def calccrc(self, data: bytes):
self.nextheadersize = len(data)
self.nextheadercrc = calculate_crc32(data)
assert self.nextheaderofs is not None
buf = io.BytesIO()
write_real_uint64(buf, self.nextheaderofs)
write_real_uint64(buf, self.nextheadersize)
write_uint32(buf, self.nextheadercrc)
startdata = buf.getvalue()
self.startheadercrc = calculate_crc32(startdata)
def _read(self, file: BinaryIO) -> None:
file.seek(len(MAGIC_7Z), 0)
self.version = read_bytes(file, 2)
self.startheadercrc, _ = read_uint32(file)
self.nextheaderofs, data = read_real_uint64(file)
crc = calculate_crc32(data)
self.nextheadersize, data = read_real_uint64(file)
crc = calculate_crc32(data, crc)
self.nextheadercrc, data = read_uint32(file)
crc = calculate_crc32(data, crc)
if crc != self.startheadercrc:
raise Bad7zFile('invalid header data')
def calccrc(self, header: Header):
buf = io.BytesIO()
header.write(buf)
data = buf.getvalue()
self.nextheadersize = len(data)
self.nextheadercrc = calculate_crc32(data)
assert self.nextheaderofs is not None
buf = io.BytesIO()
write_uint64(buf, self.nextheaderofs)
write_uint64(buf, self.nextheadersize)
write_uint32(buf, self.nextheadercrc)
data = buf.getvalue()
self.startheadercrc = calculate_crc32(data)
def compress(self, fp: BinaryIO, folder, f: Handler):
compressor = folder.get_compressor()
length = 0
for indata in f.read(Configuration.get('read_blocksize')):
arcdata = compressor.compress(indata)
folder.crc = calculate_crc32(arcdata, folder.crc)
length += len(arcdata)
fp.write(arcdata)
arcdata = compressor.flush()
folder.crc = calculate_crc32(arcdata, folder.crc)
length += len(arcdata)
fp.write(arcdata)
return length
def compress(self, fp: BinaryIO, folder, f: Handler):
"""Compress specified file-ish into folder where fp placed."""
compressor = folder.get_compressor()
length = 0
for indata in f.read(Configuration.get('read_blocksize')):
arcdata = compressor.compress(indata)
folder.crc = calculate_crc32(arcdata, folder.crc)
length += len(arcdata)
fp.write(arcdata)
arcdata = compressor.flush()
folder.crc = calculate_crc32(arcdata, folder.crc)
length += len(arcdata)
fp.write(arcdata)
return length
def _read(self, file: BinaryIO) -> None:
file.seek(len(MAGIC_7Z), 0)
major_version = file.read(1)
minor_version = file.read(1)
self.version = (major_version, minor_version)
self.startheadercrc, _ = read_uint32(file)
self.nextheaderofs, data = read_real_uint64(file)
crc = calculate_crc32(data)
self.nextheadersize, data = read_real_uint64(file)
crc = calculate_crc32(data, crc)
self.nextheadercrc, data = read_uint32(file)
crc = calculate_crc32(data, crc)
if crc != self.startheadercrc:
raise Bad7zFile("invalid header data")
def compress(self, fp: BinaryIO, folder, fq: IO[Any]):
"""Compress specified file-ish into folder where fp placed."""
compressor = folder.get_compressor()
length = 0
for indata in fq.read(READ_BLOCKSIZE):
arcdata = compressor.compress(indata)
folder.crc = calculate_crc32(arcdata, folder.crc)
length += len(arcdata)
fp.write(arcdata)
arcdata = compressor.flush()
folder.crc = calculate_crc32(arcdata, folder.crc)
length += len(arcdata)
fp.write(arcdata)
return length
def decompress(self, fp, max_length: int = -1) -> bytes:
if max_length < 0:
data = self._read_data(fp)
res = self._buf[self._pos:] + self._decompress(
self._unused + data, max_length)
self._buf = bytearray()
self._unused = bytearray()
self._pos = 0
else:
current_buf_len = len(self._buf) - self._pos
if current_buf_len >= max_length: # we already have enough data
res = self._buf[self._pos:self._pos + max_length]
self._pos += max_length
else:
data = self._read_data(fp)
if len(self._unused) > 0:
tmp = self._decompress(self._unused + data, max_length)
self._unused = bytearray()
else:
tmp = self._decompress(data, max_length)
if current_buf_len + len(tmp) <= max_length:
res = self._buf[self._pos:] + tmp
self._buf = bytearray()
self._pos = 0
else:
res = self._buf[self._pos:] + tmp[:max_length -
current_buf_len]
self._buf = bytearray(tmp[max_length - current_buf_len:])
self._pos = 0
self.digest = calculate_crc32(res, self.digest)
return res
def compress(self, fd, fp, crc=0):
data = fd.read(READ_BLOCKSIZE)
insize = len(data)
foutsize = 0
while data:
crc = calculate_crc32(data, crc)
for i, compressor in enumerate(self.chain):
self._unpacksizes[i] += len(data)
data = compressor.compress(data)
self.packsize += len(data)
self.digest = calculate_crc32(data, self.digest)
foutsize += len(data)
fp.write(data)
data = fd.read(READ_BLOCKSIZE)
insize += len(data)
return insize, foutsize, crc
def _get_headerdata_from_streams(self, fp: BinaryIO,
streams: StreamsInfo) -> BytesIO:
"""get header data from given streams.unpackinfo and packinfo.
