Refactor local copy options into dedicated module by oferchen · Pull Request #1751 · oferchen/rsync

oferchen · 2025-10-31T10:32:55Z

Summary

extract LocalCopyOptions and supporting types into local_copy::options
update local_copy.rs to re-export the new module and drop redundant imports

Testing

cargo check -p rsync-engine

https://chatgpt.com/codex/tasks/task_e_69048c60617c83238267a94174263f44

…3716) Static-analysis audit recording the runtime model decision for the io_uring integration. Recommends keeping io_uring synchronous and routing async callers through tokio::task::spawn_blocking (#1751) rather than adopting tokio-uring or building a custom poll-driven SQE submitter, on the grounds that fast_io must remain tokio-free and the session ring pool design (#1937) stays simpler when leases are synchronous.

…3867) Capture the current sync-over-fd pattern, the spawn_blocking vs tokio-uring integration trade-off, alignment with the #1751 blocking-pool plan, and the soundness risks (kernel ring fd ownership across .await, registered buffer lifetime). Recommend keeping io_uring synchronous behind fast_io and dispatching from async via spawn_blocking.

Concrete plan for replacing the synchronous accept loop with a Tokio listener bridged to the sync transfer worker via spawn_blocking. Gated behind a new async-daemon Cargo feature. Cross-references #1934 (accepted RFC) and #1751 (async migration roadmap).

…c daemon (#1751) (#3893) Designs the bridge between the tokio-driven async daemon (#1934/#1935) and rayon-dispatched CPU work (checksums, delta apply, parallel stat). Recommends a `rayon_bridge` helper in `crates/transfer/src/async_compat.rs` using `tokio::task::spawn_blocking` with a threshold short-circuit, and discusses the dedicated-pool + `block_in_place` alternative plus risks (double-spawn, panic propagation, cancellation, oversubscription).

Compare tokio-uring crate vs native fast_io::io_uring + spawn_blocking bridge. Recommend staying on the native path, bridging via tokio::task::spawn_blocking from async daemon tasks per #1751.

Expand the placeholder async migration plan into a comprehensive, opinionated design covering: current synchronous threading model per subsystem, per-subsystem cost/benefit, a phased incremental adoption strategy, tokio runtime choice with rejected alternatives, sync/async bridge patterns, backward-compat strategy, risk register, and open questions. Cross-references existing async-related tasks (#1367, #1411, #1591, #1593, #1595, #1674, #1751, #1779, #1780, #1782, #1796, #1797, #1805, #1806, #1889, #1890, #1891, #1892, #1934, #1935, #2136) and related design notes so future planners have a single anchor.

…1751) (#4196) Document the canonical sync/async bridge between rayon-dispatched CPU work and the tokio runtime that will host the async daemon listener landing in #1935. Inventories 30 rayon call sites reachable from the daemon code paths, fixes the bridge signature, sizing recipe for both pools, anti-patterns to forbid in review, migration order keyed to phase 2 of the async migration plan, and a test strategy that does not require the async daemon to exist yet.