def pack_unpack_fp(repeats, nchunks=None, chunk_size=None,
progress=False, metadata=None):
blosc_args = DEFAULT_BLOSC_ARGS
offsets = DEFAULT_OFFSETS
checksum = DEFAULT_CHECKSUM
in_fp, out_fp, dcmp_fp = StringIO(), StringIO(), StringIO()
if progress:
print("Creating test array")
create_array_fp(repeats, in_fp, progress=progress)
in_fp_size = in_fp.tell()
if progress:
print("Compressing")
in_fp.seek(0)
bloscpack._pack_fp(in_fp, out_fp, in_fp_size,
blosc_args, metadata,
nchunks, chunk_size, offsets, checksum,
DEFAULT_METADATA_ARGS)
out_fp.seek(0)
if progress:
print("Decompressing")
metadata = bloscpack._unpack_fp(out_fp, dcmp_fp)
if progress:
print("Verifying")
cmp_fp(in_fp, dcmp_fp)
if metadata:
return metadata
def test_offsets():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
bloscpack.pack_file(in_file, out_file, chunk_size='2M')
with open(out_file, 'r+b') as input_fp:
bloscpack_header = bloscpack._read_bloscpack_header(input_fp)
total_entries = bloscpack_header['nchunks'] + \
bloscpack_header['max_app_chunks']
offsets = bloscpack._read_offsets(input_fp, bloscpack_header)
# First chunks should start after header and offsets
first = BLOSCPACK_HEADER_LENGTH + 8 * total_entries
# We assume that the others are correct
nt.assert_equal(offsets[0], first)
nt.assert_equal([736, 418578, 736870, 1050327,
1363364, 1660766, 1959218, 2257703],
offsets)
# try to read the second header
input_fp.seek(offsets[1], 0)
blosc_header_raw = input_fp.read(BLOSC_HEADER_LENGTH)
expected = {'versionlz': 1,
'blocksize': 131072,
'ctbytes': 318288,
'version': 2,
'flags': 1,
'nbytes': 2097152,
'typesize': 8}
blosc_header = decode_blosc_header(blosc_header_raw)
nt.assert_equal(expected, blosc_header)
# now check the same thing again, but w/o any max_app_chunks
input_fp, output_fp = StringIO(), StringIO()
create_array_fp(1, input_fp)
nchunks, chunk_size, last_chunk_size = \
calculate_nchunks(input_fp.tell(), chunk_size='2M')
input_fp.seek(0, 0)
bloscpack_args = DEFAULT_BLOSCPACK_ARGS.copy()
bloscpack_args['max_app_chunks'] = 0
bloscpack._pack_fp(input_fp, output_fp,
nchunks, chunk_size, last_chunk_size,
bloscpack_args=bloscpack_args
)
output_fp.seek(0, 0)
bloscpack_header = bloscpack._read_bloscpack_header(output_fp)
nt.assert_equal(0, bloscpack_header['max_app_chunks'])
offsets = bloscpack._read_offsets(output_fp, bloscpack_header)
nt.assert_equal([96, 417938, 736230, 1049687,
1362724, 1660126, 1958578, 2257063],
offsets)
def test_metadata_opportunisitic_compression():
# make up some metadata that can be compressed with benefit
test_metadata = ("{'dtype': 'float64', 'shape': [1024], 'others': [],"
"'original_container': 'carray'}")
in_fp, out_fp, dcmp_fp = StringIO(), StringIO(), StringIO()
create_array_fp(1, in_fp)
in_fp_size = in_fp.tell()
in_fp.seek(0)
bloscpack._pack_fp(in_fp, out_fp, in_fp_size,
DEFAULT_BLOSC_ARGS,
test_metadata,
1,
None,
DEFAULT_OFFSETS,
DEFAULT_CHECKSUM,
DEFAULT_METADATA_ARGS)
out_fp.seek(0)
raw_header = out_fp.read(32)
header = decode_bloscpack_header(raw_header)
raw_options = header['options']
options = decode_options(raw_options)
#nt.assert_true(options['compress_meta'])
# now do the same thing, but use badly compressible metadata
test_metadata = "abc"
in_fp, out_fp, dcmp_fp = StringIO(), StringIO(), StringIO()
create_array_fp(1, in_fp)
in_fp_size = in_fp.tell()
in_fp.seek(0)
bloscpack._pack_fp(in_fp, out_fp, in_fp_size,
DEFAULT_BLOSC_ARGS,
test_metadata,
1,
None,
DEFAULT_OFFSETS,
DEFAULT_CHECKSUM,
DEFAULT_METADATA_ARGS)
out_fp.seek(0)
raw_header = out_fp.read(32)
header = decode_bloscpack_header(raw_header)
raw_options = header['options']
options = decode_options(raw_options)
def pack_unpack_fp(repeats, chunk_size=DEFAULT_CHUNK_SIZE,
progress=False, metadata=None):
in_fp, out_fp, dcmp_fp = StringIO(), StringIO(), StringIO()
if progress:
print("Creating test array")
create_array_fp(repeats, in_fp, progress=progress)
in_fp_size = in_fp.tell()
if progress:
print("Compressing")
in_fp.seek(0)
nchunks, chunk_size, last_chunk_size = \
calculate_nchunks(in_fp_size, chunk_size)
bloscpack._pack_fp(in_fp, out_fp,
nchunks, chunk_size, last_chunk_size,
metadata=metadata)
out_fp.seek(0)
if progress:
print("Decompressing")
metadata = bloscpack._unpack_fp(out_fp, dcmp_fp)
if progress:
print("Verifying")
cmp_fp(in_fp, dcmp_fp)
if metadata:
return metadata