add Cache constructor

[zhangfan2012fall]

#43 Not sure what happened to that PR, I also need to be able to create new cache instance.

Instead of a factory method, I added a constructor

[ptarjan]

why is this a constructor param instead of just using the setter after you made it?

[zhangfan2012fall]

@ptarjan I thought it would be easier to use the debug feature.
Instead of call the setter explicitly, you can just add true, when you create the instance.

[ptarjan]

sure, that would be easier for any option. I'd prefer to not single out this one.

[zhangfan2012fall]

I see, isn't debug the only option ? 😃

[ptarjan]

yes, but this library will be around for many years, and will probably get options along the way

[zhangfan2012fall]

make sense, I removed it.

[weastmann]

@zhangfan2012fall
I think the result is not entirely as intended. Creating multiple instances of Cache will refer to the same key mapping.

var Cache = require("memory-cache").Cache;

var c1 = new Cache();
c1.put("test", "thing");
var c2 = new Cache();
c2.get("test") // returns "thing" 

The tests pass because only one instance of the Cache is ever created/referred to.

[zhangfan2012fall]

@weastmann fixed, I dropped the ball here 😭

[weastmann]

@zhangfan2012fall Looks good.

[frontierpsycho]

I came to propose exactly this feature.

[michaeljones]

👍 I'd like to see this integrated as well.

[debrouxl]

I would like to see this kind of functionality integrated as well :)
I liked the hits() and misses() APIs, but the fact that memory-cache is currently a singleton eliminated it from the options for an internal project.

[ptarjan]

@debrouxl if you want to rebase it, I'm willing to take it.

[simon300000]

const cache = require('memory-cache');
delete require.cache[require.resolve('memory-cache')]
const cache2 = require('memory-cache');

cache.put('foo', '233');
cache2.put('foo', '666');

console.log(cache.get('foo'))//233
console.log(cache2.get('foo'))//666

→_→