def write_block(file, type, flags, data):
block = bytearray()
for part in data: block.extend(part)
header = S_BLK_HDR_DATA.pack(type, flags, S_BLK_HDR.size + len(block))
crc = crc32(header)
crc = crc32(block, crc)
file.write(S_SHORT.pack(crc & bitmask(16)))
file.write(header)
file.write(block)
def write_block(file, btype, flags, data):
block = bytearray()
for part in data:
block.extend(part)
header = S_BLK_HDR_DATA.pack(btype, flags, S_BLK_HDR.size + len(block))
crc = crc32(header)
crc = crc32(block, crc)
file.write(S_SHORT.pack(crc & bitmask(16)))
file.write(header)
file.write(block)
def write_file(volume,
file,
split_before,
split_after,
name,
is_unicode,
dictsize,
host_os,
attr,
accum_crc,
dostime,
xtime=None,
size=None,
pack_size=None):
size_64 = size_64_encode(pack_size, size)
header_size = file_hdr_size(name, xtime, size_64)
volume.seek(+header_size, io.SEEK_CUR)
left = pack_size
crc = 0 if split_after else accum_crc
while left > 0:
chunk = file.read(min(FILE_COPY_CRC_BUF, left))
left -= len(chunk)
volume.write(chunk)
crc = crc32(chunk, crc)
if split_after:
accum_crc = crc32(chunk, accum_crc)
parts = list()
flags = (RAR_LONG_BLOCK ^ split_before * RAR_FILE_SPLIT_BEFORE
^ split_after * RAR_FILE_SPLIT_AFTER ^ dictsize
^ is_unicode * RAR_FILE_UNICODE)
parts.append(
S_FILE_HDR.pack(pack_size & bitmask(32), size & bitmask(32), host_os,
crc, dostime, 20, ord("0"), len(name), attr))
if size_64 is not None:
flags ^= RAR_FILE_LARGE
parts.append(size_64)
parts.append(name)
if xtime is not None:
flags ^= RAR_FILE_EXTTIME
parts.append(xtime)
volume.seek(-pack_size - header_size, io.SEEK_CUR)
write_block(volume, RAR_BLOCK_FILE, flags, parts)
volume.seek(+pack_size, io.SEEK_CUR)
if split_after: return accum_crc
def file_crc32(file, size):
crc = 0
while size > 0:
chunk = file.read(min(FILE_CRC_BUF, size))
size -= len(chunk)
crc = crc32(chunk, crc)
return crc
def file_crc32(file, size):
crc = 0
while size > 0:
chunk = file.read(min(FILE_CRC_BUF, size))
size -= len(chunk)
crc = crc32(chunk, crc)
return crc
def write_file(volume, file, split_before, split_after, name, is_unicode,
dict, host_os, attr, accum_crc, dostime, xtime=None, size=None,
pack_size=None):
size_64 = size_64_encode(pack_size, size)
header_size = file_hdr_size(name, xtime, size_64)
volume.seek(+header_size, io.SEEK_CUR)
left = pack_size
crc = 0 if split_after else accum_crc
while left > 0:
chunk = file.read(min(FILE_COPY_CRC_BUF, left))
left -= len(chunk)
volume.write(chunk)
crc = crc32(chunk, crc)
if split_after:
accum_crc = crc32(chunk, accum_crc)
parts = list()
flags = (RAR_LONG_BLOCK ^ split_before * RAR_FILE_SPLIT_BEFORE ^
split_after * RAR_FILE_SPLIT_AFTER ^ dict ^
is_unicode * RAR_FILE_UNICODE)
parts.append(S_FILE_HDR.pack(
pack_size & bitmask(32), size & bitmask(32),
host_os, crc, dostime, 20, ord("0"), len(name), attr
))
if size_64 is not None:
flags ^= RAR_FILE_LARGE
parts.append(size_64)
parts.append(name)
