Add GetValuesAsync function

[mildred]

Just like there is FindPeersAsync, there should be a function to lookup a value in the DHT asynchronously, GetValuesAsync. With no maximum number of records (just a cancellable context) and a channel to get the results.

[whyrusleeping]

I think this is a pretty good idea, We should probably just change the current GetValues to return a channel instead of a slice, and then give it logic to treat nvals < 0 as infinite

[mildred]

I have a patch for this ... on top of gx/ipfs/QmRG9fdibExi5DFy8kzyxF76jvZVUb2mQBUSMNP1YaYn9M/go-libp2p-kad-dht. It keeps the current GetValues and add a GetValuesAsync that returns a channel for results

See: https://gist.github.com/mildred/19be643f54e84e31220627183f508620

[mildred]

error management is different in async mode. It may be that not everyone would want to convert to async because of that.

[mildred]

Here are the commits for all the locations that needs change:

• go-ipfs: mildred/go-ipfs@34d0e3d
• go-libp2p-kad-dht: mildred/ipfs-objects@39c20b2
• go-libp2p-routing: mildred/ipfs-objects@3be4f08

[whyrusleeping]

@mildred Go ahead and PR the dht changes into here, @Kubuxu and I will review them that way

[mildred]

Just created the PR

[bigs]

change was made via SearchValues