send suback 0x80 if subscribe authorization fails

[mocheng]

To fix #124

Since each topic should be handled respectively, I move the logic to "filter subscription already in client.subscription" into async.parallel. Just to make the indexing of authorized match packet.subscriptions.

[mcollina]

Instead of async.parallel, use async.each, it's faster in this case. (I would love to refactor the whole Mosca :)).

[mocheng]

async.each just iterates the array without collecting results.

With async.parallel, we have auth result s for each topic stored in the authorized arguments in 2nd callback argument of `async.parallel'.

[mcollina]

Yep, you can use async.map in its place. These are much lighter as they do not allocate a function for each subscription.

[mocheng]

Cool 👍

I really should watch closer on performance tips:)