158 lines
4.9 KiB
Python
158 lines
4.9 KiB
Python
|
import asyncio
|
||
|
import zlib
|
||
|
from concurrent.futures import Executor
|
||
|
from typing import Optional, cast
|
||
|
|
||
|
try:
|
||
|
try:
|
||
|
import brotlicffi as brotli
|
||
|
except ImportError:
|
||
|
import brotli
|
||
|
|
||
|
HAS_BROTLI = True
|
||
|
except ImportError: # pragma: no cover
|
||
|
HAS_BROTLI = False
|
||
|
|
||
|
MAX_SYNC_CHUNK_SIZE = 1024
|
||
|
|
||
|
|
||
|
def encoding_to_mode(
|
||
|
encoding: Optional[str] = None,
|
||
|
suppress_deflate_header: bool = False,
|
||
|
) -> int:
|
||
|
if encoding == "gzip":
|
||
|
return 16 + zlib.MAX_WBITS
|
||
|
|
||
|
return -zlib.MAX_WBITS if suppress_deflate_header else zlib.MAX_WBITS
|
||
|
|
||
|
|
||
|
class ZlibBaseHandler:
|
||
|
def __init__(
|
||
|
self,
|
||
|
mode: int,
|
||
|
executor: Optional[Executor] = None,
|
||
|
max_sync_chunk_size: Optional[int] = MAX_SYNC_CHUNK_SIZE,
|
||
|
):
|
||
|
self._mode = mode
|
||
|
self._executor = executor
|
||
|
self._max_sync_chunk_size = max_sync_chunk_size
|
||
|
|
||
|
|
||
|
class ZLibCompressor(ZlibBaseHandler):
|
||
|
def __init__(
|
||
|
self,
|
||
|
encoding: Optional[str] = None,
|
||
|
suppress_deflate_header: bool = False,
|
||
|
level: Optional[int] = None,
|
||
|
wbits: Optional[int] = None,
|
||
|
strategy: int = zlib.Z_DEFAULT_STRATEGY,
|
||
|
executor: Optional[Executor] = None,
|
||
|
max_sync_chunk_size: Optional[int] = MAX_SYNC_CHUNK_SIZE,
|
||
|
):
|
||
|
super().__init__(
|
||
|
mode=encoding_to_mode(encoding, suppress_deflate_header)
|
||
|
if wbits is None
|
||
|
else wbits,
|
||
|
executor=executor,
|
||
|
max_sync_chunk_size=max_sync_chunk_size,
|
||
|
)
|
||
|
if level is None:
|
||
|
self._compressor = zlib.compressobj(wbits=self._mode, strategy=strategy)
|
||
|
else:
|
||
|
self._compressor = zlib.compressobj(
|
||
|
wbits=self._mode, strategy=strategy, level=level
|
||
|
)
|
||
|
self._compress_lock = asyncio.Lock()
|
||
|
|
||
|
def compress_sync(self, data: bytes) -> bytes:
|
||
|
return self._compressor.compress(data)
|
||
|
|
||
|
async def compress(self, data: bytes) -> bytes:
|
||
|
async with self._compress_lock:
|
||
|
# To ensure the stream is consistent in the event
|
||
|
# there are multiple writers, we need to lock
|
||
|
# the compressor so that only one writer can
|
||
|
# compress at a time.
|
||
|
if (
|
||
|
self._max_sync_chunk_size is not None
|
||
|
and len(data) > self._max_sync_chunk_size
|
||
|
):
|
||
|
return await asyncio.get_event_loop().run_in_executor(
|
||
|
self._executor, self.compress_sync, data
|
||
|
)
|
||
|
return self.compress_sync(data)
|
||
|
|
||
|
def flush(self, mode: int = zlib.Z_FINISH) -> bytes:
|
||
|
return self._compressor.flush(mode)
|
||
|
|
||
|
|
||
|
class ZLibDecompressor(ZlibBaseHandler):
|
||
|
def __init__(
|
||
|
self,
|
||
|
encoding: Optional[str] = None,
|
||
|
suppress_deflate_header: bool = False,
|
||
|
executor: Optional[Executor] = None,
|
||
|
max_sync_chunk_size: Optional[int] = MAX_SYNC_CHUNK_SIZE,
|
||
|
):
|
||
|
super().__init__(
|
||
|
mode=encoding_to_mode(encoding, suppress_deflate_header),
|
||
|
executor=executor,
|
||
|
max_sync_chunk_size=max_sync_chunk_size,
|
||
|
)
|
||
|
self._decompressor = zlib.decompressobj(wbits=self._mode)
|
||
|
|
||
|
def decompress_sync(self, data: bytes, max_length: int = 0) -> bytes:
|
||
|
return self._decompressor.decompress(data, max_length)
|
||
|
|
||
|
async def decompress(self, data: bytes, max_length: int = 0) -> bytes:
|
||
|
if (
|
||
|
self._max_sync_chunk_size is not None
|
||
|
and len(data) > self._max_sync_chunk_size
|
||
|
):
|
||
|
return await asyncio.get_event_loop().run_in_executor(
|
||
|
self._executor, self.decompress_sync, data, max_length
|
||
|
)
|
||
|
return self.decompress_sync(data, max_length)
|
||
|
|
||
|
def flush(self, length: int = 0) -> bytes:
|
||
|
return (
|
||
|
self._decompressor.flush(length)
|
||
|
if length > 0
|
||
|
else self._decompressor.flush()
|
||
|
)
|
||
|
|
||
|
@property
|
||
|
def eof(self) -> bool:
|
||
|
return self._decompressor.eof
|
||
|
|
||
|
@property
|
||
|
def unconsumed_tail(self) -> bytes:
|
||
|
return self._decompressor.unconsumed_tail
|
||
|
|
||
|
@property
|
||
|
def unused_data(self) -> bytes:
|
||
|
return self._decompressor.unused_data
|
||
|
|
||
|
|
||
|
class BrotliDecompressor:
|
||
|
# 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 not HAS_BROTLI:
|
||
|
raise RuntimeError(
|
||
|
"The brotli decompression is not available. "
|
||
|
"Please install `Brotli` module"
|
||
|
)
|
||
|
self._obj = brotli.Decompressor()
|
||
|
|
||
|
def decompress_sync(self, data: bytes) -> bytes:
|
||
|
if hasattr(self._obj, "decompress"):
|
||
|
return cast(bytes, self._obj.decompress(data))
|
||
|
return cast(bytes, self._obj.process(data))
|
||
|
|
||
|
def flush(self) -> bytes:
|
||
|
if hasattr(self._obj, "flush"):
|
||
|
return cast(bytes, self._obj.flush())
|
||
|
return b""
|