How to download a File via nabu and CID without knowing any of the providers ahead of time

[Ghost-chu]

This is probably a stupid question... However when I following the guide in README.md to download a file by using this code:

 List<Want> wants = List.of(new Want(Cid.decode("zdpuAwfJrGYtiGFDcSV3rDpaUrqCtQZRxMjdC6Eq9PNqLqTGg")));
        Set<PeerId> retrieveFrom = Set.of(PeerId.fromBase58("QmVdFZgHnEgcedCS2G2ZNiEN59LuVrnRm7z3yXtEBv2XiF"));
        boolean addToLocal = true;
        List<HashedBlock> blocks = ipfs.getBlocks(wants, retrieveFrom, addToLocal);

I noticed that I need to know the other person's PeerID first. However I tried use the code in FindProviderTest to find any peers that provide the data, but it seems just stuck in search loop with some timeout exception and infinity sendWants tries:

**** org.peergos.protocol.bitswap.Bitswap sendWants
INFO: Send wants: 1 to [QmQCU2EcMqAqQPR2i9bChDtGNJchTbq5TbXJJ16u19uLTa, QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ, QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb, QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt] cids: [bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi]
**** org.peergos.protocol.bitswap.Bitswap sendWants
INFO: Send wants: 1 to [QmQCU2EcMqAqQPR2i9bChDtGNJchTbq5TbXJJ16u19uLTa, QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ, QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb, QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt] cids: [bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi]
**** org.peergos.protocol.bitswap.Bitswap sendWants

I tried anything that made sense, but unfortunately I still can't accomplish the simplest and most basic task - downloading files from IPFS via nabu and CID without knowing any of the providers ahead of time.

Nabu does a lot of cool work, but the lack of documentation makes it quite difficult to use.

What should I do? Is there any sample code?

[ianopolous]

Nabu doesn't have a concept of a file. You could use Nabu to build such a thing relatively easily. The main thing you would need is an implementation of unixfs in dag-pb to understand how to join the blocks into a file.

When retrieving a block the peerIds are optional. If you don't supply any it will try and find providers.

[Ghost-chu]

Thank you for your excellent work, I will try to find out what to do to make this.

Does Nabu have any ideas for integrating this part in the future?

[ianopolous]

I think Nabu wants to stay a minimal block daemon, but others can build such a thing on top.