ScanPackument and LookupVersion read with a jsontext.Decoder, skipping
values they don't keep with SkipValue and reading the one LookupVersion
returns with ReadValue, instead of decoding each into a json.RawMessage.
Repeated names and invalid UTF-8 are still accepted as encoding/json
accepts them. Go 1.27 is now required, for encoding/json/jsontext.
Benchmarks for both use the 5,000-version packument the handler benchmarks
build, now shared in internal/metadata/npm/npmbench.
npm metadata rewriting depended on handler.Proxy, which pulls SQL
drivers, cloud SDKs and metrics into its import graph. Move the
transformation into internal/metadata/npm with explicit policy,
evaluation time, public URL and hosted-version inputs, and share the
JSON scanner between npm and Composer through internal/jsonscan.
Rebased onto main: rewritten tarball URLs are still logged once per
document, now through an OnTarballsRewritten callback that reports the
count.
Rewriting a packument decoded the whole document into map[string]any and
encoded it again. For a full packument of tens of megabytes that costs many
times the document size per request, and with cooldown enabled (which skips
the rewrite cache and forces full packuments) it happens on every request.
- Rewrite npm metadata in place: walk the raw JSON for member offsets, decode
only the version names, time and dist-tags for the existing filters, and
assemble the response from slices of the original bytes with only tarball
URLs (and filtered time/dist-tags) written fresh. Untouched values now reach
clients byte for byte instead of round-tripping through encoding/json.
- Look up versions[v].dist.tarball and time[v] directly on the tarball
download path instead of decoding every version.
- Record the stored metadata's SHA-256 in metadata_cache.content_digest and
key the rewrite cache by it, so a repeat npm or Composer request inside the
TTL is served from the rewrite cache without reading or hashing the stored
document.
On a synthetic 25 MB packument with 5000 versions, rewriteMetadata drops from
~150-174 MB / 706k allocations per call to ~31 MB / 90k, and runs in about
two thirds of the time. npmVersionTarball drops from ~1 MB / 10k allocations
to one allocation.
