`
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    """
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    asset = c2c.asset_create(
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        extension=data_stream.extension, 
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        filetype=data_stream.mimetpye, 
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        channel=channel,
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        offset=datetime.now(timezone.utc) - data_stream.created_at()
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    )
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    calculate_part_size = create_part_size_calculator(data_stream.data_rate())
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    next_part_number = 0
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    while True:
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        next_payload_size = calculate_part_size(next_part_number)
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        # Waits until one or more chunks worth of data is ready for upload. Cache 
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        # whether our data stream has completed writing the file, and the current 
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        # number of bytes we have remaining to upload at this time.
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        available_bytes, stream_complete = data_stream.wait_for_available_data(
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            minimum_bytes=next_payload_size
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        )
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        # Build the list of parts to request based on our available data.
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        parts = []
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        while available_bytes > 0:
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            payload_size = calculate_part_size(next_part_number)
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            if available_bytes < payload_size and not stream_complete:
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                break
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            payload_size = min(payload_size, available_bytes)
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            parts.append(
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                c2c.RealtimeUploadPart(
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                    part_number=next_part_number,
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                    part_size=payload_size,
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                    is_final=False
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                )
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            )
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            available_bytes -= payload_size
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            next_part_number += 1
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        # If our stream is done writing, mark the last part as final.
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        if stream_complete:
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            parts[-1].is_final = True
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        # Create the part URLs using the C2C endpoint.
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        response = c2c.create_realtime_parts(
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            asset_id=asset.id,
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            asset_name=None if not stream_complete else data_stream.filename,
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            asset_filesize=None if not stream_complete else data_stream.size(),
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            parts=parts
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        )
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        # Upload each part to its URL.
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        for part, part_url in zip(parts, response.upload_urls):
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            part_data = data_stream.read(bytes=part.size)
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            c2c.upload_chunk(part_data, part_url, data_stream.mimetype)
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        if stream_complete:
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            break