Source code for autobahn.websocket.compress_base

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__all__ = (
    "PerMessageCompress",
    "PerMessageCompressOffer",
    "PerMessageCompressOfferAccept",
    "PerMessageCompressResponse",
    "PerMessageCompressResponseAccept",
)




class PerMessageCompressOffer:
    """
    Base class for WebSocket compression parameter client offers.
    """





class PerMessageCompressOfferAccept:
    """
    Base class for WebSocket compression parameter client offer accepts by the server.
    """





class PerMessageCompressResponse:
    """
    Base class for WebSocket compression parameter server responses.
    """





class PerMessageCompressResponseAccept:
    """
    Base class for WebSocket compression parameter server response accepts by client.
    """





class PerMessageCompress:
    """
    Base class for WebSocket compression negotiated parameters.

    Concrete subclasses (one per permessage-compress extension) implement the
    decompression interface used by the WebSocket protocol:

    - ``start_decompress_message(self)``
    - ``decompress_message_data(self, data, max_output_len=None)``
    - ``end_decompress_message(self)``

    Bounded-decompression contract for ``decompress_message_data``: when
    ``max_output_len`` is not ``None``, the call returns at most
    ``max_output_len`` octets of decompressed output and raises
    :class:`autobahn.exception.PayloadExceededError` if the input would produce
    more - it never silently truncates. ``max_output_len=None`` (the default)
    leaves decompression unbounded. Every backend stops decompressing near the
    budget, instead of inflating a whole frame first: deflate and bzip2 at
    exactly one octet over it, brotli at its library's output buffer
    granularity, and snappy within one framing chunk (at most 64 KiB).

    Input that cannot be decompressed (corrupt, truncated, or not the
    extension's format) raises :class:`autobahn.exception.PayloadCorruptError`
    from ``decompress_message_data`` or ``end_decompress_message``, never the
    library's own exception.
    """