def test_decode_blosc_header():
array_ = np.linspace(0, 100, 2e4).tostring()
# basic test case
blosc_args = BloscArgs()
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {
'versionlz': 1,
'blocksize': 160000,
'ctbytes': len(compressed),
'version': 2,
'flags': 1,
'nbytes': len(array_),
'typesize': blosc_args.typesize
}
nt.assert_equal(expected, header)
# deactivate shuffle
blosc_args.shuffle = False
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {
'versionlz': 1,
'blocksize': 160000,
'ctbytes': len(compressed),
'version': 2,
'flags': 0, # no shuffle flag
'nbytes': len(array_),
'typesize': blosc_args.typesize
}
nt.assert_equal(expected, header)
# uncompressible data
array_ = np.asarray(np.random.randn(23), dtype=np.float32).tostring()
blosc_args.shuffle = True
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {
'versionlz': 1,
'blocksize': 88,
'ctbytes': len(array_) + 16, # original + 16 header bytes
'version': 2,
'flags': 3, # 1 for shuffle 2 for non-compressed
'nbytes': len(array_),
'typesize': blosc_args.typesize
}
nt.assert_equal(expected, header)
def test_decode_blosc_header():
array_ = np.linspace(0, 100, 2e4).tostring()
# basic test case
blosc_args = BloscArgs()
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {'versionlz': 1,
'blocksize': 160000,
'ctbytes': len(compressed),
'version': 2,
'flags': 1,
'nbytes': len(array_),
'typesize': blosc_args.typesize}
nt.assert_equal(expected, header)
# deactivate shuffle
blosc_args.shuffle = False
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {'versionlz': 1,
'blocksize': 160000,
'ctbytes': len(compressed),
'version': 2,
'flags': 0, # no shuffle flag
'nbytes': len(array_),
'typesize': blosc_args.typesize}
nt.assert_equal(expected, header)
# uncompressible data
array_ = np.asarray(np.random.randn(23),
dtype=np.float32).tostring()
blosc_args.shuffle = True
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {'versionlz': 1,
'blocksize': 88,
'ctbytes': len(array_) + 16, # original + 16 header bytes
'version': 2,
'flags': 3, # 1 for shuffle 2 for non-compressed
'nbytes': len(array_),
'typesize': blosc_args.typesize}
nt.assert_equal(expected, header)
def test_decode_blosc_header_deactivate_shuffle():
array_ = np.ones(16000, dtype=np.uint8)
blosc_args = BloscArgs()
blosc_args.shuffle = False
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {'versionlz': 1,
'version': 2,
'flags': 0, # no shuffle flag
'nbytes': len(array_),
'typesize': blosc_args.typesize}
header_slice = dict((k, header[k]) for k in expected.keys())
nt.assert_equal(expected, header_slice)
def test_decode_blosc_header_deactivate_shuffle():
array_ = np.ones(16000, dtype=np.uint8)
blosc_args = BloscArgs()
blosc_args.shuffle = False
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {
'versionlz': 1,
'version': 2,
'flags': 0, # no shuffle flag
'nbytes': len(array_),
'typesize': blosc_args.typesize
}
header_slice = dict((k, header[k]) for k in expected.keys())
nt.assert_equal(expected, header_slice)
def test_decode_blosc_header_uncompressible_data():
array_ = np.asarray(np.random.randn(255),
dtype=np.float32).tostring()
blosc_args = BloscArgs()
blosc_args.shuffle = True
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {'versionlz': 1,
'blocksize': 1016,
'ctbytes': len(array_) + 16, # original + 16 header bytes
'version': 2,
'flags': 0x13, # 1 for shuffle 2 for non-compressed 4 for small blocksize
'nbytes': len(array_),
'typesize': blosc_args.typesize}
nt.assert_equal(expected, header)
def test_decode_blosc_header_uncompressible_data_dont_split_false():
array_ = np.asarray(np.random.randn(256), dtype=np.float32).tostring()
blosc_args = BloscArgs()
blosc_args.shuffle = True
compressed = blosc.compress(array_, **blosc_args)
header = decode_blosc_header(compressed)
expected = {
'versionlz': 1,
'version': 2,
'blocksize': 1024,
'ctbytes': len(array_) + 16, # original + 16 header bytes
'flags': 0x3, # 1 for shuffle 2 for non-compressed
'nbytes': len(array_),
'typesize': blosc_args.typesize
}
nt.assert_equal(expected, header)