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Diffstat (limited to '.venv/lib/python3.12/site-packages/httpx/_decoders.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/httpx/_decoders.py | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/httpx/_decoders.py b/.venv/lib/python3.12/site-packages/httpx/_decoders.py new file mode 100644 index 00000000..62f2c0b9 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/httpx/_decoders.py @@ -0,0 +1,371 @@ +""" +Handlers for Content-Encoding. + +See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding +""" + +from __future__ import annotations + +import codecs +import io +import typing +import zlib + +from ._compat import brotli, zstd +from ._exceptions import DecodingError + + +class ContentDecoder: + def decode(self, data: bytes) -> bytes: + raise NotImplementedError() # pragma: no cover + + def flush(self) -> bytes: + raise NotImplementedError() # pragma: no cover + + +class IdentityDecoder(ContentDecoder): + """ + Handle unencoded data. + """ + + def decode(self, data: bytes) -> bytes: + return data + + def flush(self) -> bytes: + return b"" + + +class DeflateDecoder(ContentDecoder): + """ + Handle 'deflate' decoding. + + See: https://stackoverflow.com/questions/1838699 + """ + + def __init__(self) -> None: + self.first_attempt = True + self.decompressor = zlib.decompressobj() + + def decode(self, data: bytes) -> bytes: + was_first_attempt = self.first_attempt + self.first_attempt = False + try: + return self.decompressor.decompress(data) + except zlib.error as exc: + if was_first_attempt: + self.decompressor = zlib.decompressobj(-zlib.MAX_WBITS) + return self.decode(data) + raise DecodingError(str(exc)) from exc + + def flush(self) -> bytes: + try: + return self.decompressor.flush() + except zlib.error as exc: # pragma: no cover + raise DecodingError(str(exc)) from exc + + +class GZipDecoder(ContentDecoder): + """ + Handle 'gzip' decoding. + + See: https://stackoverflow.com/questions/1838699 + """ + + def __init__(self) -> None: + self.decompressor = zlib.decompressobj(zlib.MAX_WBITS | 16) + + def decode(self, data: bytes) -> bytes: + try: + return self.decompressor.decompress(data) + except zlib.error as exc: + raise DecodingError(str(exc)) from exc + + def flush(self) -> bytes: + try: + return self.decompressor.flush() + except zlib.error as exc: # pragma: no cover + raise DecodingError(str(exc)) from exc + + +class BrotliDecoder(ContentDecoder): + """ + Handle 'brotli' decoding. + + Requires `pip install brotlipy`. See: https://brotlipy.readthedocs.io/ + or `pip install brotli`. See https://github.com/google/brotli + Supports both 'brotlipy' and 'Brotli' packages since they share an import + name. The top branches are for 'brotlipy' and bottom branches for 'Brotli' + """ + + def __init__(self) -> None: + if brotli is None: # pragma: no cover + raise ImportError( + "Using 'BrotliDecoder', but neither of the 'brotlicffi' or 'brotli' " + "packages have been installed. " + "Make sure to install httpx using `pip install httpx[brotli]`." + ) from None + + self.decompressor = brotli.Decompressor() + self.seen_data = False + self._decompress: typing.Callable[[bytes], bytes] + if hasattr(self.decompressor, "decompress"): + # The 'brotlicffi' package. + self._decompress = self.decompressor.decompress # pragma: no cover + else: + # The 'brotli' package. + self._decompress = self.decompressor.process # pragma: no cover + + def decode(self, data: bytes) -> bytes: + if not data: + return b"" + self.seen_data = True + try: + return self._decompress(data) + except brotli.error as exc: + raise DecodingError(str(exc)) from exc + + def flush(self) -> bytes: + if not self.seen_data: + return b"" + try: + if hasattr(self.decompressor, "finish"): + # Only available in the 'brotlicffi' package. + + # As the decompressor decompresses eagerly, this + # will never actually emit any data. However, it will potentially throw + # errors if a truncated or damaged data stream has been used. + self.decompressor.finish() # pragma: no cover + return b"" + except brotli.error as exc: # pragma: no cover + raise DecodingError(str(exc)) from exc + + +class ZStandardDecoder(ContentDecoder): + """ + Handle 'zstd' RFC 8878 decoding. + + Requires `pip install zstandard`. + Can be installed as a dependency of httpx using `pip install httpx[zstd]`. + """ + + # inspired by the ZstdDecoder implementation in urllib3 + def __init__(self) -> None: + if zstd is None: # pragma: no cover + raise ImportError( + "Using 'ZStandardDecoder', ..." + "Make sure to install httpx using `pip install httpx[zstd]`." + ) from None + + self.decompressor = zstd.ZstdDecompressor().decompressobj() + + def decode(self, data: bytes) -> bytes: + assert zstd is not None + output = io.BytesIO() + try: + output.write(self.decompressor.decompress(data)) + while self.decompressor.eof and self.decompressor.unused_data: + unused_data = self.decompressor.unused_data + self.decompressor = zstd.ZstdDecompressor().decompressobj() + output.write(self.decompressor.decompress(unused_data)) + except zstd.ZstdError