if xtime is not None:
flags ^= RAR_FILE_EXTTIME
parts.append(xtime)
volume.seek(-pack_size - header_size, io.SEEK_CUR)
write_block(volume, RAR_BLOCK_FILE, flags, parts)
volume.seek(+pack_size, io.SEEK_CUR)
if split_after: return accum_crc
def write_rr(version, host_os, volume, rr_count):
prot_size = volume.tell()
(rr_crcs, rr_sects) = rr_calc(volume, rr_count, prot_size)
crc = crc32(rr_crcs, RR_CRC_INIT)
for s in rr_sects:
crc = crc32(s.buffer(), crc)
prot_sect_count = len(rr_crcs) // S_SHORT.size
size = prot_sect_count * RR_CRC_SIZE + rr_count * RR_SECT_SIZE
if version < 3:
write_block(volume,
type=RAR_BLOCK_OLD_RECOVERY,
flags=RAR_LONG_BLOCK ^ RAR_SKIP_IF_UNKNOWN,
data=(
S_LONG.pack(size),
(20,),
S_SHORT.pack(rr_count),
S_LONG.pack(prot_sect_count),
RR_PROTECT_2,
))
else:
write_block(volume,
type=RAR_BLOCK_SUB,
flags=RAR_LONG_BLOCK ^ RAR_SKIP_IF_UNKNOWN,
data=(
S_FILE_HDR.pack(size, size, host_os, crc, 0, 29, ord("0"),
len(RR_SUB_NAME), 0),
RR_SUB_NAME,
RR_PROTECT_3,
S_LONG.pack(rr_count),
struct.pack("<Q", prot_sect_count),
))
volume.write(rr_crcs)
for s in rr_sects:
volume.write(s.buffer())
def write_rr(version, host_os, volume, rr_count):
prot_size = volume.tell()
(rr_crcs, rr_sects) = rr_calc(volume, rr_count, prot_size)
crc = crc32(rr_crcs, RR_CRC_INIT)
for s in rr_sects:
crc = crc32(s.buffer(), crc)
prot_sect_count = len(rr_crcs) // S_SHORT.size
size = prot_sect_count * RR_CRC_SIZE + rr_count * RR_SECT_SIZE
if version < 3:
write_block(volume,
type=RAR_BLOCK_OLD_RECOVERY,
flags=RAR_LONG_BLOCK ^ RAR_SKIP_IF_UNKNOWN,
data=(
S_LONG.pack(size),
(20, ),
S_SHORT.pack(rr_count),
S_LONG.pack(prot_sect_count),
RR_PROTECT_2,
))
else:
write_block(volume,
type=RAR_BLOCK_SUB,
flags=RAR_LONG_BLOCK ^ RAR_SKIP_IF_UNKNOWN,
data=(
S_FILE_HDR.pack(size, size, host_os, crc, 0, 29,
ord("0"), len(RR_SUB_NAME), 0),
RR_SUB_NAME,
RR_PROTECT_3,
S_LONG.pack(rr_count),
struct.pack("<Q", prot_sect_count),
))
volume.write(rr_crcs)
for s in rr_sects:
volume.write(s.buffer())
def rr_calc(volume, rr_count, size):
volume.seek(0)
rr_crcs = bytearray()
rr_sects = tuple(BitVector(RR_SECT_SIZE) for i in range(rr_count))
slice = 0
while size > 0:
if size < RR_SECT_SIZE:
chunk = volume.read(size).ljust(RR_SECT_SIZE, bytes((0,)))
size = 0
else:
chunk = volume.read(RR_SECT_SIZE)
size -= RR_SECT_SIZE
rr_crcs.extend(S_SHORT.pack(~crc32(chunk) & bitmask(16)))
rr_sects[slice].xor(chunk)
slice = (slice + 1) % rr_count
return (rr_crcs, rr_sects)
def rr_calc(volume, rr_count, size):
volume.seek(0)
rr_crcs = bytearray()
rr_sects = tuple(BitVector(RR_SECT_SIZE) for _ in range(rr_count))
aslice = 0
while size > 0:
if size < RR_SECT_SIZE:
chunk = volume.read(size).ljust(RR_SECT_SIZE, bytes((0, )))
size = 0
else:
chunk = volume.read(RR_SECT_SIZE)
size -= RR_SECT_SIZE
rr_crcs.extend(S_SHORT.pack(~crc32(chunk) & bitmask(16)))
rr_sects[aslice].xor(chunk)
aslice = (aslice + 1) % rr_count
return (rr_crcs, rr_sects)
