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95 lines
2.1 KiB
95 lines
2.1 KiB
from __future__ import absolute_import
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from ._snappy_cffi import ffi, lib
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try:
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unicode # Python 2
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except NameError:
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unicode = str # Python 3
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class UncompressError(Exception):
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pass
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class SnappyBufferSmallError(Exception):
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pass
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def prepare(data):
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_out_data = None
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_out_size = None
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_out_data = ffi.new('char[]', data)
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_out_size = ffi.cast('size_t', len(data))
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return (_out_data, _out_size)
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def compress(data):
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if isinstance(data, unicode):
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data = data.encode('utf-8')
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_input_data, _input_size = prepare(data)
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max_compressed = lib.snappy_max_compressed_length(_input_size)
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_out_data = ffi.new('char[]', max_compressed)
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_out_size = ffi.new('size_t*', max_compressed)
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rc = lib.snappy_compress(_input_data, _input_size, _out_data, _out_size)
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if rc != lib.SNAPPY_OK:
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raise SnappyBufferSmallError()
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value = ffi.buffer(ffi.cast('char*', _out_data), _out_size[0])
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return value[:]
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def uncompress(data):
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_out_data, _out_size = prepare(data)
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result = ffi.new('size_t*', 0)
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rc = lib.snappy_validate_compressed_buffer(_out_data, _out_size)
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if not rc == lib.SNAPPY_OK:
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raise UncompressError()
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rc = lib.snappy_uncompressed_length(_out_data,
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_out_size,
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result)
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if not rc == lib.SNAPPY_OK:
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raise UncompressError()
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_uncompressed_data = ffi.new('char[]', result[0])
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rc = lib.snappy_uncompress(_out_data, _out_size, _uncompressed_data, result)
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if rc != lib.SNAPPY_OK:
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raise UncompressError()
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buf = ffi.buffer(ffi.cast('char*', _uncompressed_data), result[0])
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return buf[:]
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def isValidCompressed(data):
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if isinstance(data, unicode):
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data = data.encode('utf-8')
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_out_data, _out_size= prepare(data)
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rc = lib.snappy_validate_compressed_buffer(_out_data, _out_size)
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return rc == lib.SNAPPY_OK
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decompress = uncompress
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def _crc32c(data):
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c_data = ffi.new('char[]', data)
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size = ffi.cast('int', len(data))
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return int(lib._crc32c(c_data, size))
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