feat: cache and reuse XetSession in HFClient#21
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assafvayner merged 24 commits intomainfrom Apr 10, 2026
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Store a lazily-initialized XetSession on HFClientInner behind #[cfg(feature = "xet")]. The xet_session() method creates the session on first use, probes health on subsequent calls, and transparently replaces it if the session is permanently poisoned (e.g. after abort). Call sites use inline single-retry for the narrow race between the health check and the factory call. This avoids creating a new tokio thread pool for every xet operation.
Replace zero-filled 11MB buffer with random bytes so the test exercises real xet deduplication rather than trivially compressible data.
Verify that xet_session() self-heals after both abort() and sigint_abort() by detecting the poisoned session and replacing it with a fresh one.
- Expand is_session_poisoned coverage to all XetError variants - Add inline retry pattern simulation test - Add xet error message wrapping test - Add CLI signal tests: SIGINT during xet upload and download
hub-ci does not support xet transfers. Guard write_upload_large_file and both signal abort tests with is_hub_ci() early return.
Xet transfers work on hub-ci. The guards were added in error.
…clients Move all *Params structs from repository.rs into a new types/repo_params.rs module for better organization. Rework integration test client setup for CI: - prod_api() uses HF_PROD_TOKEN against huggingface.co for read-only tests - api() uses HF_CI_TOKEN against hub-ci.huggingface.co for write tests - Local dev uses HF_TOKEN with default/env endpoint via default_api() - All client creation goes through build_client() with explicit token+endpoint
…clients - Replace huggingface-hub-rust-test-user with __DUMMY_TRANSFORMERS_USER__ across all test files (blocking, cache, cli, download) - Split CI token handling: HF_CI_TOKEN for hub-ci, HF_PROD_TOKEN for prod repos (cache xet tests, integration tests) - Remove HF_TOKEN from CI yaml; only HF_CI_TOKEN and HF_PROD_TOKEN - Add prod_api() and prod_api_with_cache() to cache_test for xet tests that reference hardcoded prod repos (mcpotato/42-xet-test-repo) - Update CliRunner to fall back to HF_CI_TOKEN when HF_TOKEN is unset
Remove the per-call health probe from xet_session() — it was creating a throwaway download group builder on every access. Instead: - xet_session() just returns the cached session or creates one - replace_xet_session() drops the cached session so the next xet_session() call builds a fresh one - Call sites: on factory error, call replace_xet_session then retry This is cheaper since the probe only runs when an actual error occurs, not on every session access.
xet_session() now returns (XetSession, generation). Call sites pass the generation to replace_xet_session(), which only clears the cached session if the generation matches. This prevents a race where T2 discards T1's fresh session: T2's stale generation won't match the new one, so the replace is a no-op.
…clients All test files now use the correct endpoint and token: - Read-only tests (hardcoded repos): always target production (HF_PROD_TOKEN + huggingface.co in CI, HF_TOKEN locally) - Write tests (create/delete repos): target hub-ci (HF_CI_TOKEN in CI, HF_TOKEN locally) Removed all is_hub_ci() branching and conditional repo names. Repo name functions now return fixed prod values since read-only tests always hit production. Files changed: - blocking_test: prod_sync_api() for reads, ci_sync_api() for writes - cache_test: api() always targets prod, removed prod_api indirection - download_test: api() always targets prod - cli/helpers: hfrs() targets prod, hfrs_ci() targets hub-ci - cli/cli_comparison: write tests use hfrs_ci(), reads use hfrs()
All CI jobs now use Swatinem/rust-cache@v2 for consistent caching.
Replace Swatinem/rust-cache with actions/cache pinned to a specific commit hash. Caches ~/.cargo/registry, ~/.cargo/git, and target/ keyed on Cargo.lock hash.
- actions/checkout pinned to de0fac2e (v6.0.2) - dtolnay/rust-toolchain pinned to 3c5f7ea2 (master) - actions/cache already pinned to 66822842 - Added explicit toolchain: nightly/stable since the hash ref no longer encodes the toolchain name
Move test environment variable names and endpoint URLs to huggingface_hub::test_utils, eliminating string literal duplication across test files. Constants: HF_TOKEN, HF_CI_TOKEN, HF_PROD_TOKEN, HF_TEST_WRITE, HF_ENDPOINT, GITHUB_ACTIONS, HF_HUB_CACHE, HF_HOME, XDG_CACHE_HOME, PROD_ENDPOINT, HUB_CI_ENDPOINT. Helpers: is_ci(), write_enabled(), resolve_ci_token(), resolve_prod_token().
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Summary
Cache and reuse
XetSessioninHFClientinstead of creating a new one per xet operation. The session is lazily initialized on first use and shared across all xet operations viaArc<HFClientInner>.Generation-based replacement:
xet_session()returns(session, generation). When a factory call fails, call sites invokereplace_xet_session(generation, &err)which only clears the cached session if the generation matches — preventing concurrent threads from discarding each other's fresh sessions.Call-site retry pattern: Each xet call site (5 total: download to local dir, download to blob, batch download, stream download, upload) retries once with a fresh session on factory errors.
Split CI test infrastructure: Read-only tests (hardcoded repos) always target production (
HF_PROD_TOKEN). Write tests target hub-ci (HF_CI_TOKEN). Removed allis_hub_ci()conditional repo name branching.Signal abort tests: CLI tests that send SIGINT during xet upload/download and verify the process terminates cleanly.
Xet error handling tests: Comprehensive
is_session_poisonedclassification, inline retry pattern simulation, error message preservation throughHFError::Otherwrapping.Test plan
cargo test -p huggingface-hub --all-features(78 unit tests pass)HF_TEST_WRITE=1 cargo test --test blocking_test(4 pass)HF_TEST_WRITE=1 cargo test --test cli_comparison -- write_(22 pass)HF_TEST_WRITE=1 cargo test --test cli_comparison -- signal_abort(2 pass)HF_TEST_WRITE=1 cargo test --test integration_test(37 pass)HF_TEST_WRITE=1 cargo test --test xet_transfer_test(10 pass)cargo test --test cache_test(47 pass)cargo test --test download_test(13 pass)HF_CI_TOKENandHF_PROD_TOKENsecrets configured in GitHub