added : TimedCache module

[mystical-prog]

What was wrong?

There was a gap in Pubsub implementation wherein there was a simple LRU based cache, instead we now have a built-in timed_cache python module which will now handle the seen_messages cache in Pubsub and it's derived protocols.

ref: https://github.com/libp2p/go-libp2p-pubsub/tree/master/timecache

[seetadev]

@mystical-prog : Excellent, Vraj :) Thank you for sharing the pull request. Looking forward to integrating and testing it with py-libp2p soon. Wish to share some key features expected in the pull request for Gossipsub in py-libp2p as discussed in the specification meeting focused on Gossipsub across libp2p modules:

✅ Gossipsub Core Implementation – Implements the core message propagation and peer scoring mechanisms.
✅ Mesh and Gossip Peering – Establishes the mesh network topology for efficient message dissemination and applies gossip propagation for improved redundancy.
✅ Validation Hooks – Introduces message validation to filter spam and ensure network integrity.
✅ Interoperability – Aligns with libp2p’s Gossipsub specs, allowing seamless integration with other libp2p implementations.

[mystical-prog]

Hey @seetadev I am creating a TODO list and will keep on updating it as I find gaps, currently I have found these two gaps and I am looking forward to close before Monday!

[seetadev]

@mystical-prog : That sounds like a great plan! 🚀 Thanks for proactively identifying and tracking these gaps. Keeping an updated TODO list will definitely help streamline the process and ensure we cover all the missing pieces efficiently.

I appreciate your initiative in closing these gaps before Monday—that will be super helpful in keeping the momentum going! Looking forward to seeing the updates!🔥

Hey @seetadev I am creating a TODO list and will keep on updating it as I find gaps, currently I have found these two gaps and I am looking forward to close before Monday!

[mystical-prog]

@seetadev
I would like to change this PR to be dedicated for timed_cache module as it is a significant change, I will similarly open small and step-by-step PRs which will help us achieve the larger goal of upgrading Gossipsub to v1.1

[mystical-prog]

hey @pacrob @seetadev
I believe this PR is ready to be reviewed, will open up more such smaller PRs for the larger goal of upgrading Gossipsub to v1.1

[seetadev]

@mystical-prog : Hi Vraj. This looks great. Kindly share a small demo video (upto 2-4 mins ) explaining the PR, integration with libp2p and also a walkthrough on the code. This will also help other devs to extend on your work.

I will wait for @pacrob 's and @dhuseby 's feedback. Will merge once I hear the feedback from them.

[mystical-prog]

Sure, I will try to share the video ASAP

[pacrob]

This looks good, @mystical-prog, thanks! Just a thought:

TimedCache is not a module of libp2p (in the libp2p sense, not the python sense), right? It's more of a tool/utility that is used within other modules? What do you think about placing it within the libp2p/tools folder?

Also, I see you've tested the changes via floodsub and pubsub, but some direct testing of your expectations for both FirstSeenCache and LastSeenCache would be appropriate.

[pacrob]

I think renaming the file to base_timed_cache.py fits better.

[pacrob]

This would be a good place to use ABC, like:

from abc import ABC

class BaseTimedCache(ABC)

You can then decorate the add and has methods with @abstractmethod and you don't have to worry about raising anything, it's handled by the ABC.

[mystical-prog]

Hey @pacrob

I will look into the changes suggested by you and get back to you ASAP

[mystical-prog]

I have made the suggested changes @pacrob
Let me know if any further modifications need to be made