folder data are stored in raw data positioned in afterheader."""
buffer = io.BytesIO()
src_start = self._start_pos
for folder in streams.unpackinfo.folders:
if folder.is_encrypted():
raise UnsupportedCompressionMethodError()
uncompressed = folder.unpacksizes
if not isinstance(uncompressed, (list, tuple)):
uncompressed = [uncompressed] * len(folder.coders)
compressed_size = streams.packinfo.packsizes[0]
uncompressed_size = uncompressed[-1]
src_start += streams.packinfo.packpos
fp.seek(src_start, 0)
decompressor = folder.get_decompressor(compressed_size)
folder_data = decompressor.decompress(
fp.read(compressed_size))[:uncompressed_size]
src_start += uncompressed_size
if folder.digestdefined:
if folder.crc != calculate_crc32(folder_data):
raise Bad7zFile('invalid block data')
buffer.write(folder_data)
buffer.seek(0, 0)
return buffer
def decompress(self, fp, max_length: int = -1) -> bytes:
# read data from disk
rest_size = self.input_size - self.consumed
read_size = min(rest_size, READ_BLOCKSIZE)
data = fp.read(read_size)
self.consumed += len(data)
#
if max_length < 0:
res = self._buf + self._decompress(self._unused + data, max_length)
self._buf = bytearray()
self._unused = bytearray()
else:
current_buf_len = len(self._buf)
if current_buf_len >= max_length:
self._unused.extend(data)
res = self._buf[:max_length]
self._buf = self._buf[max_length:]
else:
if len(self._unused) > 0:
tmp = self._decompress(self._unused + data, max_length)
self._unused = bytearray()
else:
tmp = self._decompress(data, max_length)
if current_buf_len + len(tmp) <= max_length:
res = self._buf + tmp
self._buf = bytearray()
else:
res = self._buf + tmp[:max_length - current_buf_len]
self._buf = bytearray(tmp[max_length - current_buf_len:])
self.digest = calculate_crc32(res, self.digest)
return res
def _test_digest_raw(self, pos: int, size: int, crc: int) -> bool:
self.fp.seek(pos)
remaining_size = size
digest = None
while remaining_size > 0:
block = min(READ_BLOCKSIZE, remaining_size)
digest = calculate_crc32(self.fp.read(block), digest)
remaining_size -= block
return digest == crc
def _test_digest_raw(self, pos, size, crc):
self.fp.seek(pos)
remaining_size = size
digest = None
while remaining_size > 0:
block = min(Configuration.read_blocksize, remaining_size)
digest = calculate_crc32(self.fp.read(block), digest)
remaining_size -= block
return digest == crc
def calccrc(self, length: int, header_crc: int):
self.nextheadersize = length
self.nextheadercrc = header_crc
buf = io.BytesIO()
write_real_uint64(buf, self.nextheaderofs)
write_real_uint64(buf, self.nextheadersize)
write_uint32(buf, self.nextheadercrc)
startdata = buf.getvalue()
self.startheadercrc = calculate_crc32(startdata)
def decompress(self, data: bytes, max_length: Optional[int] = None) -> bytes:
self.consumed += len(data)
if max_length is not None:
folder_data = self.decompressor.decompress(data, max_length=max_length)
else:
folder_data = self.decompressor.decompress(data)
# calculate CRC with uncompressed data
if self.crc is not None:
self.digest = calculate_crc32(folder_data, self.digest)
return folder_data
def flush(self, fp):
data = None
for i, compressor in enumerate(self.chain):
if data:
self._unpacksizes[i] += len(data)
data = compressor.compress(data)
data += compressor.flush()
else:
data = compressor.flush()
self.packsize += len(data)
self.digest = calculate_crc32(data, self.digest)
fp.write(data)
return len(data)
def _read(self, fp: BinaryIO, buffer: BytesIO, start_pos: int,
password) -> None:
"""
Decode header data or encoded header data from buffer.
