vd2org/snowflake

The Snowflake generator done right.

Hi there 👋

snowflake's Issues

How to handle None result properly?

Hello.
SnowflakeGenerator.__next__(self) returns optional integer.
I am not sure how to handle the situation when None value returned because I do need a value.
Should I wait for the next millisecond to guarantee non empty result?

getting duplicate id error in django project multi threaded environment. (#6 re-open)

previous question
I want to use snowflake ID generation in my project. so I am trying to use this library. but I am getting unique constraint error for the field primary key. I am using Django. can you please guide me, on how to set it up correctly to avoid getting duplicate IDs. like do I need any additional configurations?_

new question
I'm sorry for not getting back to you sooner. if I use a locking mechanism then can it be solved? if not can you please suggest to me how should I do it I am new to it. and our project is using UUID which I don't like. it'll be very helpful if you can provide in document, how to use it in a multi-threaded environment. I saw it everywhere but I couldn`t find it.

Here is my suggested answer.

from snowflake import SnowflakeGenerator
import threading

class ThreadSafeIdGeneratorService:
    def __init__(self, instance_id):
        self.gen = SnowflakeGenerator(ip_address_int)
        self.lock = threading.Lock()

    def generate_unique_id(self):
        with self.lock:
            return next(self.gen)
    ```

class SnowflakeGenerator MAX_TS bug

The generator method bug.
The maximum timestamp has been reached in selected epoch
OverflowError: The maximum timestamp has been reached in selected epoch, so Snowflake cannot generate more IDs!
When initialize the generator class, we get the current time, if time greater the MAX_TS, that means the epoch params is invalid, the program throws the error directly.
current = int(time() * 1000)
if current >= MAX_TS

two questions about using Snowflake

Hello, I have two questions about using Snowflake. Can you help answer them?

1st: This is my first time encountering Snowflake ID. Can you explain what the 42 means in gen = SnowflakeGenerator(42)? What guidelines should I follow when setting this value? Also, what are the roles of epoch and seq in the parse method?

2nd: When I ran the following code, I noticed that the displayed times were inconsistent.

from snowflake import SnowflakeGenerator
import datetime

current_time = datetime.datetime.now()
print("current time:", current_time)

gen = SnowflakeGenerator(42)
snow_id = next(gen)
print("generate snowflake id:", snow_id)

from snowflake import Snowflake

sf = Snowflake.parse(snow_id)

print(f"{sf.timestamp = }")
print(f"{sf.instance = }")
print(f"{sf.epoch = }")
print(f"{sf.seq = }")
print(f"{sf.seconds = }")
print(f"{sf.milliseconds = }")
print(f"{sf.datetime = }")
print(f"{int(sf) = }")

result:

current time: 2023-08-30 17:05:43.994868
generate snowflake id: 7102577116159582209
sf.timestamp = 1693386343994
sf.instance = 42
sf.epoch = 0
sf.seq = 1
sf.seconds = 1693386343.994
sf.milliseconds = 1693386343994
sf.datetime = datetime.datetime(2023, 8, 30, 9, 5, 43, 994000)
int(sf) = 7102577116159582209

optimize runtime

I think we can optimize runtime in SnowflakeGenerator by change
L74: current = int(time() * 1000) -> current = int(time() * 1000.)
L112: current = int(time() * 1000) - self._epo -> current = int(time() * 1000.) - self._epo
Because multiply 2 float is faster twice than multiply a float and int. (note that time.time() return float)

getting duplicate id in multi-threded environment (django)

I want to use snowflake ID generation in my project. so I am trying to use this library. but I am getting unique constraint error for the field primary key. I am using Django. can you please guide me, on how to set it up correctly to avoid getting duplicate IDs. like do I need any additional configurations?