Add a .all() method to cache object API

[roryf]

This is more of a question really, is there a good reason why the cache object doesn't implement a all() method (or similar) to retrieve all objects? I realise this could be achieved using keys() and iteration, but I'm wondering if it could be implemented better inside the cache.

[jmdobry]

Are you looking for something like:

myCache.put('apple', { color: 'red' });
myCache.put('banana', { color: 'yellow'});

myCache.values(); // output below

/*
[
  { color: 'red' },
  { color: 'yellow' }
]
*/

or

myCache.put('apple', { color: 'red' });
myCache.put('banana', { color: 'yellow'});

myCache.valueSet();  // output below

/*
{
    "apple": { color: 'red' },
    "banana": { color: 'yellow' }
}
*/

or both?

When you "get" an item I have to update it's "accessed" timestamp, so there isn't really a way to do that for all items at the same time. If I were to implement this, it would end up being an iteration anyway. At most these methods would save people a few lines of code. Is that a good enough reason to create them? What do you think?

[roryf]

Yes, that is what I was thinking but I understand more now the side effects of it. I think it's important that the consumer is aware of these side effects, which isn't really obvious from the suggestion above.

Taking a leaf from redis, what about a get method that took multiple keys? This reinforces that idea that you are actually accessing individual objects, but simplifies the retrieval on a client. Seems a reasonable compromise to me.

myCache.get(myCache.keys());

/*
[
  { color: 'red' },
  { color: 'yellow' }
]
*/

// or

myCache.getSet(myCache.keys());

/*
{
    "apple": { color: 'red' },
    "banana": { color: 'yellow' }
}
*/

Not sure how useful the latter would be, and perhaps getAll might be a better name?

[jmdobry]

Hmm, I like the idea of:

myCache.get( [ 'key1', 'key2' ] );
myCache.get( myCache.keys() );

I can easily make this backwards compatible with the current API.

I think it's plausible that a developer would find themselves with a hash of keys, or at least trying to build a hash of key-value pairs from the cache. getSet is a weird name, and I'm not sure if it should accept an array of keys or a hash of keys.

I'll implement the first change, and hold off on the second for now.

[roryf]

:+1:

[jmdobry]

Closing in favor of #71