Internal data needed for `cuprated`'s RPC

What

This is a discussion for what data is required for cuprated's RPC system.

Notably, this is:

Blockchain data
Transaction pool data
P2P data
General process state

The following tables (except the general process state) are newly proposed requests/responses to be added to each system's tower::Service API such that the RPC system can fulfill the request. The RPC system is assumed to have read access (and write access where needed) to all systems via tower::Service handles.

Blockchain

Request	Response	Needed for	Description
`PopBlocks(u64)`	`u64`	`/pop_blocks`	Pop `n` blocks, return the new height
`Prune`	TODO	`prune_blockchain`	Prune the blockchain
`Pruned`	`bool`	`prune_blockchain`	Is the blockchain pruned?
`Block(u64)`	`Block`	`get_block`	Retrieve block information
`BlockByHash([u8; 32])`	`Block`	`get_block`	Same as `Block`; for convenience
`TopBlock`	`Block`		Get the latest `Block`, Same as `Block`; for convenience
`TopBlockExtendedHeader`	`ExtendedBlockHeader`		Get the latest `ExtendedBlockHeader`; for convenience
`KeyImageSpent([u8; 32])`	`bool`	`/is_key_image_spent`	Singular version of already existing `KeyImagesSpent`
`TopBlockFull`	`(Block, ExtendedBlockHeader)`	`get_last_block_header`	Get information on the last block to map to `cuprate_rpc_types::misc::BlockHeader`
`TopBlockHash`	`[u8; 32]`	`get_info`	Get the top block hash.
`TotalTxCount`	`u64`	`get_info`	Get the total amount of non-coinbase transactions; `cuprate_rpc_types::json::GetInfoResponse::tx_count`
`DatabaseSize`	`(u64, u64)`	`get_info`	Return byte size of database file and available space for `cuprate_rpc_types::json::GetInfoResponse::{database_size,free_space}`
`BlockWeightLimit`	`u64`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::block_weight_limit`
`BlockWeightMedian`	`u64`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::block_weight_median`
`Difficulty(usize)`	`u128`	`get_info`	Difficulty for a specific block (input = height) `cuprate_rpc_types::json::GetInfoResponse::difficulty[_top64]`
`CurrentHardFork`	`HardFork`	`hard_fork_info`	Retrieve the latest `HardFork`
`HardForkInfo(Hardfork)`	`HardForkInfo`	`hard_fork_info`	Retrieve various information about a hardfork; `cuprate_rpc_types::json::HardForkInfoResponse`; https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454/src/rpc/core_rpc_server.cpp#L2751; https://github.com/monero-project/monero/blob/a1dc85c5373a30f14aaf7dcfdd95f5a7375d3623/src/cryptonote_basic/hardfork.cpp#L408;
`OutputHistogram`	`OutputHistogram`	`get_output_histogram`	https://github.com/monero-project/monero/blob/a1dc85c5373a30f14aaf7dcfdd95f5a7375d3623/src/blockchain_db/lmdb/db_lmdb.cpp#L4222
`CoinbaseTxSum`	`CoinbaseTxSum`	`get_coinbase_tx_sum`	https://github.com/monero-project/monero/blob/a1dc85c5373a30f14aaf7dcfdd95f5a7375d3623/src/cryptonote_core/cryptonote_core.cpp#L1265
`FeeEstimate(grace_blocks: u64)`	TODO	`get_fee_estimate`	TODO: Impl of dynamic fees required: https://github.com/monero-project/monero/blob/a1dc85c5373a30f14aaf7dcfdd95f5a7375d3623/src/cryptonote_core/blockchain.cpp#L3791
`MinerData`	TODO	`get_miner_data`	https://github.com/monero-project/monero/blob/a1dc85c5373a30f14aaf7dcfdd95f5a7375d3623/src/cryptonote_core/blockchain.cpp#L1822
TODO	TODO	`get_alternate_chains`	TODO
TODO	TODO	TODO	TODO

Transaction pool

Request	Response	Needed for	Description
`Backlog`	`Vec<TxBacklogEntry>`	`get_txpool_backlog`	Get misc information on all transactions in the pool.
`PoolSize`	`u64`	`get_info`	Number of transactions that have been broadcast but not included in a block; `cuprate_rpc_types::json::GetInfoResponse::tx_pool_size`
`Flush(Vec<[u8; 32]>)`	`()`	`flush_txpool`	Flush the given transaction hashes from the txpool (all if `Vec` is empty).
TODO	TODO	TODO	TODO

P2P

Request	Response	Needed for	Description
`RelayBlock(Block)`	`()`	`submit_block`	Relay a found block
`ConnectionInfo`	P2P connection data	`get_connections`	Must map into `cuprate_rpc_types::misc::ConnectionInfo`
`Syncing`	`bool`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::busy_syncing`
`Synced`	`bool`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::synchronized`
`Target`	`u64`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::target`
`TargetHeight`	`u64`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::target_height`
`PeerlistSize`	`(u64, u64)`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::{white,grey}_peerlist_size`
`ConnectionCount`	`(u64, u64)`	`get_info`	`cuprate_rpc_types::json::GetInfoResponse::{incoming,outgoing}_connections_count`
`SetBan(cuprate_rpc_types::json::SetBanRequest)`	`()`	`set_ban`	(Un)ban an IP for `n` seconds
`GetBan`	`cuprate_rpc_types::json::GetBan`	`banned`	Get information about a single ban
`GetBans`	`Vec<cuprate_rpc_types::json::GetBan>`	`get_ban`	Get information about all bans
TODO	TODO	TODO	TODO

`cuprated` state

There is extra state the RPC needs on the more global binary/process level.

This is state that makes sense as global statics on the cuprated-level (or some library exposed to all).

Static	Type	Needed for	Description
`START_INSTANT`, `START_INSTANT_UNIX`	`SystemTime`, `u64`	`get_info`	Start time of daemon; `cuprate_rpc_types::json::GetInfoResponse::start_time`
TODO	TODO	TODO	TODO

Cuprate / cuprate