Speedup pending_transactions()

[shawn-zil]

Refer to issue for details. These small changes result in the following speedup:

time cast rpc --rpc-url http://localhost:44201 txpool_status
{"pending":4000,"queued":1000}

real    0m0.029s
user    0m0.003s
sys     0m0.011s

[maxconway]

I'm a bit suspicious of limiting the number of pending transactions based on a timer - I'd have thought we'd want the pending transactions list to be deterministic

[github-actions]

Bencher Report

Branch	2836-speedup-pending
Testbed	self-hosted

Click to view all benchmark results

Benchmark	Latency	Benchmark Result milliseconds (ms) (Result Δ%)	Upper Boundary milliseconds (ms) (Limit %)
full-blocks-erc20-transfers/full-blocks-erc20-transfers	📈 view plot 🚷 view threshold	1,041.90 ms (-16.47%) Baseline: 1,247.34 ms	1,671.76 ms (62.32%)
full-blocks-evm-transfers/full-blocks-evm-transfers	📈 view plot 🚷 view threshold	473.66 ms (-8.14%) Baseline: 515.64 ms	667.33 ms (70.98%)
full-blocks-giant-deploy/full-blocks-giant-deploy	📈 view plot 🚷 view threshold	6,943.50 ms (-5.82%) Baseline: 7,372.82 ms	10,334.75 ms (67.19%)
full-blocks-scilla-add/full-blocks-scilla-add	📈 view plot 🚷 view threshold	1,116.70 ms (-6.28%) Baseline: 1,191.56 ms	1,648.29 ms (67.75%)
full-blocks-scilla-load/full-blocks-scilla-load	📈 view plot 🚷 view threshold	3,802.40 ms (-7.73%) Baseline: 4,121.06 ms	5,190.39 ms (73.26%)
full-blocks-scilla-store/full-blocks-scilla-store	📈 view plot 🚷 view threshold	3,261.00 ms (-5.50%) Baseline: 3,450.80 ms	4,238.24 ms (76.94%)
full-blocks-zil-transfers/full-blocks-zil-transfers	📈 view plot 🚷 view threshold	4,958.20 ms (+21.72%) Baseline: 4,073.60 ms	5,885.63 ms (84.24%)
process-empty/process-empty	📈 view plot 🚷 view threshold	11.54 ms (-5.23%) Baseline: 12.18 ms	13.74 ms (83.99%)

🐰 View full continuous benchmarking report in Bencher

[shawn-zil]

I'll leave this here @maxconway you may extend this, cherry pick bits into #2838 or abandon this. I leave that decision to you.

[shawn-zil]

Closed in favour of #2838