Esempio n. 1
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 def decode(self, buf, out=None):
     arr = ndarray_from_buffer(buf, dtype='u1')
     expect = arr[:4].view('<u4')[0]
     checksum = self.checksum(arr[4:]) & 0xffffffff
     if expect != checksum:
         raise RuntimeError('checksum failed')
     return buffer_copy(arr[4:], out)
Esempio n. 2
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        def decode(self, buf, out=None):

            # do decompression
            dec = _lzma.decompress(buf, format=self.format,
                                   filters=self.filters)

            # handle destination
            return buffer_copy(dec, out)
Esempio n. 3
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    def decode(self, buf, out=None):

        # do decompression
        dec = _zlib.decompress(buf)

        # handle destination - Python standard library zlib module does not
        # support direct decompression into buffer, so we have to copy into
        # out if given
        return buffer_copy(dec, out)
Esempio n. 4
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    def decode(self, buf, out=None):

        # view encoded data as 1D array
        enc = ndarray_from_buffer(buf, self.encode_dtype)

        # convert and copy
        dec = enc.astype(self.decode_dtype)

        # handle output
        out = buffer_copy(dec, out)

        return out
Esempio n. 5
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    def decode(self, buf, out=None):

        # interpret buffer as 1D array
        enc = ndarray_from_buffer(buf, self.astype)

        # decode scale offset
        dec = (enc / self.scale) + self.offset

        # convert dtype
        dec = dec.astype(self.dtype, copy=False)

        # handle output
        return buffer_copy(dec, out)
Esempio n. 6
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    def decode(self, buf, out=None):

        # BZ2 cannot handle ndarray directly at all, coerce everything to
        # memoryview
        if not isinstance(buf, array.array):
            buf = memoryview(buf)

        # do decompression
        dec = _bz2.decompress(buf)

        # handle destination - Python standard library bz2 module does not
        # support direct decompression into buffer, so we have to copy into
        # out if given
        return buffer_copy(dec, out)
Esempio n. 7
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    def decode(self, buf, out=None):

        # view encoded data as ndarray
        enc = ndarray_from_buffer(buf, 'u1')

        # find out how many bits were padded
        n_bits_padded = int(enc[0])

        # apply decoding
        dec = np.unpackbits(enc[1:])

        # remove padded bits
        if n_bits_padded:
            dec = dec[:-n_bits_padded]

        # view as boolean array
        dec = dec.view(bool)

        # handle destination
        return buffer_copy(dec, out)
Esempio n. 8
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    def decode(self, buf, out=None):

        # view encoded data as 1D array
        enc = ndarray_from_buffer(buf, self.astype)

        # setup decoded output
        if isinstance(out, np.ndarray):
            # optimization, can decode directly to out
            dec = out.reshape(-1, order='A')
            copy_needed = False
        else:
            dec = np.empty_like(enc, dtype=self.dtype)
            copy_needed = True

        # decode differences
        np.cumsum(enc, out=dec)

        # handle output
        if copy_needed:
            out = buffer_copy(dec, out)

        return out
Esempio n. 9
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    def decode(self, buf, out=None):

        # view encoded data as ndarray
        enc = ndarray_from_buffer(buf, self.astype)

        # setup output
        if isinstance(out, np.ndarray):
            # optimization, decode directly to output
            dec = out.reshape(-1, order='A')
            copy_needed = False
        else:
            dec = np.zeros_like(enc, dtype=self.dtype)
            copy_needed = True

        # apply decoding
        for i, l in enumerate(self.labels):
            dec[enc == (i + 1)] = l

        # handle output
        if copy_needed:
            dec = buffer_copy(dec, out)

        return dec
Esempio n. 10
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 def decode(self, buf, out=None):
     # filter is lossy, decoding is no-op
     dec = ndarray_from_buffer(buf, self.astype)
     dec = dec.astype(self.dtype, copy=False)
     return buffer_copy(dec, out)