The point was to have a 16bytes key for uuid that depends on uuid.getnode(), time.time(), and a random component. The specific way the key is built can be changed if there is a good argument for it.
Before we just used uuid.uuid4() an the problem was that when running on a HA cluster with replicated VM workers uuid.uuid4() was generating conflicts between session keys and file upload names. On 14 Lug, 17:24, Craig Younkins <cyounk...@gmail.com> wrote: > The following is the code in 1.80 for UUID generation from gluon/utils.py. > Can someone explain to me what is going on here? What's with all the > bitshifting? > > web2py_uuid_locker = thread.allocate_lock() > node_id = uuid.getnode() > milliseconds = int(time.time() * 1e3) > > def rotate(i): > a = random.randrange(256) > b = (node_id >> 4*i) % 256 > c = (milliseconds >> 4*i) % 256 > return (a + b + c) % 256 > > def web2py_uuid(): > web2py_uuid_locker.acquire() > try: > bytes = [chr(rotate(i)) for i in range(16)] > return str(uuid.UUID(bytes=bytes, version=4)) > finally: > web2py_uuid_locker.release() > > -- > Craig Younkins