When buffer consist of encoded buffer, it get stream data
from it and call itself recursively
"""
self._start_pos = start_pos
fp.seek(self._start_pos)
pid = buffer.read(1)
if not pid:
# empty archive
return
if pid == PROPERTY.HEADER:
self._extract_header_info(buffer)
return
if pid != PROPERTY.ENCODED_HEADER:
raise TypeError("Unknown field: %r" % id) # pragma: no-cover
# get from encoded header
streams = HeaderStreamsInfo.retrieve(buffer)
buffer2 = io.BytesIO()
src_start = self._start_pos
for folder in streams.unpackinfo.folders:
uncompressed = folder.unpacksizes
if not isinstance(uncompressed, (list, tuple)):
uncompressed = [uncompressed] * len(folder.coders)
compressed_size = streams.packinfo.packsizes[0]
uncompressed_size = uncompressed[-1]
folder.password = password
src_start += streams.packinfo.packpos
fp.seek(src_start, 0)
decompressor = folder.get_decompressor(compressed_size)
remaining = uncompressed_size
folder_data = bytearray()
while remaining > 0:
folder_data += decompressor.decompress(fp,
max_length=remaining)
remaining = uncompressed_size - len(folder_data)
self.size += compressed_size
src_start += compressed_size
if folder.digestdefined:
streams.packinfo.enable_digests = True
if folder.crc != calculate_crc32(folder_data):
raise Bad7zFile("invalid block data")
buffer2.write(folder_data)
buffer2.seek(0, 0)
pid = buffer2.read(1)
if pid != PROPERTY.HEADER:
raise TypeError("Unknown field: %r" % pid) # pragma: no-cover
self._extract_header_info(buffer2)
def test_simple_compress_and_decompress():
sevenzip_compressor = py7zr.compression.SevenZipCompressor()
lzc = sevenzip_compressor.compressor
out1 = lzc.compress(b"Some data\n")
out2 = lzc.compress(b"Another piece of data\n")
out3 = lzc.compress(b"Even more data\n")
out4 = lzc.flush()
result = b"".join([out1, out2, out3, out4])
size = len(result)
#
filters = sevenzip_compressor.filters
decompressor = lzma.LZMADecompressor(format=lzma.FORMAT_RAW, filters=filters)
out5 = decompressor.decompress(result)
assert out5 == b'Some data\nAnother piece of data\nEven more data\n'
#
coders = sevenzip_compressor.coders
crc = calculate_crc32(result)
decompressor = py7zr.compression.SevenZipDecompressor(coders, size, crc)
out6 = decompressor.decompress(result)
assert out6 == b'Some data\nAnother piece of data\nEven more data\n'
def write(self, file: BinaryIO, afterheader: int, encoded: bool = True):
startpos = file.tell()
if encoded:
startpos = self._encode_header(file, afterheader)
else:
write_byte(file, Property.HEADER)
# Archive properties
if self.main_streams is not None:
self.main_streams.write(file)
# Files Info
if self.files_info is not None:
self.files_info.write(file)
if self.properties is not None:
self.properties.write(file)
# AdditionalStreams
if self.additional_streams is not None:
self.additional_streams.write(file)
write_byte(file, Property.END)
endpos = file.tell()
header_len = endpos - startpos
file.seek(startpos, io.SEEK_SET)
crc = calculate_crc32(file.read(header_len))
file.seek(endpos, io.SEEK_SET)
return startpos, header_len, crc
def _read_header_data(self) -> BytesIO:
self.fp.seek(self.sig_header.nextheaderofs, os.SEEK_CUR)
buffer = io.BytesIO(self.fp.read(self.sig_header.nextheadersize))
if self.sig_header.nextheadercrc != calculate_crc32(buffer.getvalue()):
raise Bad7zFile('invalid header data')
return buffer
def write(self, data):
self.digest = calculate_crc32(data, self.digest)
return self._fp.write(data)
def _write_archive(self):
compressor = self.folder.get_compressor()
# TODO: support multiple compresssion folder; current single solid folder
outsize = 0
self.header.main_streams.packinfo.numstreams = 1
num_unpack_streams = 0
self.header.main_streams.substreamsinfo.digests = []
self.header.main_streams.substreamsinfo.digestsdefined = []
last_file_index = 0
foutsize = 0
for i, f in enumerate(self.files):
file_info = f.file_properties()
self.header.files_info.files.append(file_info)
self.header.files_info.emptyfiles.append(f.emptystream)
foutsize = 0
if f.is_symlink:
last_file_index = i
num_unpack_streams += 1
link_target = pathlib.Path(os.readlink(f.origin))
if str(link_target).startswith('\\\\?\\'):
tgt = os.readlink(f.origin).encode('utf-8')
