80 lines
2.0 KiB
Python
80 lines
2.0 KiB
Python
import struct, warnings
|
|
try:
|
|
import lz4
|
|
except:
|
|
lz4 = None
|
|
|
|
#old scheme for VERSION < 0.9 otherwise use lz4.block
|
|
|
|
def decompress(data):
|
|
(compression,) = struct.unpack(">L", data[4:8])
|
|
scheme = compression >> 27
|
|
size = compression & 0x07ffffff
|
|
if scheme == 0:
|
|
pass
|
|
elif scheme == 1 and lz4:
|
|
res = lz4.decompress(struct.pack("<L", size) + data[8:])
|
|
if len(res) != size:
|
|
warnings.warn("Table decompression failed.")
|
|
else:
|
|
data = res
|
|
else:
|
|
warnings.warn("Table is compressed with an unsupported compression scheme")
|
|
return (data, scheme)
|
|
|
|
def compress(scheme, data):
|
|
hdr = data[:4] + struct.pack(">L", (scheme << 27) + (len(data) & 0x07ffffff))
|
|
if scheme == 0 :
|
|
return data
|
|
elif scheme == 1 and lz4:
|
|
res = lz4.compress(hdr + data)
|
|
return res
|
|
else:
|
|
warnings.warn("Table failed to compress by unsupported compression scheme")
|
|
return data
|
|
|
|
def _entries(attrs, sameval):
|
|
ak = 0
|
|
vals = []
|
|
lastv = 0
|
|
for k,v in attrs:
|
|
if len(vals) and (k != ak + 1 or (sameval and v != lastv)) :
|
|
yield (ak - len(vals) + 1, len(vals), vals)
|
|
vals = []
|
|
ak = k
|
|
vals.append(v)
|
|
lastv = v
|
|
yield (ak - len(vals) + 1, len(vals), vals)
|
|
|
|
def entries(attributes, sameval = False):
|
|
g = _entries(sorted(attributes.iteritems(), key=lambda x:int(x[0])), sameval)
|
|
return g
|
|
|
|
def bininfo(num, size=1):
|
|
if num == 0:
|
|
return struct.pack(">4H", 0, 0, 0, 0)
|
|
srange = 1;
|
|
select = 0
|
|
while srange <= num:
|
|
srange *= 2
|
|
select += 1
|
|
select -= 1
|
|
srange /= 2
|
|
srange *= size
|
|
shift = num * size - srange
|
|
return struct.pack(">4H", num, srange, select, shift)
|
|
|
|
def num2tag(n):
|
|
if n < 0x200000:
|
|
return str(n)
|
|
else:
|
|
return struct.unpack('4s', struct.pack('>L', n))[0].replace('\000', '')
|
|
|
|
def tag2num(n):
|
|
try:
|
|
return int(n)
|
|
except ValueError:
|
|
n = (n+" ")[:4]
|
|
return struct.unpack('>L', n)[0]
|
|
|