Txpool state cache

[benaadams]

Changes

• Adding a state cache to txPool and building on Intra-block cache #7039 to push the changed accounts to the pool with the block so those accounts can be invalidated from the cache. (As TxPool was causing a signifcant dominance in the remaining state access)
  • When I updated the accounts rather than just invalidating them in cache that had a higher read rate; perhaps due to bringing them to the top of LRU; when they wouldn't be used in a following block, and pushing out older accounts that would. (e.g. if not included in block, are more likely to be still in tx pool in next block vs an account that was just included in a block vacating the tx pool)

Types of changes

What types of changes does your code introduce?

• Optimization

Testing

Requires testing

• Yes

If yes, did you write tests?

• Yes (ish) adjusted existing test to be cache aware and tested results against mainnet

Remarks

StateDb Reads

Before ave 51.7k ops/m, max 140k ops/m

After ave 13.5k ops/m, max 35.5k ops/m

State Tree

Before (validation) reads 4.82k op/m; (txpool) reader reads 10.9k/s

After (validation) reads 2.2k op/m; (txpool) reader reads 1.1k/s; cache hits 11.9k op/m

Trie Operations

Before RLP.Encode 103k ops/m

After RLP.Encode 20.5k ops/m

DarkPool uneffected (i.e. not over dropping txs)

Before ave 18%

After ave 16%