the index was ported from a prototype with per-node `RWMutex` lock upgrading and JSON marshalling. Its only consumer (`archive.Resolver`) builds it sequentially during extraction and then only reads it, so neither was used. `lock.go` also compared method-value pointers to tell the read lock from the write lock, which can't distinguish lock instances.
removed the locks, the upgrade and retry paths that existed only for concurrent writers, and the JSON methods and their test. The radix logic is unchanged, and the README now points at `archive.Resolver` rather than a nonexistent `archive.Index`.
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>
Alex Goodman
Keith Zantow