perf(rpc): pre-allocate vectors in eth_feeHistory#23334
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Vectors in `eth_feeHistory` were growing dynamically despite `block_count` being known upfront. Switched from `Vec::new()` to `Vec::with_capacity()` for all five vectors, eliminating ~10 reallocations per vector on large requests (block_count=1024).
mattsse
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Apr 2, 2026
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This is headed in the right direction, but I think we should make one small change before merging. The four fee/gas vectors are good candidates for preallocation, but rewards is now preallocated on every call, including the common path where reward_percentiles is omitted and no rewards are returned at all. Since this PR is framed as reducing allocations in eth_feeHistory, I would avoid introducing a new unconditional allocation on that path.
Please make the rewards capacity conditional on actually requesting reward percentiles, and this should be in good shape.
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Automated nightly update of reth dependencies from `paradigmxyz/reth` main branch. ## Upstream reth changes [`f8efc76...c82d435`](paradigmxyz/reth@f8efc76...c82d435) 🔗 Amp thread: https://ampcode.com/threads/T-019d517e-981b-75fd-b3cf-8ad2455f38f6 **RPC** - Remove `0x` prefix from `admin_peers` id and return keccak256 node ID in `admin_nodeInfo.id` to match go-ethereum format ([#23318](paradigmxyz/reth#23318), [#23319](paradigmxyz/reth#23319)) - Apply count filter only after `after` is consumed in pagination ([#23338](paradigmxyz/reth#23338)) - Pre-allocate vectors in `eth_feeHistory` ([#23334](paradigmxyz/reth#23334)) - Add `bal` RPC methods ([#23330](paradigmxyz/reth#23330)) **Engine** - Include backpressure in reported `persistence_wait`, make wait-time mimic CL slot time ([#23308](paradigmxyz/reth#23308)) **Perf** - Reduce cacheline ping-pong in workers availability ([#23321](paradigmxyz/reth#23321)) **Net** - Avoid itertools `Format` panic in tracing log ([#23331](paradigmxyz/reth#23331)) **DB** - Cap `storage_v2` unwind history by MDBX tip ([#23335](paradigmxyz/reth#23335)) **Bench** - Add warmup step for big blocks mode ([#23323](paradigmxyz/reth#23323)) - Make payload handling ethereum-only ([#23324](paradigmxyz/reth#23324)) - Use repository instead of GitHub Actions cache to track hourly runs ([#23306](paradigmxyz/reth#23306)) - Upload nightly regression results to ClickHouse ([#23344](paradigmxyz/reth#23344)) **Chore** - Migrate `allow(clippy::` to `expect(clippy::` ([#23340](paradigmxyz/reth#23340)) - Remove unused return value from `dispatch_with_chunking` ([#23341](paradigmxyz/reth#23341)) - Update nixpkgs to 25.11 and refresh flake inputs ([#23342](paradigmxyz/reth#23342)) ## Migrations 🔗 Amp thread: https://ampcode.com/threads/T-019d517e-baf0-727b-a57e-0488240af973 - **Reth dependency bump**: All `reth-*` git dependencies updated from rev `f8efc76` to `c82d435` - **New `GetBlockAccessList` trait impl**: `TempoEthApi` now implements `GetBlockAccessList` (imported from `reth_rpc_eth_api::helpers::bal`), likely a new required trait added upstream in the reth update [GitHub Workflow](https://github.com/tempoxyz/tempo/actions/runs/23933027282) --------- Co-authored-by: Arsenii Kulikov <klkvrr@gmail.com>
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Vectors in
eth_feeHistorywere growing dynamically despiteblock_countbeing known upfront. Switched fromVec::new()toVec::with_capacity()for all five vectors, eliminating ~10 reallocations per vector on large requests (block_count=1024).