def __init__(self, reader: StructReader):
with StreamDetour(reader):
self.code = opc(reader.read_byte())
self.table: Optional[Dict[int, int]] = None
try:
fmt = self.OPC_ARGMAP[self.code]
except KeyError:
self.arguments = []
else:
self.arguments = list(reader.read_struct(fmt))
if self.code == opc.newarray:
self.arguments = [JvBaseType(reader.read_byte())]
elif self.code in self.OPC_CONSTPOOL:
try:
self.arguments[0] = self.pool[self.arguments[0] - 1]
except (AttributeError, IndexError):
pass
elif self.code == opc.lookupswitch:
reader.byte_align(blocksize=4)
default, npairs = reader.read_struct('LL')
pairs = reader.read_struct(F'{npairs*2}L')
self.table = dict(zip(*([iter(pairs)] * 2)))
self.table[None] = default
elif self.code == opc.tableswitch:
reader.byte_align(blocksize=4)
default, low, high = reader.read_struct('LLL')
assert low <= high
offsets = reader.read_struct(F'{high-low+1}L')
self.table = {k + low: offset for k, offset in enumerate(offsets)}
self.table[None] = default
elif self.code == opc.wide:
argop = opc(reader.get_byte())
self.arguments = (argop, reader.u16())
if argop == opc.iinc:
self.arguments += reader.i16(),
else:
assert argop in (
opc.iload, opc.istore,
opc.fload, opc.fstore,
opc.aload, opc.astore,
opc.lload, opc.lstore,
opc.dload, opc.dstore,
opc.ret)
offset = reader.tell()
self.raw = bytes(reader.read(offset - reader.tell()))
def test_bitreader_structured(self):
items = (
0b1100101, # noqa
-0x1337, # noqa
0xDEFACED, # noqa
0xC0CAC01A, # noqa
-0o1337, # noqa
2076.171875, # noqa
math.pi # noqa
)
data = struct.pack('<bhiLqfd', *items)
sr = StructReader(data)
self.assertEqual(sr.read_nibble(), 0b101)
self.assertRaises(sr.Unaligned, lambda: sr.read_exactly(2))
sr.seek(0)
self.assertEqual(sr.read_byte(), 0b1100101)
self.assertEqual(sr.i16(), -0x1337)
self.assertEqual(sr.i32(), 0xDEFACED)
self.assertEqual(sr.u32(), 0xC0CAC01A)
self.assertEqual(sr.i64(), -0o1337)
self.assertAlmostEqual(sr.read_struct('f', True), 2076.171875)
self.assertAlmostEqual(sr.read_struct('d', True), math.pi)
self.assertTrue(sr.eof)