hp_hovercraft84 (u/hp_hovercraft84)

hp_hovercraft84 commented on Show HN: I built a Ruby gem that handles memoization with a ttl github.com/mishalzaman/me... · Posted by u/hp_hovercraft84

JamesSwift · 4 months ago

Looks good. Id suggest making your `get` wait to acquire the lock until needed. eg instead of

  @lock.synchronize do
    entry = @store[key]
    return nil unless entry

    ...

you can do

  entry = @store[key]
  return nil unless entry

  @lock.synchronize do
    entry = @store[key]

And similarly for other codepaths

hp_hovercraft84 · 4 months ago

Good call, but I think I would like to ensure it remains thread-safe as @store is a hash. Although I will consider something like this in a future update. Thanks!

hp_hovercraft84 commented on Show HN: I built a Ruby gem that handles memoization with a ttl github.com/mishalzaman/me... · Posted by u/hp_hovercraft84

madsohm · 4 months ago

Since using `def` to create a method returns a symbol with the method name, you can do something like this too:

  memoize def expensive_calculation(arg)
    @calculation_count += 1
    arg * 2
  end, ttl: 10, max_size: 2

  memoize def nil_returning_method
    @calculation_count += 1
    nil
  end

hp_hovercraft84 · 4 months ago

This is why I love working with Ruby!

hp_hovercraft84 commented on Show HN: I built a Ruby gem that handles memoization with a ttl github.com/mishalzaman/me... · Posted by u/hp_hovercraft84

JamesSwift · 4 months ago

For what its worth, ActiveSupport::CacheStore is a really flexible api that gives minimal contractual obligations (read_entry, write_entry, delete_entry is the entire set of required methods), but still allows you to layer specific functionality (eg TTL) on top with an optional 'options' param. You could get the best of both worlds by adhering to that contract and then people can swap in eg redis cache store if they wanted a network-shared store.

EDIT: see https://github.com/rails/rails/blob/main/activesupport/lib/a...

hp_hovercraft84 · 4 months ago

That's actually a really good idea! I'll definitely consider this in a future update. Thanks!

hp_hovercraft84 commented on Show HN: I built a Ruby gem that handles memoization with a ttl github.com/mishalzaman/me... · Posted by u/hp_hovercraft84

locofocos · 4 months ago

Can you pitch me on why I would want to use this, instead of Rails.cache.fetch (which supports TTL) powered by redis (with the "allkeys-lru" config option)?

hp_hovercraft84 · 4 months ago

Good question. I built this gem because I needed a few things that Rails.cache (and Redis) didn’t quite fit:

- Local and zero-dependency. It caches per object in memory, so no Redis setup, no serialization, no network latency. -Isolated and self-managed. Caches aren’t global. Each object/method manages its own LRU + TTL lifecycle and can be cleared with instance helpers. - Easy to use — You just declare the method, set the TTL and max size, and you're done. No key names, no block wrapping, no external config.

hp_hovercraft84 commented on Show HN: I built a Ruby gem that handles memoization with a ttl github.com/mishalzaman/me... · Posted by u/hp_hovercraft84

qrush · 4 months ago

Congrats on shipping your first gem!!

I found this pretty easy to read through. I'd suggest setting a description on the repo too so it's easy to find.

https://github.com/mishalzaman/memo_ttl/blob/main/lib/memo_t...

hp_hovercraft84 · 4 months ago

As in identify where the source code is in the README?

hp_hovercraft84 commented on Show HN: I built a Ruby gem that handles memoization with a ttl github.com/mishalzaman/me... · Posted by u/hp_hovercraft84

film42 · 4 months ago

Nice! In rails I end up using Rails.cache most of the time because it's always "right there" but I like how you break out the cache to be a per-method to minimize contention. Depending on your workload it might make sense to use a ReadWrite lock instead of a Monitor.

Only suggestion is to not wrap the error of the caller in your memo wrapper.

> raise MemoTTL::Error, "Failed to execute memoized method '#{method_name}': #{e.message}"

It doesn't look like you need to catch this for any operational or state tracking reason so IMO you should not catch and wrap. When errors are wrapped with a string like this (and caught/ re-raised) you lose the original stacktrace which make debugging challenging. Especially when your error is like, "pg condition failed for select" and you can't see where it failed in the driver.

hp_hovercraft84 · 4 months ago

Thanks for the feedback! That's a very good point, I'll update the gem and let it bubble up.

Posted by u/hp_hovercraft84 4 months ago

Show HN: I built a Ruby gem that handles memoization with a ttl github.com/mishalzaman/me...

hp_hovercraft84 commented on Show HN: Restapp.io – SQL Data Modeling Tool in No/Low Code os.restapp.co/signup... · Posted by u/BXScore

freecodyx · 3 years ago

The landing page should show me what i can expect, not to sign up to discover the product

hp_hovercraft84 · 3 years ago

No info about how the product works, immediate close.

u/hp_hovercraft84

KarmaCake day13September 29, 2022View Original