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uv-ffi v0.10.8.post1 - Persistent Engine

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@1minds3t 1minds3t released this 15 Mar 07:07
v0.10.8.post1
0b0ae6e

This release transforms uv-ffi into a high-performance persistent execution engine for uv's package resolver and installer. Designed for long-running processes, daemons, notebooks, and interactive tools.

Performance (warm cache, Linux NVMe, Python 3.11)

Operation uv CLI uv-ffi Speedup
No-op / satisfied check ~11–12ms ~0.4–2ms ~6–8×
Real swap (install different version) ~17–20ms ~5.4–6.5ms ~2.5–3×
Site-packages delta patch ~2.5ms (full rescan) ~25µs ~100×

The ~5–6ms floor is the hardware limit for VFS symlink create/unlink on NVMe. All software overhead above that floor is eliminated.

What's new

Persistent UvEngine singleton
Previously uv-ffi paid the full uv startup cost on every call — interpreter discovery, platform tagging, HTTP pool init, TLS setup, logging init. Now this happens once at import time and is held in a OnceLock. Every subsequent call skips directly to resolution.

Zero-clap fast path
Common pip install commands now bypass clap argument parsing entirely. Internal Rust structs are constructed directly, saving ~2ms per call.

Persistent RegistryClient
The HTTP client lives for the lifetime of the engine — eliminating ~1–2ms socket/TLS teardown per call.

Delta cache patching
patch_site_packages_cache(installed, removed) updates the in-memory site-packages map surgically in ~25µs — ~100× faster than uv's own ~2.5ms full rescan. Use this with an FS watcher to maintain coherency after external changes at near-zero cost.

Daemon-safe internals
Tokio runtime, logging, and uv globals are now idempotent. No re-init panics or resource leaks in long-running host processes.

Full dist-info compatibility
uv-ffi installs now write complete dist-info including RECORD, INSTALLER, and REQUESTED — verified compatible with uv pip uninstall and standard Python toolchain operations.

Cache coherency — important

uv-ffi trusts its in-memory cache completely. If an external tool modifies the environment without notifying uv-ffi, the next call may silently return rc=0 with no action (false no-op).

Verified behavior with external interference:

[1] uv-ffi swap:                   6.5ms   ✓ inst=[('rich','14.3.3')]
[2] external uv pip install:      18.7ms   disk changed behind our back
[3] uv-ffi (cache stale):          0.5ms   ✗ silent no-op — wrong answer
[4] uv-ffi (different target):    11.4ms   ✓ rescan detected mismatch, corrected

Solutions:

  • ~25µs — patch_site_packages_cache(installed, removed) via FS watcher (omnipkg's approach)
  • ~2.5ms — invalidate_site_packages_cache() forced rescan before each call
  • Nothing needed — if your process is the only writer

Scope

This release optimizes pip install on the fast path. Commands like uv pip uninstall, uv run, uv sync fall back to the standard clap path (~15–20ms). Bringing these into the zero-overhead path is the next focus.

Who this is for

  • Daemon and background service authors who need in-process package management
  • Notebook and REPL users who want instant dependency swaps
  • Tool builders who want uv's resolver speed without CLI overhead

This engine powers omnipkg's daemon, where sub-10ms environment swaps and real-time FS coherence are table stakes.

pip install uv-ffi==0.10.8.post1

Thank you to the uv team for the foundation this is built on.

📝 Code Changes:

  • UPDATE: crates/uv-cache/src/cli.rs (2 lines changed)
  • UPDATE: crates/uv-cli/src/compat.rs (1 lines changed)
  • UPDATE: crates/uv-cli/src/lib.rs (138 lines changed)
  • UPDATE: crates/uv-ffi/src/lib.rs (612 lines changed)
  • UPDATE: crates/uv-installer/src/site_packages.rs (8 lines changed)
  • UPDATE: crates/uv/src/commands/mod.rs (2 lines changed)
  • UPDATE: crates/uv/src/commands/pip/install.rs (130 lines changed)
  • UPDATE: crates/uv/src/commands/pip/mod.rs (2 lines changed)
  • UPDATE: crates/uv/src/commands/pip/operations.rs (19 lines changed)
  • UPDATE: crates/uv/src/lib.rs (102 lines changed)
  • UPDATE: crates/uv/src/logging.rs (19 lines changed)

📚 Documentation:

  • CHANGELOG.md (64 lines)
  • crates/uv-ffi/CHANGELOG.md (114 lines)
  • crates/uv-ffi/README.md (152 lines)

⚙️ Configuration:

  • crates/uv-ffi/Cargo.toml (16 lines)
  • crates/uv-ffi/pyproject.toml (24 lines)
  • pyproject.toml

Additional Changes:

  • docs: Prepare changelog for release.
  • docs: Restore UV's changelog.
  • docs: clarify cache coherency model and FS-scan speedup; fix Cargo version
  • feat: uv-ffi v0.10.8.post1 — persistent in-process engine & cache coherency
  • Bump toml to prepare for release.
  • perf(uv-ffi): persistent UvEngine runtime for daemon execution

Updates:

  • Update publish.yml

18 files changed, 1394 insertions(+), 282 deletions(-)

Assets 37
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