def test_offsets():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
pack_file(in_file, out_file, chunk_size='2M')
with open(out_file, 'r+b') as input_fp:
bloscpack_header = _read_bloscpack_header(input_fp)
total_entries = bloscpack_header.total_prospective_chunks
offsets = _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, 368207, 633319, 902306, 1173771, 1419535, 1666981, 1913995
], 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': 262144,
'ctbytes': 265108,
'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 = BloscpackArgs(max_app_chunks=0)
source = PlainFPSource(input_fp)
sink = CompressedFPSink(output_fp)
pack(source,
sink,
nchunks,
chunk_size,
last_chunk_size,
bloscpack_args=bloscpack_args)
output_fp.seek(0, 0)
bloscpack_header = _read_bloscpack_header(output_fp)
nt.assert_equal(0, bloscpack_header.max_app_chunks)
offsets = _read_offsets(output_fp, bloscpack_header)
nt.assert_equal(
[96, 367567, 632679, 901666, 1173131, 1418895, 1666341, 1913355],
offsets)
def test_offsets():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
pack_file_to_file(in_file, out_file, chunk_size='2M')
with open(out_file, 'r+b') as input_fp:
bloscpack_header = _read_bloscpack_header(input_fp)
total_entries = bloscpack_header.total_prospective_chunks
offsets = _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, offsets[0])
# try to read the second header
input_fp.seek(offsets[1], 0)
blosc_header_raw = input_fp.read(BLOSC_HEADER_LENGTH)
expected = {
'versionlz': 1,
'version': 2,
'flags': 1,
'nbytes': 2097152,
'typesize': 8
}
blosc_header = decode_blosc_header(blosc_header_raw)
blosc_header_slice = dict(
(k, blosc_header[k]) for k in expected.keys())
nt.assert_equal(expected, blosc_header_slice)
# 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 = BloscpackArgs(max_app_chunks=0)
source = PlainFPSource(input_fp)
sink = CompressedFPSink(output_fp)
pack(source,
sink,
nchunks,
chunk_size,
last_chunk_size,
bloscpack_args=bloscpack_args)
output_fp.seek(0, 0)
bloscpack_header = _read_bloscpack_header(output_fp)
nt.assert_equal(0, bloscpack_header.max_app_chunks)
offsets = _read_offsets(output_fp, bloscpack_header)
nt.assert_equal(96, offsets[0])
def test_offsets():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
pack_file(in_file, out_file, chunk_size='2M')
with open(out_file, 'r+b') as input_fp:
bloscpack_header = _read_bloscpack_header(input_fp)
total_entries = bloscpack_header.total_prospective_chunks
offsets = _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, 368207, 633319, 902306, 1173771,
1419535, 1666981, 1913995],
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': 262144,
'ctbytes': 265108,
'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 = BloscpackArgs(max_app_chunks=0)
source = PlainFPSource(input_fp)
sink = CompressedFPSink(output_fp)
pack(source, sink,
nchunks, chunk_size, last_chunk_size,
bloscpack_args=bloscpack_args
)
output_fp.seek(0, 0)
bloscpack_header = _read_bloscpack_header(output_fp)
nt.assert_equal(0, bloscpack_header.max_app_chunks)
offsets = _read_offsets(output_fp, bloscpack_header)
nt.assert_equal([96, 367567, 632679, 901666,
1173131, 1418895, 1666341, 1913355],
offsets)
def test_offsets():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
pack_file(in_file, out_file, chunk_size='2M')
with open(out_file, 'r+b') as input_fp:
bloscpack_header = _read_bloscpack_header(input_fp)
total_entries = bloscpack_header.total_prospective_chunks
offsets = _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 = BloscpackArgs(max_app_chunks=0)
source = PlainFPSource(input_fp)
sink = CompressedFPSink(output_fp)
pack(source, sink,
nchunks, chunk_size, last_chunk_size,
bloscpack_args=bloscpack_args
)
output_fp.seek(0, 0)
bloscpack_header = _read_bloscpack_header(output_fp)
nt.assert_equal(0, bloscpack_header.max_app_chunks)
offsets = _read_offsets(output_fp, bloscpack_header)
nt.assert_equal([96, 417938, 736230, 1049687,
1362724, 1660126, 1958578, 2257063],
offsets)
def test_offsets():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
pack_file(in_file, out_file, chunk_size='2M')
with open(out_file, 'r+b') as input_fp:
bloscpack_header = _read_bloscpack_header(input_fp)
total_entries = bloscpack_header.total_prospective_chunks
offsets = _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, offsets[0])
# try to read the second header
input_fp.seek(offsets[1], 0)
blosc_header_raw = input_fp.read(BLOSC_HEADER_LENGTH)
expected = {'versionlz': 1,
'version': 2,
'flags': 1,
'nbytes': 2097152,
'typesize': 8}
blosc_header = decode_blosc_header(blosc_header_raw)
blosc_header_slice = dict((k, blosc_header[k]) for k in expected.keys())
nt.assert_equal(expected, blosc_header_slice)
# 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 = BloscpackArgs(max_app_chunks=0)
source = PlainFPSource(input_fp)
sink = CompressedFPSink(output_fp)
pack(source, sink,
nchunks, chunk_size, last_chunk_size,
bloscpack_args=bloscpack_args
)
output_fp.seek(0, 0)
bloscpack_header = _read_bloscpack_header(output_fp)
nt.assert_equal(0, bloscpack_header.max_app_chunks)
offsets = _read_offsets(output_fp, bloscpack_header)
nt.assert_equal(96, offsets[0])
def test_file_corruption():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
pack_file(in_file, out_file)
# now go in and modify a byte in the file
with open(out_file, "r+b") as input_fp:
# read offsets and header
_read_offsets(input_fp, _read_bloscpack_header(input_fp))
# read the blosc header of the first chunk
input_fp.read(BLOSC_HEADER_LENGTH)
# read four bytes
input_fp.read(4)
# read the fifth byte
fifth = input_fp.read(1)
# figure out what to replace it by
replace = b"\x00" if fifth == b"\xff" else b"\xff"
# seek one byte back relative to current position
input_fp.seek(-1, 1)
# write the flipped byte
input_fp.write(replace)
# now attempt to unpack it
nt.assert_raises(ChecksumMismatch, unpack_file, out_file, dcmp_file)
def test_file_corruption():
with create_tmp_files() as (tdir, in_file, out_file, dcmp_file):
create_array(1, in_file)
pack_file(in_file, out_file)
# now go in and modify a byte in the file
with open(out_file, 'r+b') as input_fp:
# read offsets and header
_read_offsets(input_fp, _read_bloscpack_header(input_fp))
# read the blosc header of the first chunk
input_fp.read(BLOSC_HEADER_LENGTH)
# read four bytes
input_fp.read(4)
# read the fifth byte
fifth = input_fp.read(1)
# figure out what to replace it by
replace = b'\x00' if fifth == b'\xff' else b'\xff'
# seek one byte back relative to current position
input_fp.seek(-1, 1)
# write the flipped byte
input_fp.write(replace)
# now attempt to unpack it
nt.assert_raises(ChecksumMismatch, unpack_file, out_file, dcmp_file)
