class PpmdCompressor(ISevenZipCompressor):
"""Compress with PPMd compression algorithm"""
def __init__(self, level: int, mem: int, blocksize: Optional[int] = None):
self._buf = BufferedRW(blocksize)
self.encoder = Ppmd.Ppmd7Encoder(self._buf, level, mem) # type: ignore
def compress(self, data: Union[bytes, bytearray, memoryview]) -> bytes:
self.encoder.encode(data)
return self._buf.read()
def flush(self):
self.encoder.flush()
return self._buf.read()
class PpmdCompressor(ISevenZipCompressor):
def __init__(self, level: int, mem: int):
if Ppmd is None:
raise UnsupportedCompressionMethodError
self._buf = BufferedRW()
self.encoder = Ppmd.Ppmd7Encoder(self._buf, level, mem) # type: ignore
def compress(self, data: Union[bytes, bytearray, memoryview]) -> bytes:
self.encoder.encode(data)
return self._buf.read()
def flush(self):
self.encoder.flush()
return self._buf.read()
class ZstdDecompressor(ISevenZipDecompressor):
def __init__(self, properties):
if Zstd is None or len(properties) not in [3, 5] or (properties[0], properties[1], 0) > Zstd.ZSTD_VERSION:
raise UnsupportedCompressionMethodError
self._buf = BufferedRW()
ctx = Zstd.ZstdDecompressor() # type: ignore
self._decompressor = ctx.stream_writer(self._buf)
def decompress(self, data: Union[bytes, bytearray, memoryview], max_length: int = -1) -> bytes:
self._decompressor.write(data)
if max_length > 0:
result = self._buf.read(max_length)
else:
result = self._buf.read()
return result
class ZstdCompressor():
def __init__(self, level):
self._buf = BufferedRW()
ctx = zstandard.ZstdCompressor(level) # type: ignore
self._compressor = ctx.stream_writer(self._buf)
self.flushed = False
def compress(self, data: Union[bytes, bytearray, memoryview]) -> bytes:
self._compressor.write(data)
result = self._buf.read()
return result
def flush(self):
if self.flushed:
return None
self._compressor.flush(zstandard.FLUSH_FRAME)
self.flushed = True
result = self._buf.read()
return result
class ZstdCompressor(ISevenZipCompressor):
def __init__(self):
if Zstd is None:
raise UnsupportedCompressionMethodError
self._buf = BufferedRW()
ctx = Zstd.ZstdCompressor() # type: ignore
self._compressor = ctx.stream_writer(self._buf)
self.flushed = False
def compress(self, data: Union[bytes, bytearray, memoryview]) -> bytes:
self._compressor.write(data)
result = self._buf.read()
return result
def flush(self):
if self.flushed:
return None
self._compressor.flush(Zstd.FLUSH_FRAME)
self.flushed = True
result = self._buf.read()
return result
