2026-05-20 10:50:30 +00:00

160 lines
4.9 KiB
Python

import codecs
from typing import Any, Optional, Tuple
from .core import IDNAError, _unicode_dots_re, alabel, decode, encode, ulabel
class Codec(codecs.Codec):
"""Stateless IDNA 2008 codec.
Implements the :class:`codecs.Codec` protocol so that the whole-domain
encoder (:func:`idna.encode`) and decoder (:func:`idna.decode`) are
accessible through the standard codec machinery as ``"idna2008"``.
Only the ``"strict"`` error handler is supported; any other handler
raises :exc:`~idna.IDNAError`.
"""
def encode(self, data: str, errors: str = "strict") -> Tuple[bytes, int]: # ty: ignore[invalid-method-override]
if errors != "strict":
raise IDNAError(f'Unsupported error handling "{errors}"')
if not data:
return b"", 0
return encode(data), len(data)
def decode(self, data: bytes, errors: str = "strict") -> Tuple[str, int]: # ty: ignore[invalid-method-override]
if errors != "strict":
raise IDNAError(f'Unsupported error handling "{errors}"')
if not data:
return "", 0
return decode(data), len(data)
class IncrementalEncoder(codecs.BufferedIncrementalEncoder):
"""Incremental IDNA 2008 encoder.
Buffers a partial trailing label across calls until either the next
label separator is seen or ``final=True``, so that streamed input is
encoded one whole label at a time. Any of the four Unicode label
separators (``U+002E``, ``U+3002``, ``U+FF0E``, ``U+FF61``) ends a
label; the result always uses ``U+002E`` as the separator.
Only the ``"strict"`` error handler is supported.
"""
def _buffer_encode(self, data: str, errors: str, final: bool) -> Tuple[bytes, int]: # ty: ignore[invalid-method-override]
if errors != "strict":
raise IDNAError(f'Unsupported error handling "{errors}"')
if not data:
return b"", 0
labels = _unicode_dots_re.split(data)
trailing_dot = b""
if labels:
if not labels[-1]:
trailing_dot = b"."
del labels[-1]
elif not final:
# Keep potentially unfinished label until the next call
del labels[-1]
if labels:
trailing_dot = b"."
result = []
size = 0
for label in labels:
result.append(alabel(label))
if size:
size += 1
size += len(label)
# Join with U+002E
result_bytes = b".".join(result) + trailing_dot
size += len(trailing_dot)
return result_bytes, size
class IncrementalDecoder(codecs.BufferedIncrementalDecoder):
"""Incremental IDNA 2008 decoder.
Buffers a partial trailing label across calls until either the next
label separator is seen or ``final=True``, so that streamed input is
decoded one whole label at a time.
Only the ``"strict"`` error handler is supported.
"""
def _buffer_decode(self, data: Any, errors: str, final: bool) -> Tuple[str, int]: # ty: ignore[invalid-method-override]
if errors != "strict":
raise IDNAError(f'Unsupported error handling "{errors}"')
if not data:
return ("", 0)
if not isinstance(data, str):
data = str(data, "ascii")
labels = _unicode_dots_re.split(data)
trailing_dot = ""
if labels:
if not labels[-1]:
trailing_dot = "."
del labels[-1]
elif not final:
# Keep potentially unfinished label until the next call
del labels[-1]
if labels:
trailing_dot = "."
result = []
size = 0
for label in labels:
result.append(ulabel(label))
if size:
size += 1
size += len(label)
result_str = ".".join(result) + trailing_dot
size += len(trailing_dot)
return (result_str, size)
class StreamWriter(Codec, codecs.StreamWriter):
pass
class StreamReader(Codec, codecs.StreamReader):
pass
def search_function(name: str) -> Optional[codecs.CodecInfo]:
"""Codec search function registered with :mod:`codecs`.
Returns a :class:`codecs.CodecInfo` for the ``"idna2008"`` codec name
so that ``str.encode("idna2008")`` and ``bytes.decode("idna2008")``
invoke the IDNA 2008 codec defined in this module.
:param name: The codec name being looked up.
:returns: A :class:`codecs.CodecInfo` instance if ``name`` is
``"idna2008"``, otherwise ``None``.
"""
if name != "idna2008":
return None
return codecs.CodecInfo(
name=name,
encode=Codec().encode,
decode=Codec().decode, # type: ignore
incrementalencoder=IncrementalEncoder,
incrementaldecoder=IncrementalDecoder,
streamwriter=StreamWriter,
streamreader=StreamReader,
)
codecs.register(search_function)