else:
link_parent = pathlib.Path(
os.path.abspath(os.path.dirname(f.origin)))
tgt = str(
link_target.relative_to(link_parent)).encode('utf-8')
insize = len(tgt)
crc = calculate_crc32(tgt, 0)
out = compressor.compress(tgt)
outsize += len(out)
foutsize += len(out)
self.fp.write(out)
self.header.main_streams.substreamsinfo.digests.append(crc)
self.header.main_streams.substreamsinfo.digestsdefined.append(
True)
self.header.main_streams.substreamsinfo.unpacksizes.append(
insize)
self.header.files_info.files[i]['maxsize'] = foutsize
elif not f.emptystream:
last_file_index = i
num_unpack_streams += 1
insize = 0
with pathlib.Path(f.origin).open(mode='rb') as fd:
data = fd.read(Configuration.read_blocksize)
insize += len(data)
crc = 0 # type: int
while data:
crc = calculate_crc32(data, crc)
out = compressor.compress(data)
outsize += len(out)
foutsize += len(out)
self.fp.write(out)
data = fd.read(Configuration.read_blocksize)
insize += len(data)
self.header.main_streams.substreamsinfo.digests.append(crc)
self.header.main_streams.substreamsinfo.digestsdefined.append(
True)
self.header.files_info.files[i]['maxsize'] = foutsize
self.header.main_streams.substreamsinfo.unpacksizes.append(
insize)
else:
out = compressor.flush()
outsize += len(out)
foutsize += len(out)
self.fp.write(out)
if len(self.files) > 0:
self.header.files_info.files[last_file_index][
'maxsize'] = foutsize
# Update size data in header
self.header.main_streams.packinfo.packsizes = [outsize]
self.folder.unpacksizes = [
sum(self.header.main_streams.substreamsinfo.unpacksizes)
]
self.header.main_streams.substreamsinfo.num_unpackstreams_folders = [
num_unpack_streams
]
# Write header
(header_pos, header_len,
header_crc) = self.header.write(self.fp,
self.afterheader,
encoded=self.encoded_header_mode)
self.sig_header.nextheaderofs = header_pos - self.afterheader
self.sig_header.calccrc(header_len, header_crc)
self.sig_header.write(self.fp)
return
def archive(self, fp: BinaryIO, folder):
"""Run archive task for specified 7zip folder."""
compressor = folder.get_compressor()
outsize = 0
self.header.main_streams.packinfo.numstreams = 1
num_unpack_streams = 0
self.header.main_streams.substreamsinfo.digests = []
self.header.main_streams.substreamsinfo.digestsdefined = []
last_file_index = 0
foutsize = 0
for i, f in enumerate(self.files):
file_info = f.file_properties()
self.header.files_info.files.append(file_info)
self.header.files_info.emptyfiles.append(f.emptystream)
foutsize = 0
if f.is_symlink:
last_file_index = i
num_unpack_streams += 1
dirname = os.path.dirname(f.origin)
basename = os.path.basename(f.origin)
link_target = readlink(str(pathlib.Path(dirname) /
basename)) # type: str
tgt = link_target.encode('utf-8') # type: bytes
insize = len(tgt)
crc = calculate_crc32(tgt, 0) # type: int
out = compressor.compress(tgt)
outsize += len(out)
foutsize += len(out)
fp.write(out)
self.header.main_streams.substreamsinfo.digests.append(crc)
self.header.main_streams.substreamsinfo.digestsdefined.append(
True)
self.header.main_streams.substreamsinfo.unpacksizes.append(
insize)
self.header.files_info.files[i]['maxsize'] = foutsize
elif not f.emptystream:
last_file_index = i
num_unpack_streams += 1
insize = 0
with pathlib.Path(f.origin).open(mode='rb') as fd:
data = fd.read(READ_BLOCKSIZE)
insize += len(data)
crc = 0
while data:
crc = calculate_crc32(data, crc)
out = compressor.compress(data)
outsize += len(out)
foutsize += len(out)
fp.write(out)
data = fd.read(READ_BLOCKSIZE)
insize += len(data)
self.header.main_streams.substreamsinfo.digests.append(crc)
self.header.main_streams.substreamsinfo.digestsdefined.append(
True)
self.header.files_info.files[i]['maxsize'] = foutsize
self.header.main_streams.substreamsinfo.unpacksizes.append(
insize)
else:
out = compressor.flush()
outsize += len(out)
foutsize += len(out)
fp.write(out)
if len(self.files) > 0:
self.header.files_info.files[last_file_index][
'maxsize'] = foutsize
# Update size data in header
self.header.main_streams.packinfo.packsizes = [outsize]
folder.unpacksizes = [
sum(self.header.main_streams.substreamsinfo.unpacksizes)
]
self.header.main_streams.substreamsinfo.num_unpackstreams_folders = [
num_unpack_streams
]