as exc: + raise DecodingError(str(exc)) from exc + return output.getvalue() + + def flush(self) -> bytes: + ret = self.decompressor.flush() # note: this is a no-op + if not self.decompressor.eof: + raise DecodingError("Zstandard data is incomplete") # pragma: no cover + return bytes(ret) + + +class MultiDecoder(ContentDecoder): + """ + Handle the case where multiple encodings have been applied. + """ + + def __init__(self, children: typing.Sequence[ContentDecoder]) -> None: + """ + 'children' should be a sequence of decoders in the order in which + each was applied. + """ + # Note that we reverse the order for decoding. + self.children = list(reversed(children)) + + def decode(self, data: bytes) -> bytes: + for child in self.children: + data = child.decode(data) + return data + + def flush(self) -> bytes: + data = b"" + for child in self.children: + data = child.decode(data) + child.flush() + return data + + +class ByteChunker: + """ + Handles returning byte content in fixed-size chunks. + """ + + def __init__(self, chunk_size: int | None = None) -> None: + self._buffer = io.BytesIO() + self._chunk_size = chunk_size + + def decode(self, content: bytes) -> list[bytes]: + if self._chunk_size is None: + return [content] if content else [] + + self._buffer.write(content) + if self._buffer.tell() >= self._chunk_size: + value = self._buffer.getvalue() + chunks = [ + value[i : i + self._chunk_size] + for i in range(0, len(value), self._chunk_size) + ] + if len(chunks[-1]) == self._chunk_size: + self._buffer.seek(0) + self._buffer.truncate() + return chunks + else: + self._buffer.seek(0) + self._buffer.write(chunks[-1]) + self._buffer.truncate() + return chunks[:-1] + else: + return [] + + def flush(self) -> list[bytes]: + value = self._buffer.getvalue() + self._buffer.seek(0) + self._buffer.truncate() + return [value] if value else [] + + +class TextChunker: + """ + Handles returning text content in fixed-size chunks. + """ + + def __init__(self, chunk_size: int | None = None) -> None: + self._buffer = io.StringIO() + self._chunk_size = chunk_size + + def decode(self, content: str) -> list[str]: + if self._chunk_size is None: + return [content] if content else [] + + self._buffer.write(content) + if self._buffer.tell() >= self._chunk_size: + value = self._buffer.getvalue() + chunks = [ + value[i : i + self._chunk_size] + for i in range(0, len(value), self._chunk_size) + ] + if len(chunks[-1]) == self._chunk_size: + self._buffer.seek(0) + self._buffer.truncate() + return chunks + else: + self._buffer.seek(0) + self._buffer.write(chunks[-1]) + self._buffer.truncate() + return chunks[:-1] + else: + return [] + + def flush(self) -> list[str]: + value = self._buffer.getvalue() + self._buffer.seek(0) + self._buffer.truncate() + return [value] if value else [] + + +class TextDecoder: + """ + Handles incrementally decoding bytes into text + """ + + def __init__(self, encoding: str = "utf-8") -> None: + self.decoder = codecs.getincrementaldecoder(encoding)(errors="replace") + + def decode(self, data: bytes) -> str: + return self.decoder.decode(data) + + def flush(self) -> str: + return self.decoder.decode(b"", True) + + +class LineDecoder: + """ + Handles incrementally reading lines from text. + + Has the same behaviour as the stdllib splitlines, + but handling the input iteratively. + """ + + def __init__(self) -> None: + self.buffer: list[str] = [] + self.trailing_cr: bool = False + + def decode(self, text: str) -> list[str]: + # See https://docs.python.org/3/library/stdtypes.html#str.splitlines + NEWLINE_CHARS = "\n\r\x0b\x0c\x1c\x1d\x1e\x85\u2028\u2029" + + # We always push a trailing `\r` into the next decode iteration. + if self.trailing_cr: + text = "\r" + text + self.trailing_cr = False + if text.endswith("\r"): + self.trailing_cr = True + text = text[:-1] + + if not text: + # NOTE: the edge case input of empty text doesn't occur in practice, + # because other httpx internals filter out this value + return [] # pragma: no cover + + trailing_newline = text[-1] in NEWLINE_CHARS + lines = text.splitlines() + + if len(lines) == 1 and not trailing_newline: + # No new lines, buffer the input and continue. + self.buffer.append(lines[0]) + return [] + + if self.buffer: + # Include any existing buffer in the first portion of the + # splitlines result. + lines = ["".join(self.buffer) + lines[0]] + lines[1:] + self.buffer = [] + + if not trailing_newline: + # If the last segment of splitlines is not newline terminated, + # then drop it from our output and start a new buffer. + self.buffer = [lines.pop()] + + return lines + + def flush(self) -> list[str]: + if not self.buffer and not self.trailing_cr: + return [] + + lines = ["".join(self.buffer)] + self.buffer = [] + self.trailing_cr = False + return lines + + +SUPPORTED_DECODERS = { + "identity": IdentityDecoder, + "gzip": GZipDecoder, + "deflate": DeflateDecoder, + "br": BrotliDecoder, + "zstd": ZStandardDecoder, +} + + +if brotli is None: + SUPPORTED_DECODERS.pop("br") # pragma: no cover +if zstd is None: + SUPPORTED_DECODERS.pop("zstd") # pragma: no cover |