def extract_entry(self, e, decompress='auto'):
"""Yield blocks of data for this entry from this MAR file.
Args:
e (:obj:`mardor.format.index_entry`): An index_entry object that
refers to this file's size and offset inside the MAR file.
path (str): Where on disk to extract this file to.
decompress (str, optional): Controls whether files are decompressed
when extracted. Must be one of None, 'auto', 'bz2', or 'xz'.
Defaults to 'auto'
Yields:
Blocks of data for `e`
"""
self.fileobj.seek(e.offset)
stream = file_iter(self.fileobj)
stream = takeexactly(stream, e.size)
if decompress == 'auto':
stream = auto_decompress_stream(stream)
elif decompress == 'bz2':
stream = bz2_decompress_stream(stream)
elif decompress == 'xz':
stream = xz_decompress_stream(stream)
elif decompress is None:
pass
else:
raise ValueError("Unsupported decompression type: {}".format(decompress))
for block in stream:
yield block
def extract_entry(self, e, decompress='auto'):
"""Yield blocks of data for this entry from this MAR file.
Args:
e (:obj:`mardor.format.index_entry`): An index_entry object that
refers to this file's size and offset inside the MAR file.
path (str): Where on disk to extract this file to.
decompress (str, optional): Controls whether files are decompressed
when extracted. Must be one of None, 'auto', 'bz2', or 'xz'.
Defaults to 'auto'
Yields:
Blocks of data for `e`
"""
self.fileobj.seek(e.offset)
stream = file_iter(self.fileobj)
stream = takeexactly(stream, e.size)
if decompress == 'auto':
stream = auto_decompress_stream(stream)
elif decompress == 'bz2':
stream = bz2_decompress_stream(stream)
elif decompress == 'xz':
stream = xz_decompress_stream(stream)
elif decompress is None:
pass
else:
raise ValueError("Unsupported decompression type: {}".format(decompress))
for block in stream:
yield block
def test_takeexactly_notenough(data):
n = len(b''.join(data))
with pytest.raises(ValueError):
b''.join(takeexactly(data, n + 1))
def test_takeexactly_notenough(data, n):
assume(len(b''.join(data)) < n)
with pytest.raises(ValueError):
b''.join(takeexactly(data, n))
def test_takeexactly(data):
n = len(b''.join(data))
for i in range(n + 1):
assert len(b''.join(takeexactly(data, i))) == i
def test_takeexactly(data, n):
assume(len(b''.join(data)) >= n)
assert len(b''.join(takeexactly(data, n))) == n
def add_signature_block(src_fileobj, dest_fileobj, signing_algorithm, signature=None):
"""Add a signature block to marfile, a MarReader object.
Productversion and channel are preserved, but any existing signatures are overwritten.
Args:
src_fileobj (file object): The input MAR file to add a signature to
dest_fileobj (file object): File object to write new MAR file to. Must be open in w+b mode.
signing_algorithm (str): One of 'sha1', or 'sha384'
signature (bytes): Signature to write, or None to use a dummy signature
"""
algo_id = {'sha1': 1, 'sha384': 2}[signing_algorithm]
if not signature:
signature = make_dummy_signature(algo_id)
src_fileobj.seek(0)
mardata = mar.parse_stream(src_fileobj)
# Header
header = mardata.header
dest_fileobj.write(mar_header.build(header))
# Signature block
sig = dict(algorithm_id=algo_id,
size=len(signature),
signature=signature,
)
# This will be fixed up later
filesize = 0
sigs_offset = dest_fileobj.tell()
sigs = sigs_header.build(dict(
filesize=filesize,
count=1,
sigs=[sig],
))
dest_fileobj.write(sigs)
# Write the additional section
dest_fileobj.write(extras_header.build(mardata.additional))
# Write the data
data_offset = dest_fileobj.tell()
src_fileobj.seek(mardata.data_offset)
write_to_file(takeexactly(src_fileobj, mardata.data_length), dest_fileobj)
# Write the index
index_offset = dest_fileobj.tell()
index = mardata.index
# Adjust the offsets
data_offset_delta = data_offset - mardata.data_offset
for e in index.entries:
e.offset += data_offset_delta
dest_fileobj.write(index_header.build(index))
filesize = dest_fileobj.tell()
# Go back and update the index offset and filesize
dest_fileobj.seek(0)
header.index_offset = index_offset
dest_fileobj.write(mar_header.build(header))
dest_fileobj.seek(sigs_offset)
sigs = sigs_header.build(dict(
filesize=filesize,
count=1,
sigs=[sig],
))
dest_fileobj.write(sigs)
def test_takeexactly_notenough(data):
n = len(b''.join(data))
with pytest.raises(ValueError):
b''.join(takeexactly(data, n+1))
def test_takeexactly(data):
n = len(b''.join(data))
for i in range(n+1):
assert len(b''.join(takeexactly(data, i))) == i
def add_signature_block(src_fileobj,
dest_fileobj,
signing_algorithm,
signature=None):
"""Add a signature block to marfile, a MarReader object.
Productversion and channel are preserved, but any existing signatures are overwritten.
Args:
src_fileobj (file object): The input MAR file to add a signature to
dest_fileobj (file object): File object to write new MAR file to. Must be open in w+b mode.
signing_algorithm (str): One of 'sha1', or 'sha384'
signature (bytes): Signature to write, or None to use a dummy signature
"""
algo_id = {'sha1': 1, 'sha384': 2}[signing_algorithm]
if not signature:
signature = make_dummy_signature(algo_id)
src_fileobj.seek(0)
mardata = mar.parse_stream(src_fileobj)
# Header
header = mardata.header
dest_fileobj.write(mar_header.build(header))
# Signature block
sig = dict(
algorithm_id=algo_id,
size=len(signature),
signature=signature,
)
# This will be fixed up later
filesize = 0
sigs_offset = dest_fileobj.tell()
sigs = sigs_header.build(dict(
filesize=filesize,
count=1,
sigs=[sig],
))
dest_fileobj.write(sigs)
# Write the additional section
dest_fileobj.write(extras_header.build(mardata.additional))
# Write the data
data_offset = dest_fileobj.tell()
src_fileobj.seek(mardata.data_offset)
write_to_file(takeexactly(src_fileobj, mardata.data_length), dest_fileobj)
# Write the index
index_offset = dest_fileobj.tell()
index = mardata.index
# Adjust the offsets
data_offset_delta = data_offset - mardata.data_offset
for e in index.entries:
e.offset += data_offset_delta
dest_fileobj.write(index_header.build(index))
filesize = dest_fileobj.tell()
# Go back and update the index offset and filesize
dest_fileobj.seek(0)
header.index_offset = index_offset
dest_fileobj.write(mar_header.build(header))
dest_fileobj.seek(sigs_offset)
sigs = sigs_header.build(dict(
filesize=filesize,
count=1,
sigs=[sig],
))
dest_fileobj.write(sigs)