Get offchain Voting Anchor

[kderme]

This is similar to the off chain pool metadata that we already have.
A new thread needs to be added. The db schema is already in place, but may need adjustments.

[kderme]

Some details that may be useful during the implementation:

Related tables are VotingAnchor, AnchorOfflineData and AnchorOfflineFetchError.
VotingAnchor is the on-chain part: it includes a url and a hash.
A new thread needs to be spawned which should periodically read entries from the anchor and do http requests to get the off-chain parts. If this request is succesful and the hash of the fetched data matches the expected hash, a new entry for the AnchorOfflineData should be prepared. The AnchorOfflineData includes a json text, however the specification in which this text should be parsed is not decided, so this can remain empty. If something goes wrong with the http request, a AnchorOfflineFetchError should be prepared.

[Cmdv]

Just a couple of questions for clarification:

1. is there an example of an existing thread that checks "on-chain" with "off-chain" I could use as an example?
2. "read entries from the anchor" is this the anchors on the database if so which one?
3. "do http requests to get the off-chain parts." what url would I use? is this getting it from node or somewhere else?

[kderme]

1. yes the pool metadata thread
2. yes these are the anchors stored in voting_anchor table.
3. the url is included in the VotingAnchor so it's part of the chain.

[Cmdv]

1. do you have a name/link for the function for the "pool metadata thread"
2. 👍
3. So we're getting N VotingAnchors from db using the url in each to check the SHAs match with what is on the DB, then if valid put into AnchorOfflineData and if not then AnchorOfflineFetchError?

A new question: Once the VotingAnchor is checked/validate, do we "delete" the original or "store" somewhere the last VotingAnchor that was checked/validated so we know where to pick up from the next time the thread runs?

[kderme]

The thread name is runOfflineFetchThread. I suggest you take a look at how it works and it may give answers to your questions.

[kderme]

Note: metadata should be populated only when --disable-gov is not on. Similar to --disable-offchain-pool-data.