The digest-aware cache check discarded a stale entry before its caller
took the key. A slow caller could delete an entry another caller's
fetch had just committed, and everyone sharing that fetch then failed
to open it.
The check now only reports the miss. The caller running the shared
fetch discards the entry under the key, after the recheck, so one a
previous fetch refreshed is served, not deleted. The mismatch warning
fires once per refresh instead of once per request.
Swift HEAD no longer discards either, having no fetch to do it under.
It probes upstream as before, and the next GET replaces the entry.
Different digests or URLs, or no digest, use different keys and can
still collide on the storage path. That is the storage layout follow-up.
* Add Swift package registry support
* Fix Swift archive integrity handling
* Fix Swift registry pagination and archive HEAD requests
* Canonicalize Swift package identifiers
* Handle Swift registry cache identities
* Use stored PURLs for cache lookups
* Address review: upstream-hash refetch and cache PURL cleanup
- Re-fetch instead of 502 when a cached artifact's hash disagrees with
the upstream-declared checksum; log and discard the stale entry.
- Rename expectedHash to upstreamHash and document how the check
differs from checkCache's stream integrity verification.
- Drop the repository_url qualifier from swift cache PURLs so cache
entries survive an upstream.swift change, matching other ecosystems.
- Pass name to handleSourceArchiveHead instead of re-deriving it.
* Drop BulkCheckVulnerabilities coverage after #279 removed it
The rebase over #279 (dead-code cleanup) drops BulkCheckVulnerabilities;
remove the tests and helper that exercised the swift-identity-filtering
path through it, and the imports they pulled in.