def time_encode(tm, frac=0):
dostime = (
tm.tm_sec >> 1 << DOS_2SEC_BIT ^
tm.tm_min << DOS_MIN_BIT ^
tm.tm_hour << DOS_HOUR_BIT ^
tm.tm_mday << DOS_DAY_BIT ^
tm.tm_mon << DOS_MONTH_BIT ^
tm.tm_year - 1980 << DOS_YEAR_BIT)
one_sec = tm.tm_sec & 1
if not frac and not one_sec: return (dostime, None)
flags = 1 << TIME_VALID_BIT
flags |= one_sec << TIME_ONE_BIT
frac = int(frac * 10 ** TIME_FRAC_DIGITS)
size = TIME_FRAC_BYTES
while size > 0:
if frac & 0xFF: break
frac >>= 8
size -= 1
flags |= size << TIME_SIZE_BIT
xtime = bytearray(S_SHORT.pack(
flags << MTIME_INDEX * TIME_FLAG_BITS))
for i in range(size):
xtime.append(frac & 0xFF)
frac >>= 8
return (dostime, xtime)
def time_encode(tm, frac=0):
dostime = (tm.tm_sec >> 1 << DOS_2SEC_BIT ^ tm.tm_min << DOS_MIN_BIT
^ tm.tm_hour << DOS_HOUR_BIT ^ tm.tm_mday << DOS_DAY_BIT
^ tm.tm_mon << DOS_MONTH_BIT
^ tm.tm_year - 1980 << DOS_YEAR_BIT)
one_sec = tm.tm_sec & 1
if not frac and not one_sec: return (dostime, None)
flags = 1 << TIME_VALID_BIT
flags |= one_sec << TIME_ONE_BIT
frac = int(frac * 10**TIME_FRAC_DIGITS)
size = TIME_FRAC_BYTES
while size > 0:
if frac & 0xFF: break
frac >>= 8
size -= 1
flags |= size << TIME_SIZE_BIT
xtime = bytearray(S_SHORT.pack(flags << MTIME_INDEX * TIME_FLAG_BITS))
for _ in range(size):
xtime.append(frac & 0xFF)
frac >>= 8
return (dostime, xtime)
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_end(volume, version, flags, volnum, is_last_vol):
size = volume.tell()
volume.seek(0)
crc = file_crc32(volume, size)
if version >= 3:
flags |= (RAR_SKIP_IF_UNKNOWN ^
(not is_last_vol) * RAR_ENDARC_NEXT_VOLUME)
parts = list()
if flags & RAR_ENDARC_DATACRC:
parts.append(S_LONG.pack(crc))
if flags & RAR_ENDARC_VOLNR:
parts.append(S_SHORT.pack(volnum))
if flags & RAR_ENDARC_REVSPACE:
parts.append(0 for i in range(END_EXTRA))
write_block(volume, RAR_BLOCK_ENDARC, flags, parts)
return crc
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 write_end(volume, version, flags, volnum, is_last_vol):
size = volume.tell()
volume.seek(0)
crc = file_crc32(volume, size)
if version >= 3:
flags |= (RAR_SKIP_IF_UNKNOWN ^
(not is_last_vol) * RAR_ENDARC_NEXT_VOLUME)
parts = list()
if flags & RAR_ENDARC_DATACRC:
parts.append(S_LONG.pack(crc))
if flags & RAR_ENDARC_VOLNR:
parts.append(S_SHORT.pack(volnum))
if flags & RAR_ENDARC_REVSPACE:
parts.append(0 for _ in range(END_EXTRA))
write_block(volume, RAR_BLOCK_ENDARC, flags, parts)
return crc
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)
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())