Adding support for GET_ONLINE_ACCOUNTS_V3 to Controller, which calls OnlineAccountsManager.
With OnlineAccountsV3, instead of nodes sending their list of known online accounts (public keys),
nodes now send a summary which contains hashes of known online accounts, one per timestamp + leading-byte combo.
Thus outgoing messages are much smaller and scale better with more users.
Remote peers compare the hashes and send back lists of online accounts (for that timestamp + leading-byte combo) where hashes do not match.
Massive rewrite of OnlineAccountsManager to maintain online accounts.
Now there are three caches:
1. all online accounts, but split into sets by timestamp
2. 'hashes' of all online accounts, one hash per timestamp+leading-byte combination
Mainly for efficient use by GetOnlineAccountsV3 message constructor.
3. online accounts for the highest blocks on our chain to speed up block processing
Note that highest blocks might be way older than 'current' blocks if we're somewhat behind in syncing.
Other OnlineAccountsManager changes:
* Use scheduling executor service to manage subtasks
* Switch from 'synchronized' to 'concurrent' collections
* Generally switch from Lists to Sets - requires improved OnlineAccountData.hashCode() - further work needed
* Only send V3 messages to peers with version >= 3.2.203 (for testing)
* More info on which online accounts lists are returned depending on use-cases
To test, change your peer's version (in pom.xml?) to v3.2.203.
Reduced AT state info from per-AT address + state hash + fees to AT count + total AT fees + hash of all AT states.
Modified Block and Controller to support above. Controller needs more work regarding CachedBlockMessages.
Note that blocks fetched from archive are in old V1 format.
Changed Triple<BlockData, List<TransactionData>, List<ATStateData>> to BlockTransformation to support both V1 and V2 forms.
Set min peer version to 3.3.203 in BlockV2Message class.
Currently, new transactions take a very long time to be included in each block (or reach the intended recipient), because each node has to obtain a repository lock and import the transaction before it notifies its peers. This can take a long time due to the lock being held by the block minter or synchronizer, and this compounds with every peer that the transaction is routed through.
Validating signatures doesn't require a lock, and so can take place very soon after receipt of a new transaction. This change causes each node to broadcast a new transaction to its peers as soon as its signature is validated, rather than waiting until after the import.
When a notified peer then makes a request for the transaction data itself, this can now be loaded from the sig-valid import queue as an alternative to the repository (since they won't be in the repository until after the import, which likely won't have happened yet).
One small downside to this approach is that each unconfirmed transaction is now notified twice - once after the signature is deemed valid, and again in Controller.onNewTransaction(), but this should be an acceptable trade off given the speed improvements it should achieve. Another downside is that it could cause invalid transactions (with valid signatures) to propagate, but these would quickly be added to each peer's invalidUnconfirmedTransactions list after the import failure, and therefore be ignored.
Importing has to be single threaded since it requires the database lock, but there's nothing to stop us from validating signatures on multiple threads, as no lock is required. So it makes sense to separate these two functions to allow for possible multi threaded signature validation in the future, to speed up the process.
Everything remains single threaded in this commit. It should be functionally the same as before, to reduce risk.
Also removed CrossChainDigibyteACCTv1Resource, since this is unused, and it seems excessive to maintain support of this for every coin (and potentially every ACCT version).
