def __init__(self, reader: MemoryViewReader):
self.method_index = reader.read_int()
self.max_stack = reader.read_int()
self.local_count = reader.read_int()
self.init_scope_depth = reader.read_int()
self.max_scope_depth = reader.read_int()
self.code = reader.read(reader.read_int())
self.exceptions = read_array(reader, ASException)
self.traits = read_array(reader, ASTrait)
def read_tags(reader: MemoryViewReader) -> Iterable[Tag]:
"""
Read tags from the stream and get an iterable of tags.
"""
while not reader.is_eof():
code_length = reader.read_u16()
length = code_length & 0b111111
if length == 0x3F:
# Long tag header.
length = reader.read_u32()
try:
type_ = TagType(code_length >> 6)
except ValueError:
# Unknown tag type. Skip the tag.
reader.skip(length)
else:
yield Tag(type_=type_, raw=reader.read(length))
def decompress(reader: MemoryViewReader,
signature: Signature) -> MemoryViewReader:
"""
Decompress the rest of an SWF file, depending on its signature.
"""
if signature == Signature.UNCOMPRESSED:
return reader
if signature == Signature.LZMA:
# https://stackoverflow.com/a/39777419/359730
reader.skip(4) # skip compressed length
return MemoryViewReader(
lzma.decompress(
reader.read(5).tobytes() +
b'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF' +
reader.read_all().tobytes()))
if signature == Signature.ZLIB:
return MemoryViewReader(zlib.decompress(reader.read_all()))
assert False, 'unreachable code'
def read_string(reader: MemoryViewReader) -> str:
return reader.read(reader.read_int()).tobytes().decode('utf-8')