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 __init__(self, reader: StructReader):
def readint(length: int):
return int(bytes(reader.read(length * 2)), 16)
self.signature = reader.read(6)
if self.signature != b'070701':
raise ValueError('invalid CPIO header signature')
self.inode = readint(4)
self.mode = readint(4)
self.uid = readint(4)
self.gid = readint(4)
self.nlinks = readint(4)
mtime = readint(4)
self.mtime = datetime.utcfromtimestamp(mtime)
self.size = readint(4)
self.dev = readint(4), readint(4)
self.rdev = readint(4), readint(4)
namesize = readint(4)
self.checksum = readint(4)
self.name = bytes(reader.read(namesize)).decode('ascii').rstrip('\0')
reader.byte_align(4)
self.data = reader.read(self.size)
reader.byte_align(4)
def process(self, data: bytearray):
formatter = string.Formatter()
until = self.args.until
until = until and PythonExpression(until, all_variables_allowed=True)
reader = StructReader(memoryview(data))
mainspec = self.args.spec
byteorder = mainspec[:1]
if byteorder in '<!=@>':
mainspec = mainspec[1:]
else:
byteorder = '='
def fixorder(spec):
if spec[0] not in '<!=@>':
spec = byteorder + spec
return spec
it = itertools.count() if self.args.multi else (0, )
for index in it:
if reader.eof:
break
if index >= self.args.count:
break
meta = metavars(data, ghost=True)
meta['index'] = index
args = []
last = None
checkpoint = reader.tell()
try:
for prefix, name, spec, conversion in formatter.parse(
mainspec):
if prefix:
args.extend(reader.read_struct(fixorder(prefix)))
if name is None:
continue
if conversion:
reader.byte_align(
PythonExpression.evaluate(conversion, meta))
if spec:
spec = meta.format_str(spec, self.codec, args)
if spec != '':
try:
spec = PythonExpression.evaluate(spec, meta)
except ParserError:
pass
if spec == '':
last = value = reader.read()
elif isinstance(spec, int):
last = value = reader.read_bytes(spec)
else:
value = reader.read_struct(fixorder(spec))
if not value:
self.log_warn(F'field {name} was empty, ignoring.')
continue
if len(value) > 1:
self.log_info(
F'parsing field {name} produced {len(value)} items reading a tuple'
)
else:
value = value[0]
args.append(value)
if name == _SHARP:
raise ValueError(
'Extracting a field with name # is forbidden.')
elif name.isdecimal():
index = int(name)
limit = len(args) - 1
if index > limit:
self.log_warn(
F'cannot assign index field {name}, the highest index is {limit}'
)
else:
args[index] = value
continue
elif name:
meta[name] = value
if until and not until(meta):
self.log_info(
F'the expression ({until}) evaluated to zero; aborting.'
)
break
with StreamDetour(reader, checkpoint) as detour:
full = reader.read(detour.cursor - checkpoint)
if last is None:
last = full
outputs = []
for template in self.args.outputs:
used = set()
outputs.append(
meta.format(template,
self.codec, [full, *args], {_SHARP: last},
True,
used=used))
for key in used:
meta.pop(key, None)
for output in outputs:
chunk = self.labelled(output, **meta)
chunk.set_next_batch(index)
yield chunk
except EOF:
leftover = repr(SizeInt(len(reader) - checkpoint)).strip()
self.log_info(F'discarding {leftover} left in buffer')
break
