def set_members(self, buf):
"""Read the size and count indicator from the buffer."""
self.member_size = compat.from_bytes(buf.read(self.width), "big")
self.member_count = compat.from_bytes(buf.read(self.width), "big")
start = buf.tell() - self.width
if self.is_array():
self.member_ctr = decode_constructor(buf.read)
# Set the start of the members to the current buffer position
# minus the width of the type length, because the total length
# includes.
end = start + self.member_size
while buf.tell() < end:
node = type(self).frombuf(buf, parent=self, ctr=self.member_ctr, depth=self.depth)
self.children.append(node)
assert buf.tell() == end, "{0}!={1}".format(buf.tell(), end)
def frombuf(cls, buf, parent=None, ctr=None, depth=-1):
start = buf.tell()
if ctr is None:
ctr = decode_constructor(buf.read)
instance = cls(start, ctr, offset=buf.tell() - start, parent=parent, depth=depth)
if is_collection(ctr.format_code):
instance.set_members(buf)
elif is_variable(ctr.format_code):
instance.set_length(buf)
else:
instance.length = instance.width
buf.seek(instance.width, os.SEEK_CUR)
# If parent is None, this is the top-level node so reset
# the buffer.
# if parent is None:
# buf.seek(0)
instance.end = buf.tell()
return instance
