update_checkpoints() makes a few DNS requests and can take up to 20-30 seconds to complete (3-6 seconds on average). It is currently called from core::handle_incoming_block() which holds m_incoming_tx_lock, so it blocks all incoming transactions and blocks processing while update_checkpoints() is running. This PR moves it to until after a new block has been processed and relayed, to avoid full monerod locking.
Before the fix, it processed all transactions in the mempool which could be very slow when mempool grows to several MBs in size. I observed `get_block_template_backlog` taking up to 15 seconds of CPU time under high mempool load.
After the fix, only transactions that can potentially be mined in the next block will be processed (a bit more than the current block median weight).
Implements view tags as proposed by @UkoeHB in MRL issue
https://github.com/monero-project/research-lab/issues/73
At tx construction, the sender adds a 1-byte view tag to each
output. The view tag is derived from the sender-receiver
shared secret. When scanning for outputs, the receiver can
check the view tag for a match, in order to reduce scanning
time. When the view tag does not match, the wallet avoids the
more expensive EC operations when deriving the output public
key using the shared secret.
This comment suggests this check is unnecessary, when it is completely necessary as miner TXs can have multiple outputs *which is a statement directly, and incorrectly, contradicted by this comment*. While I don't ever see someone removing this code and getting their edits merged into Monero, someone inexperienced who thinks they're cleaning old code may break their own work, and then there's really just zero benefit to keeping this around.
avoids mining txes after a fork that are invalid by this fork's
rules, but were valid by the previous fork rules at the time
they were verified and added to the txpool.
Adds the following:
- "get_miner_data" to RPC API
- "json-miner-data" to ZeroMQ subscriber contexts
Both provide the necessary data to create a custom block template. They are used by p2pool.
Data provided:
- major fork version
- current height
- previous block id
- RandomX seed hash
- network difficulty
- median block weight
- coins mined by the network so far
- mineable mempool transactions
