- Name the proxy in the User-Agent of publish-time HEAD requests, as its
artifact downloads do, rather than Go's default, which Maven Central
asks tools not to send.
- Take a version's time from its Gradle .module as well as its .pom, so
either one fetched first carries it.
- Serve filtered metadata through the shared rewrite path, with gzip and
the stale warning like the other ecosystems.
- Say in the docs that a refused .pom or .module is still cached.
A build fetching pinned versions never reads maven-metadata.xml, so each
version's time was read with a HEAD before its download, roughly
doubling the requests to Maven Central, which answered a fresh build
with 429 and a 30-minute Retry-After. The .pom's own response now gives
the time; Maven fetches the .pom before a version's other files, so
their check reads the stored time. A HEAD is only sent for a .pom served
from the cache or a file requested before its .pom.
A 429 on that HEAD now answers 503 with the upstream's Retry-After, as
other held upstream requests do, instead of 502.
A version's publish time is the Last-Modified of its .pom, read with a
HEAD request once per version and stored in the versions table. Named
repositories store theirs under a repository_url qualifier.
Versions in cooldown are left out of maven-metadata.xml, <latest> and
<release> are moved to the last versions left, and the metadata's
checksum files are computed from what is served. Files of a version in
cooldown get 403. Only versions that can still be in cooldown are
checked: none when <lastUpdated> is older than the window, otherwise
from the end of the list back to the first old enough version.
Part of #132.
